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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Tue Apr 23 2024 Valid 231700Z - 241200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 04/23/2024 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Apr 23 2024/ ...Synopsis... A midlevel trough will advance east-southeastward from the Midwest toward the Northeast through the period, while an upper ridge encompasses much of the West. On the backside of the midlevel trough, a post-frontal air mass will infiltrate the northern and central Plains, where breezy/gusty northerly surface winds are expected. Over portions of southern NE and KS, these winds could briefly overlap 20-30 percent afternoon RH, favoring locally elevated fire-weather conditions -- given receptive fuels across the area. However, these conditions appear too brief and marginal for Elevated highlights at this time. Farther west, dry/breezy conditions are expected across the Southwest during the afternoon. However, fuels are generally not supportive of large fires at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Tue Apr 23 2024 Valid 231700Z - 241200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 04/23/2024 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Apr 23 2024/ ...Synopsis... A midlevel trough will advance east-southeastward from the Midwest toward the Northeast through the period, while an upper ridge encompasses much of the West. On the backside of the midlevel trough, a post-frontal air mass will infiltrate the northern and central Plains, where breezy/gusty northerly surface winds are expected. Over portions of southern NE and KS, these winds could briefly overlap 20-30 percent afternoon RH, favoring locally elevated fire-weather conditions -- given receptive fuels across the area. However, these conditions appear too brief and marginal for Elevated highlights at this time. Farther west, dry/breezy conditions are expected across the Southwest during the afternoon. However, fuels are generally not supportive of large fires at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Tue Apr 23 2024 Valid 231700Z - 241200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 04/23/2024 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Apr 23 2024/ ...Synopsis... A midlevel trough will advance east-southeastward from the Midwest toward the Northeast through the period, while an upper ridge encompasses much of the West. On the backside of the midlevel trough, a post-frontal air mass will infiltrate the northern and central Plains, where breezy/gusty northerly surface winds are expected. Over portions of southern NE and KS, these winds could briefly overlap 20-30 percent afternoon RH, favoring locally elevated fire-weather conditions -- given receptive fuels across the area. However, these conditions appear too brief and marginal for Elevated highlights at this time. Farther west, dry/breezy conditions are expected across the Southwest during the afternoon. However, fuels are generally not supportive of large fires at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Tue Apr 23 2024 Valid 231700Z - 241200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 04/23/2024 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Apr 23 2024/ ...Synopsis... A midlevel trough will advance east-southeastward from the Midwest toward the Northeast through the period, while an upper ridge encompasses much of the West. On the backside of the midlevel trough, a post-frontal air mass will infiltrate the northern and central Plains, where breezy/gusty northerly surface winds are expected. Over portions of southern NE and KS, these winds could briefly overlap 20-30 percent afternoon RH, favoring locally elevated fire-weather conditions -- given receptive fuels across the area. However, these conditions appear too brief and marginal for Elevated highlights at this time. Farther west, dry/breezy conditions are expected across the Southwest during the afternoon. However, fuels are generally not supportive of large fires at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Tue Apr 23 2024 Valid 231700Z - 241200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 04/23/2024 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Apr 23 2024/ ...Synopsis... A midlevel trough will advance east-southeastward from the Midwest toward the Northeast through the period, while an upper ridge encompasses much of the West. On the backside of the midlevel trough, a post-frontal air mass will infiltrate the northern and central Plains, where breezy/gusty northerly surface winds are expected. Over portions of southern NE and KS, these winds could briefly overlap 20-30 percent afternoon RH, favoring locally elevated fire-weather conditions -- given receptive fuels across the area. However, these conditions appear too brief and marginal for Elevated highlights at this time. Farther west, dry/breezy conditions are expected across the Southwest during the afternoon. However, fuels are generally not supportive of large fires at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Tue Apr 23 2024 Valid 231700Z - 241200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 04/23/2024 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Apr 23 2024/ ...Synopsis... A midlevel trough will advance east-southeastward from the Midwest toward the Northeast through the period, while an upper ridge encompasses much of the West. On the backside of the midlevel trough, a post-frontal air mass will infiltrate the northern and central Plains, where breezy/gusty northerly surface winds are expected. Over portions of southern NE and KS, these winds could briefly overlap 20-30 percent afternoon RH, favoring locally elevated fire-weather conditions -- given receptive fuels across the area. However, these conditions appear too brief and marginal for Elevated highlights at this time. Farther west, dry/breezy conditions are expected across the Southwest during the afternoon. However, fuels are generally not supportive of large fires at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Tue Apr 23 2024 Valid 231700Z - 241200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 04/23/2024 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Apr 23 2024/ ...Synopsis... A midlevel trough will advance east-southeastward from the Midwest toward the Northeast through the period, while an upper ridge encompasses much of the West. On the backside of the midlevel trough, a post-frontal air mass will infiltrate the northern and central Plains, where breezy/gusty northerly surface winds are expected. Over portions of southern NE and KS, these winds could briefly overlap 20-30 percent afternoon RH, favoring locally elevated fire-weather conditions -- given receptive fuels across the area. However, these conditions appear too brief and marginal for Elevated highlights at this time. Farther west, dry/breezy conditions are expected across the Southwest during the afternoon. However, fuels are generally not supportive of large fires at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Tue Apr 23 2024 Valid 231700Z - 241200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 04/23/2024 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Apr 23 2024/ ...Synopsis... A midlevel trough will advance east-southeastward from the Midwest toward the Northeast through the period, while an upper ridge encompasses much of the West. On the backside of the midlevel trough, a post-frontal air mass will infiltrate the northern and central Plains, where breezy/gusty northerly surface winds are expected. Over portions of southern NE and KS, these winds could briefly overlap 20-30 percent afternoon RH, favoring locally elevated fire-weather conditions -- given receptive fuels across the area. However, these conditions appear too brief and marginal for Elevated highlights at this time. Farther west, dry/breezy conditions are expected across the Southwest during the afternoon. However, fuels are generally not supportive of large fires at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Tue Apr 23 2024 Valid 231700Z - 241200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 04/23/2024 .PREV DISCUSSION... /ISSUED 0128 AM CDT Tue Apr 23 2024/ ...Synopsis... A midlevel trough will advance east-southeastward from the Midwest toward the Northeast through the period, while an upper ridge encompasses much of the West. On the backside of the midlevel trough, a post-frontal air mass will infiltrate the northern and central Plains, where breezy/gusty northerly surface winds are expected. Over portions of southern NE and KS, these winds could briefly overlap 20-30 percent afternoon RH, favoring locally elevated fire-weather conditions -- given receptive fuels across the area. However, these conditions appear too brief and marginal for Elevated highlights at this time. Farther west, dry/breezy conditions are expected across the Southwest during the afternoon. However, fuels are generally not supportive of large fires at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0726 AM CDT Tue Apr 23 2024 Valid 231300Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON/EVENING ACROSS NORTHWEST TX... ...SUMMARY... Isolated severe thunderstorms capable of producing large hail (2+ inch diameter) and gusts to 65 mph will be possible this afternoon and evening across northwest Texas. Additional strong storms producing hail up to 1 inch diameter and gusts up to 60 mph are possible from southeast Wisconsin and northern Illinois into Lower Michigan. ...Northwest TX area this afternoon/evening... No appreciable changes to the prior outlook. In the wake of a midlevel trough crossing the Great Lakes, a surface cold front will move southward across KS/OK today, eventually stalling by tonight across southeast OK and northwest TX. There will be sufficient cross-Rockies flow aloft for lee cyclogenesis across eastern NM and adjacent west central TX, which will maintain southerly low-level flow and northward advection of a modifying western Gulf air mass into the frontal zone by mid-late afternoon. Strong surface heating along the west edge of the returning moisture will result in a sharpening dryline by late afternoon, with a dryline/front triple point likely just off the Caprock. Isolated thunderstorm development will be most probable near the triple point after 21z, and convection will subsequently move southeastward before weakening by late evening. The storm environment will be characterized by moderate buoyancy (MLCAPE of 1500-2000 J/kg), steep midlevel lapse rates near 9 C/km, and sufficient deep-layer shear for supercells. Isolated very large hail of 2-2.5 inches in diameter will be the main threat, along with a few 55-65 mph outflow gusts. ...Northern IL/southeast WI/Lower MI late this afternoon/evening... Only minor changes to the MRGL risk area in lower MI. A midlevel trough over the upper MS Valley this morning will continue east-southeastward over the Great Lakes by Wednesday morning. An associated surface trough will likewise move southeastward, and this trough will be preceded by a band of rain with minimal buoyancy. Behind the rain band, surface heating with steepening low-level lapse rates and cooling midlevel temperatures will support weak surface-based buoyancy just ahead of a secondary frontal surge. Some low-topped convection will be possible in this zone late this afternoon through late evening from northern IL/southeast WI into lower MI. The storms could pose a marginal hail/wind threat. ..Thompson/Kerr.. 04/23/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0726 AM CDT Tue Apr 23 2024 Valid 231300Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON/EVENING ACROSS NORTHWEST TX... ...SUMMARY... Isolated severe thunderstorms capable of producing large hail (2+ inch diameter) and gusts to 65 mph will be possible this afternoon and evening across northwest Texas. Additional strong storms producing hail up to 1 inch diameter and gusts up to 60 mph are possible from southeast Wisconsin and northern Illinois into Lower Michigan. ...Northwest TX area this afternoon/evening... No appreciable changes to the prior outlook. In the wake of a midlevel trough crossing the Great Lakes, a surface cold front will move southward across KS/OK today, eventually stalling by tonight across southeast OK and northwest TX. There will be sufficient cross-Rockies flow aloft for lee cyclogenesis across eastern NM and adjacent west central TX, which will maintain southerly low-level flow and northward advection of a modifying western Gulf air mass into the frontal zone by mid-late afternoon. Strong surface heating along the west edge of the returning moisture will result in a sharpening dryline by late afternoon, with a dryline/front triple point likely just off the Caprock. Isolated thunderstorm development will be most probable near the triple point after 21z, and convection will subsequently move southeastward before weakening by late evening. The storm environment will be characterized by moderate buoyancy (MLCAPE of 1500-2000 J/kg), steep midlevel lapse rates near 9 C/km, and sufficient deep-layer shear for supercells. Isolated very large hail of 2-2.5 inches in diameter will be the main threat, along with a few 55-65 mph outflow gusts. ...Northern IL/southeast WI/Lower MI late this afternoon/evening... Only minor changes to the MRGL risk area in lower MI. A midlevel trough over the upper MS Valley this morning will continue east-southeastward over the Great Lakes by Wednesday morning. An associated surface trough will likewise move southeastward, and this trough will be preceded by a band of rain with minimal buoyancy. Behind the rain band, surface heating with steepening low-level lapse rates and cooling midlevel temperatures will support weak surface-based buoyancy just ahead of a secondary frontal surge. Some low-topped convection will be possible in this zone late this afternoon through late evening from northern IL/southeast WI into lower MI. The storms could pose a marginal hail/wind threat. ..Thompson/Kerr.. 04/23/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0726 AM CDT Tue Apr 23 2024 Valid 231300Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON/EVENING ACROSS NORTHWEST TX... ...SUMMARY... Isolated severe thunderstorms capable of producing large hail (2+ inch diameter) and gusts to 65 mph will be possible this afternoon and evening across northwest Texas. Additional strong storms producing hail up to 1 inch diameter and gusts up to 60 mph are possible from southeast Wisconsin and northern Illinois into Lower Michigan. ...Northwest TX area this afternoon/evening... No appreciable changes to the prior outlook. In the wake of a midlevel trough crossing the Great Lakes, a surface cold front will move southward across KS/OK today, eventually stalling by tonight across southeast OK and northwest TX. There will be sufficient cross-Rockies flow aloft for lee cyclogenesis across eastern NM and adjacent west central TX, which will maintain southerly low-level flow and northward advection of a modifying western Gulf air mass into the frontal zone by mid-late afternoon. Strong surface heating along the west edge of the returning moisture will result in a sharpening dryline by late afternoon, with a dryline/front triple point likely just off the Caprock. Isolated thunderstorm development will be most probable near the triple point after 21z, and convection will subsequently move southeastward before weakening by late evening. The storm environment will be characterized by moderate buoyancy (MLCAPE of 1500-2000 J/kg), steep midlevel lapse rates near 9 C/km, and sufficient deep-layer shear for supercells. Isolated very large hail of 2-2.5 inches in diameter will be the main threat, along with a few 55-65 mph outflow gusts. ...Northern IL/southeast WI/Lower MI late this afternoon/evening... Only minor changes to the MRGL risk area in lower MI. A midlevel trough over the upper MS Valley this morning will continue east-southeastward over the Great Lakes by Wednesday morning. An associated surface trough will likewise move southeastward, and this trough will be preceded by a band of rain with minimal buoyancy. Behind the rain band, surface heating with steepening low-level lapse rates and cooling midlevel temperatures will support weak surface-based buoyancy just ahead of a secondary frontal surge. Some low-topped convection will be possible in this zone late this afternoon through late evening from northern IL/southeast WI into lower MI. The storms could pose a marginal hail/wind threat. ..Thompson/Kerr.. 04/23/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0726 AM CDT Tue Apr 23 2024 Valid 231300Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON/EVENING ACROSS NORTHWEST TX... ...SUMMARY... Isolated severe thunderstorms capable of producing large hail (2+ inch diameter) and gusts to 65 mph will be possible this afternoon and evening across northwest Texas. Additional strong storms producing hail up to 1 inch diameter and gusts up to 60 mph are possible from southeast Wisconsin and northern Illinois into Lower Michigan. ...Northwest TX area this afternoon/evening... No appreciable changes to the prior outlook. In the wake of a midlevel trough crossing the Great Lakes, a surface cold front will move southward across KS/OK today, eventually stalling by tonight across southeast OK and northwest TX. There will be sufficient cross-Rockies flow aloft for lee cyclogenesis across eastern NM and adjacent west central TX, which will maintain southerly low-level flow and northward advection of a modifying western Gulf air mass into the frontal zone by mid-late afternoon. Strong surface heating along the west edge of the returning moisture will result in a sharpening dryline by late afternoon, with a dryline/front triple point likely just off the Caprock. Isolated thunderstorm development will be most probable near the triple point after 21z, and convection will subsequently move southeastward before weakening by late evening. The storm environment will be characterized by moderate buoyancy (MLCAPE of 1500-2000 J/kg), steep midlevel lapse rates near 9 C/km, and sufficient deep-layer shear for supercells. Isolated very large hail of 2-2.5 inches in diameter will be the main threat, along with a few 55-65 mph outflow gusts. ...Northern IL/southeast WI/Lower MI late this afternoon/evening... Only minor changes to the MRGL risk area in lower MI. A midlevel trough over the upper MS Valley this morning will continue east-southeastward over the Great Lakes by Wednesday morning. An associated surface trough will likewise move southeastward, and this trough will be preceded by a band of rain with minimal buoyancy. Behind the rain band, surface heating with steepening low-level lapse rates and cooling midlevel temperatures will support weak surface-based buoyancy just ahead of a secondary frontal surge. Some low-topped convection will be possible in this zone late this afternoon through late evening from northern IL/southeast WI into lower MI. The storms could pose a marginal hail/wind threat. ..Thompson/Kerr.. 04/23/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Tue Apr 23 2024 Valid 261200Z - 011200Z ...DISCUSSION... A complex but active pattern is expected from D4/Friday through D6/Sunday, as multiple mid/upper-level shortwave troughs impinge upon a moist and unstable environment extending from the southern/central Great Plains into parts of the Midwest and Mississippi Valley. ...D4/Friday - Central/southern Plains into the mid MS Valley... A negatively tilted shortwave trough is forecast to move northeastward from the Great Plains toward the mid/upper MS Valley on Friday. Most guidance suggests that convection developing late in the D3/Thursday period will be ongoing Friday morning, potentially posing an organized severe threat as it moves eastward. The influence of early convection on warm sector evolution by Friday afternoon/evening remains uncertain, but in general, moderate destabilization will be possible along the Pacific front/dryline in the wake of early convection, with some intensification of early storms also possible farther east. Details regarding storm mode remain uncertain at this forecast range, but in general, severe storms capable of producing large hail, damaging winds, and a few tornadoes will be possible across a broad region from the eastern Great Plains into the mid MS Valley. ...D5/Saturday - Central/southern Plains into the Midwest/mid MS Valley... The negatively tilted shortwave trough and attendant occluding surface cyclone are forecast to gradually weaken as they move across the upper Great Lakes region on Saturday. Depending on timing of the departing cyclone and magnitude of diurnal destabilization, some severe-thunderstorm threat could evolve in advance of this system through the afternoon across parts of WI/IL into MI, but confidence remains too low to include 15% probabilities for this area. Meanwhile, another strong shortwave trough is forecast to eject across parts of the central/southern Plains Saturday afternoon and evening, accompanied by strong surface cyclogenesis across the central High Plains. Moderate to locally strong instability may redevelop along/east of the dryline across central/western KS/OK into north TX, as low-level and deep-layer shear strengthen through the day. The synoptic pattern depicted by much of the extended-range guidance is suggestive of an active severe thunderstorm episode along/ahead of the dryline, though some guidance (notably recent runs of the ECMWF) suggest potential for early development across parts of OK/north TX, which could complicate the scenario by late afternoon/evening. Some severe threat could spread toward parts of the mid MS Valley late in the period. ...D6/Sunday - ArkLaTex into parts of the Midwest... Predictability begins to decrease by late in the weekend, though in general, a mid/upper-level trough and attendant surface low are forecast to move from the central Plains toward the upper Great Lakes region. A corridor of severe thunderstorm potential is forecast to extend south-southwestward from the surface low, as a trailing cold front moves through a moist, unstable, and favorably sheared environment. A 15% area has been added where confidence is currently greatest in severe-thunderstorm potential Sunday afternoon and evening. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Tue Apr 23 2024 Valid 261200Z - 011200Z ...DISCUSSION... A complex but active pattern is expected from D4/Friday through D6/Sunday, as multiple mid/upper-level shortwave troughs impinge upon a moist and unstable environment extending from the southern/central Great Plains into parts of the Midwest and Mississippi Valley. ...D4/Friday - Central/southern Plains into the mid MS Valley... A negatively tilted shortwave trough is forecast to move northeastward from the Great Plains toward the mid/upper MS Valley on Friday. Most guidance suggests that convection developing late in the D3/Thursday period will be ongoing Friday morning, potentially posing an organized severe threat as it moves eastward. The influence of early convection on warm sector evolution by Friday afternoon/evening remains uncertain, but in general, moderate destabilization will be possible along the Pacific front/dryline in the wake of early convection, with some intensification of early storms also possible farther east. Details regarding storm mode remain uncertain at this forecast range, but in general, severe storms capable of producing large hail, damaging winds, and a few tornadoes will be possible across a broad region from the eastern Great Plains into the mid MS Valley. ...D5/Saturday - Central/southern Plains into the Midwest/mid MS Valley... The negatively tilted shortwave trough and attendant occluding surface cyclone are forecast to gradually weaken as they move across the upper Great Lakes region on Saturday. Depending on timing of the departing cyclone and magnitude of diurnal destabilization, some severe-thunderstorm threat could evolve in advance of this system through the afternoon across parts of WI/IL into MI, but confidence remains too low to include 15% probabilities for this area. Meanwhile, another strong shortwave trough is forecast to eject across parts of the central/southern Plains Saturday afternoon and evening, accompanied by strong surface cyclogenesis across the central High Plains. Moderate to locally strong instability may redevelop along/east of the dryline across central/western KS/OK into north TX, as low-level and deep-layer shear strengthen through the day. The synoptic pattern depicted by much of the extended-range guidance is suggestive of an active severe thunderstorm episode along/ahead of the dryline, though some guidance (notably recent runs of the ECMWF) suggest potential for early development across parts of OK/north TX, which could complicate the scenario by late afternoon/evening. Some severe threat could spread toward parts of the mid MS Valley late in the period. ...D6/Sunday - ArkLaTex into parts of the Midwest... Predictability begins to decrease by late in the weekend, though in general, a mid/upper-level trough and attendant surface low are forecast to move from the central Plains toward the upper Great Lakes region. A corridor of severe thunderstorm potential is forecast to extend south-southwestward from the surface low, as a trailing cold front moves through a moist, unstable, and favorably sheared environment. A 15% area has been added where confidence is currently greatest in severe-thunderstorm potential Sunday afternoon and evening. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Tue Apr 23 2024 Valid 261200Z - 011200Z ...DISCUSSION... A complex but active pattern is expected from D4/Friday through D6/Sunday, as multiple mid/upper-level shortwave troughs impinge upon a moist and unstable environment extending from the southern/central Great Plains into parts of the Midwest and Mississippi Valley. ...D4/Friday - Central/southern Plains into the mid MS Valley... A negatively tilted shortwave trough is forecast to move northeastward from the Great Plains toward the mid/upper MS Valley on Friday. Most guidance suggests that convection developing late in the D3/Thursday period will be ongoing Friday morning, potentially posing an organized severe threat as it moves eastward. The influence of early convection on warm sector evolution by Friday afternoon/evening remains uncertain, but in general, moderate destabilization will be possible along the Pacific front/dryline in the wake of early convection, with some intensification of early storms also possible farther east. Details regarding storm mode remain uncertain at this forecast range, but in general, severe storms capable of producing large hail, damaging winds, and a few tornadoes will be possible across a broad region from the eastern Great Plains into the mid MS Valley. ...D5/Saturday - Central/southern Plains into the Midwest/mid MS Valley... The negatively tilted shortwave trough and attendant occluding surface cyclone are forecast to gradually weaken as they move across the upper Great Lakes region on Saturday. Depending on timing of the departing cyclone and magnitude of diurnal destabilization, some severe-thunderstorm threat could evolve in advance of this system through the afternoon across parts of WI/IL into MI, but confidence remains too low to include 15% probabilities for this area. Meanwhile, another strong shortwave trough is forecast to eject across parts of the central/southern Plains Saturday afternoon and evening, accompanied by strong surface cyclogenesis across the central High Plains. Moderate to locally strong instability may redevelop along/east of the dryline across central/western KS/OK into north TX, as low-level and deep-layer shear strengthen through the day. The synoptic pattern depicted by much of the extended-range guidance is suggestive of an active severe thunderstorm episode along/ahead of the dryline, though some guidance (notably recent runs of the ECMWF) suggest potential for early development across parts of OK/north TX, which could complicate the scenario by late afternoon/evening. Some severe threat could spread toward parts of the mid MS Valley late in the period. ...D6/Sunday - ArkLaTex into parts of the Midwest... Predictability begins to decrease by late in the weekend, though in general, a mid/upper-level trough and attendant surface low are forecast to move from the central Plains toward the upper Great Lakes region. A corridor of severe thunderstorm potential is forecast to extend south-southwestward from the surface low, as a trailing cold front moves through a moist, unstable, and favorably sheared environment. A 15% area has been added where confidence is currently greatest in severe-thunderstorm potential Sunday afternoon and evening. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Tue Apr 23 2024 Valid 261200Z - 011200Z ...DISCUSSION... A complex but active pattern is expected from D4/Friday through D6/Sunday, as multiple mid/upper-level shortwave troughs impinge upon a moist and unstable environment extending from the southern/central Great Plains into parts of the Midwest and Mississippi Valley. ...D4/Friday - Central/southern Plains into the mid MS Valley... A negatively tilted shortwave trough is forecast to move northeastward from the Great Plains toward the mid/upper MS Valley on Friday. Most guidance suggests that convection developing late in the D3/Thursday period will be ongoing Friday morning, potentially posing an organized severe threat as it moves eastward. The influence of early convection on warm sector evolution by Friday afternoon/evening remains uncertain, but in general, moderate destabilization will be possible along the Pacific front/dryline in the wake of early convection, with some intensification of early storms also possible farther east. Details regarding storm mode remain uncertain at this forecast range, but in general, severe storms capable of producing large hail, damaging winds, and a few tornadoes will be possible across a broad region from the eastern Great Plains into the mid MS Valley. ...D5/Saturday - Central/southern Plains into the Midwest/mid MS Valley... The negatively tilted shortwave trough and attendant occluding surface cyclone are forecast to gradually weaken as they move across the upper Great Lakes region on Saturday. Depending on timing of the departing cyclone and magnitude of diurnal destabilization, some severe-thunderstorm threat could evolve in advance of this system through the afternoon across parts of WI/IL into MI, but confidence remains too low to include 15% probabilities for this area. Meanwhile, another strong shortwave trough is forecast to eject across parts of the central/southern Plains Saturday afternoon and evening, accompanied by strong surface cyclogenesis across the central High Plains. Moderate to locally strong instability may redevelop along/east of the dryline across central/western KS/OK into north TX, as low-level and deep-layer shear strengthen through the day. The synoptic pattern depicted by much of the extended-range guidance is suggestive of an active severe thunderstorm episode along/ahead of the dryline, though some guidance (notably recent runs of the ECMWF) suggest potential for early development across parts of OK/north TX, which could complicate the scenario by late afternoon/evening. Some severe threat could spread toward parts of the mid MS Valley late in the period. ...D6/Sunday - ArkLaTex into parts of the Midwest... Predictability begins to decrease by late in the weekend, though in general, a mid/upper-level trough and attendant surface low are forecast to move from the central Plains toward the upper Great Lakes region. A corridor of severe thunderstorm potential is forecast to extend south-southwestward from the surface low, as a trailing cold front moves through a moist, unstable, and favorably sheared environment. A 15% area has been added where confidence is currently greatest in severe-thunderstorm potential Sunday afternoon and evening. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CDT Tue Apr 23 2024 Valid 261200Z - 011200Z ...DISCUSSION... A complex but active pattern is expected from D4/Friday through D6/Sunday, as multiple mid/upper-level shortwave troughs impinge upon a moist and unstable environment extending from the southern/central Great Plains into parts of the Midwest and Mississippi Valley. ...D4/Friday - Central/southern Plains into the mid MS Valley... A negatively tilted shortwave trough is forecast to move northeastward from the Great Plains toward the mid/upper MS Valley on Friday. Most guidance suggests that convection developing late in the D3/Thursday period will be ongoing Friday morning, potentially posing an organized severe threat as it moves eastward. The influence of early convection on warm sector evolution by Friday afternoon/evening remains uncertain, but in general, moderate destabilization will be possible along the Pacific front/dryline in the wake of early convection, with some intensification of early storms also possible farther east. Details regarding storm mode remain uncertain at this forecast range, but in general, severe storms capable of producing large hail, damaging winds, and a few tornadoes will be possible across a broad region from the eastern Great Plains into the mid MS Valley. ...D5/Saturday - Central/southern Plains into the Midwest/mid MS Valley... The negatively tilted shortwave trough and attendant occluding surface cyclone are forecast to gradually weaken as they move across the upper Great Lakes region on Saturday. Depending on timing of the departing cyclone and magnitude of diurnal destabilization, some severe-thunderstorm threat could evolve in advance of this system through the afternoon across parts of WI/IL into MI, but confidence remains too low to include 15% probabilities for this area. Meanwhile, another strong shortwave trough is forecast to eject across parts of the central/southern Plains Saturday afternoon and evening, accompanied by strong surface cyclogenesis across the central High Plains. Moderate to locally strong instability may redevelop along/east of the dryline across central/western KS/OK into north TX, as low-level and deep-layer shear strengthen through the day. The synoptic pattern depicted by much of the extended-range guidance is suggestive of an active severe thunderstorm episode along/ahead of the dryline, though some guidance (notably recent runs of the ECMWF) suggest potential for early development across parts of OK/north TX, which could complicate the scenario by late afternoon/evening. Some severe threat could spread toward parts of the mid MS Valley late in the period. ...D6/Sunday - ArkLaTex into parts of the Midwest... Predictability begins to decrease by late in the weekend, though in general, a mid/upper-level trough and attendant surface low are forecast to move from the central Plains toward the upper Great Lakes region. A corridor of severe thunderstorm potential is forecast to extend south-southwestward from the surface low, as a trailing cold front moves through a moist, unstable, and favorably sheared environment. A 15% area has been added where confidence is currently greatest in severe-thunderstorm potential Sunday afternoon and evening. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Tue Apr 23 2024 Valid 251200Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTHERN AND CENTRAL GREAT PLAINS... ...SUMMARY... Severe thunderstorms may develop late Thursday afternoon into Thursday night across parts of the central and southern Great Plains. Large hail, severe wind gusts, and a few tornadoes will all be possible. ...Synopsis... A shortwave trough initially over the Southwest is forecast to take on an increasingly negative tilt as it moves eastward towards the central/southern Plains by Thursday night into Friday morning. In response, a surface low will consolidate and deepen across the central High Plains through the day, before moving northeastward toward northwest KS/southwest NE by Friday morning. An initially stationary surface boundary will move northward as a warm front across the central Plains through the day. Along/south of the warm front, relatively rich low-level moisture will stream northward to the east of a dryline that will become established from the eastern TX Panhandle into western KS and eastern CO. ...Southern/central Great Plains... Coverage of the severe-thunderstorm threat remains somewhat uncertain, but a couple intense supercells are possible by Thursday evening near the dryline from western KS into western OK and the TX/OK Panhandles. Another round of overnight convection will potentially bring the severe threat eastward into a larger portion of the central/southern Plains. The warm sector of the deepening cyclone will likely remain capped for much of the day, though elevated convection may persist from parts of central/eastern KS into eastern OK, to the north of the effective warm front. Increasing moisture beneath steep midlevel lapse rates will support MLCAPE in excess of 2000 J/kg along/east of the dryline, as deep-layer shear strengthens across the region through the day. Ascent attendant to the approaching shortwave trough will begin to impinge upon the warm sector by late afternoon, with isolated supercell development possible near the surface low across southwest KS and southward down the dryline into the TX Panhandle. Very large hail (potentially 2-3 inches in diameter) will likely be the primary initial hazard. A notable increase in low-level flow/shear near and after 00Z will also support a tornado threat with any supercells that can persist into the evening across parts of western KS/OK. While any initial dryline storms may weaken by mid/late evening due to increasing MLCINH with eastward extent, renewed storm development is possible overnight along the Pacific cold front from southwest TX into western/central KS/OK as stronger large-scale ascent overspreads the region. Steep midlevel lapse rates, moderate buoyancy, and strong low-level and deep-layer shear will conditionally support a severe threat with overnight convection across the warm sector, though storm mode may become complex and tend toward a linear evolution with time. Severe wind gusts may become an increasing threat with the nocturnal convection, though hail and a couple tornadoes will also be possible if semi-discrete or embedded supercells can be maintained. ...NE/WY border region into northeast CO... Low-level southeasterly flow will support modest moisture return into parts of northeast CO, southeast WY, and western NE, to the north of the deepening cyclone. Thunderstorm development will be possible near and to the cool side of the effective warm front during the afternoon. While deep-layer shear will be weaker compared to areas farther southeast, steep midlevel lapse rates will support an isolated hail threat. A tornado also cannot be ruled out, if surface-based storms can be maintained within this regime. ..Dean.. 04/23/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Tue Apr 23 2024 Valid 251200Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTHERN AND CENTRAL GREAT PLAINS... ...SUMMARY... Severe thunderstorms may develop late Thursday afternoon into Thursday night across parts of the central and southern Great Plains. Large hail, severe wind gusts, and a few tornadoes will all be possible. ...Synopsis... A shortwave trough initially over the Southwest is forecast to take on an increasingly negative tilt as it moves eastward towards the central/southern Plains by Thursday night into Friday morning. In response, a surface low will consolidate and deepen across the central High Plains through the day, before moving northeastward toward northwest KS/southwest NE by Friday morning. An initially stationary surface boundary will move northward as a warm front across the central Plains through the day. Along/south of the warm front, relatively rich low-level moisture will stream northward to the east of a dryline that will become established from the eastern TX Panhandle into western KS and eastern CO. ...Southern/central Great Plains... Coverage of the severe-thunderstorm threat remains somewhat uncertain, but a couple intense supercells are possible by Thursday evening near the dryline from western KS into western OK and the TX/OK Panhandles. Another round of overnight convection will potentially bring the severe threat eastward into a larger portion of the central/southern Plains. The warm sector of the deepening cyclone will likely remain capped for much of the day, though elevated convection may persist from parts of central/eastern KS into eastern OK, to the north of the effective warm front. Increasing moisture beneath steep midlevel lapse rates will support MLCAPE in excess of 2000 J/kg along/east of the dryline, as deep-layer shear strengthens across the region through the day. Ascent attendant to the approaching shortwave trough will begin to impinge upon the warm sector by late afternoon, with isolated supercell development possible near the surface low across southwest KS and southward down the dryline into the TX Panhandle. Very large hail (potentially 2-3 inches in diameter) will likely be the primary initial hazard. A notable increase in low-level flow/shear near and after 00Z will also support a tornado threat with any supercells that can persist into the evening across parts of western KS/OK. While any initial dryline storms may weaken by mid/late evening due to increasing MLCINH with eastward extent, renewed storm development is possible overnight along the Pacific cold front from southwest TX into western/central KS/OK as stronger large-scale ascent overspreads the region. Steep midlevel lapse rates, moderate buoyancy, and strong low-level and deep-layer shear will conditionally support a severe threat with overnight convection across the warm sector, though storm mode may become complex and tend toward a linear evolution with time. Severe wind gusts may become an increasing threat with the nocturnal convection, though hail and a couple tornadoes will also be possible if semi-discrete or embedded supercells can be maintained. ...NE/WY border region into northeast CO... Low-level southeasterly flow will support modest moisture return into parts of northeast CO, southeast WY, and western NE, to the north of the deepening cyclone. Thunderstorm development will be possible near and to the cool side of the effective warm front during the afternoon. While deep-layer shear will be weaker compared to areas farther southeast, steep midlevel lapse rates will support an isolated hail threat. A tornado also cannot be ruled out, if surface-based storms can be maintained within this regime. ..Dean.. 04/23/2024 Read more