SPC MD 233

49 minutes 38 seconds ago
MD 0233 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHEASTERN MISSOURI INTO WEST-CENTRAL ILLINOIS
Mesoscale Discussion 0233 NWS Storm Prediction Center Norman OK 0342 PM CDT Sun Mar 24 2019 Areas affected...Northeastern Missouri into west-central Illinois Concerning...Severe potential...Watch unlikely Valid 242042Z - 242215Z Probability of Watch Issuance...20 percent SUMMARY...Storms have recently increased near/north of Columbia over the past half hour. Another cell persists into Hancock County Illinois. These storms may briefly approach severe limits, although a WW issuance is not anticipated. DISCUSSION...Recent convective development has occurred from near Columbia, Missouri to just west of Quincy, Illinois over the past half hour. Another persistent storm has maintained itself into portions of Hancock County, Illinois as well. These storms are in a relatively stable low-level environment compared to areas south, with minimal surface-based CAPE and any instability likely tied to cold mid-level temperatures (-22 to -24 C at 500 mb). Continued ascent tied to the approach of the mid-level wave centered just northwest of the region and cool temperatures aloft should support a risk of hail in the strongest cores, with only isolated instances of 1" stones. A strong wind gust may also occur with the strongest activity. The overall magnitude of the severe risk in this area will likely preclude a WW issuance. ..Cook.. 03/24/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ILX...LSX...DVN...EAX... LAT...LON 39169241 39539240 39989214 40169204 40469150 40549093 40349042 39889018 39369023 38979071 38909157 38889222 39169241 Read more

SPC MD 232

1 hour 3 minutes ago
MD 0232 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR PORTIONS OF EASTERN OK...NORTHEAST TX...AND MUCH OF WESTERN/CENTRAL AR
Mesoscale Discussion 0232 NWS Storm Prediction Center Norman OK 0328 PM CDT Sun Mar 24 2019 Areas affected...Portions of eastern OK...northeast TX...and much of western/central AR Concerning...Severe potential...Watch likely Valid 242028Z - 242300Z Probability of Watch Issuance...80 percent SUMMARY...Increasing severe threat this afternoon and evening will likely require watch issuance by 22-23Z (5-6 pm CDT). Large hail and damaging winds should be the main threats. DISCUSSION...Surface temperatures have warmed into the low to mid 70s across eastern OK ahead of a slow moving cold front. Even though large-scale forcing for ascent should remain modest, convective inhibition has mostly eroded this afternoon over parts of eastern OK, western AR, and northeast TX as low-level moisture has gradually increased across the warm sector. Some increase in cumulus development has recently occurred in east-central OK per recent visible satellite imagery, and an attempt at convective initiation is underway in Cherokee County OK as of 2025Z. As a weak cap centered around 790 mb on the 18Z SGF sounding continues to slowly erode, additional attempts at convective initiation appear increasingly likely by 22Z (5 pm CDT) along the cold front in eastern OK/western AR. Some steepening of mid-level lapse rates to around 7 C/km has occurred across this region, which along with the gradually increasing low-level moisture and daytime heating is contributing to 500-1000 J/kg of MLCAPE at 20Z. Instability may potentially reach the 1000-1500 J/kg range by peak heating based on several RAP forecast soundings. Strengthening westerly flow above 3 km is supporting 40-50 kt of effective bulk shear, and supercells will probably be the dominant storm mode initially. Given the long, mostly straight hodographs noted on forecast soundings across this region, large hail appears likely with any supercell that can form along/ahead of the front. Isolated damaging winds may also occur where low-level lapse rates can steepen and act to accelerate convective downdrafts. Low-level winds are generally veered to southwesterly and relatively weak (less than 25 kt at 850 mb). Accordingly, the tornado threat will probably remain limited, but it is not zero. Short-term CAM guidance suggests that greater storm coverage may be realized from the vicinity of Fort Smith, AR into far southeastern OK, west-central into southwestern AR, and perhaps northeast TX through this evening where relatively greater instability should be present. Regardless, the increasing severe threat across this region will likely require watch issuance in the next couple of hours. ..Gleason/Hart.. 03/24/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LZK...SHV...TSA...FWD...OUN... LAT...LON 35449487 36489378 36479087 35399139 33959267 33179393 32989473 32889540 32889595 32999646 33299668 33909628 35449487 Read more

SPC Mar 24, 2019 2000 UTC Day 1 Convective Outlook

1 hour 25 minutes ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Mar 24 2019 Valid 242000Z - 251200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF THE MID MISSISSIPPI VALLEY AND ARKLATEX REGIONS... ...SUMMARY... Severe thunderstorms are expected from north Texas to southern Missouri and southwestern Illinois, mainly offering hail and damaging gusts. ...20Z update... Based on observational trends and short-term guidance, minimal updates necessary as Slight/Enhanced Risks appear to capture main corridor of severe weather that is expected to unfold through the afternoon and evening. See discussion below for additional details. Some spatial adjustments were made across the Middle Mississippi Valley for a northward expansion of mainly isolated/marginal hail potential. ..Guyer.. 03/24/2019 .PREV DISCUSSION... /ISSUED 1126 AM CDT Sun Mar 24 2019/ ...MO/IL... Morning water vapor loop shows a progressive upper low over southeast NE, with an associated mid-level speed max over KS/OK. This feature will track eastward today into the middle MS Valley, providing increasing ascent and deep-layer vertical shear for thunderstorm development/organization. Visible imagery shows substantial clearing/heating is occurring across southern MO and southwest IL, where surface dewpoints are rising into the 50s and low level lapse rates are steepening. This should aid in the development of scattered thunderstorms by mid-afternoon across southern MO. Forecast soundings show shear profiles favorable for discrete supercells capable of large hail. The tornado risk will be limited by veering low level winds and rather low dewpoint values. However, the damaging wind threat should increase as storms track eastward into southern IL during the late afternoon. Have added an ENH risk area for hail coverage across parts of southeast MO and southwest IL, where 12z CAM solutions provide greatest confidence. ...Arklatex Region... Latest surface analysis shows a weak warm front extending from southeast OK into southern AR. The air mass south of this front is relatively moist and moderately unstable with dewpoints near 60F. Models are consistent in the development of scattered intense storms this afternoon, with supercells capable of hail expected. This activity is likely to organize into a more linear structure through the evening, but continue to pose a risk of hail along with locally damaging winds. Activity may remain strong well into the night, affecting southeast AR/northeast LA and western MS. Similar to northern area, parameters and confidence support inclusion of ENH risk area for afternoon/evening hail risk. Read more

SPC Mar 24, 2019 2000 UTC Day 1 Convective Outlook

1 hour 25 minutes ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Mar 24 2019 Valid 242000Z - 251200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF THE MID MISSISSIPPI VALLEY AND ARKLATEX REGIONS... ...SUMMARY... Severe thunderstorms are expected from north Texas to southern Missouri and southwestern Illinois, mainly offering hail and damaging gusts. ...20Z update... Based on observational trends and short-term guidance, minimal updates necessary as Slight/Enhanced Risks appear to capture main corridor of severe weather that is expected to unfold through the afternoon and evening. See discussion below for additional details. Some spatial adjustments were made across the Middle Mississippi Valley for a northward expansion of mainly isolated/marginal hail potential. ..Guyer.. 03/24/2019 .PREV DISCUSSION... /ISSUED 1126 AM CDT Sun Mar 24 2019/ ...MO/IL... Morning water vapor loop shows a progressive upper low over southeast NE, with an associated mid-level speed max over KS/OK. This feature will track eastward today into the middle MS Valley, providing increasing ascent and deep-layer vertical shear for thunderstorm development/organization. Visible imagery shows substantial clearing/heating is occurring across southern MO and southwest IL, where surface dewpoints are rising into the 50s and low level lapse rates are steepening. This should aid in the development of scattered thunderstorms by mid-afternoon across southern MO. Forecast soundings show shear profiles favorable for discrete supercells capable of large hail. The tornado risk will be limited by veering low level winds and rather low dewpoint values. However, the damaging wind threat should increase as storms track eastward into southern IL during the late afternoon. Have added an ENH risk area for hail coverage across parts of southeast MO and southwest IL, where 12z CAM solutions provide greatest confidence. ...Arklatex Region... Latest surface analysis shows a weak warm front extending from southeast OK into southern AR. The air mass south of this front is relatively moist and moderately unstable with dewpoints near 60F. Models are consistent in the development of scattered intense storms this afternoon, with supercells capable of hail expected. This activity is likely to organize into a more linear structure through the evening, but continue to pose a risk of hail along with locally damaging winds. Activity may remain strong well into the night, affecting southeast AR/northeast LA and western MS. Similar to northern area, parameters and confidence support inclusion of ENH risk area for afternoon/evening hail risk. Read more

SPC Severe Thunderstorm Watch 32

1 hour 42 minutes ago
WW 32 SEVERE TSTM IL MO 241950Z - 250300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 32 NWS Storm Prediction Center Norman OK 250 PM CDT Sun Mar 24 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southwest Illinois Southern and Southeast Missouri * Effective this Sunday afternoon and evening from 250 PM until 1000 PM CDT. * Primary threats include... Widespread large hail likely with isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...Thunderstorms are beginning to form ahead of boundary over southern Missouri. These storms will track across the watch area this afternoon and evening, posing a primary risk of large hail. Damaging winds are also possible later this afternoon, along with the threat of an isolated tornado or two. The severe thunderstorm watch area is approximately along and 100 statute miles east and west of a line from 15 miles south southeast of West Plains MO to 10 miles northwest of Scott Afb IL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 26030. ...Hart Read more

SPC Day 2 Fire Weather Outlook

2 hours 19 minutes ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0211 PM CDT Sun Mar 24 2019 Valid 251200Z - 261200Z ...NO CRITICAL AREAS... The forecast remains on track, with no changes made. ..Squitieri.. 03/24/2019 .PREV DISCUSSION... /ISSUED 0104 AM CDT Sun Mar 24 2019/ ...Synopsis... An upper-level ridge will build over the Intermountain West and into Alberta/Saskatchewan with upper-level troughs over the Pacific Coast/eastern CONUS on Monday. A surface cold front will continue pushing southward across Texas and the Southeast with cooler/drier conditions behind it. Lighter mid-level flow (15-25 knots) is expected over the Southwest/southern High Plains, which will reduce lee troughing and the surface pressure gradient. Additionally, while deep boundary-layer mixing will occur, winds will remain weak due to the lack of flow through most of the vertical profile. This will lead to warm/dry/quiescent conditions across the Southwest/southern High Plains on Monday, and dampen the fire threat. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook

2 hours 19 minutes ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0211 PM CDT Sun Mar 24 2019 Valid 251200Z - 261200Z ...NO CRITICAL AREAS... The forecast remains on track, with no changes made. ..Squitieri.. 03/24/2019 .PREV DISCUSSION... /ISSUED 0104 AM CDT Sun Mar 24 2019/ ...Synopsis... An upper-level ridge will build over the Intermountain West and into Alberta/Saskatchewan with upper-level troughs over the Pacific Coast/eastern CONUS on Monday. A surface cold front will continue pushing southward across Texas and the Southeast with cooler/drier conditions behind it. Lighter mid-level flow (15-25 knots) is expected over the Southwest/southern High Plains, which will reduce lee troughing and the surface pressure gradient. Additionally, while deep boundary-layer mixing will occur, winds will remain weak due to the lack of flow through most of the vertical profile. This will lead to warm/dry/quiescent conditions across the Southwest/southern High Plains on Monday, and dampen the fire threat. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC MD 231

2 hours 38 minutes ago
MD 0231 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR CENTRAL/SOUTHERN MISSOURI EASTWARD INTO SOUTHERN ILLINOIS
Mesoscale Discussion 0231 NWS Storm Prediction Center Norman OK 0153 PM CDT Sun Mar 24 2019 Areas affected...Central/southern Missouri eastward into southern Illinois Concerning...Severe potential...Watch likely Valid 241853Z - 242130Z Probability of Watch Issuance...80 percent SUMMARY...Storms should gradually increase across the discussion area over the course of the afternoon, with initial development occurring in the 20-22Z timeframe. A WW is likely to be issued before 21Z. DISCUSSION...Latest observations and analyses indicate a deepening boundary layer cumulus field across central/south-central Missouri as surface temperatures warm into the mid 60s F. This warming was occurring beneath cold mid-levels (associated with a mid-level low over northwestern Missouri) and steep lapse rates (8.6 deg C/km on the 18Z RAOB from SGF). Storms should gradually develop across western and central portions of the discussion area as the weak mid-level inversion across the area erodes, with favorable shear profiles for updraft rotation. Hail and damaging wind gusts should be the primary threats. The 12Z Nam4 and latest runs of the HRRR suggest initiation occurring around 19-20Z and downstream propagation toward the St. Louis Metro and portions of southern Illinois over time. Given the expected evolution of the severe threat, a Severe Thunderstorm Watch will probably be needed before 21Z. ..Cook/Hart.. 03/24/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PAH...LSX...SGF... LAT...LON 37739334 38329277 38589207 38849112 38989003 38918913 38698873 38028880 37338916 37058951 36728977 36619025 36519104 36519218 36619317 36679367 36909384 37209375 37739334 Read more

SPC Mar 24, 2019 1730 UTC Day 2 Convective Outlook

3 hours 57 minutes ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sun Mar 24 2019 Valid 251200Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEAST STATES... ...SUMMARY... Thunderstorms are possible across portions of the Lower Mississippi Valley and Southeast States on Monday, with some of these storms potentially severe from parts of Mississippi and Alabama into western/northern Georgia. ...Synopsis... Within the southern stream of a split belt of westerlies, a shortwave trough will spread southeastward over the Tennessee Valley toward the Carolinas on Monday, while a secondary low-amplitude trough amplifies over the central Plains toward the Ozarks. Ahead of a prominent trough over the eastern Pacific, a lead shortwave will eject northeastward toward northern California and the coastal Pacific Northwest, contributing to isolated thunderstorm potential across the region. ...Tennessee Valley/Southeast States... Given the large-scale scenario as previously described, southwesterly low-level trajectories will lead to additional boundary layer moistening in advance of a southeastward-moving cold front. That said, moisture will remain modest overall with boundary layer dewpoints likely to remain sub-60F from eastern Alabama east/northeastward, with low 50s F dewpoints common into Tennessee and across the southern Appalachians vicinity. Strengthening cyclonic curved upper-level flow will otherwise overspread the region with lengthening hodographs in conjunction with slightly cooler mid-level temperatures. A key forecast uncertainty is the influence of lingering early-day showers and thunderstorms across parts of Tennessee/northern Alabama into Mississippi Monday morning near and ahead of the advancing front. Several convection-allowing models imply initial surface-based storm intensification across southern middle/southeast Tennessee during the afternoon, although this potential should be effectively shunted a bit south, more so across Alabama and parts of Georgia, on the presumption of differential heating being a factor. While acknowledging some spatial uncertainty exists, even with relatively modest moisture/destabilization overall, enhanced mid-level flow and relatively long supercell-conducive hodographs and relatively cool mid-level temperatures should allow for at least a few strong to severe thunderstorms mainly during the afternoon, although modest moisture/buoyancy should curb the overall risk. Hail and damaging wind gusts would be possible, with relatively weak/veered low-level winds otherwise keeping the tornado threat very low. It is possible that a semi-focused corridor of somewhat higher severe probabilities (Slight Risk-caliber) could be warranted in the Day 1 time frame pending greater certainty in a spatial corridor of more appreciable destabilization. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: 5% - Marginal Hail: 5% - Marginal ..Guyer.. 03/24/2019 Read more

SPC Mar 24, 2019 1730 UTC Day 2 Convective Outlook

3 hours 57 minutes ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sun Mar 24 2019 Valid 251200Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEAST STATES... ...SUMMARY... Thunderstorms are possible across portions of the Lower Mississippi Valley and Southeast States on Monday, with some of these storms potentially severe from parts of Mississippi and Alabama into western/northern Georgia. ...Synopsis... Within the southern stream of a split belt of westerlies, a shortwave trough will spread southeastward over the Tennessee Valley toward the Carolinas on Monday, while a secondary low-amplitude trough amplifies over the central Plains toward the Ozarks. Ahead of a prominent trough over the eastern Pacific, a lead shortwave will eject northeastward toward northern California and the coastal Pacific Northwest, contributing to isolated thunderstorm potential across the region. ...Tennessee Valley/Southeast States... Given the large-scale scenario as previously described, southwesterly low-level trajectories will lead to additional boundary layer moistening in advance of a southeastward-moving cold front. That said, moisture will remain modest overall with boundary layer dewpoints likely to remain sub-60F from eastern Alabama east/northeastward, with low 50s F dewpoints common into Tennessee and across the southern Appalachians vicinity. Strengthening cyclonic curved upper-level flow will otherwise overspread the region with lengthening hodographs in conjunction with slightly cooler mid-level temperatures. A key forecast uncertainty is the influence of lingering early-day showers and thunderstorms across parts of Tennessee/northern Alabama into Mississippi Monday morning near and ahead of the advancing front. Several convection-allowing models imply initial surface-based storm intensification across southern middle/southeast Tennessee during the afternoon, although this potential should be effectively shunted a bit south, more so across Alabama and parts of Georgia, on the presumption of differential heating being a factor. While acknowledging some spatial uncertainty exists, even with relatively modest moisture/destabilization overall, enhanced mid-level flow and relatively long supercell-conducive hodographs and relatively cool mid-level temperatures should allow for at least a few strong to severe thunderstorms mainly during the afternoon, although modest moisture/buoyancy should curb the overall risk. Hail and damaging wind gusts would be possible, with relatively weak/veered low-level winds otherwise keeping the tornado threat very low. It is possible that a semi-focused corridor of somewhat higher severe probabilities (Slight Risk-caliber) could be warranted in the Day 1 time frame pending greater certainty in a spatial corridor of more appreciable destabilization. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: 5% - Marginal Hail: 5% - Marginal ..Guyer.. 03/24/2019 Read more

SPC Mar 24, 2019 1730 UTC Day 2 Convective Outlook

3 hours 57 minutes ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sun Mar 24 2019 Valid 251200Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEAST STATES... ...SUMMARY... Thunderstorms are possible across portions of the Lower Mississippi Valley and Southeast States on Monday, with some of these storms potentially severe from parts of Mississippi and Alabama into western/northern Georgia. ...Synopsis... Within the southern stream of a split belt of westerlies, a shortwave trough will spread southeastward over the Tennessee Valley toward the Carolinas on Monday, while a secondary low-amplitude trough amplifies over the central Plains toward the Ozarks. Ahead of a prominent trough over the eastern Pacific, a lead shortwave will eject northeastward toward northern California and the coastal Pacific Northwest, contributing to isolated thunderstorm potential across the region. ...Tennessee Valley/Southeast States... Given the large-scale scenario as previously described, southwesterly low-level trajectories will lead to additional boundary layer moistening in advance of a southeastward-moving cold front. That said, moisture will remain modest overall with boundary layer dewpoints likely to remain sub-60F from eastern Alabama east/northeastward, with low 50s F dewpoints common into Tennessee and across the southern Appalachians vicinity. Strengthening cyclonic curved upper-level flow will otherwise overspread the region with lengthening hodographs in conjunction with slightly cooler mid-level temperatures. A key forecast uncertainty is the influence of lingering early-day showers and thunderstorms across parts of Tennessee/northern Alabama into Mississippi Monday morning near and ahead of the advancing front. Several convection-allowing models imply initial surface-based storm intensification across southern middle/southeast Tennessee during the afternoon, although this potential should be effectively shunted a bit south, more so across Alabama and parts of Georgia, on the presumption of differential heating being a factor. While acknowledging some spatial uncertainty exists, even with relatively modest moisture/destabilization overall, enhanced mid-level flow and relatively long supercell-conducive hodographs and relatively cool mid-level temperatures should allow for at least a few strong to severe thunderstorms mainly during the afternoon, although modest moisture/buoyancy should curb the overall risk. Hail and damaging wind gusts would be possible, with relatively weak/veered low-level winds otherwise keeping the tornado threat very low. It is possible that a semi-focused corridor of somewhat higher severe probabilities (Slight Risk-caliber) could be warranted in the Day 1 time frame pending greater certainty in a spatial corridor of more appreciable destabilization. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: 5% - Marginal Hail: 5% - Marginal ..Guyer.. 03/24/2019 Read more

SPC Mar 24, 2019 1730 UTC Day 2 Convective Outlook

3 hours 57 minutes ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sun Mar 24 2019 Valid 251200Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHEAST STATES... ...SUMMARY... Thunderstorms are possible across portions of the Lower Mississippi Valley and Southeast States on Monday, with some of these storms potentially severe from parts of Mississippi and Alabama into western/northern Georgia. ...Synopsis... Within the southern stream of a split belt of westerlies, a shortwave trough will spread southeastward over the Tennessee Valley toward the Carolinas on Monday, while a secondary low-amplitude trough amplifies over the central Plains toward the Ozarks. Ahead of a prominent trough over the eastern Pacific, a lead shortwave will eject northeastward toward northern California and the coastal Pacific Northwest, contributing to isolated thunderstorm potential across the region. ...Tennessee Valley/Southeast States... Given the large-scale scenario as previously described, southwesterly low-level trajectories will lead to additional boundary layer moistening in advance of a southeastward-moving cold front. That said, moisture will remain modest overall with boundary layer dewpoints likely to remain sub-60F from eastern Alabama east/northeastward, with low 50s F dewpoints common into Tennessee and across the southern Appalachians vicinity. Strengthening cyclonic curved upper-level flow will otherwise overspread the region with lengthening hodographs in conjunction with slightly cooler mid-level temperatures. A key forecast uncertainty is the influence of lingering early-day showers and thunderstorms across parts of Tennessee/northern Alabama into Mississippi Monday morning near and ahead of the advancing front. Several convection-allowing models imply initial surface-based storm intensification across southern middle/southeast Tennessee during the afternoon, although this potential should be effectively shunted a bit south, more so across Alabama and parts of Georgia, on the presumption of differential heating being a factor. While acknowledging some spatial uncertainty exists, even with relatively modest moisture/destabilization overall, enhanced mid-level flow and relatively long supercell-conducive hodographs and relatively cool mid-level temperatures should allow for at least a few strong to severe thunderstorms mainly during the afternoon, although modest moisture/buoyancy should curb the overall risk. Hail and damaging wind gusts would be possible, with relatively weak/veered low-level winds otherwise keeping the tornado threat very low. It is possible that a semi-focused corridor of somewhat higher severe probabilities (Slight Risk-caliber) could be warranted in the Day 1 time frame pending greater certainty in a spatial corridor of more appreciable destabilization. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: 5% - Marginal Hail: 5% - Marginal ..Guyer.. 03/24/2019 Read more

SPC Mar 24, 2019 1630 UTC Day 1 Convective Outlook

4 hours 59 minutes ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Sun Mar 24 2019 Valid 241630Z - 251200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF THE MID MISSISSIPPI VALLEY AND ARKLATEX REGIONS.... ...SUMMARY... Severe thunderstorms are expected from north Texas to southern Missouri and southwestern Illinois, mainly offering hail and damaging gusts. ...MO/IL... Morning water vapor loop shows a progressive upper low over southeast NE, with an associated mid-level speed max over KS/OK. This feature will track eastward today into the middle MS Valley, providing increasing ascent and deep-layer vertical shear for thunderstorm development/organization. Visible imagery shows substantial clearing/heating is occurring across southern MO and southwest IL, where surface dewpoints are rising into the 50s and low level lapse rates are steepening. This should aid in the development of scattered thunderstorms by mid-afternoon across southern MO. Forecast soundings show shear profiles favorable for discrete supercells capable of large hail. The tornado risk will be limited by veering low level winds and rather low dewpoint values. However, the damaging wind threat should increase as storms track eastward into southern IL during the late afternoon. Have added an ENH risk area for hail coverage across parts of southeast MO and southwest IL, where 12z CAM solutions provide greatest confidence. ...Arklatex Region... Latest surface analysis shows a weak warm front extending from southeast OK into southern AR. The air mass south of this front is relatively moist and moderately unstable with dewpoints near 60F. Models are consistent in the development of scattered intense storms this afternoon, with supercells capable of hail expected. This activity is likely to organize into a more linear structure through the evening, but continue to pose a risk of hail along with locally damaging winds. Activity may remain strong well into the night, affecting southeast AR/northeast LA and western MS. Similar to northern area, parameters and confidence support inclusion of ENH risk area for afternoon/evening hail risk. ..Hart/Gleason.. 03/24/2019 Read more

SPC Mar 24, 2019 1630 UTC Day 1 Convective Outlook

4 hours 59 minutes ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Sun Mar 24 2019 Valid 241630Z - 251200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF THE MID MISSISSIPPI VALLEY AND ARKLATEX REGIONS.... ...SUMMARY... Severe thunderstorms are expected from north Texas to southern Missouri and southwestern Illinois, mainly offering hail and damaging gusts. ...MO/IL... Morning water vapor loop shows a progressive upper low over southeast NE, with an associated mid-level speed max over KS/OK. This feature will track eastward today into the middle MS Valley, providing increasing ascent and deep-layer vertical shear for thunderstorm development/organization. Visible imagery shows substantial clearing/heating is occurring across southern MO and southwest IL, where surface dewpoints are rising into the 50s and low level lapse rates are steepening. This should aid in the development of scattered thunderstorms by mid-afternoon across southern MO. Forecast soundings show shear profiles favorable for discrete supercells capable of large hail. The tornado risk will be limited by veering low level winds and rather low dewpoint values. However, the damaging wind threat should increase as storms track eastward into southern IL during the late afternoon. Have added an ENH risk area for hail coverage across parts of southeast MO and southwest IL, where 12z CAM solutions provide greatest confidence. ...Arklatex Region... Latest surface analysis shows a weak warm front extending from southeast OK into southern AR. The air mass south of this front is relatively moist and moderately unstable with dewpoints near 60F. Models are consistent in the development of scattered intense storms this afternoon, with supercells capable of hail expected. This activity is likely to organize into a more linear structure through the evening, but continue to pose a risk of hail along with locally damaging winds. Activity may remain strong well into the night, affecting southeast AR/northeast LA and western MS. Similar to northern area, parameters and confidence support inclusion of ENH risk area for afternoon/evening hail risk. ..Hart/Gleason.. 03/24/2019 Read more

SPC Mar 24, 2019 1630 UTC Day 1 Convective Outlook

4 hours 59 minutes ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Sun Mar 24 2019 Valid 241630Z - 251200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF THE MID MISSISSIPPI VALLEY AND ARKLATEX REGIONS.... ...SUMMARY... Severe thunderstorms are expected from north Texas to southern Missouri and southwestern Illinois, mainly offering hail and damaging gusts. ...MO/IL... Morning water vapor loop shows a progressive upper low over southeast NE, with an associated mid-level speed max over KS/OK. This feature will track eastward today into the middle MS Valley, providing increasing ascent and deep-layer vertical shear for thunderstorm development/organization. Visible imagery shows substantial clearing/heating is occurring across southern MO and southwest IL, where surface dewpoints are rising into the 50s and low level lapse rates are steepening. This should aid in the development of scattered thunderstorms by mid-afternoon across southern MO. Forecast soundings show shear profiles favorable for discrete supercells capable of large hail. The tornado risk will be limited by veering low level winds and rather low dewpoint values. However, the damaging wind threat should increase as storms track eastward into southern IL during the late afternoon. Have added an ENH risk area for hail coverage across parts of southeast MO and southwest IL, where 12z CAM solutions provide greatest confidence. ...Arklatex Region... Latest surface analysis shows a weak warm front extending from southeast OK into southern AR. The air mass south of this front is relatively moist and moderately unstable with dewpoints near 60F. Models are consistent in the development of scattered intense storms this afternoon, with supercells capable of hail expected. This activity is likely to organize into a more linear structure through the evening, but continue to pose a risk of hail along with locally damaging winds. Activity may remain strong well into the night, affecting southeast AR/northeast LA and western MS. Similar to northern area, parameters and confidence support inclusion of ENH risk area for afternoon/evening hail risk. ..Hart/Gleason.. 03/24/2019 Read more

SPC Mar 24, 2019 1630 UTC Day 1 Convective Outlook

4 hours 59 minutes ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Sun Mar 24 2019 Valid 241630Z - 251200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF THE MID MISSISSIPPI VALLEY AND ARKLATEX REGIONS.... ...SUMMARY... Severe thunderstorms are expected from north Texas to southern Missouri and southwestern Illinois, mainly offering hail and damaging gusts. ...MO/IL... Morning water vapor loop shows a progressive upper low over southeast NE, with an associated mid-level speed max over KS/OK. This feature will track eastward today into the middle MS Valley, providing increasing ascent and deep-layer vertical shear for thunderstorm development/organization. Visible imagery shows substantial clearing/heating is occurring across southern MO and southwest IL, where surface dewpoints are rising into the 50s and low level lapse rates are steepening. This should aid in the development of scattered thunderstorms by mid-afternoon across southern MO. Forecast soundings show shear profiles favorable for discrete supercells capable of large hail. The tornado risk will be limited by veering low level winds and rather low dewpoint values. However, the damaging wind threat should increase as storms track eastward into southern IL during the late afternoon. Have added an ENH risk area for hail coverage across parts of southeast MO and southwest IL, where 12z CAM solutions provide greatest confidence. ...Arklatex Region... Latest surface analysis shows a weak warm front extending from southeast OK into southern AR. The air mass south of this front is relatively moist and moderately unstable with dewpoints near 60F. Models are consistent in the development of scattered intense storms this afternoon, with supercells capable of hail expected. This activity is likely to organize into a more linear structure through the evening, but continue to pose a risk of hail along with locally damaging winds. Activity may remain strong well into the night, affecting southeast AR/northeast LA and western MS. Similar to northern area, parameters and confidence support inclusion of ENH risk area for afternoon/evening hail risk. ..Hart/Gleason.. 03/24/2019 Read more
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Severe Storms
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