Severe Storms

WW 0114 Status Updates
STATUS REPORT ON WW 114 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 SE MMO TO 25 ESE RFD. ..SQUITIERI..04/04/23 ATTN...WFO...LOT... STATUS REPORT FOR WS 114 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC007-031-043-089-091-097-111-041940- IL . ILLINOIS COUNTIES INCLUDED ARE BOONE COOK DUPAGE KANE KANKAKEE LAKE MCHENRY INC089-041940- IN . INDIANA COUNTIES INCLUDED ARE LAKE LMZ740-741-742-743-744-041940- CW . ADJACENT COASTAL WATERS INCLUDED ARE WINTHROP HARBOR TO WILMETTE HARBOR IL Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Tue Apr 04 2023 Valid 051200Z - 061200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE LOWER OHIO RIVER VALLEY TO THE GREAT LAKES REGION... ...SUMMARY... Scattered severe storms posing a risk for strong tornadoes and large hail are expected in a corridor across eastern Illinois through Lower Michigan Wednesday, with organizing clusters or lines of storms accompanied by potentially damaging wind gusts, and a few tornadoes across the Ohio Valley vicinity. ...Synopsis... Recent water-vapor imagery continues to depict a robust upper wave over the central Rockies with an accompanying surface low noted in mid-morning surface observations across the central Plains. Guidance continues to show reasonably good agreement in the evolution of these features over the next 48 hours as the upper wave ejects into the Plains and the surface low tracks northeastward through the Upper Great Lakes region by late Wednesday. A trailing cold front is expected to impinge on a broad warm sector beginning late tonight as it migrates southeast through the Midwest, mid-MS River Valley, and TX Gulf coast through the day Wednesday. Strong to severe thunderstorms will likely be ongoing at the beginning of the period along much of the cold front, and more organized cells and/or clusters may persist into the afternoon hours given the strongly sheared environment and diurnal warming/destabilization. Locations that see weakening of early-morning convection will likely see re-intensification either along the cold or residual outflow boundaries by late afternoon. Given the broad warm sector (featuring 60+ F dewpoints) and strong flow over the region, organized convection appears likely across a large swath of the Midwest to south-central CONUS. One notable trend for this update is a westward shift in probabilities driven by a slower eastward progression of the synoptic wave/surface low that has consistently emerged in recent global and mesoscale guidance. ...IL to OH and lower MI... Confidence in the severe threat remains highest across portions of the Midwest. Open warm sector convection may be ongoing by 12 UTC across parts of eastern MO/IL and will propagate into parts of IN, OH, and lower MI through the day. Poleward moisture advection in the wake of morning convection will maintain a buoyant air mass prior to the frontal passage in the late morning/afternoon when a second round of storms appears likely. The combination of the mid-level jet max aloft and strong low-level pressure gradient winds will result in a strongly sheared environment featuring effective bulk shear values near 50s knots and 150-200 m2/s2 of 0-1 km SRH. This kinematic environment will support a tornado threat, including the potential for a strong tornado, especially if more discrete storm modes can be realized (though it is unclear if boundary-relative storm motions and deep-layer shear vectors will be sufficient to maintain discrete modes given considerable along-boundary mean flow). Regardless, the strong low-level flow will support the potential for damaging to severe winds. ...Middle MS and lower OH River Valleys... Forcing for ascent along the middle MS and lower OH River Valleys is expected to diminish through the day as stronger synoptic ascent becomes increasingly displaced to the north/northeast. Strong flow aloft on the southern periphery of the jet max will support elongated hodographs, which when coupled with 1500-2000 J/kg MLCAPE and residual ascent along the slowing cold front, will likely be favorable for semi-discrete cells to clusters with an attendant threat for large hail, damaging winds, and perhaps a tornado. ..Moore/Jewell.. 04/04/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1229 PM CDT Tue Apr 04 2023 Valid 051200Z - 061200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE LOWER OHIO RIVER VALLEY TO THE GREAT LAKES REGION... ...SUMMARY... Scattered severe storms posing a risk for strong tornadoes and large hail are expected in a corridor across eastern Illinois through Lower Michigan Wednesday, with organizing clusters or lines of storms accompanied by potentially damaging wind gusts, and a few tornadoes across the Ohio Valley vicinity. ...Synopsis... Recent water-vapor imagery continues to depict a robust upper wave over the central Rockies with an accompanying surface low noted in mid-morning surface observations across the central Plains. Guidance continues to show reasonably good agreement in the evolution of these features over the next 48 hours as the upper wave ejects into the Plains and the surface low tracks northeastward through the Upper Great Lakes region by late Wednesday. A trailing cold front is expected to impinge on a broad warm sector beginning late tonight as it migrates southeast through the Midwest, mid-MS River Valley, and TX Gulf coast through the day Wednesday. Strong to severe thunderstorms will likely be ongoing at the beginning of the period along much of the cold front, and more organized cells and/or clusters may persist into the afternoon hours given the strongly sheared environment and diurnal warming/destabilization. Locations that see weakening of early-morning convection will likely see re-intensification either along the cold or residual outflow boundaries by late afternoon. Given the broad warm sector (featuring 60+ F dewpoints) and strong flow over the region, organized convection appears likely across a large swath of the Midwest to south-central CONUS. One notable trend for this update is a westward shift in probabilities driven by a slower eastward progression of the synoptic wave/surface low that has consistently emerged in recent global and mesoscale guidance. ...IL to OH and lower MI... Confidence in the severe threat remains highest across portions of the Midwest. Open warm sector convection may be ongoing by 12 UTC across parts of eastern MO/IL and will propagate into parts of IN, OH, and lower MI through the day. Poleward moisture advection in the wake of morning convection will maintain a buoyant air mass prior to the frontal passage in the late morning/afternoon when a second round of storms appears likely. The combination of the mid-level jet max aloft and strong low-level pressure gradient winds will result in a strongly sheared environment featuring effective bulk shear values near 50s knots and 150-200 m2/s2 of 0-1 km SRH. This kinematic environment will support a tornado threat, including the potential for a strong tornado, especially if more discrete storm modes can be realized (though it is unclear if boundary-relative storm motions and deep-layer shear vectors will be sufficient to maintain discrete modes given considerable along-boundary mean flow). Regardless, the strong low-level flow will support the potential for damaging to severe winds. ...Middle MS and lower OH River Valleys... Forcing for ascent along the middle MS and lower OH River Valleys is expected to diminish through the day as stronger synoptic ascent becomes increasingly displaced to the north/northeast. Strong flow aloft on the southern periphery of the jet max will support elongated hodographs, which when coupled with 1500-2000 J/kg MLCAPE and residual ascent along the slowing cold front, will likely be favorable for semi-discrete cells to clusters with an attendant threat for large hail, damaging winds, and perhaps a tornado. ..Moore/Jewell.. 04/04/2023 Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1136 AM CDT TUE APR 04 2023 ...Severe thunderstorms expected over parts of the Select a General Area this afternoon and tonight... * LOCATIONS... Western Arkansas Eastern Iowa Southern Missouri Northwest Illinois * HAZARDS... Several tornadoes, a few intense Scattered large hail, some baseball size Scattered damaging winds * SUMMARY... Tornadoes, severe thunderstorm gusts and large hail are possible today and tonight from the Upper Great Lakes to central Texas. Tornado potential is focused today over parts of Iowa/Illinois this afternoon, and especially tonight over parts of the Ozarks to the Arklatex region. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A tornado watch means that conditions are favorable for tornadoes to form during the next several hours. If a tornado warning is issued for your area, move to a place of safety, ideally in a basement or interior room on the lowest floor of a sturdy building. && Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1136 AM CDT TUE APR 04 2023 ...Severe thunderstorms expected over parts of the Select a General Area this afternoon and tonight... * LOCATIONS... Western Arkansas Eastern Iowa Southern Missouri Northwest Illinois * HAZARDS... Several tornadoes, a few intense Scattered large hail, some baseball size Scattered damaging winds * SUMMARY... Tornadoes, severe thunderstorm gusts and large hail are possible today and tonight from the Upper Great Lakes to central Texas. Tornado potential is focused today over parts of Iowa/Illinois this afternoon, and especially tonight over parts of the Ozarks to the Arklatex region. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A tornado watch means that conditions are favorable for tornadoes to form during the next several hours. If a tornado warning is issued for your area, move to a place of safety, ideally in a basement or interior room on the lowest floor of a sturdy building. && Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Tue Apr 04 2023 Valid 041630Z - 051200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER PARTS OF EASTERN IOWA AND NORTHERN ILLINOIS THIS AFTERNOON...AND OVER PARTS OF ARKANSAS AND MISSOURI TONIGHT.... ...SUMMARY... Tornadoes, severe thunderstorm gusts and large hail are possible today and tonight from the Upper Great Lakes to central Texas. Tornado potential is focused today over parts of Iowa/Illinois this afternoon, and especially tonight over parts of the Ozarks to the Arklatex region. ...IA/IL/MO... A large upper trough is deepening over the Rockies today, with an 80-90 knot mid level speed max rotating across the Plains. The associated surface low will track from central KS into IA this afternoon while a warm front lifts northward across eastern IA and northern IL. This will result in a large unstable warm sector across parts of IA/IL/MO where forecast soundings show strong low-level shear profiles and ample CAPE for severe/supercell storms. This scenario is quite different than last Friday, with more concerns for capping in the warm sector and pockets of dry low-level air that reduces confidence in the number of storms and intense tornado potential. Nevertheless, scattered supercells are expected later today with very large hail, tornadoes, and damaging winds expected. Isolated strong tornadoes may occur. By mid-late afternoon, thunderstorms are expected to erupt near the surface low and along the trailing cold front over central IA/northern MO. Intense wind fields will be present in this area, along with strong linear forcing. Large hail and damaging winds are expected with this activity, along with the risk of supercell and/or QLCS tornadoes. ...ArkLaTex into southern MO/IL Tonight... By early evening, forecast soundings from most 12z guidance shows that a broad area of high conditional risk of tornadic supercells will develop from eastern OK into much of AR and southern MO. This area will still be somewhat capped and the mechanisms for convective initiation are uncertain. However, a consensus of guidance shows multiple clusters of supercells forming across this area and persisting through the evening. Wind fields will strengthen throughout the night and capping will weaken, leading to a serious concern for nocturnal tornadoes over the southern MDT risk area in MO/AR. Again, model guidance provides confidence in the risk of widely scattered supercells throughout the night across the area, although details of location and timing are uncertain. Strong or even violent tornadoes are possible in this scenario. ..Hart/Lyons.. 04/04/2023 Read more

No watches are valid as of Mon Apr 3 21:02:01 UTC 2023.

MD 0449 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF CENTRAL TEXAS
Mesoscale Discussion 0449 NWS Storm Prediction Center Norman OK 0348 PM CDT Mon Apr 03 2023 Areas affected...portions of central Texas Concerning...Severe potential...Watch unlikely Valid 032048Z - 032215Z Probability of Watch Issuance...20 percent SUMMARY...Initiation attempts along the dryline may result in an isolated supercell risk late this afternoon into the evening. Hail and damaging winds would be possible if storms can maintain intensity. DISCUSSION...As of 2045 UTC, area visible imagery showed deepening cumulus towers along the dryline at the nose of returning surface moisture over portions of central TX. A subtle southern stream perturbation and surface temperatures warming into the mid 90s F to the west of the dryline have removed most of the inhibition immediately along the boundary from proximity RAP soundings. However the strong heating has mixed surface dewpoints into the 50s F keeping buoyancy limited to around 1000 J/kg of MLCAPE. Farther east the cooler and more moist airmass (surface dewpoints in the upper 60s F) remains somewhat capped. Should storms develop and sustain themselves, strong mid-level flow with 40-50 kt of effective shear would support organized storms including supercells. If able to realize the deeper moisture and shear east, 2000 J/kg of MLCAPE and steep lapse rates will support a risk for large hail and damaging winds. Some Hi-Res guidance does depict an isolated storm potentially continuing into early evening across central TX, but uncertainty remains relatively high. Trends will be monitored for a possible weather watch should multiple storms persist and pose a more significant severe threat. ..Lyons/Gleason.. 04/03/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FWD...EWX...SJT... LAT...LON 30269975 31399943 32219837 32439758 32409710 32099689 31379709 30589721 30069755 29239823 29209875 29499947 29719956 30269975 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook AMEND 1 NWS Storm Prediction Center Norman OK 0302 PM CDT Mon Apr 03 2023 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS WEDNESDAY FROM THE GREAT LAKES REGION AND OHIO VALLEY SOUTHWESTWARD INTO THE LOWER MISSISSIPPI VALLEY... AMENDED FOR SLOWING UPPER TROUGH, WESTWARD EXPANSION OF SEVERE THREAT ...SUMMARY... Severe thunderstorms are possible over a large area from the Great Lakes region southwestward to the Lower Mississippi Valley Wednesday. This may include cells capable of producing tornadoes and extensive wind damage, primarily north of the Ohio River, with other severe storms expected into the lower Mississippi Valley. This amendment is primary due to the slowing upper trough, and the westward expansion of severe probabilities. Severe storms may be ongoing as far west as the St. Louis area at 12Z Wednesday, with favorable conditions remaining for tornadoes and damaging winds expending mainly northeastward. Farther south, lower 70s F dewpoints and heating ahead of a cold front is expected to support scattered storms during the day into the lower MS Valley, where mainly hail and damaging gusts will be possible. This westward demarcation of the severe threat will likely be adjusted further incoming updates. ...PREVIOUS DISCUSSION... ...Synopsis... Within the more amplified branch of split flow emanating from the mid-latitude Pacific, the center of a broad and deep, occluding cyclone is forecast to migrate across and northeast of the Lake Superior vicinity before beginning to weaken Wednesday through Wednesday night. As this occurs, it appears that mid-level ridging centered along an axis across the Yucatan Peninsula into western Atlantic will remain a prominent influence across much of the Southeast, while short wave ridging also overspreads the Northeast and Canadian Maritimes. Models indicate that a narrow corridor of increasing low-level moisture, ahead of the cold front trailing the cyclone, will overspread much of the Ohio Valley and lower Great Lakes region. The trailing flank of the cold front probably will stall across the lower Mississippi Valley into northwestern Gulf coastal plain, beneath the northwestern periphery of the mid-level ridging. ...Lower Great Lakes into lower Mississippi Valley vicinity... Most model output generally indicates that the core of stronger southerly low-level flow, initially including 50+ kt around 850 from the Mid South through lower Michigan, will rapidly shift across the lower Great Lakes region and weaken some by mid afternoon, However, southwesterly mean flow on the order of 40-70 kt may linger as far southwest as the lower Ohio Valley through much of the day. This will contribute to an environment at least conditionally support of organized severe thunderstorm development. With sufficient destabilization, this may include an evolving squall line with embedded and perhaps preceding discrete supercells. Destabilization remains a bit uncertain, based on the latest model output, with perhaps considerable warm sector cloud cover inhibiting insolation. Based on ensemble output, the 03/00Z NAM might be a bit of an outlier indicating sizable mixed-layer CAPE developing across southern lower Michigan and adjacent portions of Indiana/Ohio by early Wednesday afternoon, perhaps beneath a remnant plume of modestly steep mid-level lapse rates. If it becomes more apparent in subsequent model output that this environment will materialize, severe probabilities will probably need to be increased, with the risk including at least a bit more appreciable potential for a couple of strong tornadoes. South of the Ohio Valley, through lower Mississippi Valley, severe weather potential appears more limited as low-level flow weakens along the stalling frontal zone. ..Jewell.. 04/03/2023 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Mon Apr 03 2023 Valid 032000Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEAST STATES AND OVER PORTIONS OF CENTRAL TO NORTHERN TEXAS... ...SUMMARY... Isolated strong to severe thunderstorms may occur across parts of the Southeast and Texas this afternoon and evening. Damaging winds will be the primary concern, but a few instances of severe hail, and perhaps a tornado, are possible. ...Southern Georgia/northern Florida... A cluster of thunderstorms continues to propagate to the east/southeast along a diffuse warm frontal zone/surface theta-e gradient across southern GA into northern FL. Although several damaging wind reports have been noted with this activity, IR cloud top temperatures have shown a steady warming trend over the past 1-2 hours, and an undercutting outflow boundary is noted ahead of most of the deeper cells in the line, implying gradual weakening of the system. The expectation is for this line/cluster to continue to pose an isolated damaging wind risk into northern FL over the next several hours, but the threat for scattered damaging/severe winds appears sufficiently low to warrant a reduction in probabilities. ...Central/north Texas... Recent visible imagery shows a growing cumulus field along a diffuse dryline across central TX. While a few towers within the field show increasing vertical development, convergence along the dryline remains weak and a nearby ACARS sounding sampled residual capping over the region. These observations are in line with recent HRRR/RAP guidance, which shows little to no convective precipitation signal and continues to cast uncertainty into the probability for robust convective initiation. Given these concerns, the Marginal risk is maintained for this update. However, the environment over the region remains highly favorable for organized supercells if a mature storm or two can become established late this afternoon/evening. ..Moore/Gleason.. 04/03/2023 .PREV DISCUSSION... /ISSUED 1128 AM CDT Mon Apr 03 2023/ ...Southeast... Water-vapor satellite imagery shows a low-amplitude shortwave trough centered over portions of the Southeast late this morning. This trough will move eastward off the NC/SC Coast by this evening. An ongoing cluster of thunderstorms over southeast AL and southwest GA will develop east-southeastward along/near a surface warm front which will attempt to advance northeast from the Gulf Coast. This will result in the cluster becoming gradually separated from the low-amplitude wave. Still, some tornado threat should continue into the afternoon with this activity until the low-level flow slowly weakens and veers. Damaging winds will also be possible farther east into southern GA and north FL as at least modest destabilization and filtered daytime heating occur ahead of the ongoing cluster. In the wake of this activity, a couple of thunderstorms may redevelop along residual convective outflow or the northward-developing warm front during the late afternoon to early evening across eastern MS and southern/central AL. Minimal large-scale ascent results in low confidence in this scenario occurring. But, if convection becomes sustained, a strongly sheared and destabilizing warm sector may support severe hail and/or damaging winds. ...North/Central Texas... Moderate to strong buoyancy and 50+ kt of deep-layer shear will support a conditionally favorable supercell environment along/just ahead of a dryline late this afternoon and early evening over parts of north/central TX. Near-neutral mid-level heights with minor downstream ridging is expected across the dryline. This area will also be well removed from a deepening upper trough across the western CONUS. Low-level convergence along the dryline should remain weak, but could be relatively maximized in the early evening across central TX as the dryline starts to retreat. Some 12Z convection-allowing models suggest a thunderstorm or two may briefly develop. However, uncertainty remains high regarding a particular location. Any sustained supercell would pose a conditional risk of all severe hazards, but large hail is likely if a thunderstorm can form and be sustained. Given the uncertainty in whether any convection will initiate given the negligible large-scale ascent, will maintain low severe probabilities with this update. But, observational and short-term model trends will be closely monitored for a possible upgrade to Slight Risk at 20Z, if warranted. ...Illinois/Indiana... Gradual destabilization this afternoon will occur south of a quasi-stationary front that bisects MO to central IL and northern IN. However, a building mid-level ridge along with the expansion of a stout EML suggest the chance for surface-based development today is low. Still, modest lift to the cool side of the front may support a few stronger elevated updrafts this evening through tonight. A weak combination of buoyancy/shear and warm-advection-related ascent suggests that small hail should be the most likely hazard. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0234 PM CDT Mon Apr 03 2023 Valid 041200Z - 051200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR EAST-CENTRAL NEW MEXICO ACROSS THE TX/OK PANHANDLES AND NORTHWEST OKLAHOMA AND INTO SOUTHWEST AND SOUTH-CENTRAL KANSAS... ...CRITICAL FIRE WEATHER AREA FOR A LARGE PORTION OF THE CENTRAL AND SOUTHERN PLAINS... After coordination with local fuel experts and forecast offices, an Extremely Critical delineation was added for parts of east-central New Mexico northeast to south-central Kansas. This is the region most likely to see single digit (potentially less than 5%) relative humidity and sustained winds of 30-40 mph and gusts 50-60+ mph. In addition, northern portions of this Extremely Critical area are in D4/exceptional drought which has made remaining fuels even more receptive to fire. Multiple large, dangerous, fast-moving fires are expected on Tuesday. ..Bentley.. 04/03/2023 .PREV DISCUSSION... /ISSUED 0202 AM CDT Mon Apr 03 2023/ ...Synopsis... Dangerous fire weather conditions are expected across the Southern and Central High Plains on Tuesday as winds increase in response to a strong trough and surface low advancing eastward across the Plains. Elevated to Critical fire weather conditions are expected with locally Extremely Critical conditions across a narrow corridor of the Southern Plains. ...Central and Western Kansas, South Eastern Colorado, Western Oklahoma, Western Texas, Eastern New Mexico... Dry and windy conditions Monday and poor recoveries Monday night will set the stage for Critical to locally Extremely Critical fire weather on Tuesday afternoon. Surface winds will not entirely decouple overnight across western Texas/Oklahoma with sustained winds around 15 mph overnight amid relative humidity hover around 15-20 percent. By daybreak Tuesday morning, winds will quickly begin to increase through the afternoon when peak heating will allow for a deeply mixed boundary layer behind the Central Plains dry line. Relative humidity reductions to 5-10 percent will be possible with sustained surface winds as high as 30-35 mph (locally 40+ mph). Given the severe to extreme drought conditions, ERCs approaching 80-90th percentile, and forecast conditions, a Critical region was introduced with this outlook. An Extremely critical delineation across some smaller portion of the Critical area will be considered pending status of fuels after Monday. Potential for wind driven grass fires will be very high and extreme caution should be used to avoid open flames and sparks. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1255 PM CDT Mon Apr 03 2023 Valid 041200Z - 051200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM EASTERN IOWA INTO NORTHWEST ILLINOIS...AND FROM SOUTHERN MISSOURI SOUTHWESTWARD TOWARD THE ARKLATEX.... ...SUMMARY... A large area of severe potential will exist from Tuesday afternoon into Wednesday morning, from eastern portions of the Plains into the Missouri and mid/upper Mississippi Valleys. Strong tornadoes and particularly damaging winds are expected. Both afternoon and overnight potential will exist across various regions, including the risk of dangerous nighttime tornadoes. ...Synopsis... A large upper trough will move from the Rockies into the Plains on Tuesday, with an upper low tracking from WY to northern MN by Wednesday morning, deepening after 00Z. Meanwhile, upper ridging will occur over the eastern states. A strong 100 kt midlevel jet max will be positioned from NM into western KS during the day, with an intensifying jet core Tuesday night from KS into IA. Just ahead of the primary upper trough/jet, a leading speed max will strengthen from OK into KS and MO during the day, perhaps with a subtle lobe of cooling aloft. At the surface, low pressure will exist over eastern CO Tuesday morning, and will shift eastward across KS during the day, translating east/northeast along a cold front. This low will shift into IA by evening, and into WI by 12Z Wednesday. Ahead of the low, a prominent warm front will move rapidly north, beginning the day from northeast KS into central IL, and reaching near I-80 from IA into northern IL by 00Z. This boundary will continue north into southern WI and western Lower MI overnight, ahead of the surface low. Behind the low, a cold front will make an eastward push during the late evening and overnight across IA, northwest MO and eastern KS. South of the low, a dryline will stretch from eastern KS into central OK and north TX at 00Z, and may become stationary or even back westward over the southern Plains during the late evening and prior to the cold front arriving from the north. Given relatively high heights over the eastern CONUS preceding the upper trough, a very wide warm sector will develop from the surface low and dryline eastward well east of the MS River, with upper 60s F dewpoints common from eastern OK and AR southward. The combination of an expansive warm sector and strong shear, for long duration and in various forcing regimes, suggests that significant severe weather is likely. However, subtleties regarding timing with regard to the diurnal cycle, capping, and conflicting model output will make this prediction challenging, especially when weighing potential impacts to life and property. ...IA...northern MO...IL...southern WI - DAYTIME... The area near the warm front and later in late into the overnight hours ahead of the surface low will be a favored area for supercells and tornadoes. Storms are expected to form from northern MO into IA during the late afternoon, shifting northeastward with the warm. Low-level shear will be extremely favorable for tornadoes, as with over 300 m2/s2 SRH and MUCAPE perhaps up to 3000 J/kg. The steep lapse rates aloft will maximize updraft strength as well, resulting in strong tornadoes. This threat may persist farther northeast into southern WI and northern IL into the night as the warm and unstable air with the warm front continues to move north with this strong system. ...Northeast TX into AR and into MO - OVERNIGHT... Confidence is increasing in the potential for rare and dangerous overnight tornadoes and damaging winds, and a Moderate Risk has been introduced for this region. The air mass will remain capped during the day, as boundary-layer moisture builds. Steep lapse rates will exist above the capping layer, which will not be particularly strong overnight due to robust moisture. As the cold front approaches from the west, the low-level jet will remain strong providing theta-e advection through the night. Nocturnal storms are forecast to erupt after 06Z, and perhaps closer to 08Z from southwest MO into western AR and into northeast TX. Hodographs will strongly favor tornadic supercells with effective SRH near 400 m2/s2. Further, steep lapse rates aloft and ample instability will favor strong tornadoes, and a long tracked tornado cannot be ruled out. This appears to be a rare case where the front may act more like a dryline during the overnight hours, with veering at 850 mb being more gradual. Capping is most likely to limit the eastward extent of the threat for southern areas near LA. ..Jewell.. 04/03/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1128 AM CDT Mon Apr 03 2023 Valid 031630Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR SOUTHEAST ALABAMA...SOUTHERN GEORGIA...AND THE FLORIDA PANHANDLE... ...SUMMARY... Isolated severe thunderstorms will be possible today over parts of the Southeast and Texas. A more concentrated corridor with a threat for damaging winds and perhaps a couple of tornadoes should remain focused across parts of far southeast Alabama, southern Georgia, and the Florida Panhandle through the afternoon. ...Southeast... Water-vapor satellite imagery shows a low-amplitude shortwave trough centered over portions of the Southeast late this morning. This trough will move eastward off the NC/SC Coast by this evening. An ongoing cluster of thunderstorms over southeast AL and southwest GA will develop east-southeastward along/near a surface warm front which will attempt to advance northeast from the Gulf Coast. This will result in the cluster becoming gradually separated from the low-amplitude wave. Still, some tornado threat should continue into the afternoon with this activity until the low-level flow slowly weakens and veers. Damaging winds will also be possible farther east into southern GA and north FL as at least modest destabilization and filtered daytime heating occur ahead of the ongoing cluster. In the wake of this activity, a couple of thunderstorms may redevelop along residual convective outflow or the northward-developing warm front during the late afternoon to early evening across eastern MS and southern/central AL. Minimal large-scale ascent results in low confidence in this scenario occurring. But, if convection becomes sustained, a strongly sheared and destabilizing warm sector may support severe hail and/or damaging winds. ...North/Central Texas... Moderate to strong buoyancy and 50+ kt of deep-layer shear will support a conditionally favorable supercell environment along/just ahead of a dryline late this afternoon and early evening over parts of north/central TX. Near-neutral mid-level heights with minor downstream ridging is expected across the dryline. This area will also be well removed from a deepening upper trough across the western CONUS. Low-level convergence along the dryline should remain weak, but could be relatively maximized in the early evening across central TX as the dryline starts to retreat. Some 12Z convection-allowing models suggest a thunderstorm or two may briefly develop. However, uncertainty remains high regarding a particular location. Any sustained supercell would pose a conditional risk of all severe hazards, but large hail is likely if a thunderstorm can form and be sustained. Given the uncertainty in whether any convection will initiate given the negligible large-scale ascent, will maintain low severe probabilities with this update. But, observational and short-term model trends will be closely monitored for a possible upgrade to Slight Risk at 20Z, if warranted. ...Illinois/Indiana... Gradual destabilization this afternoon will occur south of a quasi-stationary front that bisects MO to central IL and northern IN. However, a building mid-level ridge along with the expansion of a stout EML suggest the chance for surface-based development today is low. Still, modest lift to the cool side of the front may support a few stronger elevated updrafts this evening through tonight. A weak combination of buoyancy/shear and warm-advection-related ascent suggests that small hail should be the most likely hazard. ..Gleason/Lyons.. 04/03/2023 Read more

No Mesoscale Discussions are in effect as of Sun Apr 2 21:20:04 UTC 2023.

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Apr 02 2023 Valid 022000Z - 031200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF NORTH-CENTRAL/NORTHEAST TEXAS... ...SUMMARY... Scattered severe thunderstorms are expected across central to northeast Texas this afternoon through about midnight CDT. Very large hail and several tornadoes are possible, a couple of which may be strong. ...20Z Update... Convection has been gradually increasing in coverage and intensity across parts of western north TX this afternoon as a shortwave trough ejects eastward over the southern Plains. Current expectations are for supercells to develop from both the ongoing activity, and with additional development this afternoon along an eastward-mixing dryline. Large to very large hail will be a concern with any supercell that can be sustained, as steep mid-level lapse rates and strong effective bulk shear foster robust updrafts and hail growth. A strong tornado also remains a possibility, particularly this evening across parts of north-central TX. As convection eventually grows upscale this evening, the damaging wind threat should likewise gradually increase. For more details on the near-term severe threat across central/north TX and southern OK, see Mesoscale Discussion 437 and recently issued Tornado Watch 110. Otherwise, the Marginal Risk has been expanded slightly eastward across parts of southern/central MS for late tonight into early Monday morning, where an isolated hail/wind threat may persist. ..Gleason.. 04/02/2023 .PREV DISCUSSION... /ISSUED 1115 AM CDT Sun Apr 02 2023/ ...TX/OK/LA... Morning water vapor loop shows a well-defined and compact midlevel shortwave trough moving quickly eastward across NM/Southwest TX. This trough and its associated 60-70kt midlevel jet will track across TX this afternoon and evening, providing large scale ascent for a round of intense thunderstorms. Low-level moisture is returning northward quickly this morning, with dewpoints in the 60s expected as far north as the Red River. A combination of relatively strong surface heating, very steep midlevel lapse rates, and rapid cooling of midlevel temperatures will yield a corridor of afternoon MLCAPE values ~2000 J/kg along and east of the dryline. Current indications are that thunderstorms will form quickly by mid-afternoon along and east of the dryline over western North Texas and southwest OK as the upper trough arrives. These storms will likely intensify rapidly into supercells with a risk of very large hail and a tornado or two. This activity will increase in coverage as it spreads eastward along the northern edge of rapid moisture return toward the DFW metro area. Very large hail will remain a concern, but most model guidance also shows strengthening low-level wind fields and shear, promoting an increasing risk of tornadoes and damaging wind gusts. A strong tornado or two will be possible. By mid-evening, activity will likely congeal into an MCS tracking eastward into northeast TX and northwest LA. Damaging wind risk will increase, while the risk of hail and a tornado or two persists. There is uncertainty how far east this MCS will maintain a severe risk. Will not adjust the outlook areas at this time, but will re-evaluate the need for SLGT farther east in later updates. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Sun Apr 02 2023 Valid 031200Z - 041200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN HIGH PLAINS... Both the Elevated and Critical areas were expanded somewhat to account for the latest forecast guidance, but overall the forecast remains on track. See previous discussion below. ..Bentley.. 04/02/2023 .PREV DISCUSSION... /ISSUED 0148 AM CDT Sun Apr 02 2023/ ...Synopsis... On Monday strong mid-level flow will overspread the Southwest and Southern High Plains as a lee cyclone begins to develop with increasing surface pressure gradients across the Southern Plains. Elevated to Critical fire weather conditions are expected across portions of the Southwest and Southern High Plains as this pattern brings windy and dry conditions. ...Southwest and Southern High Plains... Deep boundary layer mixing is expected Monday afternoon allowing relative humidity reductions to 5-15 percent across a broad region of the High Plains and into the Southwest. Southwesterly surface winds will be sustained around 20-25 mph. Fuels across western Texas and Oklahoma into eastern Colorado and New Mexico have seen several periods of windy/dry conditions with ERCs forecast to be within 80-90th percentile for dryness supporting introduction of a Critical delineation. Fuels across the Southwest are beginning to become more supportive of fire spread but remain around or below the 60th percentile, precluding the need to include a larger area within the D2 Critical. Elevated to critical relative humidity and winds will remain possible across much of Arizona and New Mexico. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0110 Status Updates
STATUS FOR WATCH 0110 HAS NOT BEEN ISSUED YET Read more

WW 110 TORNADO OK TX 021945Z - 030400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 110 NWS Storm Prediction Center Norman OK 245 PM CDT Sun Apr 2 2023 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Southern Oklahoma North and Central Texas * Effective this Sunday afternoon and evening from 245 PM until 1100 PM CDT. * Primary threats include... A few tornadoes likely with a couple intense tornadoes possible Widespread large hail and isolated very large hail events to 3 inches in diameter likely Scattered damaging wind gusts to 70 mph possible SUMMARY...Supercell thunderstorms are expected to intensify along a dryline over western North Texas, while other intense storms form eastward across the watch. Very large hail will be possible with this activity, along with an increasing risk of tornadoes and damaging wind gusts through the afternoon. The tornado watch area is approximately along and 115 statute miles east and west of a line from 45 miles west northwest of Ardmore OK to 25 miles south of Temple TX. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27035. ...Hart Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 PM CDT Sun Apr 02 2023 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL GULF COAST STATES...SOUTHERN PLAINS...AND MID MISSISSIPPI VALLEY/MIDWEST... ...SUMMARY... Isolated to widely scattered severe thunderstorms appear possible across parts of the central Gulf Coast states, mainly through early Monday evening. More isolated strong to severe thunderstorms may occur across portions of the southern Plains, and mid Mississippi Valley/Midwest vicinity, late Monday afternoon through Monday night. ...Synopsis... A pronounced western CONUS upper trough is forecast to amplify further on Monday as it digs over the Great Basin and Southwest. Strong surface lee cyclogenesis will occur in earnest over the central High Plains as large-scale ascent overspreads this region through the period. Low-level moisture emanating from the open Gulf of Mexico will stream northward Monday across parts of the southern/central Plains, lower/mid MS Valley, Southeast, and Midwest. A surface dryline will mix eastward through Monday afternoon over portions of central/eastern OK/TX. ...Lower Mississippi Valley/Mid-South into the Southeast... A low-amplitude shortwave trough should move quickly eastward across the Southeast and towards the East Coast Monday morning. Ascent associated with this feature and related low-level warm advection will likely aid thunderstorms that should be ongoing Monday morning over parts of MS into AL. At least weak destabilization should occur through Monday afternoon over parts of southern AL/GA and the FL Panhandle as daytime heating occurs and surface dewpoints increase into the mid to upper 60s along/south of a front. A mix of multicells and perhaps occasional supercell structures may persist and spread slowly east-southeastward across this area, as deep-layer shear should remain strong enough to support continued updraft organization. Isolated damaging winds and large hail should be the main threats with this activity, but sufficient low-level shear should be present along/near the front for some updraft rotation and perhaps a tornado or two. ...Southern Plains... Well ahead of the western CONUS upper trough, mid-level heights are forecast to remain neutral on Monday, or even rise slightly through the day. The surface dryline is expected to mix eastward across parts of central/eastern OK/TX by late Monday afternoon. Nebulous/weak large-scale ascent and a persistent low-level inversion associated with an EML/steepening mid-level lapse rates should inhibit convective development for much of the day. Latest (12Z) guidance shows generally little signal for thunderstorms to initiate along the dryline Monday afternoon/early evening. But, there still appears to be a conditional threat for a supercell to develop by peak afternoon heating. If a thunderstorm can form, it would exist in rather favorable thermodynamic and kinematic environment to support both large hail and damaging winds. Have adjusted the Marginal Risk based on the consensus of the forecast position of the dryline, but confidence in convection occurring remains too low to include higher severe hail/wind probabilities. ...Central Plains into the Mid Mississippi Valley and Midwest... Modest low-level moisture should return slowly northward across this region as a warm front gradually sharpens by Monday evening. Most guidance suggests that a cap will limit robust thunderstorm development through much of the day. But, increasing ascent attendant to a strengthening west-southwesterly low-level jet may aid convective initiation along/north of the front Monday evening and overnight. If thunderstorms can form, they would likely remain elevated and pose a threat for mainly isolated hail as they move eastward from parts of the mid MS Valley to the Midwest. ..Gleason.. 04/02/2023 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 02 2023 Valid 021700Z - 031200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN/CENTRAL HIGH PLAINS... No changes were made. Morning guidance is not as bullish with wind speeds across southeast New Mexico and portions of West Texas. However, surface observations show a few locations with 20 mph winds as of 16Z. Therefore, this area will remain in the Critical delineation. ..Bentley.. 04/02/2023 .PREV DISCUSSION... /ISSUED 0105 AM CDT Sun Apr 02 2023/ ...Synopsis... A shortwave will move across the Central and Southern High Plains on Sunday bringing increasing westerly winds aloft. Windy and very dry conditions are expected behind the dry line, where Elevated to Critical fire weather is expected this afternoon. ...Eastern New Mexico, Southeastern Colorado, Oklahoma Panhandle, West Texas... Behind the dry line, strong westerly downslope flow and a deeply mixed boundary layer will allow relative humidity reductions to around 10-15 percent. Ensemble guidance highlights the highest confidence of overlap in the strongest winds and dry conditions across eastern New Mexico northward into Colorado and eastward into the Oklahoma Panhandle and western Texas. Fuels within this region are notably drying with lack of recent rainfall and several windy/dry periods. Critical fire weather conditions are expected with little change made to the previously forecast region. ...Please see www.spc.noaa.gov/fire for graphic product... Read more