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The city of Laredo is adding surcharges to homes and businesses that use more than a certain amount of water as the city is in Stage 3 water restrictions due to heat, drought and a lack of water payments from Mexico. Water users will be billed a $10 surcharge for each 1,000 gallons above a certain amount. The Laredo mayor and some city council members voiced their criticism of other communities along the Rio Grande River that were not choosing to ration water. Border Report (McAllen, Texas), June 13, 2024

MD 1248 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR THE HIGH PLAINS OF EASTERN COLORADO...WESTERN KANSAS...FAR NORTHEASTERN NM...AND THE PANHANDLES OF TEXAS AND OKLAHOMA
Mesoscale Discussion 1248 NWS Storm Prediction Center Norman OK 0153 PM CDT Thu Jun 13 2024 Areas affected...The High Plains of eastern Colorado...western Kansas...far northeastern NM...and the Panhandles of Texas and Oklahoma Concerning...Severe potential...Watch possible Valid 131853Z - 132130Z Probability of Watch Issuance...40 percent SUMMARY...Isolated to widely scattered strong to severe thunderstorms are expected to develop over the next 1-3 hours across the High Plains. Severe wind gusts near 60-75 mph, and perhaps localized instances of marginally severe hail, may accompany a few of the thunderstorms. DISCUSSION...Rapid warming has led to temperatures climbing into the upper 90s and low triple digits across the High Plains this afternoon ahead of an approaching cold front. Recent visible satellite imagery, radar, and lightning data suggest convective initiation is underway along a quasi-dryline/surface trough across far northeastern NM and CO. Farther north across northern CO, convergence and upslope flow are aiding in additional moist convection. Finally, to the east across western KS, a few cumulus are now visible along a prefrontal trough near a surface low. As more of the area continues to reach convective temperatures, a few robust updrafts and multicell clusters will be possible. Although deep layer effective shear is fairly weak across this region, some stronger mid to upper-level flow and slightly cooler temperatures aloft over northern CO could support transient organization and brief marginally severe hail. However, the main severe concern this afternoon through early this evening will be severe damaging wind gusts given a deeply mixed boundary layer/very large DCAPE, especially near western KS and eastern CO where clustering appears the most likely within a zone of maximum surface convergence. Trends will be monitored for a possible watch. ..Barnes/Gleason.. 06/13/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DDC...GLD...AMA...PUB...BOU...CYS...ABQ... LAT...LON 39870338 40300392 40740420 40920435 41360486 41390523 41380555 41220574 40860576 40550568 40150550 39660526 39170482 38910442 38660404 38470361 38300337 38230335 37930328 37650330 36970376 36580404 36320414 35960410 35710384 35660343 35890289 35990236 36340188 36890122 37200059 37970015 38549999 39019992 39340008 39470058 39750179 39870338 Read more

MD 1249 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR NORTHWEST/WEST-CENTRAL IL...SOUTHERN IA...NORTHERN MO...FAR SOUTHEAST NE...NORTHEAST KS
Mesoscale Discussion 1249 NWS Storm Prediction Center Norman OK 0202 PM CDT Thu Jun 13 2024 Areas affected...Northwest/West-Central IL...Southern IA...Northern MO...Far Southeast NE...Northeast KS Concerning...Severe potential...Watch likely Valid 131902Z - 132100Z Probability of Watch Issuance...95 percent SUMMARY...Severe thunderstorms are expected to develop along and ahead of a cold front from northwest/west-central Illinois into far southeast Nebraska and northeast Kansas this afternoon. Very large hail up to 3" in diameter and gusts from 60 to 80 mph are possible and a watch will be needed to cover this severe potential. DISCUSSION...Recent visible satellite imagery has recently shown an increase in deepening cumulus along a pre-frontal trough from northwest/west-central IL west-southwestward into far southeast NE and northeast KS. Temperatures in this region have warmed into the upper 80s/low 90s amid dewpoints in the low 70s, contributing to very strong buoyancy. Recent mesoanalysis estimates MLCAPE currently ranges from 2500 J/kg over IL to over 3500 J/kg across far southeast NE and northeast KS. These values will likely increase as strong diurnal heating persists throughout the afternoon. As observed in recent ACARS soundings and the 18Z DVN sounding, some convective inhibition remains in place, but continued diurnal heating should help to erode this inhibition as well. Robust thunderstorm development is expected to take place quickly once inhibition erodes and convective initiation occurs. Large to very large hail up to 3" in diameter is possible with the initial, more cellular development. Strong buoyancy amid high cloud bases and steep low-level lapse rates will foster strong outflow, with the potential for this outflow to amalgamate with resultant upscale growth into a coherent convective line. When this occurs, the primary severe risk should shift to severe gusts (i.e. 60 to 80 mph). Veered low-level flow and a mixed boundary layer should mitigate the tornado potential, although a low probability for a tornado or two exists whenever there is a predominantly supercellular mode. ..Mosier/Gleason.. 06/13/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ILX...LSX...DVN...DMX...EAX...OAX...TOP... LAT...LON 41828982 41308948 40268979 39839035 39449156 38959420 39019582 40349654 41159471 41469241 41899111 41828982 Read more

WW 0409 Status Updates
STATUS FOR WATCH 0409 HAS NOT BEEN ISSUED YET Read more

MD 1247 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR MUCH OF LOWER MI...NORTHERN IN...NORTH-CENTRAL/NORTHEAST IL
Mesoscale Discussion 1247 NWS Storm Prediction Center Norman OK 0102 PM CDT Thu Jun 13 2024 Areas affected...Much of Lower MI...Northern IN...North-Central/Northeast IL Concerning...Severe potential...Watch possible Valid 131802Z - 132000Z Probability of Watch Issuance...60 percent SUMMARY...Thunderstorm coverage is expected to increase this afternoon. Some large hail (up to 2" in diameter) and/or damaging gusts are possible, and a watch will probably be needed. DISCUSSION...Visible satellite imagery has shown increasingly agitated cumulus from Lower MI southwestward into north-central IL, well ahead of the cold front farther west that extends from central Upper MI southwestward into west-central IA. This cumulus is coincident with increasing mid to upper level cloudiness, suggesting that it is likely in response to modestly increasing large-scale ascent attendant to the low-amplitude shortwave trough beginning to enter the Upper Great Lakes region. Some convective inhibition currently remains present within the airmass across much of the region, but gradual destabilization is anticipated throughout the afternoon. Destabilization is expected first across Lower MI where mid-level temperatures are cooler and greater large-scale ascent is anticipated, before gradually moving westward with time as strong diurnal heating continues. Thunderstorm initiation will likely follow the same pattern, beginning over Lower MI and then expanding westward with time. There is a chance that a brief thunderstorm or two could develop across northern/northeastern IL first as large-scale ascent combines within modest mesoscale ascent along the pre-frontal trough. Buoyancy will likely remain modest across Lower MI, with MLCAPE likely remaining below 1500 J/kg. Stronger buoyancy is anticipated across northern IN and north-central/northeast IL, where dewpoints in the mid to upper 60s will help foster MLCAPE over 2000 J/kg. Vertical shear is expected to be greatest over portions of northern IL and northern IN as well, with effective bulk shear likely reaching over 40-45 kt this afternoon. Consequently, the greatest severe potential is anticipated across northern IL and northern IN, with more isolated coverage expected across Lower MI. Large hail is possible with initial development, but relatively high cloud bases and steep low-level lapse rates suggest a relatively quick evolution to outflow-dominant structures capable of damaging wind gusts. A watch will probably be needed across portions of the area to cover this severe potential. ..Mosier/Gleason.. 06/13/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DTX...APX...IWX...GRR...IND...LOT...ILX...DVN... LAT...LON 40408796 40338929 40838984 41398996 42108923 42318826 42458737 42778669 43248639 43868597 44528530 44638427 43938351 43188334 42458360 41728441 40978570 40408796 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Thu Jun 13 2024 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHERN IA...NORTHERN MO...AND NORTHERN/CENTRAL IL... ...SUMMARY... Severe thunderstorms are expected late this afternoon and early evening across parts of southern Iowa into northern Missouri and northern/central Illinois. Very large hail, destructive wind gusts, and a couple of tornadoes all appear possible. A broader corridor of severe hail/wind potential will extend from portions of the southern/central High Plains to the Great Lakes. ...20Z Update... Overall prior forecast appears reasonably on-track. Only minor changes were made based on latest observational trends. This was largely to the west/north side of ongoing convection/frontal placement from MI to IA and in south FL. For additional short-term forecast information, please see MCD 1248 regarding the south-central High Plains and MCD 1249 for the Mid-MS to Lower MO Valleys. ..Grams.. 06/13/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Jun 13 2024/ ...Great Lakes... A mid-level shortwave trough with associated westerly mid/upper-level jet will move eastward across the Upper Midwest and Great Lakes today. An attendant surface cold front will likewise sweep eastward across these regions through this evening, with the primary surface cyclone forecast to remain in Canada. Partly cloudy skies this morning should give way to better opportunity for diurnal heating this afternoon. Increasing low-level convergence along the front, along with ascent associated with shortwave trough/mid-level jet, should encourage convective development along/near the front by mid afternoon across parts of Lower MI into northern IL/IN and vicinity. Sufficient instability and deep-layer shear are forecast to support robust thunderstorms with a threat for scattered damaging winds and severe hail. The magnitude of the severe threat will be dependent on how much instability can develop, with differences remaining in high-resolution guidance regarding both how much convection develops, and how intense it will become. Regardless, some severe threat remains apparent, and the Marginal/Slight Risks have been maintained across this region with minimal changes for this update. ...Mid Mississippi Valley... A surface cold front is progged to sag more slowly south-southeastward across the mid MS Valley today, with better forcing aloft generally remaining to the north across the Upper Midwest and Great Lakes. A rather moist low-level airmass, with surface dewpoints generally in the upper 60s to low 70s, will remain along/south of this boundary across the mid MS Valley. Robust daytime heating of this airmass, along with steep mid-level lapse rates, will promote moderate to strong instability (MLCAPE 2500-3500 J/kg) by mid/late afternoon from southeast NE/northeast KS into southern IA/northern MO and vicinity. Warm mid-level temperatures noted on area 12Z soundings (700 mb temperatures of 13+ C) will likely inhibit robust convective development for much of the day, until surface temperatures reach at least the low 90s and finally erode lingering MLCIN. Explosive thunderstorm development is likely by 20-22Z along/near the front, as strong instability combines with enhanced deep-layer shear to support an threat for multiple intense supercells. Very large hail of at least 2-3 inches in diameter, and perhaps a couple tornadoes, will be a threat with these initially discrete supercells. With mid-level westerly flow largely parallel to the surface boundary, a quick transition/upscale growth into one or more bowing clusters seems likely by early evening. This activity should tend to have a greater threat for severe/damaging winds, including the potential for some significant gusts of 75-80 mph. The severe wind/hail threat should continue in a relatively narrow corridor this evening across the mid MS Valley, before increasing MLCIN and nocturnal cooling gradually reduce the overall severe risk tonight. ...Kansas into the Southern/Central High Plains... A hot and deeply mixed airmass is anticipated along/near the front across KS into the southern/central High Plains. This region will generally be displaced to the south of stronger forcing aloft, and warm mid-level temperatures may inhibit convection for much of the day. Still, most guidance suggests isolated to scattered thunderstorms will develop with a very well mixed boundary layer and steepened low/mid-level lapse rates. Severe/damaging downdraft winds appear to be the main threat with this activity, although some hail may also occur with any marginal supercell structures that can form. Based on latest guidance trends, the Slight Risk has been expanded westward to include more of western KS and eastern CO. Isolated significant severe wind gusts (75+ mph) may occur with any loosely organized clusters across KS. But, weaker deep-layer shear compared with locations farther east suggests the overall severe threat will probably remain fairly isolated. ...South Florida... A loosely organized band of convection is ongoing across parts of south FL. While mid-level lapse rates are expected to remain poor, sufficient instability and deep-layer shear may support occasional strong/gusty winds with the more robust activity this afternoon and early evening. A brief tornado or two may also occur given modestly enhanced low-level flow. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Thu Jun 13 2024 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHERN IA...NORTHERN MO...AND NORTHERN/CENTRAL IL... ...SUMMARY... Severe thunderstorms are expected late this afternoon and early evening across parts of southern Iowa into northern Missouri and northern/central Illinois. Very large hail, destructive wind gusts, and a couple of tornadoes all appear possible. A broader corridor of severe hail/wind potential will extend from portions of the southern/central High Plains to the Great Lakes. ...20Z Update... Overall prior forecast appears reasonably on-track. Only minor changes were made based on latest observational trends. This was largely to the west/north side of ongoing convection/frontal placement from MI to IA and in south FL. For additional short-term forecast information, please see MCD 1248 regarding the south-central High Plains and MCD 1249 for the Mid-MS to Lower MO Valleys. ..Grams.. 06/13/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Jun 13 2024/ ...Great Lakes... A mid-level shortwave trough with associated westerly mid/upper-level jet will move eastward across the Upper Midwest and Great Lakes today. An attendant surface cold front will likewise sweep eastward across these regions through this evening, with the primary surface cyclone forecast to remain in Canada. Partly cloudy skies this morning should give way to better opportunity for diurnal heating this afternoon. Increasing low-level convergence along the front, along with ascent associated with shortwave trough/mid-level jet, should encourage convective development along/near the front by mid afternoon across parts of Lower MI into northern IL/IN and vicinity. Sufficient instability and deep-layer shear are forecast to support robust thunderstorms with a threat for scattered damaging winds and severe hail. The magnitude of the severe threat will be dependent on how much instability can develop, with differences remaining in high-resolution guidance regarding both how much convection develops, and how intense it will become. Regardless, some severe threat remains apparent, and the Marginal/Slight Risks have been maintained across this region with minimal changes for this update. ...Mid Mississippi Valley... A surface cold front is progged to sag more slowly south-southeastward across the mid MS Valley today, with better forcing aloft generally remaining to the north across the Upper Midwest and Great Lakes. A rather moist low-level airmass, with surface dewpoints generally in the upper 60s to low 70s, will remain along/south of this boundary across the mid MS Valley. Robust daytime heating of this airmass, along with steep mid-level lapse rates, will promote moderate to strong instability (MLCAPE 2500-3500 J/kg) by mid/late afternoon from southeast NE/northeast KS into southern IA/northern MO and vicinity. Warm mid-level temperatures noted on area 12Z soundings (700 mb temperatures of 13+ C) will likely inhibit robust convective development for much of the day, until surface temperatures reach at least the low 90s and finally erode lingering MLCIN. Explosive thunderstorm development is likely by 20-22Z along/near the front, as strong instability combines with enhanced deep-layer shear to support an threat for multiple intense supercells. Very large hail of at least 2-3 inches in diameter, and perhaps a couple tornadoes, will be a threat with these initially discrete supercells. With mid-level westerly flow largely parallel to the surface boundary, a quick transition/upscale growth into one or more bowing clusters seems likely by early evening. This activity should tend to have a greater threat for severe/damaging winds, including the potential for some significant gusts of 75-80 mph. The severe wind/hail threat should continue in a relatively narrow corridor this evening across the mid MS Valley, before increasing MLCIN and nocturnal cooling gradually reduce the overall severe risk tonight. ...Kansas into the Southern/Central High Plains... A hot and deeply mixed airmass is anticipated along/near the front across KS into the southern/central High Plains. This region will generally be displaced to the south of stronger forcing aloft, and warm mid-level temperatures may inhibit convection for much of the day. Still, most guidance suggests isolated to scattered thunderstorms will develop with a very well mixed boundary layer and steepened low/mid-level lapse rates. Severe/damaging downdraft winds appear to be the main threat with this activity, although some hail may also occur with any marginal supercell structures that can form. Based on latest guidance trends, the Slight Risk has been expanded westward to include more of western KS and eastern CO. Isolated significant severe wind gusts (75+ mph) may occur with any loosely organized clusters across KS. But, weaker deep-layer shear compared with locations farther east suggests the overall severe threat will probably remain fairly isolated. ...South Florida... A loosely organized band of convection is ongoing across parts of south FL. While mid-level lapse rates are expected to remain poor, sufficient instability and deep-layer shear may support occasional strong/gusty winds with the more robust activity this afternoon and early evening. A brief tornado or two may also occur given modestly enhanced low-level flow. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Thu Jun 13 2024 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHERN IA...NORTHERN MO...AND NORTHERN/CENTRAL IL... ...SUMMARY... Severe thunderstorms are expected late this afternoon and early evening across parts of southern Iowa into northern Missouri and northern/central Illinois. Very large hail, destructive wind gusts, and a couple of tornadoes all appear possible. A broader corridor of severe hail/wind potential will extend from portions of the southern/central High Plains to the Great Lakes. ...20Z Update... Overall prior forecast appears reasonably on-track. Only minor changes were made based on latest observational trends. This was largely to the west/north side of ongoing convection/frontal placement from MI to IA and in south FL. For additional short-term forecast information, please see MCD 1248 regarding the south-central High Plains and MCD 1249 for the Mid-MS to Lower MO Valleys. ..Grams.. 06/13/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Jun 13 2024/ ...Great Lakes... A mid-level shortwave trough with associated westerly mid/upper-level jet will move eastward across the Upper Midwest and Great Lakes today. An attendant surface cold front will likewise sweep eastward across these regions through this evening, with the primary surface cyclone forecast to remain in Canada. Partly cloudy skies this morning should give way to better opportunity for diurnal heating this afternoon. Increasing low-level convergence along the front, along with ascent associated with shortwave trough/mid-level jet, should encourage convective development along/near the front by mid afternoon across parts of Lower MI into northern IL/IN and vicinity. Sufficient instability and deep-layer shear are forecast to support robust thunderstorms with a threat for scattered damaging winds and severe hail. The magnitude of the severe threat will be dependent on how much instability can develop, with differences remaining in high-resolution guidance regarding both how much convection develops, and how intense it will become. Regardless, some severe threat remains apparent, and the Marginal/Slight Risks have been maintained across this region with minimal changes for this update. ...Mid Mississippi Valley... A surface cold front is progged to sag more slowly south-southeastward across the mid MS Valley today, with better forcing aloft generally remaining to the north across the Upper Midwest and Great Lakes. A rather moist low-level airmass, with surface dewpoints generally in the upper 60s to low 70s, will remain along/south of this boundary across the mid MS Valley. Robust daytime heating of this airmass, along with steep mid-level lapse rates, will promote moderate to strong instability (MLCAPE 2500-3500 J/kg) by mid/late afternoon from southeast NE/northeast KS into southern IA/northern MO and vicinity. Warm mid-level temperatures noted on area 12Z soundings (700 mb temperatures of 13+ C) will likely inhibit robust convective development for much of the day, until surface temperatures reach at least the low 90s and finally erode lingering MLCIN. Explosive thunderstorm development is likely by 20-22Z along/near the front, as strong instability combines with enhanced deep-layer shear to support an threat for multiple intense supercells. Very large hail of at least 2-3 inches in diameter, and perhaps a couple tornadoes, will be a threat with these initially discrete supercells. With mid-level westerly flow largely parallel to the surface boundary, a quick transition/upscale growth into one or more bowing clusters seems likely by early evening. This activity should tend to have a greater threat for severe/damaging winds, including the potential for some significant gusts of 75-80 mph. The severe wind/hail threat should continue in a relatively narrow corridor this evening across the mid MS Valley, before increasing MLCIN and nocturnal cooling gradually reduce the overall severe risk tonight. ...Kansas into the Southern/Central High Plains... A hot and deeply mixed airmass is anticipated along/near the front across KS into the southern/central High Plains. This region will generally be displaced to the south of stronger forcing aloft, and warm mid-level temperatures may inhibit convection for much of the day. Still, most guidance suggests isolated to scattered thunderstorms will develop with a very well mixed boundary layer and steepened low/mid-level lapse rates. Severe/damaging downdraft winds appear to be the main threat with this activity, although some hail may also occur with any marginal supercell structures that can form. Based on latest guidance trends, the Slight Risk has been expanded westward to include more of western KS and eastern CO. Isolated significant severe wind gusts (75+ mph) may occur with any loosely organized clusters across KS. But, weaker deep-layer shear compared with locations farther east suggests the overall severe threat will probably remain fairly isolated. ...South Florida... A loosely organized band of convection is ongoing across parts of south FL. While mid-level lapse rates are expected to remain poor, sufficient instability and deep-layer shear may support occasional strong/gusty winds with the more robust activity this afternoon and early evening. A brief tornado or two may also occur given modestly enhanced low-level flow. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Thu Jun 13 2024 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHERN IA...NORTHERN MO...AND NORTHERN/CENTRAL IL... ...SUMMARY... Severe thunderstorms are expected late this afternoon and early evening across parts of southern Iowa into northern Missouri and northern/central Illinois. Very large hail, destructive wind gusts, and a couple of tornadoes all appear possible. A broader corridor of severe hail/wind potential will extend from portions of the southern/central High Plains to the Great Lakes. ...20Z Update... Overall prior forecast appears reasonably on-track. Only minor changes were made based on latest observational trends. This was largely to the west/north side of ongoing convection/frontal placement from MI to IA and in south FL. For additional short-term forecast information, please see MCD 1248 regarding the south-central High Plains and MCD 1249 for the Mid-MS to Lower MO Valleys. ..Grams.. 06/13/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Jun 13 2024/ ...Great Lakes... A mid-level shortwave trough with associated westerly mid/upper-level jet will move eastward across the Upper Midwest and Great Lakes today. An attendant surface cold front will likewise sweep eastward across these regions through this evening, with the primary surface cyclone forecast to remain in Canada. Partly cloudy skies this morning should give way to better opportunity for diurnal heating this afternoon. Increasing low-level convergence along the front, along with ascent associated with shortwave trough/mid-level jet, should encourage convective development along/near the front by mid afternoon across parts of Lower MI into northern IL/IN and vicinity. Sufficient instability and deep-layer shear are forecast to support robust thunderstorms with a threat for scattered damaging winds and severe hail. The magnitude of the severe threat will be dependent on how much instability can develop, with differences remaining in high-resolution guidance regarding both how much convection develops, and how intense it will become. Regardless, some severe threat remains apparent, and the Marginal/Slight Risks have been maintained across this region with minimal changes for this update. ...Mid Mississippi Valley... A surface cold front is progged to sag more slowly south-southeastward across the mid MS Valley today, with better forcing aloft generally remaining to the north across the Upper Midwest and Great Lakes. A rather moist low-level airmass, with surface dewpoints generally in the upper 60s to low 70s, will remain along/south of this boundary across the mid MS Valley. Robust daytime heating of this airmass, along with steep mid-level lapse rates, will promote moderate to strong instability (MLCAPE 2500-3500 J/kg) by mid/late afternoon from southeast NE/northeast KS into southern IA/northern MO and vicinity. Warm mid-level temperatures noted on area 12Z soundings (700 mb temperatures of 13+ C) will likely inhibit robust convective development for much of the day, until surface temperatures reach at least the low 90s and finally erode lingering MLCIN. Explosive thunderstorm development is likely by 20-22Z along/near the front, as strong instability combines with enhanced deep-layer shear to support an threat for multiple intense supercells. Very large hail of at least 2-3 inches in diameter, and perhaps a couple tornadoes, will be a threat with these initially discrete supercells. With mid-level westerly flow largely parallel to the surface boundary, a quick transition/upscale growth into one or more bowing clusters seems likely by early evening. This activity should tend to have a greater threat for severe/damaging winds, including the potential for some significant gusts of 75-80 mph. The severe wind/hail threat should continue in a relatively narrow corridor this evening across the mid MS Valley, before increasing MLCIN and nocturnal cooling gradually reduce the overall severe risk tonight. ...Kansas into the Southern/Central High Plains... A hot and deeply mixed airmass is anticipated along/near the front across KS into the southern/central High Plains. This region will generally be displaced to the south of stronger forcing aloft, and warm mid-level temperatures may inhibit convection for much of the day. Still, most guidance suggests isolated to scattered thunderstorms will develop with a very well mixed boundary layer and steepened low/mid-level lapse rates. Severe/damaging downdraft winds appear to be the main threat with this activity, although some hail may also occur with any marginal supercell structures that can form. Based on latest guidance trends, the Slight Risk has been expanded westward to include more of western KS and eastern CO. Isolated significant severe wind gusts (75+ mph) may occur with any loosely organized clusters across KS. But, weaker deep-layer shear compared with locations farther east suggests the overall severe threat will probably remain fairly isolated. ...South Florida... A loosely organized band of convection is ongoing across parts of south FL. While mid-level lapse rates are expected to remain poor, sufficient instability and deep-layer shear may support occasional strong/gusty winds with the more robust activity this afternoon and early evening. A brief tornado or two may also occur given modestly enhanced low-level flow. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Thu Jun 13 2024 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHERN IA...NORTHERN MO...AND NORTHERN/CENTRAL IL... ...SUMMARY... Severe thunderstorms are expected late this afternoon and early evening across parts of southern Iowa into northern Missouri and northern/central Illinois. Very large hail, destructive wind gusts, and a couple of tornadoes all appear possible. A broader corridor of severe hail/wind potential will extend from portions of the southern/central High Plains to the Great Lakes. ...20Z Update... Overall prior forecast appears reasonably on-track. Only minor changes were made based on latest observational trends. This was largely to the west/north side of ongoing convection/frontal placement from MI to IA and in south FL. For additional short-term forecast information, please see MCD 1248 regarding the south-central High Plains and MCD 1249 for the Mid-MS to Lower MO Valleys. ..Grams.. 06/13/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Jun 13 2024/ ...Great Lakes... A mid-level shortwave trough with associated westerly mid/upper-level jet will move eastward across the Upper Midwest and Great Lakes today. An attendant surface cold front will likewise sweep eastward across these regions through this evening, with the primary surface cyclone forecast to remain in Canada. Partly cloudy skies this morning should give way to better opportunity for diurnal heating this afternoon. Increasing low-level convergence along the front, along with ascent associated with shortwave trough/mid-level jet, should encourage convective development along/near the front by mid afternoon across parts of Lower MI into northern IL/IN and vicinity. Sufficient instability and deep-layer shear are forecast to support robust thunderstorms with a threat for scattered damaging winds and severe hail. The magnitude of the severe threat will be dependent on how much instability can develop, with differences remaining in high-resolution guidance regarding both how much convection develops, and how intense it will become. Regardless, some severe threat remains apparent, and the Marginal/Slight Risks have been maintained across this region with minimal changes for this update. ...Mid Mississippi Valley... A surface cold front is progged to sag more slowly south-southeastward across the mid MS Valley today, with better forcing aloft generally remaining to the north across the Upper Midwest and Great Lakes. A rather moist low-level airmass, with surface dewpoints generally in the upper 60s to low 70s, will remain along/south of this boundary across the mid MS Valley. Robust daytime heating of this airmass, along with steep mid-level lapse rates, will promote moderate to strong instability (MLCAPE 2500-3500 J/kg) by mid/late afternoon from southeast NE/northeast KS into southern IA/northern MO and vicinity. Warm mid-level temperatures noted on area 12Z soundings (700 mb temperatures of 13+ C) will likely inhibit robust convective development for much of the day, until surface temperatures reach at least the low 90s and finally erode lingering MLCIN. Explosive thunderstorm development is likely by 20-22Z along/near the front, as strong instability combines with enhanced deep-layer shear to support an threat for multiple intense supercells. Very large hail of at least 2-3 inches in diameter, and perhaps a couple tornadoes, will be a threat with these initially discrete supercells. With mid-level westerly flow largely parallel to the surface boundary, a quick transition/upscale growth into one or more bowing clusters seems likely by early evening. This activity should tend to have a greater threat for severe/damaging winds, including the potential for some significant gusts of 75-80 mph. The severe wind/hail threat should continue in a relatively narrow corridor this evening across the mid MS Valley, before increasing MLCIN and nocturnal cooling gradually reduce the overall severe risk tonight. ...Kansas into the Southern/Central High Plains... A hot and deeply mixed airmass is anticipated along/near the front across KS into the southern/central High Plains. This region will generally be displaced to the south of stronger forcing aloft, and warm mid-level temperatures may inhibit convection for much of the day. Still, most guidance suggests isolated to scattered thunderstorms will develop with a very well mixed boundary layer and steepened low/mid-level lapse rates. Severe/damaging downdraft winds appear to be the main threat with this activity, although some hail may also occur with any marginal supercell structures that can form. Based on latest guidance trends, the Slight Risk has been expanded westward to include more of western KS and eastern CO. Isolated significant severe wind gusts (75+ mph) may occur with any loosely organized clusters across KS. But, weaker deep-layer shear compared with locations farther east suggests the overall severe threat will probably remain fairly isolated. ...South Florida... A loosely organized band of convection is ongoing across parts of south FL. While mid-level lapse rates are expected to remain poor, sufficient instability and deep-layer shear may support occasional strong/gusty winds with the more robust activity this afternoon and early evening. A brief tornado or two may also occur given modestly enhanced low-level flow. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Thu Jun 13 2024 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHERN IA...NORTHERN MO...AND NORTHERN/CENTRAL IL... ...SUMMARY... Severe thunderstorms are expected late this afternoon and early evening across parts of southern Iowa into northern Missouri and northern/central Illinois. Very large hail, destructive wind gusts, and a couple of tornadoes all appear possible. A broader corridor of severe hail/wind potential will extend from portions of the southern/central High Plains to the Great Lakes. ...20Z Update... Overall prior forecast appears reasonably on-track. Only minor changes were made based on latest observational trends. This was largely to the west/north side of ongoing convection/frontal placement from MI to IA and in south FL. For additional short-term forecast information, please see MCD 1248 regarding the south-central High Plains and MCD 1249 for the Mid-MS to Lower MO Valleys. ..Grams.. 06/13/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Jun 13 2024/ ...Great Lakes... A mid-level shortwave trough with associated westerly mid/upper-level jet will move eastward across the Upper Midwest and Great Lakes today. An attendant surface cold front will likewise sweep eastward across these regions through this evening, with the primary surface cyclone forecast to remain in Canada. Partly cloudy skies this morning should give way to better opportunity for diurnal heating this afternoon. Increasing low-level convergence along the front, along with ascent associated with shortwave trough/mid-level jet, should encourage convective development along/near the front by mid afternoon across parts of Lower MI into northern IL/IN and vicinity. Sufficient instability and deep-layer shear are forecast to support robust thunderstorms with a threat for scattered damaging winds and severe hail. The magnitude of the severe threat will be dependent on how much instability can develop, with differences remaining in high-resolution guidance regarding both how much convection develops, and how intense it will become. Regardless, some severe threat remains apparent, and the Marginal/Slight Risks have been maintained across this region with minimal changes for this update. ...Mid Mississippi Valley... A surface cold front is progged to sag more slowly south-southeastward across the mid MS Valley today, with better forcing aloft generally remaining to the north across the Upper Midwest and Great Lakes. A rather moist low-level airmass, with surface dewpoints generally in the upper 60s to low 70s, will remain along/south of this boundary across the mid MS Valley. Robust daytime heating of this airmass, along with steep mid-level lapse rates, will promote moderate to strong instability (MLCAPE 2500-3500 J/kg) by mid/late afternoon from southeast NE/northeast KS into southern IA/northern MO and vicinity. Warm mid-level temperatures noted on area 12Z soundings (700 mb temperatures of 13+ C) will likely inhibit robust convective development for much of the day, until surface temperatures reach at least the low 90s and finally erode lingering MLCIN. Explosive thunderstorm development is likely by 20-22Z along/near the front, as strong instability combines with enhanced deep-layer shear to support an threat for multiple intense supercells. Very large hail of at least 2-3 inches in diameter, and perhaps a couple tornadoes, will be a threat with these initially discrete supercells. With mid-level westerly flow largely parallel to the surface boundary, a quick transition/upscale growth into one or more bowing clusters seems likely by early evening. This activity should tend to have a greater threat for severe/damaging winds, including the potential for some significant gusts of 75-80 mph. The severe wind/hail threat should continue in a relatively narrow corridor this evening across the mid MS Valley, before increasing MLCIN and nocturnal cooling gradually reduce the overall severe risk tonight. ...Kansas into the Southern/Central High Plains... A hot and deeply mixed airmass is anticipated along/near the front across KS into the southern/central High Plains. This region will generally be displaced to the south of stronger forcing aloft, and warm mid-level temperatures may inhibit convection for much of the day. Still, most guidance suggests isolated to scattered thunderstorms will develop with a very well mixed boundary layer and steepened low/mid-level lapse rates. Severe/damaging downdraft winds appear to be the main threat with this activity, although some hail may also occur with any marginal supercell structures that can form. Based on latest guidance trends, the Slight Risk has been expanded westward to include more of western KS and eastern CO. Isolated significant severe wind gusts (75+ mph) may occur with any loosely organized clusters across KS. But, weaker deep-layer shear compared with locations farther east suggests the overall severe threat will probably remain fairly isolated. ...South Florida... A loosely organized band of convection is ongoing across parts of south FL. While mid-level lapse rates are expected to remain poor, sufficient instability and deep-layer shear may support occasional strong/gusty winds with the more robust activity this afternoon and early evening. A brief tornado or two may also occur given modestly enhanced low-level flow. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Thu Jun 13 2024 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHERN IA...NORTHERN MO...AND NORTHERN/CENTRAL IL... ...SUMMARY... Severe thunderstorms are expected late this afternoon and early evening across parts of southern Iowa into northern Missouri and northern/central Illinois. Very large hail, destructive wind gusts, and a couple of tornadoes all appear possible. A broader corridor of severe hail/wind potential will extend from portions of the southern/central High Plains to the Great Lakes. ...20Z Update... Overall prior forecast appears reasonably on-track. Only minor changes were made based on latest observational trends. This was largely to the west/north side of ongoing convection/frontal placement from MI to IA and in south FL. For additional short-term forecast information, please see MCD 1248 regarding the south-central High Plains and MCD 1249 for the Mid-MS to Lower MO Valleys. ..Grams.. 06/13/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Jun 13 2024/ ...Great Lakes... A mid-level shortwave trough with associated westerly mid/upper-level jet will move eastward across the Upper Midwest and Great Lakes today. An attendant surface cold front will likewise sweep eastward across these regions through this evening, with the primary surface cyclone forecast to remain in Canada. Partly cloudy skies this morning should give way to better opportunity for diurnal heating this afternoon. Increasing low-level convergence along the front, along with ascent associated with shortwave trough/mid-level jet, should encourage convective development along/near the front by mid afternoon across parts of Lower MI into northern IL/IN and vicinity. Sufficient instability and deep-layer shear are forecast to support robust thunderstorms with a threat for scattered damaging winds and severe hail. The magnitude of the severe threat will be dependent on how much instability can develop, with differences remaining in high-resolution guidance regarding both how much convection develops, and how intense it will become. Regardless, some severe threat remains apparent, and the Marginal/Slight Risks have been maintained across this region with minimal changes for this update. ...Mid Mississippi Valley... A surface cold front is progged to sag more slowly south-southeastward across the mid MS Valley today, with better forcing aloft generally remaining to the north across the Upper Midwest and Great Lakes. A rather moist low-level airmass, with surface dewpoints generally in the upper 60s to low 70s, will remain along/south of this boundary across the mid MS Valley. Robust daytime heating of this airmass, along with steep mid-level lapse rates, will promote moderate to strong instability (MLCAPE 2500-3500 J/kg) by mid/late afternoon from southeast NE/northeast KS into southern IA/northern MO and vicinity. Warm mid-level temperatures noted on area 12Z soundings (700 mb temperatures of 13+ C) will likely inhibit robust convective development for much of the day, until surface temperatures reach at least the low 90s and finally erode lingering MLCIN. Explosive thunderstorm development is likely by 20-22Z along/near the front, as strong instability combines with enhanced deep-layer shear to support an threat for multiple intense supercells. Very large hail of at least 2-3 inches in diameter, and perhaps a couple tornadoes, will be a threat with these initially discrete supercells. With mid-level westerly flow largely parallel to the surface boundary, a quick transition/upscale growth into one or more bowing clusters seems likely by early evening. This activity should tend to have a greater threat for severe/damaging winds, including the potential for some significant gusts of 75-80 mph. The severe wind/hail threat should continue in a relatively narrow corridor this evening across the mid MS Valley, before increasing MLCIN and nocturnal cooling gradually reduce the overall severe risk tonight. ...Kansas into the Southern/Central High Plains... A hot and deeply mixed airmass is anticipated along/near the front across KS into the southern/central High Plains. This region will generally be displaced to the south of stronger forcing aloft, and warm mid-level temperatures may inhibit convection for much of the day. Still, most guidance suggests isolated to scattered thunderstorms will develop with a very well mixed boundary layer and steepened low/mid-level lapse rates. Severe/damaging downdraft winds appear to be the main threat with this activity, although some hail may also occur with any marginal supercell structures that can form. Based on latest guidance trends, the Slight Risk has been expanded westward to include more of western KS and eastern CO. Isolated significant severe wind gusts (75+ mph) may occur with any loosely organized clusters across KS. But, weaker deep-layer shear compared with locations farther east suggests the overall severe threat will probably remain fairly isolated. ...South Florida... A loosely organized band of convection is ongoing across parts of south FL. While mid-level lapse rates are expected to remain poor, sufficient instability and deep-layer shear may support occasional strong/gusty winds with the more robust activity this afternoon and early evening. A brief tornado or two may also occur given modestly enhanced low-level flow. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Thu Jun 13 2024 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHERN IA...NORTHERN MO...AND NORTHERN/CENTRAL IL... ...SUMMARY... Severe thunderstorms are expected late this afternoon and early evening across parts of southern Iowa into northern Missouri and northern/central Illinois. Very large hail, destructive wind gusts, and a couple of tornadoes all appear possible. A broader corridor of severe hail/wind potential will extend from portions of the southern/central High Plains to the Great Lakes. ...20Z Update... Overall prior forecast appears reasonably on-track. Only minor changes were made based on latest observational trends. This was largely to the west/north side of ongoing convection/frontal placement from MI to IA and in south FL. For additional short-term forecast information, please see MCD 1248 regarding the south-central High Plains and MCD 1249 for the Mid-MS to Lower MO Valleys. ..Grams.. 06/13/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Jun 13 2024/ ...Great Lakes... A mid-level shortwave trough with associated westerly mid/upper-level jet will move eastward across the Upper Midwest and Great Lakes today. An attendant surface cold front will likewise sweep eastward across these regions through this evening, with the primary surface cyclone forecast to remain in Canada. Partly cloudy skies this morning should give way to better opportunity for diurnal heating this afternoon. Increasing low-level convergence along the front, along with ascent associated with shortwave trough/mid-level jet, should encourage convective development along/near the front by mid afternoon across parts of Lower MI into northern IL/IN and vicinity. Sufficient instability and deep-layer shear are forecast to support robust thunderstorms with a threat for scattered damaging winds and severe hail. The magnitude of the severe threat will be dependent on how much instability can develop, with differences remaining in high-resolution guidance regarding both how much convection develops, and how intense it will become. Regardless, some severe threat remains apparent, and the Marginal/Slight Risks have been maintained across this region with minimal changes for this update. ...Mid Mississippi Valley... A surface cold front is progged to sag more slowly south-southeastward across the mid MS Valley today, with better forcing aloft generally remaining to the north across the Upper Midwest and Great Lakes. A rather moist low-level airmass, with surface dewpoints generally in the upper 60s to low 70s, will remain along/south of this boundary across the mid MS Valley. Robust daytime heating of this airmass, along with steep mid-level lapse rates, will promote moderate to strong instability (MLCAPE 2500-3500 J/kg) by mid/late afternoon from southeast NE/northeast KS into southern IA/northern MO and vicinity. Warm mid-level temperatures noted on area 12Z soundings (700 mb temperatures of 13+ C) will likely inhibit robust convective development for much of the day, until surface temperatures reach at least the low 90s and finally erode lingering MLCIN. Explosive thunderstorm development is likely by 20-22Z along/near the front, as strong instability combines with enhanced deep-layer shear to support an threat for multiple intense supercells. Very large hail of at least 2-3 inches in diameter, and perhaps a couple tornadoes, will be a threat with these initially discrete supercells. With mid-level westerly flow largely parallel to the surface boundary, a quick transition/upscale growth into one or more bowing clusters seems likely by early evening. This activity should tend to have a greater threat for severe/damaging winds, including the potential for some significant gusts of 75-80 mph. The severe wind/hail threat should continue in a relatively narrow corridor this evening across the mid MS Valley, before increasing MLCIN and nocturnal cooling gradually reduce the overall severe risk tonight. ...Kansas into the Southern/Central High Plains... A hot and deeply mixed airmass is anticipated along/near the front across KS into the southern/central High Plains. This region will generally be displaced to the south of stronger forcing aloft, and warm mid-level temperatures may inhibit convection for much of the day. Still, most guidance suggests isolated to scattered thunderstorms will develop with a very well mixed boundary layer and steepened low/mid-level lapse rates. Severe/damaging downdraft winds appear to be the main threat with this activity, although some hail may also occur with any marginal supercell structures that can form. Based on latest guidance trends, the Slight Risk has been expanded westward to include more of western KS and eastern CO. Isolated significant severe wind gusts (75+ mph) may occur with any loosely organized clusters across KS. But, weaker deep-layer shear compared with locations farther east suggests the overall severe threat will probably remain fairly isolated. ...South Florida... A loosely organized band of convection is ongoing across parts of south FL. While mid-level lapse rates are expected to remain poor, sufficient instability and deep-layer shear may support occasional strong/gusty winds with the more robust activity this afternoon and early evening. A brief tornado or two may also occur given modestly enhanced low-level flow. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Thu Jun 13 2024 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHERN IA...NORTHERN MO...AND NORTHERN/CENTRAL IL... ...SUMMARY... Severe thunderstorms are expected late this afternoon and early evening across parts of southern Iowa into northern Missouri and northern/central Illinois. Very large hail, destructive wind gusts, and a couple of tornadoes all appear possible. A broader corridor of severe hail/wind potential will extend from portions of the southern/central High Plains to the Great Lakes. ...20Z Update... Overall prior forecast appears reasonably on-track. Only minor changes were made based on latest observational trends. This was largely to the west/north side of ongoing convection/frontal placement from MI to IA and in south FL. For additional short-term forecast information, please see MCD 1248 regarding the south-central High Plains and MCD 1249 for the Mid-MS to Lower MO Valleys. ..Grams.. 06/13/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Jun 13 2024/ ...Great Lakes... A mid-level shortwave trough with associated westerly mid/upper-level jet will move eastward across the Upper Midwest and Great Lakes today. An attendant surface cold front will likewise sweep eastward across these regions through this evening, with the primary surface cyclone forecast to remain in Canada. Partly cloudy skies this morning should give way to better opportunity for diurnal heating this afternoon. Increasing low-level convergence along the front, along with ascent associated with shortwave trough/mid-level jet, should encourage convective development along/near the front by mid afternoon across parts of Lower MI into northern IL/IN and vicinity. Sufficient instability and deep-layer shear are forecast to support robust thunderstorms with a threat for scattered damaging winds and severe hail. The magnitude of the severe threat will be dependent on how much instability can develop, with differences remaining in high-resolution guidance regarding both how much convection develops, and how intense it will become. Regardless, some severe threat remains apparent, and the Marginal/Slight Risks have been maintained across this region with minimal changes for this update. ...Mid Mississippi Valley... A surface cold front is progged to sag more slowly south-southeastward across the mid MS Valley today, with better forcing aloft generally remaining to the north across the Upper Midwest and Great Lakes. A rather moist low-level airmass, with surface dewpoints generally in the upper 60s to low 70s, will remain along/south of this boundary across the mid MS Valley. Robust daytime heating of this airmass, along with steep mid-level lapse rates, will promote moderate to strong instability (MLCAPE 2500-3500 J/kg) by mid/late afternoon from southeast NE/northeast KS into southern IA/northern MO and vicinity. Warm mid-level temperatures noted on area 12Z soundings (700 mb temperatures of 13+ C) will likely inhibit robust convective development for much of the day, until surface temperatures reach at least the low 90s and finally erode lingering MLCIN. Explosive thunderstorm development is likely by 20-22Z along/near the front, as strong instability combines with enhanced deep-layer shear to support an threat for multiple intense supercells. Very large hail of at least 2-3 inches in diameter, and perhaps a couple tornadoes, will be a threat with these initially discrete supercells. With mid-level westerly flow largely parallel to the surface boundary, a quick transition/upscale growth into one or more bowing clusters seems likely by early evening. This activity should tend to have a greater threat for severe/damaging winds, including the potential for some significant gusts of 75-80 mph. The severe wind/hail threat should continue in a relatively narrow corridor this evening across the mid MS Valley, before increasing MLCIN and nocturnal cooling gradually reduce the overall severe risk tonight. ...Kansas into the Southern/Central High Plains... A hot and deeply mixed airmass is anticipated along/near the front across KS into the southern/central High Plains. This region will generally be displaced to the south of stronger forcing aloft, and warm mid-level temperatures may inhibit convection for much of the day. Still, most guidance suggests isolated to scattered thunderstorms will develop with a very well mixed boundary layer and steepened low/mid-level lapse rates. Severe/damaging downdraft winds appear to be the main threat with this activity, although some hail may also occur with any marginal supercell structures that can form. Based on latest guidance trends, the Slight Risk has been expanded westward to include more of western KS and eastern CO. Isolated significant severe wind gusts (75+ mph) may occur with any loosely organized clusters across KS. But, weaker deep-layer shear compared with locations farther east suggests the overall severe threat will probably remain fairly isolated. ...South Florida... A loosely organized band of convection is ongoing across parts of south FL. While mid-level lapse rates are expected to remain poor, sufficient instability and deep-layer shear may support occasional strong/gusty winds with the more robust activity this afternoon and early evening. A brief tornado or two may also occur given modestly enhanced low-level flow. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Thu Jun 13 2024 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHERN IA...NORTHERN MO...AND NORTHERN/CENTRAL IL... ...SUMMARY... Severe thunderstorms are expected late this afternoon and early evening across parts of southern Iowa into northern Missouri and northern/central Illinois. Very large hail, destructive wind gusts, and a couple of tornadoes all appear possible. A broader corridor of severe hail/wind potential will extend from portions of the southern/central High Plains to the Great Lakes. ...20Z Update... Overall prior forecast appears reasonably on-track. Only minor changes were made based on latest observational trends. This was largely to the west/north side of ongoing convection/frontal placement from MI to IA and in south FL. For additional short-term forecast information, please see MCD 1248 regarding the south-central High Plains and MCD 1249 for the Mid-MS to Lower MO Valleys. ..Grams.. 06/13/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Jun 13 2024/ ...Great Lakes... A mid-level shortwave trough with associated westerly mid/upper-level jet will move eastward across the Upper Midwest and Great Lakes today. An attendant surface cold front will likewise sweep eastward across these regions through this evening, with the primary surface cyclone forecast to remain in Canada. Partly cloudy skies this morning should give way to better opportunity for diurnal heating this afternoon. Increasing low-level convergence along the front, along with ascent associated with shortwave trough/mid-level jet, should encourage convective development along/near the front by mid afternoon across parts of Lower MI into northern IL/IN and vicinity. Sufficient instability and deep-layer shear are forecast to support robust thunderstorms with a threat for scattered damaging winds and severe hail. The magnitude of the severe threat will be dependent on how much instability can develop, with differences remaining in high-resolution guidance regarding both how much convection develops, and how intense it will become. Regardless, some severe threat remains apparent, and the Marginal/Slight Risks have been maintained across this region with minimal changes for this update. ...Mid Mississippi Valley... A surface cold front is progged to sag more slowly south-southeastward across the mid MS Valley today, with better forcing aloft generally remaining to the north across the Upper Midwest and Great Lakes. A rather moist low-level airmass, with surface dewpoints generally in the upper 60s to low 70s, will remain along/south of this boundary across the mid MS Valley. Robust daytime heating of this airmass, along with steep mid-level lapse rates, will promote moderate to strong instability (MLCAPE 2500-3500 J/kg) by mid/late afternoon from southeast NE/northeast KS into southern IA/northern MO and vicinity. Warm mid-level temperatures noted on area 12Z soundings (700 mb temperatures of 13+ C) will likely inhibit robust convective development for much of the day, until surface temperatures reach at least the low 90s and finally erode lingering MLCIN. Explosive thunderstorm development is likely by 20-22Z along/near the front, as strong instability combines with enhanced deep-layer shear to support an threat for multiple intense supercells. Very large hail of at least 2-3 inches in diameter, and perhaps a couple tornadoes, will be a threat with these initially discrete supercells. With mid-level westerly flow largely parallel to the surface boundary, a quick transition/upscale growth into one or more bowing clusters seems likely by early evening. This activity should tend to have a greater threat for severe/damaging winds, including the potential for some significant gusts of 75-80 mph. The severe wind/hail threat should continue in a relatively narrow corridor this evening across the mid MS Valley, before increasing MLCIN and nocturnal cooling gradually reduce the overall severe risk tonight. ...Kansas into the Southern/Central High Plains... A hot and deeply mixed airmass is anticipated along/near the front across KS into the southern/central High Plains. This region will generally be displaced to the south of stronger forcing aloft, and warm mid-level temperatures may inhibit convection for much of the day. Still, most guidance suggests isolated to scattered thunderstorms will develop with a very well mixed boundary layer and steepened low/mid-level lapse rates. Severe/damaging downdraft winds appear to be the main threat with this activity, although some hail may also occur with any marginal supercell structures that can form. Based on latest guidance trends, the Slight Risk has been expanded westward to include more of western KS and eastern CO. Isolated significant severe wind gusts (75+ mph) may occur with any loosely organized clusters across KS. But, weaker deep-layer shear compared with locations farther east suggests the overall severe threat will probably remain fairly isolated. ...South Florida... A loosely organized band of convection is ongoing across parts of south FL. While mid-level lapse rates are expected to remain poor, sufficient instability and deep-layer shear may support occasional strong/gusty winds with the more robust activity this afternoon and early evening. A brief tornado or two may also occur given modestly enhanced low-level flow. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Thu Jun 13 2024 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHERN IA...NORTHERN MO...AND NORTHERN/CENTRAL IL... ...SUMMARY... Severe thunderstorms are expected late this afternoon and early evening across parts of southern Iowa into northern Missouri and northern/central Illinois. Very large hail, destructive wind gusts, and a couple of tornadoes all appear possible. A broader corridor of severe hail/wind potential will extend from portions of the southern/central High Plains to the Great Lakes. ...20Z Update... Overall prior forecast appears reasonably on-track. Only minor changes were made based on latest observational trends. This was largely to the west/north side of ongoing convection/frontal placement from MI to IA and in south FL. For additional short-term forecast information, please see MCD 1248 regarding the south-central High Plains and MCD 1249 for the Mid-MS to Lower MO Valleys. ..Grams.. 06/13/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Jun 13 2024/ ...Great Lakes... A mid-level shortwave trough with associated westerly mid/upper-level jet will move eastward across the Upper Midwest and Great Lakes today. An attendant surface cold front will likewise sweep eastward across these regions through this evening, with the primary surface cyclone forecast to remain in Canada. Partly cloudy skies this morning should give way to better opportunity for diurnal heating this afternoon. Increasing low-level convergence along the front, along with ascent associated with shortwave trough/mid-level jet, should encourage convective development along/near the front by mid afternoon across parts of Lower MI into northern IL/IN and vicinity. Sufficient instability and deep-layer shear are forecast to support robust thunderstorms with a threat for scattered damaging winds and severe hail. The magnitude of the severe threat will be dependent on how much instability can develop, with differences remaining in high-resolution guidance regarding both how much convection develops, and how intense it will become. Regardless, some severe threat remains apparent, and the Marginal/Slight Risks have been maintained across this region with minimal changes for this update. ...Mid Mississippi Valley... A surface cold front is progged to sag more slowly south-southeastward across the mid MS Valley today, with better forcing aloft generally remaining to the north across the Upper Midwest and Great Lakes. A rather moist low-level airmass, with surface dewpoints generally in the upper 60s to low 70s, will remain along/south of this boundary across the mid MS Valley. Robust daytime heating of this airmass, along with steep mid-level lapse rates, will promote moderate to strong instability (MLCAPE 2500-3500 J/kg) by mid/late afternoon from southeast NE/northeast KS into southern IA/northern MO and vicinity. Warm mid-level temperatures noted on area 12Z soundings (700 mb temperatures of 13+ C) will likely inhibit robust convective development for much of the day, until surface temperatures reach at least the low 90s and finally erode lingering MLCIN. Explosive thunderstorm development is likely by 20-22Z along/near the front, as strong instability combines with enhanced deep-layer shear to support an threat for multiple intense supercells. Very large hail of at least 2-3 inches in diameter, and perhaps a couple tornadoes, will be a threat with these initially discrete supercells. With mid-level westerly flow largely parallel to the surface boundary, a quick transition/upscale growth into one or more bowing clusters seems likely by early evening. This activity should tend to have a greater threat for severe/damaging winds, including the potential for some significant gusts of 75-80 mph. The severe wind/hail threat should continue in a relatively narrow corridor this evening across the mid MS Valley, before increasing MLCIN and nocturnal cooling gradually reduce the overall severe risk tonight. ...Kansas into the Southern/Central High Plains... A hot and deeply mixed airmass is anticipated along/near the front across KS into the southern/central High Plains. This region will generally be displaced to the south of stronger forcing aloft, and warm mid-level temperatures may inhibit convection for much of the day. Still, most guidance suggests isolated to scattered thunderstorms will develop with a very well mixed boundary layer and steepened low/mid-level lapse rates. Severe/damaging downdraft winds appear to be the main threat with this activity, although some hail may also occur with any marginal supercell structures that can form. Based on latest guidance trends, the Slight Risk has been expanded westward to include more of western KS and eastern CO. Isolated significant severe wind gusts (75+ mph) may occur with any loosely organized clusters across KS. But, weaker deep-layer shear compared with locations farther east suggests the overall severe threat will probably remain fairly isolated. ...South Florida... A loosely organized band of convection is ongoing across parts of south FL. While mid-level lapse rates are expected to remain poor, sufficient instability and deep-layer shear may support occasional strong/gusty winds with the more robust activity this afternoon and early evening. A brief tornado or two may also occur given modestly enhanced low-level flow. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Thu Jun 13 2024 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHERN IA...NORTHERN MO...AND NORTHERN/CENTRAL IL... ...SUMMARY... Severe thunderstorms are expected late this afternoon and early evening across parts of southern Iowa into northern Missouri and northern/central Illinois. Very large hail, destructive wind gusts, and a couple of tornadoes all appear possible. A broader corridor of severe hail/wind potential will extend from portions of the southern/central High Plains to the Great Lakes. ...20Z Update... Overall prior forecast appears reasonably on-track. Only minor changes were made based on latest observational trends. This was largely to the west/north side of ongoing convection/frontal placement from MI to IA and in south FL. For additional short-term forecast information, please see MCD 1248 regarding the south-central High Plains and MCD 1249 for the Mid-MS to Lower MO Valleys. ..Grams.. 06/13/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Jun 13 2024/ ...Great Lakes... A mid-level shortwave trough with associated westerly mid/upper-level jet will move eastward across the Upper Midwest and Great Lakes today. An attendant surface cold front will likewise sweep eastward across these regions through this evening, with the primary surface cyclone forecast to remain in Canada. Partly cloudy skies this morning should give way to better opportunity for diurnal heating this afternoon. Increasing low-level convergence along the front, along with ascent associated with shortwave trough/mid-level jet, should encourage convective development along/near the front by mid afternoon across parts of Lower MI into northern IL/IN and vicinity. Sufficient instability and deep-layer shear are forecast to support robust thunderstorms with a threat for scattered damaging winds and severe hail. The magnitude of the severe threat will be dependent on how much instability can develop, with differences remaining in high-resolution guidance regarding both how much convection develops, and how intense it will become. Regardless, some severe threat remains apparent, and the Marginal/Slight Risks have been maintained across this region with minimal changes for this update. ...Mid Mississippi Valley... A surface cold front is progged to sag more slowly south-southeastward across the mid MS Valley today, with better forcing aloft generally remaining to the north across the Upper Midwest and Great Lakes. A rather moist low-level airmass, with surface dewpoints generally in the upper 60s to low 70s, will remain along/south of this boundary across the mid MS Valley. Robust daytime heating of this airmass, along with steep mid-level lapse rates, will promote moderate to strong instability (MLCAPE 2500-3500 J/kg) by mid/late afternoon from southeast NE/northeast KS into southern IA/northern MO and vicinity. Warm mid-level temperatures noted on area 12Z soundings (700 mb temperatures of 13+ C) will likely inhibit robust convective development for much of the day, until surface temperatures reach at least the low 90s and finally erode lingering MLCIN. Explosive thunderstorm development is likely by 20-22Z along/near the front, as strong instability combines with enhanced deep-layer shear to support an threat for multiple intense supercells. Very large hail of at least 2-3 inches in diameter, and perhaps a couple tornadoes, will be a threat with these initially discrete supercells. With mid-level westerly flow largely parallel to the surface boundary, a quick transition/upscale growth into one or more bowing clusters seems likely by early evening. This activity should tend to have a greater threat for severe/damaging winds, including the potential for some significant gusts of 75-80 mph. The severe wind/hail threat should continue in a relatively narrow corridor this evening across the mid MS Valley, before increasing MLCIN and nocturnal cooling gradually reduce the overall severe risk tonight. ...Kansas into the Southern/Central High Plains... A hot and deeply mixed airmass is anticipated along/near the front across KS into the southern/central High Plains. This region will generally be displaced to the south of stronger forcing aloft, and warm mid-level temperatures may inhibit convection for much of the day. Still, most guidance suggests isolated to scattered thunderstorms will develop with a very well mixed boundary layer and steepened low/mid-level lapse rates. Severe/damaging downdraft winds appear to be the main threat with this activity, although some hail may also occur with any marginal supercell structures that can form. Based on latest guidance trends, the Slight Risk has been expanded westward to include more of western KS and eastern CO. Isolated significant severe wind gusts (75+ mph) may occur with any loosely organized clusters across KS. But, weaker deep-layer shear compared with locations farther east suggests the overall severe threat will probably remain fairly isolated. ...South Florida... A loosely organized band of convection is ongoing across parts of south FL. While mid-level lapse rates are expected to remain poor, sufficient instability and deep-layer shear may support occasional strong/gusty winds with the more robust activity this afternoon and early evening. A brief tornado or two may also occur given modestly enhanced low-level flow. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Thu Jun 13 2024 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHERN IA...NORTHERN MO...AND NORTHERN/CENTRAL IL... ...SUMMARY... Severe thunderstorms are expected late this afternoon and early evening across parts of southern Iowa into northern Missouri and northern/central Illinois. Very large hail, destructive wind gusts, and a couple of tornadoes all appear possible. A broader corridor of severe hail/wind potential will extend from portions of the southern/central High Plains to the Great Lakes. ...20Z Update... Overall prior forecast appears reasonably on-track. Only minor changes were made based on latest observational trends. This was largely to the west/north side of ongoing convection/frontal placement from MI to IA and in south FL. For additional short-term forecast information, please see MCD 1248 regarding the south-central High Plains and MCD 1249 for the Mid-MS to Lower MO Valleys. ..Grams.. 06/13/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Jun 13 2024/ ...Great Lakes... A mid-level shortwave trough with associated westerly mid/upper-level jet will move eastward across the Upper Midwest and Great Lakes today. An attendant surface cold front will likewise sweep eastward across these regions through this evening, with the primary surface cyclone forecast to remain in Canada. Partly cloudy skies this morning should give way to better opportunity for diurnal heating this afternoon. Increasing low-level convergence along the front, along with ascent associated with shortwave trough/mid-level jet, should encourage convective development along/near the front by mid afternoon across parts of Lower MI into northern IL/IN and vicinity. Sufficient instability and deep-layer shear are forecast to support robust thunderstorms with a threat for scattered damaging winds and severe hail. The magnitude of the severe threat will be dependent on how much instability can develop, with differences remaining in high-resolution guidance regarding both how much convection develops, and how intense it will become. Regardless, some severe threat remains apparent, and the Marginal/Slight Risks have been maintained across this region with minimal changes for this update. ...Mid Mississippi Valley... A surface cold front is progged to sag more slowly south-southeastward across the mid MS Valley today, with better forcing aloft generally remaining to the north across the Upper Midwest and Great Lakes. A rather moist low-level airmass, with surface dewpoints generally in the upper 60s to low 70s, will remain along/south of this boundary across the mid MS Valley. Robust daytime heating of this airmass, along with steep mid-level lapse rates, will promote moderate to strong instability (MLCAPE 2500-3500 J/kg) by mid/late afternoon from southeast NE/northeast KS into southern IA/northern MO and vicinity. Warm mid-level temperatures noted on area 12Z soundings (700 mb temperatures of 13+ C) will likely inhibit robust convective development for much of the day, until surface temperatures reach at least the low 90s and finally erode lingering MLCIN. Explosive thunderstorm development is likely by 20-22Z along/near the front, as strong instability combines with enhanced deep-layer shear to support an threat for multiple intense supercells. Very large hail of at least 2-3 inches in diameter, and perhaps a couple tornadoes, will be a threat with these initially discrete supercells. With mid-level westerly flow largely parallel to the surface boundary, a quick transition/upscale growth into one or more bowing clusters seems likely by early evening. This activity should tend to have a greater threat for severe/damaging winds, including the potential for some significant gusts of 75-80 mph. The severe wind/hail threat should continue in a relatively narrow corridor this evening across the mid MS Valley, before increasing MLCIN and nocturnal cooling gradually reduce the overall severe risk tonight. ...Kansas into the Southern/Central High Plains... A hot and deeply mixed airmass is anticipated along/near the front across KS into the southern/central High Plains. This region will generally be displaced to the south of stronger forcing aloft, and warm mid-level temperatures may inhibit convection for much of the day. Still, most guidance suggests isolated to scattered thunderstorms will develop with a very well mixed boundary layer and steepened low/mid-level lapse rates. Severe/damaging downdraft winds appear to be the main threat with this activity, although some hail may also occur with any marginal supercell structures that can form. Based on latest guidance trends, the Slight Risk has been expanded westward to include more of western KS and eastern CO. Isolated significant severe wind gusts (75+ mph) may occur with any loosely organized clusters across KS. But, weaker deep-layer shear compared with locations farther east suggests the overall severe threat will probably remain fairly isolated. ...South Florida... A loosely organized band of convection is ongoing across parts of south FL. While mid-level lapse rates are expected to remain poor, sufficient instability and deep-layer shear may support occasional strong/gusty winds with the more robust activity this afternoon and early evening. A brief tornado or two may also occur given modestly enhanced low-level flow. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Thu Jun 13 2024 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHERN IA...NORTHERN MO...AND NORTHERN/CENTRAL IL... ...SUMMARY... Severe thunderstorms are expected late this afternoon and early evening across parts of southern Iowa into northern Missouri and northern/central Illinois. Very large hail, destructive wind gusts, and a couple of tornadoes all appear possible. A broader corridor of severe hail/wind potential will extend from portions of the southern/central High Plains to the Great Lakes. ...20Z Update... Overall prior forecast appears reasonably on-track. Only minor changes were made based on latest observational trends. This was largely to the west/north side of ongoing convection/frontal placement from MI to IA and in south FL. For additional short-term forecast information, please see MCD 1248 regarding the south-central High Plains and MCD 1249 for the Mid-MS to Lower MO Valleys. ..Grams.. 06/13/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Jun 13 2024/ ...Great Lakes... A mid-level shortwave trough with associated westerly mid/upper-level jet will move eastward across the Upper Midwest and Great Lakes today. An attendant surface cold front will likewise sweep eastward across these regions through this evening, with the primary surface cyclone forecast to remain in Canada. Partly cloudy skies this morning should give way to better opportunity for diurnal heating this afternoon. Increasing low-level convergence along the front, along with ascent associated with shortwave trough/mid-level jet, should encourage convective development along/near the front by mid afternoon across parts of Lower MI into northern IL/IN and vicinity. Sufficient instability and deep-layer shear are forecast to support robust thunderstorms with a threat for scattered damaging winds and severe hail. The magnitude of the severe threat will be dependent on how much instability can develop, with differences remaining in high-resolution guidance regarding both how much convection develops, and how intense it will become. Regardless, some severe threat remains apparent, and the Marginal/Slight Risks have been maintained across this region with minimal changes for this update. ...Mid Mississippi Valley... A surface cold front is progged to sag more slowly south-southeastward across the mid MS Valley today, with better forcing aloft generally remaining to the north across the Upper Midwest and Great Lakes. A rather moist low-level airmass, with surface dewpoints generally in the upper 60s to low 70s, will remain along/south of this boundary across the mid MS Valley. Robust daytime heating of this airmass, along with steep mid-level lapse rates, will promote moderate to strong instability (MLCAPE 2500-3500 J/kg) by mid/late afternoon from southeast NE/northeast KS into southern IA/northern MO and vicinity. Warm mid-level temperatures noted on area 12Z soundings (700 mb temperatures of 13+ C) will likely inhibit robust convective development for much of the day, until surface temperatures reach at least the low 90s and finally erode lingering MLCIN. Explosive thunderstorm development is likely by 20-22Z along/near the front, as strong instability combines with enhanced deep-layer shear to support an threat for multiple intense supercells. Very large hail of at least 2-3 inches in diameter, and perhaps a couple tornadoes, will be a threat with these initially discrete supercells. With mid-level westerly flow largely parallel to the surface boundary, a quick transition/upscale growth into one or more bowing clusters seems likely by early evening. This activity should tend to have a greater threat for severe/damaging winds, including the potential for some significant gusts of 75-80 mph. The severe wind/hail threat should continue in a relatively narrow corridor this evening across the mid MS Valley, before increasing MLCIN and nocturnal cooling gradually reduce the overall severe risk tonight. ...Kansas into the Southern/Central High Plains... A hot and deeply mixed airmass is anticipated along/near the front across KS into the southern/central High Plains. This region will generally be displaced to the south of stronger forcing aloft, and warm mid-level temperatures may inhibit convection for much of the day. Still, most guidance suggests isolated to scattered thunderstorms will develop with a very well mixed boundary layer and steepened low/mid-level lapse rates. Severe/damaging downdraft winds appear to be the main threat with this activity, although some hail may also occur with any marginal supercell structures that can form. Based on latest guidance trends, the Slight Risk has been expanded westward to include more of western KS and eastern CO. Isolated significant severe wind gusts (75+ mph) may occur with any loosely organized clusters across KS. But, weaker deep-layer shear compared with locations farther east suggests the overall severe threat will probably remain fairly isolated. ...South Florida... A loosely organized band of convection is ongoing across parts of south FL. While mid-level lapse rates are expected to remain poor, sufficient instability and deep-layer shear may support occasional strong/gusty winds with the more robust activity this afternoon and early evening. A brief tornado or two may also occur given modestly enhanced low-level flow. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Thu Jun 13 2024 Valid 132000Z - 141200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN SOUTHERN IA...NORTHERN MO...AND NORTHERN/CENTRAL IL... ...SUMMARY... Severe thunderstorms are expected late this afternoon and early evening across parts of southern Iowa into northern Missouri and northern/central Illinois. Very large hail, destructive wind gusts, and a couple of tornadoes all appear possible. A broader corridor of severe hail/wind potential will extend from portions of the southern/central High Plains to the Great Lakes. ...20Z Update... Overall prior forecast appears reasonably on-track. Only minor changes were made based on latest observational trends. This was largely to the west/north side of ongoing convection/frontal placement from MI to IA and in south FL. For additional short-term forecast information, please see MCD 1248 regarding the south-central High Plains and MCD 1249 for the Mid-MS to Lower MO Valleys. ..Grams.. 06/13/2024 .PREV DISCUSSION... /ISSUED 1128 AM CDT Thu Jun 13 2024/ ...Great Lakes... A mid-level shortwave trough with associated westerly mid/upper-level jet will move eastward across the Upper Midwest and Great Lakes today. An attendant surface cold front will likewise sweep eastward across these regions through this evening, with the primary surface cyclone forecast to remain in Canada. Partly cloudy skies this morning should give way to better opportunity for diurnal heating this afternoon. Increasing low-level convergence along the front, along with ascent associated with shortwave trough/mid-level jet, should encourage convective development along/near the front by mid afternoon across parts of Lower MI into northern IL/IN and vicinity. Sufficient instability and deep-layer shear are forecast to support robust thunderstorms with a threat for scattered damaging winds and severe hail. The magnitude of the severe threat will be dependent on how much instability can develop, with differences remaining in high-resolution guidance regarding both how much convection develops, and how intense it will become. Regardless, some severe threat remains apparent, and the Marginal/Slight Risks have been maintained across this region with minimal changes for this update. ...Mid Mississippi Valley... A surface cold front is progged to sag more slowly south-southeastward across the mid MS Valley today, with better forcing aloft generally remaining to the north across the Upper Midwest and Great Lakes. A rather moist low-level airmass, with surface dewpoints generally in the upper 60s to low 70s, will remain along/south of this boundary across the mid MS Valley. Robust daytime heating of this airmass, along with steep mid-level lapse rates, will promote moderate to strong instability (MLCAPE 2500-3500 J/kg) by mid/late afternoon from southeast NE/northeast KS into southern IA/northern MO and vicinity. Warm mid-level temperatures noted on area 12Z soundings (700 mb temperatures of 13+ C) will likely inhibit robust convective development for much of the day, until surface temperatures reach at least the low 90s and finally erode lingering MLCIN. Explosive thunderstorm development is likely by 20-22Z along/near the front, as strong instability combines with enhanced deep-layer shear to support an threat for multiple intense supercells. Very large hail of at least 2-3 inches in diameter, and perhaps a couple tornadoes, will be a threat with these initially discrete supercells. With mid-level westerly flow largely parallel to the surface boundary, a quick transition/upscale growth into one or more bowing clusters seems likely by early evening. This activity should tend to have a greater threat for severe/damaging winds, including the potential for some significant gusts of 75-80 mph. The severe wind/hail threat should continue in a relatively narrow corridor this evening across the mid MS Valley, before increasing MLCIN and nocturnal cooling gradually reduce the overall severe risk tonight. ...Kansas into the Southern/Central High Plains... A hot and deeply mixed airmass is anticipated along/near the front across KS into the southern/central High Plains. This region will generally be displaced to the south of stronger forcing aloft, and warm mid-level temperatures may inhibit convection for much of the day. Still, most guidance suggests isolated to scattered thunderstorms will develop with a very well mixed boundary layer and steepened low/mid-level lapse rates. Severe/damaging downdraft winds appear to be the main threat with this activity, although some hail may also occur with any marginal supercell structures that can form. Based on latest guidance trends, the Slight Risk has been expanded westward to include more of western KS and eastern CO. Isolated significant severe wind gusts (75+ mph) may occur with any loosely organized clusters across KS. But, weaker deep-layer shear compared with locations farther east suggests the overall severe threat will probably remain fairly isolated. ...South Florida... A loosely organized band of convection is ongoing across parts of south FL. While mid-level lapse rates are expected to remain poor, sufficient instability and deep-layer shear may support occasional strong/gusty winds with the more robust activity this afternoon and early evening. A brief tornado or two may also occur given modestly enhanced low-level flow. Read more