Severe Storms

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0413 PM CDT Wed Mar 19 2025 Valid 211200Z - 271200Z Early in the extended period D3-5 (Friday-Sunday), breezy and dry conditions will be possible across the central and southern Plains. However, a much cooler air mass along with recent rain and snowfall across portions of the central Plains will help keep fire weather concerns low and mostly across the southern high Plains. After this period, an upper level high is expected to build in across the central US, with lighter winds but continued dry conditions across the southern Plains. ...D3 - Friday through D4 - Saturday, Southern High Plains... A surface low will develop across the central Plains on D3 - Friday, with Elevated to locally Critical fire weather conditions possible across eastern New Mexico into the Texas Panhandle. The main upper-level trough has continued to show a more progressive track, with much cooler air filtering in across portions of eastern Colorado and southwestern Kansas behind the passing cold front. Some portion of this region has also seen recent rain and snowfall over the last 24-48 hours. This has led to removal of the 70 percent probabilities and shrinking of 40 percent probabilities. A secondary wave will move across the central Plains on D4 - Saturday with another surface low developing across eastern Colorado into the Oklahoma/Texas Panhandle. 850 mb flow will strengthen with lee troughing, however, the main area of strongest flow aloft will stay north of the driest fuels. Some overlap of windy/dry conditions will be possible across the Oklahoma Panhandle southward into the Texas Panhandle and eastern New Mexico. A 40 percent area was maintained with this outlook. ..Thornton.. 03/19/2025 ...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 0413 PM CDT Wed Mar 19 2025 Valid 211200Z - 271200Z Early in the extended period D3-5 (Friday-Sunday), breezy and dry conditions will be possible across the central and southern Plains. However, a much cooler air mass along with recent rain and snowfall across portions of the central Plains will help keep fire weather concerns low and mostly across the southern high Plains. After this period, an upper level high is expected to build in across the central US, with lighter winds but continued dry conditions across the southern Plains. ...D3 - Friday through D4 - Saturday, Southern High Plains... A surface low will develop across the central Plains on D3 - Friday, with Elevated to locally Critical fire weather conditions possible across eastern New Mexico into the Texas Panhandle. The main upper-level trough has continued to show a more progressive track, with much cooler air filtering in across portions of eastern Colorado and southwestern Kansas behind the passing cold front. Some portion of this region has also seen recent rain and snowfall over the last 24-48 hours. This has led to removal of the 70 percent probabilities and shrinking of 40 percent probabilities. A secondary wave will move across the central Plains on D4 - Saturday with another surface low developing across eastern Colorado into the Oklahoma/Texas Panhandle. 850 mb flow will strengthen with lee troughing, however, the main area of strongest flow aloft will stay north of the driest fuels. Some overlap of windy/dry conditions will be possible across the Oklahoma Panhandle southward into the Texas Panhandle and eastern New Mexico. A 40 percent area was maintained with this outlook. ..Thornton.. 03/19/2025 ...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 0413 PM CDT Wed Mar 19 2025 Valid 211200Z - 271200Z Early in the extended period D3-5 (Friday-Sunday), breezy and dry conditions will be possible across the central and southern Plains. However, a much cooler air mass along with recent rain and snowfall across portions of the central Plains will help keep fire weather concerns low and mostly across the southern high Plains. After this period, an upper level high is expected to build in across the central US, with lighter winds but continued dry conditions across the southern Plains. ...D3 - Friday through D4 - Saturday, Southern High Plains... A surface low will develop across the central Plains on D3 - Friday, with Elevated to locally Critical fire weather conditions possible across eastern New Mexico into the Texas Panhandle. The main upper-level trough has continued to show a more progressive track, with much cooler air filtering in across portions of eastern Colorado and southwestern Kansas behind the passing cold front. Some portion of this region has also seen recent rain and snowfall over the last 24-48 hours. This has led to removal of the 70 percent probabilities and shrinking of 40 percent probabilities. A secondary wave will move across the central Plains on D4 - Saturday with another surface low developing across eastern Colorado into the Oklahoma/Texas Panhandle. 850 mb flow will strengthen with lee troughing, however, the main area of strongest flow aloft will stay north of the driest fuels. Some overlap of windy/dry conditions will be possible across the Oklahoma Panhandle southward into the Texas Panhandle and eastern New Mexico. A 40 percent area was maintained with this outlook. ..Thornton.. 03/19/2025 ...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 0413 PM CDT Wed Mar 19 2025 Valid 211200Z - 271200Z Early in the extended period D3-5 (Friday-Sunday), breezy and dry conditions will be possible across the central and southern Plains. However, a much cooler air mass along with recent rain and snowfall across portions of the central Plains will help keep fire weather concerns low and mostly across the southern high Plains. After this period, an upper level high is expected to build in across the central US, with lighter winds but continued dry conditions across the southern Plains. ...D3 - Friday through D4 - Saturday, Southern High Plains... A surface low will develop across the central Plains on D3 - Friday, with Elevated to locally Critical fire weather conditions possible across eastern New Mexico into the Texas Panhandle. The main upper-level trough has continued to show a more progressive track, with much cooler air filtering in across portions of eastern Colorado and southwestern Kansas behind the passing cold front. Some portion of this region has also seen recent rain and snowfall over the last 24-48 hours. This has led to removal of the 70 percent probabilities and shrinking of 40 percent probabilities. A secondary wave will move across the central Plains on D4 - Saturday with another surface low developing across eastern Colorado into the Oklahoma/Texas Panhandle. 850 mb flow will strengthen with lee troughing, however, the main area of strongest flow aloft will stay north of the driest fuels. Some overlap of windy/dry conditions will be possible across the Oklahoma Panhandle southward into the Texas Panhandle and eastern New Mexico. A 40 percent area was maintained with this outlook. ..Thornton.. 03/19/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0057 Status Updates
STATUS REPORT ON WW 57 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 W SPI TO 15 NNW PIA TO 35 SSW RFD AND 30 WNW PIA TO 30 WNW PIA. ..BUNTING..03/19/25 ATTN...WFO...DVN...LSX...ILX...LOT...IND... STATUS REPORT FOR WT 57 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC005-019-021-023-025-027-029-033-035-039-041-045-049-051-053- 063-075-079-091-093-099-101-105-107-113-115-121-123-125-129-135- 139-143-147-155-159-167-173-179-183-197-203-192140- IL . ILLINOIS COUNTIES INCLUDED ARE BOND CHAMPAIGN CHRISTIAN CLARK CLAY CLINTON COLES CRAWFORD CUMBERLAND DE WITT DOUGLAS EDGAR EFFINGHAM FAYETTE FORD GRUNDY IROQUOIS JASPER KANKAKEE KENDALL LA SALLE LAWRENCE LIVINGSTON LOGAN MCLEAN MACON MARION MARSHALL MASON MENARD MONTGOMERY MOULTRIE PEORIA PIATT PUTNAM RICHLAND SANGAMON SHELBY TAZEWELL VERMILION WILL WOODFORD INC007-021-027-045-055-083-101-107-111-119-121-133-153-157-165- 167-171-192140- Read more

WW 0058 Status Updates
STATUS FOR WATCH 0058 HAS NOT BEEN ISSUED YET Read more

WW 0058 Status Updates
STATUS FOR WATCH 0058 HAS NOT BEEN ISSUED YET Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Mar 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF CENTRAL/NORTHERN ILLINOIS AND WEST CENTRAL INDIANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...20Z Update... The primary change with this update was a southward extension of the Slight risk area to the TN/KY border. Current expectations are for a broken band of thunderstorms to track eastward into this area this afternoon into the evening. Here, filtered diurnal heating amid gradual boundary-layer moistening should yield enough low-level destabilization for a threat of scattered severe wind gusts and an embedded tornado risk -- given favorable low-level hodograph size and curvature. Elsewhere, severe probabilities were trimmed from the west behind the eastward-advancing dryline. For details on the near-term severe risk, reference Tornado Watch #57 and MCD #245. ..Weinman.. 03/19/2025 .PREV DISCUSSION... /ISSUED 1059 AM CDT Wed Mar 19 2025/ ...IL/IN vicinity into early tonight... A deep (990mb) surface low over northwest MO this morning will continue to shift east into northern IL through late afternoon, and into IN/MI and southern Ontario overnight. Meanwhile, the exit region of a 90-100+ kt 500 mb jet will overspread IL/IN this afternoon into early evening. Cloud cover and elevated convection this morning across IA and northern IL, along with lofted dust moving over the region may inhibit heating to some degree into the afternoon. Furthermore, boundary layer moisture is expected to remain modest, most likely in the 51-54 F range given 15z upstream observations in the low 50s F. If any stronger heating occurs, mixing may further limit dewpoints from climbing into the mid/upper 50s F as suggested by some forecast guidance. Nevertheless, cold temperatures aloft (-17 C on 12z RAOBs from DVN) will support steep midlevel lapse rates and modest destabilization into the early afternoon. A dryline is noted across central MO at 15z. This feature will continue to sweep east into the afternoon and become a focus for stronger thunderstorm development across IL by 18-19z. Vertical shear will be favorable for supercells given elongated hodographs with enlarged, looping low-level hodographs. These vertical wind profiles are already evident in VWP data from DVN and LOT where a west to east oriented surface warm front is roughly aligned across east-central IA/northern IL. Evolution of modest boundary layer moisture will be key for determining the tornado risk this afternoon across IL/IN. If dewpoints can reach 55-56 F, a localized area of enhanced tornado potential may develop. While some risk for tornadoes will still exist with lower dewpoints, the risk would be more muted and likely less intense. Given the conditional risk for a strong tornado or two, will maintain the 10 percent SIG tornado risk. Otherwise, somewhat low-topped supercells will also pose a risk for damaging gusts of 60-70 mph and isolated large hail up to 1-1.5 inches in diameter. Isolated convection may develop southward along the dryline/cold front into western/central KY by late afternoon before convection weakens after sunset. ...TN/MS/AL vicinity this afternoon/evening... Dewpoints have gradually increased into the mid 50s late this morning. Continued warm advection ahead of a wind shift this afternoon should allow dewpoints to reach the upper 50s to low 60s F. While forcing for ascent will be weak compared to further north, it should be sufficient to erode capping in the persistent warm advection regime. Instability will remain modest, generally near/less than 500 J/kg MLCAPE. While vertical shear will be quite strong, this should limit updraft intensity/longevity. A broken band of storms may still pose a risk for a few strong gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Mar 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF CENTRAL/NORTHERN ILLINOIS AND WEST CENTRAL INDIANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...20Z Update... The primary change with this update was a southward extension of the Slight risk area to the TN/KY border. Current expectations are for a broken band of thunderstorms to track eastward into this area this afternoon into the evening. Here, filtered diurnal heating amid gradual boundary-layer moistening should yield enough low-level destabilization for a threat of scattered severe wind gusts and an embedded tornado risk -- given favorable low-level hodograph size and curvature. Elsewhere, severe probabilities were trimmed from the west behind the eastward-advancing dryline. For details on the near-term severe risk, reference Tornado Watch #57 and MCD #245. ..Weinman.. 03/19/2025 .PREV DISCUSSION... /ISSUED 1059 AM CDT Wed Mar 19 2025/ ...IL/IN vicinity into early tonight... A deep (990mb) surface low over northwest MO this morning will continue to shift east into northern IL through late afternoon, and into IN/MI and southern Ontario overnight. Meanwhile, the exit region of a 90-100+ kt 500 mb jet will overspread IL/IN this afternoon into early evening. Cloud cover and elevated convection this morning across IA and northern IL, along with lofted dust moving over the region may inhibit heating to some degree into the afternoon. Furthermore, boundary layer moisture is expected to remain modest, most likely in the 51-54 F range given 15z upstream observations in the low 50s F. If any stronger heating occurs, mixing may further limit dewpoints from climbing into the mid/upper 50s F as suggested by some forecast guidance. Nevertheless, cold temperatures aloft (-17 C on 12z RAOBs from DVN) will support steep midlevel lapse rates and modest destabilization into the early afternoon. A dryline is noted across central MO at 15z. This feature will continue to sweep east into the afternoon and become a focus for stronger thunderstorm development across IL by 18-19z. Vertical shear will be favorable for supercells given elongated hodographs with enlarged, looping low-level hodographs. These vertical wind profiles are already evident in VWP data from DVN and LOT where a west to east oriented surface warm front is roughly aligned across east-central IA/northern IL. Evolution of modest boundary layer moisture will be key for determining the tornado risk this afternoon across IL/IN. If dewpoints can reach 55-56 F, a localized area of enhanced tornado potential may develop. While some risk for tornadoes will still exist with lower dewpoints, the risk would be more muted and likely less intense. Given the conditional risk for a strong tornado or two, will maintain the 10 percent SIG tornado risk. Otherwise, somewhat low-topped supercells will also pose a risk for damaging gusts of 60-70 mph and isolated large hail up to 1-1.5 inches in diameter. Isolated convection may develop southward along the dryline/cold front into western/central KY by late afternoon before convection weakens after sunset. ...TN/MS/AL vicinity this afternoon/evening... Dewpoints have gradually increased into the mid 50s late this morning. Continued warm advection ahead of a wind shift this afternoon should allow dewpoints to reach the upper 50s to low 60s F. While forcing for ascent will be weak compared to further north, it should be sufficient to erode capping in the persistent warm advection regime. Instability will remain modest, generally near/less than 500 J/kg MLCAPE. While vertical shear will be quite strong, this should limit updraft intensity/longevity. A broken band of storms may still pose a risk for a few strong gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Mar 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF CENTRAL/NORTHERN ILLINOIS AND WEST CENTRAL INDIANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...20Z Update... The primary change with this update was a southward extension of the Slight risk area to the TN/KY border. Current expectations are for a broken band of thunderstorms to track eastward into this area this afternoon into the evening. Here, filtered diurnal heating amid gradual boundary-layer moistening should yield enough low-level destabilization for a threat of scattered severe wind gusts and an embedded tornado risk -- given favorable low-level hodograph size and curvature. Elsewhere, severe probabilities were trimmed from the west behind the eastward-advancing dryline. For details on the near-term severe risk, reference Tornado Watch #57 and MCD #245. ..Weinman.. 03/19/2025 .PREV DISCUSSION... /ISSUED 1059 AM CDT Wed Mar 19 2025/ ...IL/IN vicinity into early tonight... A deep (990mb) surface low over northwest MO this morning will continue to shift east into northern IL through late afternoon, and into IN/MI and southern Ontario overnight. Meanwhile, the exit region of a 90-100+ kt 500 mb jet will overspread IL/IN this afternoon into early evening. Cloud cover and elevated convection this morning across IA and northern IL, along with lofted dust moving over the region may inhibit heating to some degree into the afternoon. Furthermore, boundary layer moisture is expected to remain modest, most likely in the 51-54 F range given 15z upstream observations in the low 50s F. If any stronger heating occurs, mixing may further limit dewpoints from climbing into the mid/upper 50s F as suggested by some forecast guidance. Nevertheless, cold temperatures aloft (-17 C on 12z RAOBs from DVN) will support steep midlevel lapse rates and modest destabilization into the early afternoon. A dryline is noted across central MO at 15z. This feature will continue to sweep east into the afternoon and become a focus for stronger thunderstorm development across IL by 18-19z. Vertical shear will be favorable for supercells given elongated hodographs with enlarged, looping low-level hodographs. These vertical wind profiles are already evident in VWP data from DVN and LOT where a west to east oriented surface warm front is roughly aligned across east-central IA/northern IL. Evolution of modest boundary layer moisture will be key for determining the tornado risk this afternoon across IL/IN. If dewpoints can reach 55-56 F, a localized area of enhanced tornado potential may develop. While some risk for tornadoes will still exist with lower dewpoints, the risk would be more muted and likely less intense. Given the conditional risk for a strong tornado or two, will maintain the 10 percent SIG tornado risk. Otherwise, somewhat low-topped supercells will also pose a risk for damaging gusts of 60-70 mph and isolated large hail up to 1-1.5 inches in diameter. Isolated convection may develop southward along the dryline/cold front into western/central KY by late afternoon before convection weakens after sunset. ...TN/MS/AL vicinity this afternoon/evening... Dewpoints have gradually increased into the mid 50s late this morning. Continued warm advection ahead of a wind shift this afternoon should allow dewpoints to reach the upper 50s to low 60s F. While forcing for ascent will be weak compared to further north, it should be sufficient to erode capping in the persistent warm advection regime. Instability will remain modest, generally near/less than 500 J/kg MLCAPE. While vertical shear will be quite strong, this should limit updraft intensity/longevity. A broken band of storms may still pose a risk for a few strong gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Mar 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF CENTRAL/NORTHERN ILLINOIS AND WEST CENTRAL INDIANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...20Z Update... The primary change with this update was a southward extension of the Slight risk area to the TN/KY border. Current expectations are for a broken band of thunderstorms to track eastward into this area this afternoon into the evening. Here, filtered diurnal heating amid gradual boundary-layer moistening should yield enough low-level destabilization for a threat of scattered severe wind gusts and an embedded tornado risk -- given favorable low-level hodograph size and curvature. Elsewhere, severe probabilities were trimmed from the west behind the eastward-advancing dryline. For details on the near-term severe risk, reference Tornado Watch #57 and MCD #245. ..Weinman.. 03/19/2025 .PREV DISCUSSION... /ISSUED 1059 AM CDT Wed Mar 19 2025/ ...IL/IN vicinity into early tonight... A deep (990mb) surface low over northwest MO this morning will continue to shift east into northern IL through late afternoon, and into IN/MI and southern Ontario overnight. Meanwhile, the exit region of a 90-100+ kt 500 mb jet will overspread IL/IN this afternoon into early evening. Cloud cover and elevated convection this morning across IA and northern IL, along with lofted dust moving over the region may inhibit heating to some degree into the afternoon. Furthermore, boundary layer moisture is expected to remain modest, most likely in the 51-54 F range given 15z upstream observations in the low 50s F. If any stronger heating occurs, mixing may further limit dewpoints from climbing into the mid/upper 50s F as suggested by some forecast guidance. Nevertheless, cold temperatures aloft (-17 C on 12z RAOBs from DVN) will support steep midlevel lapse rates and modest destabilization into the early afternoon. A dryline is noted across central MO at 15z. This feature will continue to sweep east into the afternoon and become a focus for stronger thunderstorm development across IL by 18-19z. Vertical shear will be favorable for supercells given elongated hodographs with enlarged, looping low-level hodographs. These vertical wind profiles are already evident in VWP data from DVN and LOT where a west to east oriented surface warm front is roughly aligned across east-central IA/northern IL. Evolution of modest boundary layer moisture will be key for determining the tornado risk this afternoon across IL/IN. If dewpoints can reach 55-56 F, a localized area of enhanced tornado potential may develop. While some risk for tornadoes will still exist with lower dewpoints, the risk would be more muted and likely less intense. Given the conditional risk for a strong tornado or two, will maintain the 10 percent SIG tornado risk. Otherwise, somewhat low-topped supercells will also pose a risk for damaging gusts of 60-70 mph and isolated large hail up to 1-1.5 inches in diameter. Isolated convection may develop southward along the dryline/cold front into western/central KY by late afternoon before convection weakens after sunset. ...TN/MS/AL vicinity this afternoon/evening... Dewpoints have gradually increased into the mid 50s late this morning. Continued warm advection ahead of a wind shift this afternoon should allow dewpoints to reach the upper 50s to low 60s F. While forcing for ascent will be weak compared to further north, it should be sufficient to erode capping in the persistent warm advection regime. Instability will remain modest, generally near/less than 500 J/kg MLCAPE. While vertical shear will be quite strong, this should limit updraft intensity/longevity. A broken band of storms may still pose a risk for a few strong gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Mar 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF CENTRAL/NORTHERN ILLINOIS AND WEST CENTRAL INDIANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...20Z Update... The primary change with this update was a southward extension of the Slight risk area to the TN/KY border. Current expectations are for a broken band of thunderstorms to track eastward into this area this afternoon into the evening. Here, filtered diurnal heating amid gradual boundary-layer moistening should yield enough low-level destabilization for a threat of scattered severe wind gusts and an embedded tornado risk -- given favorable low-level hodograph size and curvature. Elsewhere, severe probabilities were trimmed from the west behind the eastward-advancing dryline. For details on the near-term severe risk, reference Tornado Watch #57 and MCD #245. ..Weinman.. 03/19/2025 .PREV DISCUSSION... /ISSUED 1059 AM CDT Wed Mar 19 2025/ ...IL/IN vicinity into early tonight... A deep (990mb) surface low over northwest MO this morning will continue to shift east into northern IL through late afternoon, and into IN/MI and southern Ontario overnight. Meanwhile, the exit region of a 90-100+ kt 500 mb jet will overspread IL/IN this afternoon into early evening. Cloud cover and elevated convection this morning across IA and northern IL, along with lofted dust moving over the region may inhibit heating to some degree into the afternoon. Furthermore, boundary layer moisture is expected to remain modest, most likely in the 51-54 F range given 15z upstream observations in the low 50s F. If any stronger heating occurs, mixing may further limit dewpoints from climbing into the mid/upper 50s F as suggested by some forecast guidance. Nevertheless, cold temperatures aloft (-17 C on 12z RAOBs from DVN) will support steep midlevel lapse rates and modest destabilization into the early afternoon. A dryline is noted across central MO at 15z. This feature will continue to sweep east into the afternoon and become a focus for stronger thunderstorm development across IL by 18-19z. Vertical shear will be favorable for supercells given elongated hodographs with enlarged, looping low-level hodographs. These vertical wind profiles are already evident in VWP data from DVN and LOT where a west to east oriented surface warm front is roughly aligned across east-central IA/northern IL. Evolution of modest boundary layer moisture will be key for determining the tornado risk this afternoon across IL/IN. If dewpoints can reach 55-56 F, a localized area of enhanced tornado potential may develop. While some risk for tornadoes will still exist with lower dewpoints, the risk would be more muted and likely less intense. Given the conditional risk for a strong tornado or two, will maintain the 10 percent SIG tornado risk. Otherwise, somewhat low-topped supercells will also pose a risk for damaging gusts of 60-70 mph and isolated large hail up to 1-1.5 inches in diameter. Isolated convection may develop southward along the dryline/cold front into western/central KY by late afternoon before convection weakens after sunset. ...TN/MS/AL vicinity this afternoon/evening... Dewpoints have gradually increased into the mid 50s late this morning. Continued warm advection ahead of a wind shift this afternoon should allow dewpoints to reach the upper 50s to low 60s F. While forcing for ascent will be weak compared to further north, it should be sufficient to erode capping in the persistent warm advection regime. Instability will remain modest, generally near/less than 500 J/kg MLCAPE. While vertical shear will be quite strong, this should limit updraft intensity/longevity. A broken band of storms may still pose a risk for a few strong gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Mar 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF CENTRAL/NORTHERN ILLINOIS AND WEST CENTRAL INDIANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...20Z Update... The primary change with this update was a southward extension of the Slight risk area to the TN/KY border. Current expectations are for a broken band of thunderstorms to track eastward into this area this afternoon into the evening. Here, filtered diurnal heating amid gradual boundary-layer moistening should yield enough low-level destabilization for a threat of scattered severe wind gusts and an embedded tornado risk -- given favorable low-level hodograph size and curvature. Elsewhere, severe probabilities were trimmed from the west behind the eastward-advancing dryline. For details on the near-term severe risk, reference Tornado Watch #57 and MCD #245. ..Weinman.. 03/19/2025 .PREV DISCUSSION... /ISSUED 1059 AM CDT Wed Mar 19 2025/ ...IL/IN vicinity into early tonight... A deep (990mb) surface low over northwest MO this morning will continue to shift east into northern IL through late afternoon, and into IN/MI and southern Ontario overnight. Meanwhile, the exit region of a 90-100+ kt 500 mb jet will overspread IL/IN this afternoon into early evening. Cloud cover and elevated convection this morning across IA and northern IL, along with lofted dust moving over the region may inhibit heating to some degree into the afternoon. Furthermore, boundary layer moisture is expected to remain modest, most likely in the 51-54 F range given 15z upstream observations in the low 50s F. If any stronger heating occurs, mixing may further limit dewpoints from climbing into the mid/upper 50s F as suggested by some forecast guidance. Nevertheless, cold temperatures aloft (-17 C on 12z RAOBs from DVN) will support steep midlevel lapse rates and modest destabilization into the early afternoon. A dryline is noted across central MO at 15z. This feature will continue to sweep east into the afternoon and become a focus for stronger thunderstorm development across IL by 18-19z. Vertical shear will be favorable for supercells given elongated hodographs with enlarged, looping low-level hodographs. These vertical wind profiles are already evident in VWP data from DVN and LOT where a west to east oriented surface warm front is roughly aligned across east-central IA/northern IL. Evolution of modest boundary layer moisture will be key for determining the tornado risk this afternoon across IL/IN. If dewpoints can reach 55-56 F, a localized area of enhanced tornado potential may develop. While some risk for tornadoes will still exist with lower dewpoints, the risk would be more muted and likely less intense. Given the conditional risk for a strong tornado or two, will maintain the 10 percent SIG tornado risk. Otherwise, somewhat low-topped supercells will also pose a risk for damaging gusts of 60-70 mph and isolated large hail up to 1-1.5 inches in diameter. Isolated convection may develop southward along the dryline/cold front into western/central KY by late afternoon before convection weakens after sunset. ...TN/MS/AL vicinity this afternoon/evening... Dewpoints have gradually increased into the mid 50s late this morning. Continued warm advection ahead of a wind shift this afternoon should allow dewpoints to reach the upper 50s to low 60s F. While forcing for ascent will be weak compared to further north, it should be sufficient to erode capping in the persistent warm advection regime. Instability will remain modest, generally near/less than 500 J/kg MLCAPE. While vertical shear will be quite strong, this should limit updraft intensity/longevity. A broken band of storms may still pose a risk for a few strong gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Mar 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF CENTRAL/NORTHERN ILLINOIS AND WEST CENTRAL INDIANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...20Z Update... The primary change with this update was a southward extension of the Slight risk area to the TN/KY border. Current expectations are for a broken band of thunderstorms to track eastward into this area this afternoon into the evening. Here, filtered diurnal heating amid gradual boundary-layer moistening should yield enough low-level destabilization for a threat of scattered severe wind gusts and an embedded tornado risk -- given favorable low-level hodograph size and curvature. Elsewhere, severe probabilities were trimmed from the west behind the eastward-advancing dryline. For details on the near-term severe risk, reference Tornado Watch #57 and MCD #245. ..Weinman.. 03/19/2025 .PREV DISCUSSION... /ISSUED 1059 AM CDT Wed Mar 19 2025/ ...IL/IN vicinity into early tonight... A deep (990mb) surface low over northwest MO this morning will continue to shift east into northern IL through late afternoon, and into IN/MI and southern Ontario overnight. Meanwhile, the exit region of a 90-100+ kt 500 mb jet will overspread IL/IN this afternoon into early evening. Cloud cover and elevated convection this morning across IA and northern IL, along with lofted dust moving over the region may inhibit heating to some degree into the afternoon. Furthermore, boundary layer moisture is expected to remain modest, most likely in the 51-54 F range given 15z upstream observations in the low 50s F. If any stronger heating occurs, mixing may further limit dewpoints from climbing into the mid/upper 50s F as suggested by some forecast guidance. Nevertheless, cold temperatures aloft (-17 C on 12z RAOBs from DVN) will support steep midlevel lapse rates and modest destabilization into the early afternoon. A dryline is noted across central MO at 15z. This feature will continue to sweep east into the afternoon and become a focus for stronger thunderstorm development across IL by 18-19z. Vertical shear will be favorable for supercells given elongated hodographs with enlarged, looping low-level hodographs. These vertical wind profiles are already evident in VWP data from DVN and LOT where a west to east oriented surface warm front is roughly aligned across east-central IA/northern IL. Evolution of modest boundary layer moisture will be key for determining the tornado risk this afternoon across IL/IN. If dewpoints can reach 55-56 F, a localized area of enhanced tornado potential may develop. While some risk for tornadoes will still exist with lower dewpoints, the risk would be more muted and likely less intense. Given the conditional risk for a strong tornado or two, will maintain the 10 percent SIG tornado risk. Otherwise, somewhat low-topped supercells will also pose a risk for damaging gusts of 60-70 mph and isolated large hail up to 1-1.5 inches in diameter. Isolated convection may develop southward along the dryline/cold front into western/central KY by late afternoon before convection weakens after sunset. ...TN/MS/AL vicinity this afternoon/evening... Dewpoints have gradually increased into the mid 50s late this morning. Continued warm advection ahead of a wind shift this afternoon should allow dewpoints to reach the upper 50s to low 60s F. While forcing for ascent will be weak compared to further north, it should be sufficient to erode capping in the persistent warm advection regime. Instability will remain modest, generally near/less than 500 J/kg MLCAPE. While vertical shear will be quite strong, this should limit updraft intensity/longevity. A broken band of storms may still pose a risk for a few strong gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Mar 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF CENTRAL/NORTHERN ILLINOIS AND WEST CENTRAL INDIANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...20Z Update... The primary change with this update was a southward extension of the Slight risk area to the TN/KY border. Current expectations are for a broken band of thunderstorms to track eastward into this area this afternoon into the evening. Here, filtered diurnal heating amid gradual boundary-layer moistening should yield enough low-level destabilization for a threat of scattered severe wind gusts and an embedded tornado risk -- given favorable low-level hodograph size and curvature. Elsewhere, severe probabilities were trimmed from the west behind the eastward-advancing dryline. For details on the near-term severe risk, reference Tornado Watch #57 and MCD #245. ..Weinman.. 03/19/2025 .PREV DISCUSSION... /ISSUED 1059 AM CDT Wed Mar 19 2025/ ...IL/IN vicinity into early tonight... A deep (990mb) surface low over northwest MO this morning will continue to shift east into northern IL through late afternoon, and into IN/MI and southern Ontario overnight. Meanwhile, the exit region of a 90-100+ kt 500 mb jet will overspread IL/IN this afternoon into early evening. Cloud cover and elevated convection this morning across IA and northern IL, along with lofted dust moving over the region may inhibit heating to some degree into the afternoon. Furthermore, boundary layer moisture is expected to remain modest, most likely in the 51-54 F range given 15z upstream observations in the low 50s F. If any stronger heating occurs, mixing may further limit dewpoints from climbing into the mid/upper 50s F as suggested by some forecast guidance. Nevertheless, cold temperatures aloft (-17 C on 12z RAOBs from DVN) will support steep midlevel lapse rates and modest destabilization into the early afternoon. A dryline is noted across central MO at 15z. This feature will continue to sweep east into the afternoon and become a focus for stronger thunderstorm development across IL by 18-19z. Vertical shear will be favorable for supercells given elongated hodographs with enlarged, looping low-level hodographs. These vertical wind profiles are already evident in VWP data from DVN and LOT where a west to east oriented surface warm front is roughly aligned across east-central IA/northern IL. Evolution of modest boundary layer moisture will be key for determining the tornado risk this afternoon across IL/IN. If dewpoints can reach 55-56 F, a localized area of enhanced tornado potential may develop. While some risk for tornadoes will still exist with lower dewpoints, the risk would be more muted and likely less intense. Given the conditional risk for a strong tornado or two, will maintain the 10 percent SIG tornado risk. Otherwise, somewhat low-topped supercells will also pose a risk for damaging gusts of 60-70 mph and isolated large hail up to 1-1.5 inches in diameter. Isolated convection may develop southward along the dryline/cold front into western/central KY by late afternoon before convection weakens after sunset. ...TN/MS/AL vicinity this afternoon/evening... Dewpoints have gradually increased into the mid 50s late this morning. Continued warm advection ahead of a wind shift this afternoon should allow dewpoints to reach the upper 50s to low 60s F. While forcing for ascent will be weak compared to further north, it should be sufficient to erode capping in the persistent warm advection regime. Instability will remain modest, generally near/less than 500 J/kg MLCAPE. While vertical shear will be quite strong, this should limit updraft intensity/longevity. A broken band of storms may still pose a risk for a few strong gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Mar 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF CENTRAL/NORTHERN ILLINOIS AND WEST CENTRAL INDIANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...20Z Update... The primary change with this update was a southward extension of the Slight risk area to the TN/KY border. Current expectations are for a broken band of thunderstorms to track eastward into this area this afternoon into the evening. Here, filtered diurnal heating amid gradual boundary-layer moistening should yield enough low-level destabilization for a threat of scattered severe wind gusts and an embedded tornado risk -- given favorable low-level hodograph size and curvature. Elsewhere, severe probabilities were trimmed from the west behind the eastward-advancing dryline. For details on the near-term severe risk, reference Tornado Watch #57 and MCD #245. ..Weinman.. 03/19/2025 .PREV DISCUSSION... /ISSUED 1059 AM CDT Wed Mar 19 2025/ ...IL/IN vicinity into early tonight... A deep (990mb) surface low over northwest MO this morning will continue to shift east into northern IL through late afternoon, and into IN/MI and southern Ontario overnight. Meanwhile, the exit region of a 90-100+ kt 500 mb jet will overspread IL/IN this afternoon into early evening. Cloud cover and elevated convection this morning across IA and northern IL, along with lofted dust moving over the region may inhibit heating to some degree into the afternoon. Furthermore, boundary layer moisture is expected to remain modest, most likely in the 51-54 F range given 15z upstream observations in the low 50s F. If any stronger heating occurs, mixing may further limit dewpoints from climbing into the mid/upper 50s F as suggested by some forecast guidance. Nevertheless, cold temperatures aloft (-17 C on 12z RAOBs from DVN) will support steep midlevel lapse rates and modest destabilization into the early afternoon. A dryline is noted across central MO at 15z. This feature will continue to sweep east into the afternoon and become a focus for stronger thunderstorm development across IL by 18-19z. Vertical shear will be favorable for supercells given elongated hodographs with enlarged, looping low-level hodographs. These vertical wind profiles are already evident in VWP data from DVN and LOT where a west to east oriented surface warm front is roughly aligned across east-central IA/northern IL. Evolution of modest boundary layer moisture will be key for determining the tornado risk this afternoon across IL/IN. If dewpoints can reach 55-56 F, a localized area of enhanced tornado potential may develop. While some risk for tornadoes will still exist with lower dewpoints, the risk would be more muted and likely less intense. Given the conditional risk for a strong tornado or two, will maintain the 10 percent SIG tornado risk. Otherwise, somewhat low-topped supercells will also pose a risk for damaging gusts of 60-70 mph and isolated large hail up to 1-1.5 inches in diameter. Isolated convection may develop southward along the dryline/cold front into western/central KY by late afternoon before convection weakens after sunset. ...TN/MS/AL vicinity this afternoon/evening... Dewpoints have gradually increased into the mid 50s late this morning. Continued warm advection ahead of a wind shift this afternoon should allow dewpoints to reach the upper 50s to low 60s F. While forcing for ascent will be weak compared to further north, it should be sufficient to erode capping in the persistent warm advection regime. Instability will remain modest, generally near/less than 500 J/kg MLCAPE. While vertical shear will be quite strong, this should limit updraft intensity/longevity. A broken band of storms may still pose a risk for a few strong gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Mar 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF CENTRAL/NORTHERN ILLINOIS AND WEST CENTRAL INDIANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...20Z Update... The primary change with this update was a southward extension of the Slight risk area to the TN/KY border. Current expectations are for a broken band of thunderstorms to track eastward into this area this afternoon into the evening. Here, filtered diurnal heating amid gradual boundary-layer moistening should yield enough low-level destabilization for a threat of scattered severe wind gusts and an embedded tornado risk -- given favorable low-level hodograph size and curvature. Elsewhere, severe probabilities were trimmed from the west behind the eastward-advancing dryline. For details on the near-term severe risk, reference Tornado Watch #57 and MCD #245. ..Weinman.. 03/19/2025 .PREV DISCUSSION... /ISSUED 1059 AM CDT Wed Mar 19 2025/ ...IL/IN vicinity into early tonight... A deep (990mb) surface low over northwest MO this morning will continue to shift east into northern IL through late afternoon, and into IN/MI and southern Ontario overnight. Meanwhile, the exit region of a 90-100+ kt 500 mb jet will overspread IL/IN this afternoon into early evening. Cloud cover and elevated convection this morning across IA and northern IL, along with lofted dust moving over the region may inhibit heating to some degree into the afternoon. Furthermore, boundary layer moisture is expected to remain modest, most likely in the 51-54 F range given 15z upstream observations in the low 50s F. If any stronger heating occurs, mixing may further limit dewpoints from climbing into the mid/upper 50s F as suggested by some forecast guidance. Nevertheless, cold temperatures aloft (-17 C on 12z RAOBs from DVN) will support steep midlevel lapse rates and modest destabilization into the early afternoon. A dryline is noted across central MO at 15z. This feature will continue to sweep east into the afternoon and become a focus for stronger thunderstorm development across IL by 18-19z. Vertical shear will be favorable for supercells given elongated hodographs with enlarged, looping low-level hodographs. These vertical wind profiles are already evident in VWP data from DVN and LOT where a west to east oriented surface warm front is roughly aligned across east-central IA/northern IL. Evolution of modest boundary layer moisture will be key for determining the tornado risk this afternoon across IL/IN. If dewpoints can reach 55-56 F, a localized area of enhanced tornado potential may develop. While some risk for tornadoes will still exist with lower dewpoints, the risk would be more muted and likely less intense. Given the conditional risk for a strong tornado or two, will maintain the 10 percent SIG tornado risk. Otherwise, somewhat low-topped supercells will also pose a risk for damaging gusts of 60-70 mph and isolated large hail up to 1-1.5 inches in diameter. Isolated convection may develop southward along the dryline/cold front into western/central KY by late afternoon before convection weakens after sunset. ...TN/MS/AL vicinity this afternoon/evening... Dewpoints have gradually increased into the mid 50s late this morning. Continued warm advection ahead of a wind shift this afternoon should allow dewpoints to reach the upper 50s to low 60s F. While forcing for ascent will be weak compared to further north, it should be sufficient to erode capping in the persistent warm advection regime. Instability will remain modest, generally near/less than 500 J/kg MLCAPE. While vertical shear will be quite strong, this should limit updraft intensity/longevity. A broken band of storms may still pose a risk for a few strong gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Mar 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF CENTRAL/NORTHERN ILLINOIS AND WEST CENTRAL INDIANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...20Z Update... The primary change with this update was a southward extension of the Slight risk area to the TN/KY border. Current expectations are for a broken band of thunderstorms to track eastward into this area this afternoon into the evening. Here, filtered diurnal heating amid gradual boundary-layer moistening should yield enough low-level destabilization for a threat of scattered severe wind gusts and an embedded tornado risk -- given favorable low-level hodograph size and curvature. Elsewhere, severe probabilities were trimmed from the west behind the eastward-advancing dryline. For details on the near-term severe risk, reference Tornado Watch #57 and MCD #245. ..Weinman.. 03/19/2025 .PREV DISCUSSION... /ISSUED 1059 AM CDT Wed Mar 19 2025/ ...IL/IN vicinity into early tonight... A deep (990mb) surface low over northwest MO this morning will continue to shift east into northern IL through late afternoon, and into IN/MI and southern Ontario overnight. Meanwhile, the exit region of a 90-100+ kt 500 mb jet will overspread IL/IN this afternoon into early evening. Cloud cover and elevated convection this morning across IA and northern IL, along with lofted dust moving over the region may inhibit heating to some degree into the afternoon. Furthermore, boundary layer moisture is expected to remain modest, most likely in the 51-54 F range given 15z upstream observations in the low 50s F. If any stronger heating occurs, mixing may further limit dewpoints from climbing into the mid/upper 50s F as suggested by some forecast guidance. Nevertheless, cold temperatures aloft (-17 C on 12z RAOBs from DVN) will support steep midlevel lapse rates and modest destabilization into the early afternoon. A dryline is noted across central MO at 15z. This feature will continue to sweep east into the afternoon and become a focus for stronger thunderstorm development across IL by 18-19z. Vertical shear will be favorable for supercells given elongated hodographs with enlarged, looping low-level hodographs. These vertical wind profiles are already evident in VWP data from DVN and LOT where a west to east oriented surface warm front is roughly aligned across east-central IA/northern IL. Evolution of modest boundary layer moisture will be key for determining the tornado risk this afternoon across IL/IN. If dewpoints can reach 55-56 F, a localized area of enhanced tornado potential may develop. While some risk for tornadoes will still exist with lower dewpoints, the risk would be more muted and likely less intense. Given the conditional risk for a strong tornado or two, will maintain the 10 percent SIG tornado risk. Otherwise, somewhat low-topped supercells will also pose a risk for damaging gusts of 60-70 mph and isolated large hail up to 1-1.5 inches in diameter. Isolated convection may develop southward along the dryline/cold front into western/central KY by late afternoon before convection weakens after sunset. ...TN/MS/AL vicinity this afternoon/evening... Dewpoints have gradually increased into the mid 50s late this morning. Continued warm advection ahead of a wind shift this afternoon should allow dewpoints to reach the upper 50s to low 60s F. While forcing for ascent will be weak compared to further north, it should be sufficient to erode capping in the persistent warm advection regime. Instability will remain modest, generally near/less than 500 J/kg MLCAPE. While vertical shear will be quite strong, this should limit updraft intensity/longevity. A broken band of storms may still pose a risk for a few strong gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Mar 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF CENTRAL/NORTHERN ILLINOIS AND WEST CENTRAL INDIANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...20Z Update... The primary change with this update was a southward extension of the Slight risk area to the TN/KY border. Current expectations are for a broken band of thunderstorms to track eastward into this area this afternoon into the evening. Here, filtered diurnal heating amid gradual boundary-layer moistening should yield enough low-level destabilization for a threat of scattered severe wind gusts and an embedded tornado risk -- given favorable low-level hodograph size and curvature. Elsewhere, severe probabilities were trimmed from the west behind the eastward-advancing dryline. For details on the near-term severe risk, reference Tornado Watch #57 and MCD #245. ..Weinman.. 03/19/2025 .PREV DISCUSSION... /ISSUED 1059 AM CDT Wed Mar 19 2025/ ...IL/IN vicinity into early tonight... A deep (990mb) surface low over northwest MO this morning will continue to shift east into northern IL through late afternoon, and into IN/MI and southern Ontario overnight. Meanwhile, the exit region of a 90-100+ kt 500 mb jet will overspread IL/IN this afternoon into early evening. Cloud cover and elevated convection this morning across IA and northern IL, along with lofted dust moving over the region may inhibit heating to some degree into the afternoon. Furthermore, boundary layer moisture is expected to remain modest, most likely in the 51-54 F range given 15z upstream observations in the low 50s F. If any stronger heating occurs, mixing may further limit dewpoints from climbing into the mid/upper 50s F as suggested by some forecast guidance. Nevertheless, cold temperatures aloft (-17 C on 12z RAOBs from DVN) will support steep midlevel lapse rates and modest destabilization into the early afternoon. A dryline is noted across central MO at 15z. This feature will continue to sweep east into the afternoon and become a focus for stronger thunderstorm development across IL by 18-19z. Vertical shear will be favorable for supercells given elongated hodographs with enlarged, looping low-level hodographs. These vertical wind profiles are already evident in VWP data from DVN and LOT where a west to east oriented surface warm front is roughly aligned across east-central IA/northern IL. Evolution of modest boundary layer moisture will be key for determining the tornado risk this afternoon across IL/IN. If dewpoints can reach 55-56 F, a localized area of enhanced tornado potential may develop. While some risk for tornadoes will still exist with lower dewpoints, the risk would be more muted and likely less intense. Given the conditional risk for a strong tornado or two, will maintain the 10 percent SIG tornado risk. Otherwise, somewhat low-topped supercells will also pose a risk for damaging gusts of 60-70 mph and isolated large hail up to 1-1.5 inches in diameter. Isolated convection may develop southward along the dryline/cold front into western/central KY by late afternoon before convection weakens after sunset. ...TN/MS/AL vicinity this afternoon/evening... Dewpoints have gradually increased into the mid 50s late this morning. Continued warm advection ahead of a wind shift this afternoon should allow dewpoints to reach the upper 50s to low 60s F. While forcing for ascent will be weak compared to further north, it should be sufficient to erode capping in the persistent warm advection regime. Instability will remain modest, generally near/less than 500 J/kg MLCAPE. While vertical shear will be quite strong, this should limit updraft intensity/longevity. A broken band of storms may still pose a risk for a few strong gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Mar 19 2025 Valid 192000Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF CENTRAL/NORTHERN ILLINOIS AND WEST CENTRAL INDIANA... ...SUMMARY... Scattered severe thunderstorms are expected this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...20Z Update... The primary change with this update was a southward extension of the Slight risk area to the TN/KY border. Current expectations are for a broken band of thunderstorms to track eastward into this area this afternoon into the evening. Here, filtered diurnal heating amid gradual boundary-layer moistening should yield enough low-level destabilization for a threat of scattered severe wind gusts and an embedded tornado risk -- given favorable low-level hodograph size and curvature. Elsewhere, severe probabilities were trimmed from the west behind the eastward-advancing dryline. For details on the near-term severe risk, reference Tornado Watch #57 and MCD #245. ..Weinman.. 03/19/2025 .PREV DISCUSSION... /ISSUED 1059 AM CDT Wed Mar 19 2025/ ...IL/IN vicinity into early tonight... A deep (990mb) surface low over northwest MO this morning will continue to shift east into northern IL through late afternoon, and into IN/MI and southern Ontario overnight. Meanwhile, the exit region of a 90-100+ kt 500 mb jet will overspread IL/IN this afternoon into early evening. Cloud cover and elevated convection this morning across IA and northern IL, along with lofted dust moving over the region may inhibit heating to some degree into the afternoon. Furthermore, boundary layer moisture is expected to remain modest, most likely in the 51-54 F range given 15z upstream observations in the low 50s F. If any stronger heating occurs, mixing may further limit dewpoints from climbing into the mid/upper 50s F as suggested by some forecast guidance. Nevertheless, cold temperatures aloft (-17 C on 12z RAOBs from DVN) will support steep midlevel lapse rates and modest destabilization into the early afternoon. A dryline is noted across central MO at 15z. This feature will continue to sweep east into the afternoon and become a focus for stronger thunderstorm development across IL by 18-19z. Vertical shear will be favorable for supercells given elongated hodographs with enlarged, looping low-level hodographs. These vertical wind profiles are already evident in VWP data from DVN and LOT where a west to east oriented surface warm front is roughly aligned across east-central IA/northern IL. Evolution of modest boundary layer moisture will be key for determining the tornado risk this afternoon across IL/IN. If dewpoints can reach 55-56 F, a localized area of enhanced tornado potential may develop. While some risk for tornadoes will still exist with lower dewpoints, the risk would be more muted and likely less intense. Given the conditional risk for a strong tornado or two, will maintain the 10 percent SIG tornado risk. Otherwise, somewhat low-topped supercells will also pose a risk for damaging gusts of 60-70 mph and isolated large hail up to 1-1.5 inches in diameter. Isolated convection may develop southward along the dryline/cold front into western/central KY by late afternoon before convection weakens after sunset. ...TN/MS/AL vicinity this afternoon/evening... Dewpoints have gradually increased into the mid 50s late this morning. Continued warm advection ahead of a wind shift this afternoon should allow dewpoints to reach the upper 50s to low 60s F. While forcing for ascent will be weak compared to further north, it should be sufficient to erode capping in the persistent warm advection regime. Instability will remain modest, generally near/less than 500 J/kg MLCAPE. While vertical shear will be quite strong, this should limit updraft intensity/longevity. A broken band of storms may still pose a risk for a few strong gusts. Read more