SPC Mar 19, 2025 1630 UTC Day 1 Convective Outlook

5 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1059 AM CDT Wed Mar 19 2025 Valid 191630Z - 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 possible this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...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. ..Leitman/Bunting.. 03/19/2025 Read more

SPC Mar 19, 2025 1630 UTC Day 1 Convective Outlook

5 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1059 AM CDT Wed Mar 19 2025 Valid 191630Z - 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 possible this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...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. ..Leitman/Bunting.. 03/19/2025 Read more

SPC Mar 19, 2025 1630 UTC Day 1 Convective Outlook

5 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1059 AM CDT Wed Mar 19 2025 Valid 191630Z - 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 possible this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...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. ..Leitman/Bunting.. 03/19/2025 Read more

SPC Mar 19, 2025 1630 UTC Day 1 Convective Outlook

5 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1059 AM CDT Wed Mar 19 2025 Valid 191630Z - 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 possible this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...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. ..Leitman/Bunting.. 03/19/2025 Read more

SPC Mar 19, 2025 1630 UTC Day 1 Convective Outlook

5 months ago
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1059 AM CDT Wed Mar 19 2025 Valid 191630Z - 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 possible this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...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. ..Leitman/Bunting.. 03/19/2025 Read more

SPC MD 241

5 months ago
MD 0241 CONCERNING BLIZZARD FOR PARTS OF WESTERN/CENTRAL KS INTO CENTRAL/EASTERN NE...NORTHWEST IA...AND EXTREME SOUTHEAST SD/SOUTH-CENTRAL MN
Mesoscale Discussion 0241 NWS Storm Prediction Center Norman OK 0554 AM CDT Wed Mar 19 2025 Areas affected...Parts of western/central KS into central/eastern NE...northwest IA...and extreme southeast SD/south-central MN Concerning...Blizzard Valid 191054Z - 191600Z SUMMARY...Blizzard conditions will gradually spread eastward through the morning. Snow rates of 1-2+ inches per hour are possible, along with widespread 50-60+ mph gusts. DISCUSSION...Blizzard conditions are ongoing this morning from southwest/south-central NE into western KS, to the northwest of a powerful 987 mb cyclone centered over northeast KS. Very strong deep-layer ascent will continue to support heavy precipitation rates through the morning, aided by very favorable low/midlevel frontogenesis, and the presence of elevated buoyancy and regenerative convection along the eastern periphery of heavier precipitation, near the midlevel dry slot. The heaviest precipitation rates will gradually shift eastward through the morning, in conjunction with the movement of the cyclone, while low-level cold advection and strong ascent result in cooling of the column and a changeover to snow in areas that are currently in the mid/upper 30s F. Meanwhile, very strong low-level flow increasing to near/above 70 kt at 1 km AGL (as noted on the KUEX VWP) will continue to support wind gusts in the 50-70 mph range (as already noted through the night across parts of KS/NE), resulting in widespread blowing snow and blizzard conditions. Short-term guidance generally suggests that the heaviest snow rates will become focused from central/northern KS into northeast NE/northwest IA later this morning. Areas within the most intense snow bands may experience rates of 1-2+ inches per hour, along with wind gusts near/above 60 mph, near-zero visibility, and occasional lightning. A rather sharp gradient in snow rates is expected along the eastern periphery of the heavier precipitation, though the very strong wind gusts may result in blizzard conditions even in areas that experience only light to moderate snow. ..Dean.. 03/19/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MPX...DMX...FSD...OAX...TOP...ICT...GID...LBF... DDC...GLD... LAT...LON 38510077 40719967 42119789 43089633 43699472 43879405 43959356 42839368 42219429 40569637 39399748 38399811 38009859 37749935 37659990 37690043 37810075 38510077 Read more

SPC Mar 19, 2025 1300 UTC Day 1 Convective Outlook

5 months ago
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Wed Mar 19 2025 Valid 191300Z - 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 possible this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...IL/IN this afternoon into early tonight... A deep (989 mb) cyclone near the northeast KS/northwest MO border will move northeastward to northern IL by this evening and Lower MI overnight, in conjunction with a deep midlevel trough and 100+ kt midlevel jet streak. Elevated convection is ongoing this morning in a zone of focused ascent with warm advection/frontogenesis across IA, where isolated large hail may occur with MUCAPE around 500 J/kg and steep midlevel lapse rates/cool midlevel temperatures. The warm sector of the cyclone is characterized by a narrow/modest corridor of returning moisture (low-mid 50s boundary-layer dewpoints) that will overspread MO/IL through the afternoon. Surface heating in cloud breaks, continued moisture advection and relatively cool midlevel temperatures will all contribute to warm sector destabilization (MLCAPE 500-750 J/kg) through the afternoon across IL. Surface-based thunderstorm development will become probable by early-mid afternoon in a broken band along and just ahead of a remnant dryline moving from MO into IL, and storms will subsequently move eastward/northeastward into IN by early tonight before weakening gradually. The deeper buoyancy profiles will be on the cyclonic side of the midlevel jet, where 500 mb temperatures will be < -20 C. Forecast wind profiles suggest supercell potential with long hodographs (effective bulk shear vectors >50 kt), and sufficient low-level hodograph curvature/shear for tornado potential. The primary uncertainty centers of the degree of low-level moistening/destabilization, and the current forecast represents a conditional/reasonable worst case scenario. Otherwise, occasional large hail (1-1.5 inches in diameter) will be possible in IL this afternoon/evening, and the threat for damaging gusts (60-70 mph) and a couple of tornadoes will persist into IN through early tonight. ...TN/MS/AL this afternoon/evening... Boundary-layer dewpoints will slowly increase to the upper 50s/lower 60s ahead of the surface wind shift moving across AR/LA this afternoon. Forcing for ascent should be sufficient to remove the cap, allowing some deep convection in a broken band this afternoon/evening. Buoyancy will be relatively weak compared to the vertical shear, so it will be difficult to get sustained severe storms and isolated wind damage will be the most probable threat. ..Thompson/Dean.. 03/19/2025 Read more

SPC Mar 19, 2025 1300 UTC Day 1 Convective Outlook

5 months ago
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Wed Mar 19 2025 Valid 191300Z - 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 possible this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...IL/IN this afternoon into early tonight... A deep (989 mb) cyclone near the northeast KS/northwest MO border will move northeastward to northern IL by this evening and Lower MI overnight, in conjunction with a deep midlevel trough and 100+ kt midlevel jet streak. Elevated convection is ongoing this morning in a zone of focused ascent with warm advection/frontogenesis across IA, where isolated large hail may occur with MUCAPE around 500 J/kg and steep midlevel lapse rates/cool midlevel temperatures. The warm sector of the cyclone is characterized by a narrow/modest corridor of returning moisture (low-mid 50s boundary-layer dewpoints) that will overspread MO/IL through the afternoon. Surface heating in cloud breaks, continued moisture advection and relatively cool midlevel temperatures will all contribute to warm sector destabilization (MLCAPE 500-750 J/kg) through the afternoon across IL. Surface-based thunderstorm development will become probable by early-mid afternoon in a broken band along and just ahead of a remnant dryline moving from MO into IL, and storms will subsequently move eastward/northeastward into IN by early tonight before weakening gradually. The deeper buoyancy profiles will be on the cyclonic side of the midlevel jet, where 500 mb temperatures will be < -20 C. Forecast wind profiles suggest supercell potential with long hodographs (effective bulk shear vectors >50 kt), and sufficient low-level hodograph curvature/shear for tornado potential. The primary uncertainty centers of the degree of low-level moistening/destabilization, and the current forecast represents a conditional/reasonable worst case scenario. Otherwise, occasional large hail (1-1.5 inches in diameter) will be possible in IL this afternoon/evening, and the threat for damaging gusts (60-70 mph) and a couple of tornadoes will persist into IN through early tonight. ...TN/MS/AL this afternoon/evening... Boundary-layer dewpoints will slowly increase to the upper 50s/lower 60s ahead of the surface wind shift moving across AR/LA this afternoon. Forcing for ascent should be sufficient to remove the cap, allowing some deep convection in a broken band this afternoon/evening. Buoyancy will be relatively weak compared to the vertical shear, so it will be difficult to get sustained severe storms and isolated wind damage will be the most probable threat. ..Thompson/Dean.. 03/19/2025 Read more

SPC Mar 19, 2025 1300 UTC Day 1 Convective Outlook

5 months ago
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Wed Mar 19 2025 Valid 191300Z - 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 possible this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...IL/IN this afternoon into early tonight... A deep (989 mb) cyclone near the northeast KS/northwest MO border will move northeastward to northern IL by this evening and Lower MI overnight, in conjunction with a deep midlevel trough and 100+ kt midlevel jet streak. Elevated convection is ongoing this morning in a zone of focused ascent with warm advection/frontogenesis across IA, where isolated large hail may occur with MUCAPE around 500 J/kg and steep midlevel lapse rates/cool midlevel temperatures. The warm sector of the cyclone is characterized by a narrow/modest corridor of returning moisture (low-mid 50s boundary-layer dewpoints) that will overspread MO/IL through the afternoon. Surface heating in cloud breaks, continued moisture advection and relatively cool midlevel temperatures will all contribute to warm sector destabilization (MLCAPE 500-750 J/kg) through the afternoon across IL. Surface-based thunderstorm development will become probable by early-mid afternoon in a broken band along and just ahead of a remnant dryline moving from MO into IL, and storms will subsequently move eastward/northeastward into IN by early tonight before weakening gradually. The deeper buoyancy profiles will be on the cyclonic side of the midlevel jet, where 500 mb temperatures will be < -20 C. Forecast wind profiles suggest supercell potential with long hodographs (effective bulk shear vectors >50 kt), and sufficient low-level hodograph curvature/shear for tornado potential. The primary uncertainty centers of the degree of low-level moistening/destabilization, and the current forecast represents a conditional/reasonable worst case scenario. Otherwise, occasional large hail (1-1.5 inches in diameter) will be possible in IL this afternoon/evening, and the threat for damaging gusts (60-70 mph) and a couple of tornadoes will persist into IN through early tonight. ...TN/MS/AL this afternoon/evening... Boundary-layer dewpoints will slowly increase to the upper 50s/lower 60s ahead of the surface wind shift moving across AR/LA this afternoon. Forcing for ascent should be sufficient to remove the cap, allowing some deep convection in a broken band this afternoon/evening. Buoyancy will be relatively weak compared to the vertical shear, so it will be difficult to get sustained severe storms and isolated wind damage will be the most probable threat. ..Thompson/Dean.. 03/19/2025 Read more

SPC Mar 19, 2025 1300 UTC Day 1 Convective Outlook

5 months ago
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Wed Mar 19 2025 Valid 191300Z - 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 possible this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...IL/IN this afternoon into early tonight... A deep (989 mb) cyclone near the northeast KS/northwest MO border will move northeastward to northern IL by this evening and Lower MI overnight, in conjunction with a deep midlevel trough and 100+ kt midlevel jet streak. Elevated convection is ongoing this morning in a zone of focused ascent with warm advection/frontogenesis across IA, where isolated large hail may occur with MUCAPE around 500 J/kg and steep midlevel lapse rates/cool midlevel temperatures. The warm sector of the cyclone is characterized by a narrow/modest corridor of returning moisture (low-mid 50s boundary-layer dewpoints) that will overspread MO/IL through the afternoon. Surface heating in cloud breaks, continued moisture advection and relatively cool midlevel temperatures will all contribute to warm sector destabilization (MLCAPE 500-750 J/kg) through the afternoon across IL. Surface-based thunderstorm development will become probable by early-mid afternoon in a broken band along and just ahead of a remnant dryline moving from MO into IL, and storms will subsequently move eastward/northeastward into IN by early tonight before weakening gradually. The deeper buoyancy profiles will be on the cyclonic side of the midlevel jet, where 500 mb temperatures will be < -20 C. Forecast wind profiles suggest supercell potential with long hodographs (effective bulk shear vectors >50 kt), and sufficient low-level hodograph curvature/shear for tornado potential. The primary uncertainty centers of the degree of low-level moistening/destabilization, and the current forecast represents a conditional/reasonable worst case scenario. Otherwise, occasional large hail (1-1.5 inches in diameter) will be possible in IL this afternoon/evening, and the threat for damaging gusts (60-70 mph) and a couple of tornadoes will persist into IN through early tonight. ...TN/MS/AL this afternoon/evening... Boundary-layer dewpoints will slowly increase to the upper 50s/lower 60s ahead of the surface wind shift moving across AR/LA this afternoon. Forcing for ascent should be sufficient to remove the cap, allowing some deep convection in a broken band this afternoon/evening. Buoyancy will be relatively weak compared to the vertical shear, so it will be difficult to get sustained severe storms and isolated wind damage will be the most probable threat. ..Thompson/Dean.. 03/19/2025 Read more

SPC Mar 19, 2025 1300 UTC Day 1 Convective Outlook

5 months ago
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Wed Mar 19 2025 Valid 191300Z - 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 possible this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...IL/IN this afternoon into early tonight... A deep (989 mb) cyclone near the northeast KS/northwest MO border will move northeastward to northern IL by this evening and Lower MI overnight, in conjunction with a deep midlevel trough and 100+ kt midlevel jet streak. Elevated convection is ongoing this morning in a zone of focused ascent with warm advection/frontogenesis across IA, where isolated large hail may occur with MUCAPE around 500 J/kg and steep midlevel lapse rates/cool midlevel temperatures. The warm sector of the cyclone is characterized by a narrow/modest corridor of returning moisture (low-mid 50s boundary-layer dewpoints) that will overspread MO/IL through the afternoon. Surface heating in cloud breaks, continued moisture advection and relatively cool midlevel temperatures will all contribute to warm sector destabilization (MLCAPE 500-750 J/kg) through the afternoon across IL. Surface-based thunderstorm development will become probable by early-mid afternoon in a broken band along and just ahead of a remnant dryline moving from MO into IL, and storms will subsequently move eastward/northeastward into IN by early tonight before weakening gradually. The deeper buoyancy profiles will be on the cyclonic side of the midlevel jet, where 500 mb temperatures will be < -20 C. Forecast wind profiles suggest supercell potential with long hodographs (effective bulk shear vectors >50 kt), and sufficient low-level hodograph curvature/shear for tornado potential. The primary uncertainty centers of the degree of low-level moistening/destabilization, and the current forecast represents a conditional/reasonable worst case scenario. Otherwise, occasional large hail (1-1.5 inches in diameter) will be possible in IL this afternoon/evening, and the threat for damaging gusts (60-70 mph) and a couple of tornadoes will persist into IN through early tonight. ...TN/MS/AL this afternoon/evening... Boundary-layer dewpoints will slowly increase to the upper 50s/lower 60s ahead of the surface wind shift moving across AR/LA this afternoon. Forcing for ascent should be sufficient to remove the cap, allowing some deep convection in a broken band this afternoon/evening. Buoyancy will be relatively weak compared to the vertical shear, so it will be difficult to get sustained severe storms and isolated wind damage will be the most probable threat. ..Thompson/Dean.. 03/19/2025 Read more

SPC Mar 19, 2025 1300 UTC Day 1 Convective Outlook

5 months ago
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Wed Mar 19 2025 Valid 191300Z - 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 possible this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...IL/IN this afternoon into early tonight... A deep (989 mb) cyclone near the northeast KS/northwest MO border will move northeastward to northern IL by this evening and Lower MI overnight, in conjunction with a deep midlevel trough and 100+ kt midlevel jet streak. Elevated convection is ongoing this morning in a zone of focused ascent with warm advection/frontogenesis across IA, where isolated large hail may occur with MUCAPE around 500 J/kg and steep midlevel lapse rates/cool midlevel temperatures. The warm sector of the cyclone is characterized by a narrow/modest corridor of returning moisture (low-mid 50s boundary-layer dewpoints) that will overspread MO/IL through the afternoon. Surface heating in cloud breaks, continued moisture advection and relatively cool midlevel temperatures will all contribute to warm sector destabilization (MLCAPE 500-750 J/kg) through the afternoon across IL. Surface-based thunderstorm development will become probable by early-mid afternoon in a broken band along and just ahead of a remnant dryline moving from MO into IL, and storms will subsequently move eastward/northeastward into IN by early tonight before weakening gradually. The deeper buoyancy profiles will be on the cyclonic side of the midlevel jet, where 500 mb temperatures will be < -20 C. Forecast wind profiles suggest supercell potential with long hodographs (effective bulk shear vectors >50 kt), and sufficient low-level hodograph curvature/shear for tornado potential. The primary uncertainty centers of the degree of low-level moistening/destabilization, and the current forecast represents a conditional/reasonable worst case scenario. Otherwise, occasional large hail (1-1.5 inches in diameter) will be possible in IL this afternoon/evening, and the threat for damaging gusts (60-70 mph) and a couple of tornadoes will persist into IN through early tonight. ...TN/MS/AL this afternoon/evening... Boundary-layer dewpoints will slowly increase to the upper 50s/lower 60s ahead of the surface wind shift moving across AR/LA this afternoon. Forcing for ascent should be sufficient to remove the cap, allowing some deep convection in a broken band this afternoon/evening. Buoyancy will be relatively weak compared to the vertical shear, so it will be difficult to get sustained severe storms and isolated wind damage will be the most probable threat. ..Thompson/Dean.. 03/19/2025 Read more

SPC Mar 19, 2025 1300 UTC Day 1 Convective Outlook

5 months ago
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Wed Mar 19 2025 Valid 191300Z - 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 possible this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...IL/IN this afternoon into early tonight... A deep (989 mb) cyclone near the northeast KS/northwest MO border will move northeastward to northern IL by this evening and Lower MI overnight, in conjunction with a deep midlevel trough and 100+ kt midlevel jet streak. Elevated convection is ongoing this morning in a zone of focused ascent with warm advection/frontogenesis across IA, where isolated large hail may occur with MUCAPE around 500 J/kg and steep midlevel lapse rates/cool midlevel temperatures. The warm sector of the cyclone is characterized by a narrow/modest corridor of returning moisture (low-mid 50s boundary-layer dewpoints) that will overspread MO/IL through the afternoon. Surface heating in cloud breaks, continued moisture advection and relatively cool midlevel temperatures will all contribute to warm sector destabilization (MLCAPE 500-750 J/kg) through the afternoon across IL. Surface-based thunderstorm development will become probable by early-mid afternoon in a broken band along and just ahead of a remnant dryline moving from MO into IL, and storms will subsequently move eastward/northeastward into IN by early tonight before weakening gradually. The deeper buoyancy profiles will be on the cyclonic side of the midlevel jet, where 500 mb temperatures will be < -20 C. Forecast wind profiles suggest supercell potential with long hodographs (effective bulk shear vectors >50 kt), and sufficient low-level hodograph curvature/shear for tornado potential. The primary uncertainty centers of the degree of low-level moistening/destabilization, and the current forecast represents a conditional/reasonable worst case scenario. Otherwise, occasional large hail (1-1.5 inches in diameter) will be possible in IL this afternoon/evening, and the threat for damaging gusts (60-70 mph) and a couple of tornadoes will persist into IN through early tonight. ...TN/MS/AL this afternoon/evening... Boundary-layer dewpoints will slowly increase to the upper 50s/lower 60s ahead of the surface wind shift moving across AR/LA this afternoon. Forcing for ascent should be sufficient to remove the cap, allowing some deep convection in a broken band this afternoon/evening. Buoyancy will be relatively weak compared to the vertical shear, so it will be difficult to get sustained severe storms and isolated wind damage will be the most probable threat. ..Thompson/Dean.. 03/19/2025 Read more

SPC Mar 19, 2025 1300 UTC Day 1 Convective Outlook

5 months ago
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Wed Mar 19 2025 Valid 191300Z - 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 possible this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...IL/IN this afternoon into early tonight... A deep (989 mb) cyclone near the northeast KS/northwest MO border will move northeastward to northern IL by this evening and Lower MI overnight, in conjunction with a deep midlevel trough and 100+ kt midlevel jet streak. Elevated convection is ongoing this morning in a zone of focused ascent with warm advection/frontogenesis across IA, where isolated large hail may occur with MUCAPE around 500 J/kg and steep midlevel lapse rates/cool midlevel temperatures. The warm sector of the cyclone is characterized by a narrow/modest corridor of returning moisture (low-mid 50s boundary-layer dewpoints) that will overspread MO/IL through the afternoon. Surface heating in cloud breaks, continued moisture advection and relatively cool midlevel temperatures will all contribute to warm sector destabilization (MLCAPE 500-750 J/kg) through the afternoon across IL. Surface-based thunderstorm development will become probable by early-mid afternoon in a broken band along and just ahead of a remnant dryline moving from MO into IL, and storms will subsequently move eastward/northeastward into IN by early tonight before weakening gradually. The deeper buoyancy profiles will be on the cyclonic side of the midlevel jet, where 500 mb temperatures will be < -20 C. Forecast wind profiles suggest supercell potential with long hodographs (effective bulk shear vectors >50 kt), and sufficient low-level hodograph curvature/shear for tornado potential. The primary uncertainty centers of the degree of low-level moistening/destabilization, and the current forecast represents a conditional/reasonable worst case scenario. Otherwise, occasional large hail (1-1.5 inches in diameter) will be possible in IL this afternoon/evening, and the threat for damaging gusts (60-70 mph) and a couple of tornadoes will persist into IN through early tonight. ...TN/MS/AL this afternoon/evening... Boundary-layer dewpoints will slowly increase to the upper 50s/lower 60s ahead of the surface wind shift moving across AR/LA this afternoon. Forcing for ascent should be sufficient to remove the cap, allowing some deep convection in a broken band this afternoon/evening. Buoyancy will be relatively weak compared to the vertical shear, so it will be difficult to get sustained severe storms and isolated wind damage will be the most probable threat. ..Thompson/Dean.. 03/19/2025 Read more

SPC Mar 19, 2025 1300 UTC Day 1 Convective Outlook

5 months ago
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 AM CDT Wed Mar 19 2025 Valid 191300Z - 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 possible this afternoon/evening from central/northern Illinois to western Indiana. A few tornadoes, large hail, and damaging wind gusts will be possible. ...IL/IN this afternoon into early tonight... A deep (989 mb) cyclone near the northeast KS/northwest MO border will move northeastward to northern IL by this evening and Lower MI overnight, in conjunction with a deep midlevel trough and 100+ kt midlevel jet streak. Elevated convection is ongoing this morning in a zone of focused ascent with warm advection/frontogenesis across IA, where isolated large hail may occur with MUCAPE around 500 J/kg and steep midlevel lapse rates/cool midlevel temperatures. The warm sector of the cyclone is characterized by a narrow/modest corridor of returning moisture (low-mid 50s boundary-layer dewpoints) that will overspread MO/IL through the afternoon. Surface heating in cloud breaks, continued moisture advection and relatively cool midlevel temperatures will all contribute to warm sector destabilization (MLCAPE 500-750 J/kg) through the afternoon across IL. Surface-based thunderstorm development will become probable by early-mid afternoon in a broken band along and just ahead of a remnant dryline moving from MO into IL, and storms will subsequently move eastward/northeastward into IN by early tonight before weakening gradually. The deeper buoyancy profiles will be on the cyclonic side of the midlevel jet, where 500 mb temperatures will be < -20 C. Forecast wind profiles suggest supercell potential with long hodographs (effective bulk shear vectors >50 kt), and sufficient low-level hodograph curvature/shear for tornado potential. The primary uncertainty centers of the degree of low-level moistening/destabilization, and the current forecast represents a conditional/reasonable worst case scenario. Otherwise, occasional large hail (1-1.5 inches in diameter) will be possible in IL this afternoon/evening, and the threat for damaging gusts (60-70 mph) and a couple of tornadoes will persist into IN through early tonight. ...TN/MS/AL this afternoon/evening... Boundary-layer dewpoints will slowly increase to the upper 50s/lower 60s ahead of the surface wind shift moving across AR/LA this afternoon. Forcing for ascent should be sufficient to remove the cap, allowing some deep convection in a broken band this afternoon/evening. Buoyancy will be relatively weak compared to the vertical shear, so it will be difficult to get sustained severe storms and isolated wind damage will be the most probable threat. ..Thompson/Dean.. 03/19/2025 Read more

SPC MD 240

5 months ago
MD 0240 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF IA INTO EXTREME NORTHWEST IL
Mesoscale Discussion 0240 NWS Storm Prediction Center Norman OK 0437 AM CDT Wed Mar 19 2025 Areas affected...Parts of IA into extreme northwest IL Concerning...Severe potential...Watch unlikely Valid 190937Z - 191130Z Probability of Watch Issuance...5 percent SUMMARY...Isolated hail and strong thunderstorm gusts are possible early this morning. DISCUSSION...An arc of elevated convection has recently intensified from west-central into eastern IA, aided by ascent attendant to a powerful cyclone moving across KS, and within an environment characterized by MUCAPE of around 500 J/kg and cold temperatures aloft. Increasing midlevel flow northeast of the cyclone is supporting effective shear of 30-40 kt, assuming a sufficiently deep updraft. Some transient storm organization will remain possible through the early morning, with a favorable thermodynamic environment for production of small to isolated severe hail, as noted earlier north of Omaha. Localized strong gusts also cannot be ruled out with any more organized and sustained cells. ..Dean/Thompson.. 03/19/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DVN...ARX...DMX...FSD... LAT...LON 42609501 43149325 42999171 41919009 40439084 41449350 41949503 42189528 42609501 Read more

SPC Mar 19, 2025 Day 4-8 Severe Weather Outlook

5 months ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0350 AM CDT Wed Mar 19 2025 Valid 221200Z - 271200Z ...DISCUSSION... ...Saturday/Day 4 to Sunday/Day 5... A mid-level trough will move through the central U.S. on Saturday and Sunday, as moisture advection takes place across the southern Plains, lower Mississippi Valley and Ark-La-Tex. Thunderstorm development will likely take place ahead of the trough on Sunday afternoon and evening, along the northern edge of the moist airmass from the Red River Valley eastward into the lower Mississippi Valley. A threat for large hail and severe wind gusts will be possible within the more organized components of a developing MCS. The MCS is forecast to move southeastward through the lower Mississippi valley during the overnight period. ...Monday/Day 6 to Wednesday/Day 8... On Monday, the trough is forecast to become amplified across the Ohio and Tennessee Valleys, as a cold front moves southward through the Gulf Coast states. Isolated severe storms could occur near the central Gulf Coast early in the day, but the majority of the storms are expected to move offshore into the Gulf. On Tuesday and Wednesday, surface high pressure is forecast to settle over the eastern half of the nation. This dry and cool airmass will make conditions unfavorable for thunderstorms over most of the continental U.S. Read more

SPC Mar 19, 2025 Day 4-8 Severe Weather Outlook

5 months ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0350 AM CDT Wed Mar 19 2025 Valid 221200Z - 271200Z ...DISCUSSION... ...Saturday/Day 4 to Sunday/Day 5... A mid-level trough will move through the central U.S. on Saturday and Sunday, as moisture advection takes place across the southern Plains, lower Mississippi Valley and Ark-La-Tex. Thunderstorm development will likely take place ahead of the trough on Sunday afternoon and evening, along the northern edge of the moist airmass from the Red River Valley eastward into the lower Mississippi Valley. A threat for large hail and severe wind gusts will be possible within the more organized components of a developing MCS. The MCS is forecast to move southeastward through the lower Mississippi valley during the overnight period. ...Monday/Day 6 to Wednesday/Day 8... On Monday, the trough is forecast to become amplified across the Ohio and Tennessee Valleys, as a cold front moves southward through the Gulf Coast states. Isolated severe storms could occur near the central Gulf Coast early in the day, but the majority of the storms are expected to move offshore into the Gulf. On Tuesday and Wednesday, surface high pressure is forecast to settle over the eastern half of the nation. This dry and cool airmass will make conditions unfavorable for thunderstorms over most of the continental U.S. Read more

SPC Mar 19, 2025 Day 4-8 Severe Weather Outlook

5 months ago
Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0350 AM CDT Wed Mar 19 2025 Valid 221200Z - 271200Z ...DISCUSSION... ...Saturday/Day 4 to Sunday/Day 5... A mid-level trough will move through the central U.S. on Saturday and Sunday, as moisture advection takes place across the southern Plains, lower Mississippi Valley and Ark-La-Tex. Thunderstorm development will likely take place ahead of the trough on Sunday afternoon and evening, along the northern edge of the moist airmass from the Red River Valley eastward into the lower Mississippi Valley. A threat for large hail and severe wind gusts will be possible within the more organized components of a developing MCS. The MCS is forecast to move southeastward through the lower Mississippi valley during the overnight period. ...Monday/Day 6 to Wednesday/Day 8... On Monday, the trough is forecast to become amplified across the Ohio and Tennessee Valleys, as a cold front moves southward through the Gulf Coast states. Isolated severe storms could occur near the central Gulf Coast early in the day, but the majority of the storms are expected to move offshore into the Gulf. On Tuesday and Wednesday, surface high pressure is forecast to settle over the eastern half of the nation. This dry and cool airmass will make conditions unfavorable for thunderstorms over most of the continental U.S. Read more