Severe Storms

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0355 PM CST Tue Feb 27 2024 Valid 291200Z - 061200Z The main features of interest during the extended period will be a shortwave trough moving through parts of the southern Plains on Thursday and a more potent trough ejecting into the Plains this weekend. The initial trough may produce precipitation over some of the drier fuels in the High Plains. Model guidance has trended farther north and less intense recently with the secondary trough. Fire weather concerns still appear likely in parts of the southern into the central Plains during the weekend, but the intensity of these conditions is a bit more unclear than yesterday. ...Central Plains... There will be a quick return to southerly flow by Thursday across the region as the surface high shifts into the Ohio Valley. Confidence in winds of 15-20 mph is higher than critically low RH as temperatures will be a bit cooler. Given the state of fuels, there is some chance fire weather concerns will be elevated, but confidence in RH reductions being sufficient is low. Additional fire weather into the central Plains is possible during the upcoming weekend as the trough ejects into the Plains. Given the increase in model variability over the last day, uncertainty is too high to add highlights. These areas will continue to be monitored. ...Southern High Plains... Despite the increase in model variability, confidence in potentially critical fire weather remains highest in the southern High Plains this weekend. An increase in probabilities was considered for this outlook, but it seems prudent to wait another few model cycles given the recent northward shift of the trough and the decrease in amplitude. That uncertainty is on top of the potential for at least light precipitation with the shortwave trough passing through the region on Thursday. ..Wendt.. 02/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0355 PM CST Tue Feb 27 2024 Valid 291200Z - 061200Z The main features of interest during the extended period will be a shortwave trough moving through parts of the southern Plains on Thursday and a more potent trough ejecting into the Plains this weekend. The initial trough may produce precipitation over some of the drier fuels in the High Plains. Model guidance has trended farther north and less intense recently with the secondary trough. Fire weather concerns still appear likely in parts of the southern into the central Plains during the weekend, but the intensity of these conditions is a bit more unclear than yesterday. ...Central Plains... There will be a quick return to southerly flow by Thursday across the region as the surface high shifts into the Ohio Valley. Confidence in winds of 15-20 mph is higher than critically low RH as temperatures will be a bit cooler. Given the state of fuels, there is some chance fire weather concerns will be elevated, but confidence in RH reductions being sufficient is low. Additional fire weather into the central Plains is possible during the upcoming weekend as the trough ejects into the Plains. Given the increase in model variability over the last day, uncertainty is too high to add highlights. These areas will continue to be monitored. ...Southern High Plains... Despite the increase in model variability, confidence in potentially critical fire weather remains highest in the southern High Plains this weekend. An increase in probabilities was considered for this outlook, but it seems prudent to wait another few model cycles given the recent northward shift of the trough and the decrease in amplitude. That uncertainty is on top of the potential for at least light precipitation with the shortwave trough passing through the region on Thursday. ..Wendt.. 02/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0355 PM CST Tue Feb 27 2024 Valid 291200Z - 061200Z The main features of interest during the extended period will be a shortwave trough moving through parts of the southern Plains on Thursday and a more potent trough ejecting into the Plains this weekend. The initial trough may produce precipitation over some of the drier fuels in the High Plains. Model guidance has trended farther north and less intense recently with the secondary trough. Fire weather concerns still appear likely in parts of the southern into the central Plains during the weekend, but the intensity of these conditions is a bit more unclear than yesterday. ...Central Plains... There will be a quick return to southerly flow by Thursday across the region as the surface high shifts into the Ohio Valley. Confidence in winds of 15-20 mph is higher than critically low RH as temperatures will be a bit cooler. Given the state of fuels, there is some chance fire weather concerns will be elevated, but confidence in RH reductions being sufficient is low. Additional fire weather into the central Plains is possible during the upcoming weekend as the trough ejects into the Plains. Given the increase in model variability over the last day, uncertainty is too high to add highlights. These areas will continue to be monitored. ...Southern High Plains... Despite the increase in model variability, confidence in potentially critical fire weather remains highest in the southern High Plains this weekend. An increase in probabilities was considered for this outlook, but it seems prudent to wait another few model cycles given the recent northward shift of the trough and the decrease in amplitude. That uncertainty is on top of the potential for at least light precipitation with the shortwave trough passing through the region on Thursday. ..Wendt.. 02/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0355 PM CST Tue Feb 27 2024 Valid 291200Z - 061200Z The main features of interest during the extended period will be a shortwave trough moving through parts of the southern Plains on Thursday and a more potent trough ejecting into the Plains this weekend. The initial trough may produce precipitation over some of the drier fuels in the High Plains. Model guidance has trended farther north and less intense recently with the secondary trough. Fire weather concerns still appear likely in parts of the southern into the central Plains during the weekend, but the intensity of these conditions is a bit more unclear than yesterday. ...Central Plains... There will be a quick return to southerly flow by Thursday across the region as the surface high shifts into the Ohio Valley. Confidence in winds of 15-20 mph is higher than critically low RH as temperatures will be a bit cooler. Given the state of fuels, there is some chance fire weather concerns will be elevated, but confidence in RH reductions being sufficient is low. Additional fire weather into the central Plains is possible during the upcoming weekend as the trough ejects into the Plains. Given the increase in model variability over the last day, uncertainty is too high to add highlights. These areas will continue to be monitored. ...Southern High Plains... Despite the increase in model variability, confidence in potentially critical fire weather remains highest in the southern High Plains this weekend. An increase in probabilities was considered for this outlook, but it seems prudent to wait another few model cycles given the recent northward shift of the trough and the decrease in amplitude. That uncertainty is on top of the potential for at least light precipitation with the shortwave trough passing through the region on Thursday. ..Wendt.. 02/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0355 PM CST Tue Feb 27 2024 Valid 291200Z - 061200Z The main features of interest during the extended period will be a shortwave trough moving through parts of the southern Plains on Thursday and a more potent trough ejecting into the Plains this weekend. The initial trough may produce precipitation over some of the drier fuels in the High Plains. Model guidance has trended farther north and less intense recently with the secondary trough. Fire weather concerns still appear likely in parts of the southern into the central Plains during the weekend, but the intensity of these conditions is a bit more unclear than yesterday. ...Central Plains... There will be a quick return to southerly flow by Thursday across the region as the surface high shifts into the Ohio Valley. Confidence in winds of 15-20 mph is higher than critically low RH as temperatures will be a bit cooler. Given the state of fuels, there is some chance fire weather concerns will be elevated, but confidence in RH reductions being sufficient is low. Additional fire weather into the central Plains is possible during the upcoming weekend as the trough ejects into the Plains. Given the increase in model variability over the last day, uncertainty is too high to add highlights. These areas will continue to be monitored. ...Southern High Plains... Despite the increase in model variability, confidence in potentially critical fire weather remains highest in the southern High Plains this weekend. An increase in probabilities was considered for this outlook, but it seems prudent to wait another few model cycles given the recent northward shift of the trough and the decrease in amplitude. That uncertainty is on top of the potential for at least light precipitation with the shortwave trough passing through the region on Thursday. ..Wendt.. 02/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0355 PM CST Tue Feb 27 2024 Valid 291200Z - 061200Z The main features of interest during the extended period will be a shortwave trough moving through parts of the southern Plains on Thursday and a more potent trough ejecting into the Plains this weekend. The initial trough may produce precipitation over some of the drier fuels in the High Plains. Model guidance has trended farther north and less intense recently with the secondary trough. Fire weather concerns still appear likely in parts of the southern into the central Plains during the weekend, but the intensity of these conditions is a bit more unclear than yesterday. ...Central Plains... There will be a quick return to southerly flow by Thursday across the region as the surface high shifts into the Ohio Valley. Confidence in winds of 15-20 mph is higher than critically low RH as temperatures will be a bit cooler. Given the state of fuels, there is some chance fire weather concerns will be elevated, but confidence in RH reductions being sufficient is low. Additional fire weather into the central Plains is possible during the upcoming weekend as the trough ejects into the Plains. Given the increase in model variability over the last day, uncertainty is too high to add highlights. These areas will continue to be monitored. ...Southern High Plains... Despite the increase in model variability, confidence in potentially critical fire weather remains highest in the southern High Plains this weekend. An increase in probabilities was considered for this outlook, but it seems prudent to wait another few model cycles given the recent northward shift of the trough and the decrease in amplitude. That uncertainty is on top of the potential for at least light precipitation with the shortwave trough passing through the region on Thursday. ..Wendt.. 02/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0355 PM CST Tue Feb 27 2024 Valid 291200Z - 061200Z The main features of interest during the extended period will be a shortwave trough moving through parts of the southern Plains on Thursday and a more potent trough ejecting into the Plains this weekend. The initial trough may produce precipitation over some of the drier fuels in the High Plains. Model guidance has trended farther north and less intense recently with the secondary trough. Fire weather concerns still appear likely in parts of the southern into the central Plains during the weekend, but the intensity of these conditions is a bit more unclear than yesterday. ...Central Plains... There will be a quick return to southerly flow by Thursday across the region as the surface high shifts into the Ohio Valley. Confidence in winds of 15-20 mph is higher than critically low RH as temperatures will be a bit cooler. Given the state of fuels, there is some chance fire weather concerns will be elevated, but confidence in RH reductions being sufficient is low. Additional fire weather into the central Plains is possible during the upcoming weekend as the trough ejects into the Plains. Given the increase in model variability over the last day, uncertainty is too high to add highlights. These areas will continue to be monitored. ...Southern High Plains... Despite the increase in model variability, confidence in potentially critical fire weather remains highest in the southern High Plains this weekend. An increase in probabilities was considered for this outlook, but it seems prudent to wait another few model cycles given the recent northward shift of the trough and the decrease in amplitude. That uncertainty is on top of the potential for at least light precipitation with the shortwave trough passing through the region on Thursday. ..Wendt.. 02/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0355 PM CST Tue Feb 27 2024 Valid 291200Z - 061200Z The main features of interest during the extended period will be a shortwave trough moving through parts of the southern Plains on Thursday and a more potent trough ejecting into the Plains this weekend. The initial trough may produce precipitation over some of the drier fuels in the High Plains. Model guidance has trended farther north and less intense recently with the secondary trough. Fire weather concerns still appear likely in parts of the southern into the central Plains during the weekend, but the intensity of these conditions is a bit more unclear than yesterday. ...Central Plains... There will be a quick return to southerly flow by Thursday across the region as the surface high shifts into the Ohio Valley. Confidence in winds of 15-20 mph is higher than critically low RH as temperatures will be a bit cooler. Given the state of fuels, there is some chance fire weather concerns will be elevated, but confidence in RH reductions being sufficient is low. Additional fire weather into the central Plains is possible during the upcoming weekend as the trough ejects into the Plains. Given the increase in model variability over the last day, uncertainty is too high to add highlights. These areas will continue to be monitored. ...Southern High Plains... Despite the increase in model variability, confidence in potentially critical fire weather remains highest in the southern High Plains this weekend. An increase in probabilities was considered for this outlook, but it seems prudent to wait another few model cycles given the recent northward shift of the trough and the decrease in amplitude. That uncertainty is on top of the potential for at least light precipitation with the shortwave trough passing through the region on Thursday. ..Wendt.. 02/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0355 PM CST Tue Feb 27 2024 Valid 291200Z - 061200Z The main features of interest during the extended period will be a shortwave trough moving through parts of the southern Plains on Thursday and a more potent trough ejecting into the Plains this weekend. The initial trough may produce precipitation over some of the drier fuels in the High Plains. Model guidance has trended farther north and less intense recently with the secondary trough. Fire weather concerns still appear likely in parts of the southern into the central Plains during the weekend, but the intensity of these conditions is a bit more unclear than yesterday. ...Central Plains... There will be a quick return to southerly flow by Thursday across the region as the surface high shifts into the Ohio Valley. Confidence in winds of 15-20 mph is higher than critically low RH as temperatures will be a bit cooler. Given the state of fuels, there is some chance fire weather concerns will be elevated, but confidence in RH reductions being sufficient is low. Additional fire weather into the central Plains is possible during the upcoming weekend as the trough ejects into the Plains. Given the increase in model variability over the last day, uncertainty is too high to add highlights. These areas will continue to be monitored. ...Southern High Plains... Despite the increase in model variability, confidence in potentially critical fire weather remains highest in the southern High Plains this weekend. An increase in probabilities was considered for this outlook, but it seems prudent to wait another few model cycles given the recent northward shift of the trough and the decrease in amplitude. That uncertainty is on top of the potential for at least light precipitation with the shortwave trough passing through the region on Thursday. ..Wendt.. 02/27/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0025 Status Updates
STATUS REPORT ON WW 11 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 NE MOB TO 45 NW GZH TO 35 SSE TCL. ..KERR..01/25/24 ATTN...WFO...MOB...BMX...JAN... STATUS REPORT FOR WS 11 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ALC047-099-131-252040- AL . ALABAMA COUNTIES INCLUDED ARE DALLAS MONROE WILCOX THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

No watches are valid as of Tue Feb 27 21:35:02 UTC 2024.

MD 0162 CONCERNING SNOW SQUALL FOR CENTRAL COLORADO...NORTHWEST KANSAS...AND A LARGE PORTION OF NEBRASKA
Mesoscale Discussion 0162 NWS Storm Prediction Center Norman OK 0129 PM CST Tue Feb 27 2024 Areas affected...Central Colorado...northwest Kansas...and a large portion of Nebraska Concerning...Snow Squall Valid 271929Z - 272200Z SUMMARY...A band of heavy snow and strong winds will continue to produce reduced visibilities as it moves east through the afternoon. DISCUSSION...A frontogenetical band of snow has been been producing snow-squall like conditions across Nebraska and eastern Colorado this morning and early afternoon. This band is expected to persist through the afternoon with rapid onset of heavy snow. Synoptic sustained winds winds of 25 to 30 knots with gusts to 40+ knots are being observed across a large portion of the Plains. These strong winds will lead to additional visibility reduction as the heavy snow band arrives. This band is not expected to weaken until this evening when ascent moves north of the region. Therefore, expect this band to continue eastward through the afternoon with continued snow squall conditions. ..Bentley/Hart.. 02/27/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FSD...OAX...GID...LBF...GLD...PUB...BOU... LAT...LON 38250553 38860454 40580207 41540062 42529948 42909805 42729700 42119676 41259721 40189859 38970085 38110289 37770528 38250553 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Tue Feb 27 2024 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST IL AND FAR NORTHWEST IN THIS EVENING...AND ACROSS PORTIONS OF THE LOWER AND MIDDLE OH VALLEY THIS EVENING THROUGH TONIGHT.... ...SUMMARY... Severe thunderstorms, associated with large hail, damaging gusts, and tornadoes, some of which may be significant, will be possible from late this afternoon into the overnight, across portions of northeast Illinois and northwest Indiana as well as the Lower and Middle Ohio Valley. ...20Z Update... ...Northern IL/Southern WI This Evening... Recent surface analysis places a low near the IA/MO/IL border intersection. A dryline arcs southeast from this low to near STL and then back southwest into north-central AR. Dewpoints behind this dryline are in the 40s, while dewpoints across much of IL are in the upper 50s/low 60s. A warm front also arcs northeastward from this low to just north of the ORD, then eastward across southern Lake Michigan, and southeastward across northern IN into far west-central OH. General expectation outlined in the previous discussion remains valid, with convective initiation anticipated near this low, with the resulting storms then tracking northeastward in the vicinity of the warm front. It remains uncertain whether or not these storms will be on the warm side of the boundary. Given the kinematic fields, any surface-based storms would likely be supercellular and capable of all severe hazards, including tornadoes. Recent guidance include the 18Z and 19Z WoFS as well as the 12Z MPAS runs all suggest an increasing likelihood for surface-based, warm sector storms. Given these trends, expanded the Enhanced southeastward to include more of northeast IL and far northwest IN and also introduced a 10% significant tornado probability. ...OH Valley This Evening and Overnight... Overall expectation outlined in the previous outlook remains unchanged for tonight across the OH Valley. As the night progresses, activity will likely evolve into fast-moving bowing structures with an enhanced risk of damaging wind gusts and a few tornadoes. Given the strengthening low-level flow, destructive wind gusts around 75 mph are possible, with a strong tornado or two possible as well. ..Mosier.. 02/27/2024 .PREV DISCUSSION... /ISSUED 1026 AM CST Tue Feb 27 2024/ ...OH Valley... A fast-moving southern-stream shortwave trough over the central Plains will track eastward today and begin affecting parts of MO by late afternoon or early evening. Most 12z guidance suggests that at least isolated thunderstorm development will begin around/after dusk as the large-scale forcing overspreads the northern extent of moist/unstable air mass from southwest MO into southern IL. These storms will intensify and track eastward overnight roughly along the OH river, moving into parts of OH/WV/PA by early morning Wednesday. Initial storms may be discrete, with sufficient vertical shear for supercells structures capable of all severe hazards. As the night progresses, activity will likely evolve into fast-moving bowing structures with an enhanced risk of damaging wind gusts and a few tornadoes. A strong tornado or two cannot be ruled out. Have added an ENH risk area for this scenario overnight. ...IL/WI... A compact surface low is forecast to deepen across eastern IA this afternoon, with a narrow warm sector pulling northward into much of northern IL. Strong forcing near the low and along the associated warm front will lead to intense thunderstorms across portions of northern IL after 22z. Forecast soundings show steep low and mid level lapse rates and sufficient CAPE, along with strong low and deep layer shear profiles. This will be conducive to supercell structures capable of very large hail and damaging winds. There remains uncertainty whether these storms will be in the warm-sector, or will be undercut by nearby cold air. Have upgraded a small part of this area to ENH risk for hail, but there is also concern for tornadoes if the activity remains surface-based. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Tue Feb 27 2024 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST IL AND FAR NORTHWEST IN THIS EVENING...AND ACROSS PORTIONS OF THE LOWER AND MIDDLE OH VALLEY THIS EVENING THROUGH TONIGHT.... ...SUMMARY... Severe thunderstorms, associated with large hail, damaging gusts, and tornadoes, some of which may be significant, will be possible from late this afternoon into the overnight, across portions of northeast Illinois and northwest Indiana as well as the Lower and Middle Ohio Valley. ...20Z Update... ...Northern IL/Southern WI This Evening... Recent surface analysis places a low near the IA/MO/IL border intersection. A dryline arcs southeast from this low to near STL and then back southwest into north-central AR. Dewpoints behind this dryline are in the 40s, while dewpoints across much of IL are in the upper 50s/low 60s. A warm front also arcs northeastward from this low to just north of the ORD, then eastward across southern Lake Michigan, and southeastward across northern IN into far west-central OH. General expectation outlined in the previous discussion remains valid, with convective initiation anticipated near this low, with the resulting storms then tracking northeastward in the vicinity of the warm front. It remains uncertain whether or not these storms will be on the warm side of the boundary. Given the kinematic fields, any surface-based storms would likely be supercellular and capable of all severe hazards, including tornadoes. Recent guidance include the 18Z and 19Z WoFS as well as the 12Z MPAS runs all suggest an increasing likelihood for surface-based, warm sector storms. Given these trends, expanded the Enhanced southeastward to include more of northeast IL and far northwest IN and also introduced a 10% significant tornado probability. ...OH Valley This Evening and Overnight... Overall expectation outlined in the previous outlook remains unchanged for tonight across the OH Valley. As the night progresses, activity will likely evolve into fast-moving bowing structures with an enhanced risk of damaging wind gusts and a few tornadoes. Given the strengthening low-level flow, destructive wind gusts around 75 mph are possible, with a strong tornado or two possible as well. ..Mosier.. 02/27/2024 .PREV DISCUSSION... /ISSUED 1026 AM CST Tue Feb 27 2024/ ...OH Valley... A fast-moving southern-stream shortwave trough over the central Plains will track eastward today and begin affecting parts of MO by late afternoon or early evening. Most 12z guidance suggests that at least isolated thunderstorm development will begin around/after dusk as the large-scale forcing overspreads the northern extent of moist/unstable air mass from southwest MO into southern IL. These storms will intensify and track eastward overnight roughly along the OH river, moving into parts of OH/WV/PA by early morning Wednesday. Initial storms may be discrete, with sufficient vertical shear for supercells structures capable of all severe hazards. As the night progresses, activity will likely evolve into fast-moving bowing structures with an enhanced risk of damaging wind gusts and a few tornadoes. A strong tornado or two cannot be ruled out. Have added an ENH risk area for this scenario overnight. ...IL/WI... A compact surface low is forecast to deepen across eastern IA this afternoon, with a narrow warm sector pulling northward into much of northern IL. Strong forcing near the low and along the associated warm front will lead to intense thunderstorms across portions of northern IL after 22z. Forecast soundings show steep low and mid level lapse rates and sufficient CAPE, along with strong low and deep layer shear profiles. This will be conducive to supercell structures capable of very large hail and damaging winds. There remains uncertainty whether these storms will be in the warm-sector, or will be undercut by nearby cold air. Have upgraded a small part of this area to ENH risk for hail, but there is also concern for tornadoes if the activity remains surface-based. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Tue Feb 27 2024 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST IL AND FAR NORTHWEST IN THIS EVENING...AND ACROSS PORTIONS OF THE LOWER AND MIDDLE OH VALLEY THIS EVENING THROUGH TONIGHT.... ...SUMMARY... Severe thunderstorms, associated with large hail, damaging gusts, and tornadoes, some of which may be significant, will be possible from late this afternoon into the overnight, across portions of northeast Illinois and northwest Indiana as well as the Lower and Middle Ohio Valley. ...20Z Update... ...Northern IL/Southern WI This Evening... Recent surface analysis places a low near the IA/MO/IL border intersection. A dryline arcs southeast from this low to near STL and then back southwest into north-central AR. Dewpoints behind this dryline are in the 40s, while dewpoints across much of IL are in the upper 50s/low 60s. A warm front also arcs northeastward from this low to just north of the ORD, then eastward across southern Lake Michigan, and southeastward across northern IN into far west-central OH. General expectation outlined in the previous discussion remains valid, with convective initiation anticipated near this low, with the resulting storms then tracking northeastward in the vicinity of the warm front. It remains uncertain whether or not these storms will be on the warm side of the boundary. Given the kinematic fields, any surface-based storms would likely be supercellular and capable of all severe hazards, including tornadoes. Recent guidance include the 18Z and 19Z WoFS as well as the 12Z MPAS runs all suggest an increasing likelihood for surface-based, warm sector storms. Given these trends, expanded the Enhanced southeastward to include more of northeast IL and far northwest IN and also introduced a 10% significant tornado probability. ...OH Valley This Evening and Overnight... Overall expectation outlined in the previous outlook remains unchanged for tonight across the OH Valley. As the night progresses, activity will likely evolve into fast-moving bowing structures with an enhanced risk of damaging wind gusts and a few tornadoes. Given the strengthening low-level flow, destructive wind gusts around 75 mph are possible, with a strong tornado or two possible as well. ..Mosier.. 02/27/2024 .PREV DISCUSSION... /ISSUED 1026 AM CST Tue Feb 27 2024/ ...OH Valley... A fast-moving southern-stream shortwave trough over the central Plains will track eastward today and begin affecting parts of MO by late afternoon or early evening. Most 12z guidance suggests that at least isolated thunderstorm development will begin around/after dusk as the large-scale forcing overspreads the northern extent of moist/unstable air mass from southwest MO into southern IL. These storms will intensify and track eastward overnight roughly along the OH river, moving into parts of OH/WV/PA by early morning Wednesday. Initial storms may be discrete, with sufficient vertical shear for supercells structures capable of all severe hazards. As the night progresses, activity will likely evolve into fast-moving bowing structures with an enhanced risk of damaging wind gusts and a few tornadoes. A strong tornado or two cannot be ruled out. Have added an ENH risk area for this scenario overnight. ...IL/WI... A compact surface low is forecast to deepen across eastern IA this afternoon, with a narrow warm sector pulling northward into much of northern IL. Strong forcing near the low and along the associated warm front will lead to intense thunderstorms across portions of northern IL after 22z. Forecast soundings show steep low and mid level lapse rates and sufficient CAPE, along with strong low and deep layer shear profiles. This will be conducive to supercell structures capable of very large hail and damaging winds. There remains uncertainty whether these storms will be in the warm-sector, or will be undercut by nearby cold air. Have upgraded a small part of this area to ENH risk for hail, but there is also concern for tornadoes if the activity remains surface-based. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Tue Feb 27 2024 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST IL AND FAR NORTHWEST IN THIS EVENING...AND ACROSS PORTIONS OF THE LOWER AND MIDDLE OH VALLEY THIS EVENING THROUGH TONIGHT.... ...SUMMARY... Severe thunderstorms, associated with large hail, damaging gusts, and tornadoes, some of which may be significant, will be possible from late this afternoon into the overnight, across portions of northeast Illinois and northwest Indiana as well as the Lower and Middle Ohio Valley. ...20Z Update... ...Northern IL/Southern WI This Evening... Recent surface analysis places a low near the IA/MO/IL border intersection. A dryline arcs southeast from this low to near STL and then back southwest into north-central AR. Dewpoints behind this dryline are in the 40s, while dewpoints across much of IL are in the upper 50s/low 60s. A warm front also arcs northeastward from this low to just north of the ORD, then eastward across southern Lake Michigan, and southeastward across northern IN into far west-central OH. General expectation outlined in the previous discussion remains valid, with convective initiation anticipated near this low, with the resulting storms then tracking northeastward in the vicinity of the warm front. It remains uncertain whether or not these storms will be on the warm side of the boundary. Given the kinematic fields, any surface-based storms would likely be supercellular and capable of all severe hazards, including tornadoes. Recent guidance include the 18Z and 19Z WoFS as well as the 12Z MPAS runs all suggest an increasing likelihood for surface-based, warm sector storms. Given these trends, expanded the Enhanced southeastward to include more of northeast IL and far northwest IN and also introduced a 10% significant tornado probability. ...OH Valley This Evening and Overnight... Overall expectation outlined in the previous outlook remains unchanged for tonight across the OH Valley. As the night progresses, activity will likely evolve into fast-moving bowing structures with an enhanced risk of damaging wind gusts and a few tornadoes. Given the strengthening low-level flow, destructive wind gusts around 75 mph are possible, with a strong tornado or two possible as well. ..Mosier.. 02/27/2024 .PREV DISCUSSION... /ISSUED 1026 AM CST Tue Feb 27 2024/ ...OH Valley... A fast-moving southern-stream shortwave trough over the central Plains will track eastward today and begin affecting parts of MO by late afternoon or early evening. Most 12z guidance suggests that at least isolated thunderstorm development will begin around/after dusk as the large-scale forcing overspreads the northern extent of moist/unstable air mass from southwest MO into southern IL. These storms will intensify and track eastward overnight roughly along the OH river, moving into parts of OH/WV/PA by early morning Wednesday. Initial storms may be discrete, with sufficient vertical shear for supercells structures capable of all severe hazards. As the night progresses, activity will likely evolve into fast-moving bowing structures with an enhanced risk of damaging wind gusts and a few tornadoes. A strong tornado or two cannot be ruled out. Have added an ENH risk area for this scenario overnight. ...IL/WI... A compact surface low is forecast to deepen across eastern IA this afternoon, with a narrow warm sector pulling northward into much of northern IL. Strong forcing near the low and along the associated warm front will lead to intense thunderstorms across portions of northern IL after 22z. Forecast soundings show steep low and mid level lapse rates and sufficient CAPE, along with strong low and deep layer shear profiles. This will be conducive to supercell structures capable of very large hail and damaging winds. There remains uncertainty whether these storms will be in the warm-sector, or will be undercut by nearby cold air. Have upgraded a small part of this area to ENH risk for hail, but there is also concern for tornadoes if the activity remains surface-based. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Tue Feb 27 2024 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST IL AND FAR NORTHWEST IN THIS EVENING...AND ACROSS PORTIONS OF THE LOWER AND MIDDLE OH VALLEY THIS EVENING THROUGH TONIGHT.... ...SUMMARY... Severe thunderstorms, associated with large hail, damaging gusts, and tornadoes, some of which may be significant, will be possible from late this afternoon into the overnight, across portions of northeast Illinois and northwest Indiana as well as the Lower and Middle Ohio Valley. ...20Z Update... ...Northern IL/Southern WI This Evening... Recent surface analysis places a low near the IA/MO/IL border intersection. A dryline arcs southeast from this low to near STL and then back southwest into north-central AR. Dewpoints behind this dryline are in the 40s, while dewpoints across much of IL are in the upper 50s/low 60s. A warm front also arcs northeastward from this low to just north of the ORD, then eastward across southern Lake Michigan, and southeastward across northern IN into far west-central OH. General expectation outlined in the previous discussion remains valid, with convective initiation anticipated near this low, with the resulting storms then tracking northeastward in the vicinity of the warm front. It remains uncertain whether or not these storms will be on the warm side of the boundary. Given the kinematic fields, any surface-based storms would likely be supercellular and capable of all severe hazards, including tornadoes. Recent guidance include the 18Z and 19Z WoFS as well as the 12Z MPAS runs all suggest an increasing likelihood for surface-based, warm sector storms. Given these trends, expanded the Enhanced southeastward to include more of northeast IL and far northwest IN and also introduced a 10% significant tornado probability. ...OH Valley This Evening and Overnight... Overall expectation outlined in the previous outlook remains unchanged for tonight across the OH Valley. As the night progresses, activity will likely evolve into fast-moving bowing structures with an enhanced risk of damaging wind gusts and a few tornadoes. Given the strengthening low-level flow, destructive wind gusts around 75 mph are possible, with a strong tornado or two possible as well. ..Mosier.. 02/27/2024 .PREV DISCUSSION... /ISSUED 1026 AM CST Tue Feb 27 2024/ ...OH Valley... A fast-moving southern-stream shortwave trough over the central Plains will track eastward today and begin affecting parts of MO by late afternoon or early evening. Most 12z guidance suggests that at least isolated thunderstorm development will begin around/after dusk as the large-scale forcing overspreads the northern extent of moist/unstable air mass from southwest MO into southern IL. These storms will intensify and track eastward overnight roughly along the OH river, moving into parts of OH/WV/PA by early morning Wednesday. Initial storms may be discrete, with sufficient vertical shear for supercells structures capable of all severe hazards. As the night progresses, activity will likely evolve into fast-moving bowing structures with an enhanced risk of damaging wind gusts and a few tornadoes. A strong tornado or two cannot be ruled out. Have added an ENH risk area for this scenario overnight. ...IL/WI... A compact surface low is forecast to deepen across eastern IA this afternoon, with a narrow warm sector pulling northward into much of northern IL. Strong forcing near the low and along the associated warm front will lead to intense thunderstorms across portions of northern IL after 22z. Forecast soundings show steep low and mid level lapse rates and sufficient CAPE, along with strong low and deep layer shear profiles. This will be conducive to supercell structures capable of very large hail and damaging winds. There remains uncertainty whether these storms will be in the warm-sector, or will be undercut by nearby cold air. Have upgraded a small part of this area to ENH risk for hail, but there is also concern for tornadoes if the activity remains surface-based. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Tue Feb 27 2024 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST IL AND FAR NORTHWEST IN THIS EVENING...AND ACROSS PORTIONS OF THE LOWER AND MIDDLE OH VALLEY THIS EVENING THROUGH TONIGHT.... ...SUMMARY... Severe thunderstorms, associated with large hail, damaging gusts, and tornadoes, some of which may be significant, will be possible from late this afternoon into the overnight, across portions of northeast Illinois and northwest Indiana as well as the Lower and Middle Ohio Valley. ...20Z Update... ...Northern IL/Southern WI This Evening... Recent surface analysis places a low near the IA/MO/IL border intersection. A dryline arcs southeast from this low to near STL and then back southwest into north-central AR. Dewpoints behind this dryline are in the 40s, while dewpoints across much of IL are in the upper 50s/low 60s. A warm front also arcs northeastward from this low to just north of the ORD, then eastward across southern Lake Michigan, and southeastward across northern IN into far west-central OH. General expectation outlined in the previous discussion remains valid, with convective initiation anticipated near this low, with the resulting storms then tracking northeastward in the vicinity of the warm front. It remains uncertain whether or not these storms will be on the warm side of the boundary. Given the kinematic fields, any surface-based storms would likely be supercellular and capable of all severe hazards, including tornadoes. Recent guidance include the 18Z and 19Z WoFS as well as the 12Z MPAS runs all suggest an increasing likelihood for surface-based, warm sector storms. Given these trends, expanded the Enhanced southeastward to include more of northeast IL and far northwest IN and also introduced a 10% significant tornado probability. ...OH Valley This Evening and Overnight... Overall expectation outlined in the previous outlook remains unchanged for tonight across the OH Valley. As the night progresses, activity will likely evolve into fast-moving bowing structures with an enhanced risk of damaging wind gusts and a few tornadoes. Given the strengthening low-level flow, destructive wind gusts around 75 mph are possible, with a strong tornado or two possible as well. ..Mosier.. 02/27/2024 .PREV DISCUSSION... /ISSUED 1026 AM CST Tue Feb 27 2024/ ...OH Valley... A fast-moving southern-stream shortwave trough over the central Plains will track eastward today and begin affecting parts of MO by late afternoon or early evening. Most 12z guidance suggests that at least isolated thunderstorm development will begin around/after dusk as the large-scale forcing overspreads the northern extent of moist/unstable air mass from southwest MO into southern IL. These storms will intensify and track eastward overnight roughly along the OH river, moving into parts of OH/WV/PA by early morning Wednesday. Initial storms may be discrete, with sufficient vertical shear for supercells structures capable of all severe hazards. As the night progresses, activity will likely evolve into fast-moving bowing structures with an enhanced risk of damaging wind gusts and a few tornadoes. A strong tornado or two cannot be ruled out. Have added an ENH risk area for this scenario overnight. ...IL/WI... A compact surface low is forecast to deepen across eastern IA this afternoon, with a narrow warm sector pulling northward into much of northern IL. Strong forcing near the low and along the associated warm front will lead to intense thunderstorms across portions of northern IL after 22z. Forecast soundings show steep low and mid level lapse rates and sufficient CAPE, along with strong low and deep layer shear profiles. This will be conducive to supercell structures capable of very large hail and damaging winds. There remains uncertainty whether these storms will be in the warm-sector, or will be undercut by nearby cold air. Have upgraded a small part of this area to ENH risk for hail, but there is also concern for tornadoes if the activity remains surface-based. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Tue Feb 27 2024 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST IL AND FAR NORTHWEST IN THIS EVENING...AND ACROSS PORTIONS OF THE LOWER AND MIDDLE OH VALLEY THIS EVENING THROUGH TONIGHT.... ...SUMMARY... Severe thunderstorms, associated with large hail, damaging gusts, and tornadoes, some of which may be significant, will be possible from late this afternoon into the overnight, across portions of northeast Illinois and northwest Indiana as well as the Lower and Middle Ohio Valley. ...20Z Update... ...Northern IL/Southern WI This Evening... Recent surface analysis places a low near the IA/MO/IL border intersection. A dryline arcs southeast from this low to near STL and then back southwest into north-central AR. Dewpoints behind this dryline are in the 40s, while dewpoints across much of IL are in the upper 50s/low 60s. A warm front also arcs northeastward from this low to just north of the ORD, then eastward across southern Lake Michigan, and southeastward across northern IN into far west-central OH. General expectation outlined in the previous discussion remains valid, with convective initiation anticipated near this low, with the resulting storms then tracking northeastward in the vicinity of the warm front. It remains uncertain whether or not these storms will be on the warm side of the boundary. Given the kinematic fields, any surface-based storms would likely be supercellular and capable of all severe hazards, including tornadoes. Recent guidance include the 18Z and 19Z WoFS as well as the 12Z MPAS runs all suggest an increasing likelihood for surface-based, warm sector storms. Given these trends, expanded the Enhanced southeastward to include more of northeast IL and far northwest IN and also introduced a 10% significant tornado probability. ...OH Valley This Evening and Overnight... Overall expectation outlined in the previous outlook remains unchanged for tonight across the OH Valley. As the night progresses, activity will likely evolve into fast-moving bowing structures with an enhanced risk of damaging wind gusts and a few tornadoes. Given the strengthening low-level flow, destructive wind gusts around 75 mph are possible, with a strong tornado or two possible as well. ..Mosier.. 02/27/2024 .PREV DISCUSSION... /ISSUED 1026 AM CST Tue Feb 27 2024/ ...OH Valley... A fast-moving southern-stream shortwave trough over the central Plains will track eastward today and begin affecting parts of MO by late afternoon or early evening. Most 12z guidance suggests that at least isolated thunderstorm development will begin around/after dusk as the large-scale forcing overspreads the northern extent of moist/unstable air mass from southwest MO into southern IL. These storms will intensify and track eastward overnight roughly along the OH river, moving into parts of OH/WV/PA by early morning Wednesday. Initial storms may be discrete, with sufficient vertical shear for supercells structures capable of all severe hazards. As the night progresses, activity will likely evolve into fast-moving bowing structures with an enhanced risk of damaging wind gusts and a few tornadoes. A strong tornado or two cannot be ruled out. Have added an ENH risk area for this scenario overnight. ...IL/WI... A compact surface low is forecast to deepen across eastern IA this afternoon, with a narrow warm sector pulling northward into much of northern IL. Strong forcing near the low and along the associated warm front will lead to intense thunderstorms across portions of northern IL after 22z. Forecast soundings show steep low and mid level lapse rates and sufficient CAPE, along with strong low and deep layer shear profiles. This will be conducive to supercell structures capable of very large hail and damaging winds. There remains uncertainty whether these storms will be in the warm-sector, or will be undercut by nearby cold air. Have upgraded a small part of this area to ENH risk for hail, but there is also concern for tornadoes if the activity remains surface-based. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Tue Feb 27 2024 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST IL AND FAR NORTHWEST IN THIS EVENING...AND ACROSS PORTIONS OF THE LOWER AND MIDDLE OH VALLEY THIS EVENING THROUGH TONIGHT.... ...SUMMARY... Severe thunderstorms, associated with large hail, damaging gusts, and tornadoes, some of which may be significant, will be possible from late this afternoon into the overnight, across portions of northeast Illinois and northwest Indiana as well as the Lower and Middle Ohio Valley. ...20Z Update... ...Northern IL/Southern WI This Evening... Recent surface analysis places a low near the IA/MO/IL border intersection. A dryline arcs southeast from this low to near STL and then back southwest into north-central AR. Dewpoints behind this dryline are in the 40s, while dewpoints across much of IL are in the upper 50s/low 60s. A warm front also arcs northeastward from this low to just north of the ORD, then eastward across southern Lake Michigan, and southeastward across northern IN into far west-central OH. General expectation outlined in the previous discussion remains valid, with convective initiation anticipated near this low, with the resulting storms then tracking northeastward in the vicinity of the warm front. It remains uncertain whether or not these storms will be on the warm side of the boundary. Given the kinematic fields, any surface-based storms would likely be supercellular and capable of all severe hazards, including tornadoes. Recent guidance include the 18Z and 19Z WoFS as well as the 12Z MPAS runs all suggest an increasing likelihood for surface-based, warm sector storms. Given these trends, expanded the Enhanced southeastward to include more of northeast IL and far northwest IN and also introduced a 10% significant tornado probability. ...OH Valley This Evening and Overnight... Overall expectation outlined in the previous outlook remains unchanged for tonight across the OH Valley. As the night progresses, activity will likely evolve into fast-moving bowing structures with an enhanced risk of damaging wind gusts and a few tornadoes. Given the strengthening low-level flow, destructive wind gusts around 75 mph are possible, with a strong tornado or two possible as well. ..Mosier.. 02/27/2024 .PREV DISCUSSION... /ISSUED 1026 AM CST Tue Feb 27 2024/ ...OH Valley... A fast-moving southern-stream shortwave trough over the central Plains will track eastward today and begin affecting parts of MO by late afternoon or early evening. Most 12z guidance suggests that at least isolated thunderstorm development will begin around/after dusk as the large-scale forcing overspreads the northern extent of moist/unstable air mass from southwest MO into southern IL. These storms will intensify and track eastward overnight roughly along the OH river, moving into parts of OH/WV/PA by early morning Wednesday. Initial storms may be discrete, with sufficient vertical shear for supercells structures capable of all severe hazards. As the night progresses, activity will likely evolve into fast-moving bowing structures with an enhanced risk of damaging wind gusts and a few tornadoes. A strong tornado or two cannot be ruled out. Have added an ENH risk area for this scenario overnight. ...IL/WI... A compact surface low is forecast to deepen across eastern IA this afternoon, with a narrow warm sector pulling northward into much of northern IL. Strong forcing near the low and along the associated warm front will lead to intense thunderstorms across portions of northern IL after 22z. Forecast soundings show steep low and mid level lapse rates and sufficient CAPE, along with strong low and deep layer shear profiles. This will be conducive to supercell structures capable of very large hail and damaging winds. There remains uncertainty whether these storms will be in the warm-sector, or will be undercut by nearby cold air. Have upgraded a small part of this area to ENH risk for hail, but there is also concern for tornadoes if the activity remains surface-based. Read more