Storm Prediction Center

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0334 PM CST Sat Dec 27 2025 Valid 291200Z - 041200Z The mid-level ridge across the central United States will finally be suppressed to the south by the start of this forecast period as a strong cyclone evolves across the Great Lakes. This strong cyclone will drive a cold front southward into the Gulf of America and through the Southeast, ushering in a cold, dry continental airmass across much of the eastern US. Despite the cooler airmass, elevated to locally critical fire weather conditions may develop across portions of the Southern Plains on Monday (D3) and Tuesday (D4). On Monday the dry airmass will be fully entrenched across the Plains as a strong surface anticyclone takes hold from the Northern Plains into the Southern Plains. The result will be minimum afternoon relative humidity will be lower than on Sunday, falling into the teens and twenty percent range. Winds, however, will be considerably weaker than on Sunday, with maximum gusts likely in the 10-20 mph range. The result will be elevated to locally critical fire conditions for at least a couple of hours during the afternoon. On Tuesday the center of the surface anticyclone will slide east of the Plains resulting in winds turning to the west and southwest. This will set the stage for a potential dry return flow regime across western Oklahoma. Minimum relative humidity will once again be in the teens in the presence of potentially gusty afternoon winds. This may once again result in elevated to locally critical fire weather concerns. Through the rest of the forecast period, the large-scale pattern across the CONUS will consist of a northwest flow regime owing to a western ridge and eastern trough. The northwest flow pattern will limit appreciable moisture return into the eastern US, such that any embedded disturbance within the larger-scale flow pattern could result in elevated fire weather concerns. However, the subtlety of any of these features is such that the timing of any such feature is below the scale of predictability at these time ranges. ..Marsh.. 12/27/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Sat Dec 27 2025 Valid 272000Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...20z Update... The previous forecast remains on track with no changes required. Latest high-res guidance continues to show limited thunderstorm potential until around/after 06z tonight across portions of northeast KS into northern MO and western IL. See the previous discussion below for additional details. ..Moore.. 12/27/2025 .PREV DISCUSSION... /ISSUED 1016 AM CST Sat Dec 27 2025/ ...Synopsis and Discussion... A large-scale upper trough with multiple embedded perturbations will move eastward from the western CONUS across much of the Plains through the period. While cold mid-level temperatures will accompany this upper trough, meager low-level moisture and cool surface temperatures should generally limit instability and the potential for lightning with any convective showers that can develop this afternoon across the Great Basin/Rockies. Low-level moisture will gradually return northward through tonight across the lower/mid MS Valley and lower OH Valley ahead of a strong cold front and deepening surface low over the central Plains and mid MO Valley. Increasing warm/moist advection associated with a low-level jet should eventually support weak MUCAPE and isolated thunderstorm potential across parts of eastern KS into MO and central IL late tonight/early Sunday morning. With MUCAPE forecast to remain generally less than 750 J/kg, the potential for severe hail with elevated convection appears low even though deep-layer shear will be strong. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Sat Dec 27 2025 Valid 272000Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...20z Update... The previous forecast remains on track with no changes required. Latest high-res guidance continues to show limited thunderstorm potential until around/after 06z tonight across portions of northeast KS into northern MO and western IL. See the previous discussion below for additional details. ..Moore.. 12/27/2025 .PREV DISCUSSION... /ISSUED 1016 AM CST Sat Dec 27 2025/ ...Synopsis and Discussion... A large-scale upper trough with multiple embedded perturbations will move eastward from the western CONUS across much of the Plains through the period. While cold mid-level temperatures will accompany this upper trough, meager low-level moisture and cool surface temperatures should generally limit instability and the potential for lightning with any convective showers that can develop this afternoon across the Great Basin/Rockies. Low-level moisture will gradually return northward through tonight across the lower/mid MS Valley and lower OH Valley ahead of a strong cold front and deepening surface low over the central Plains and mid MO Valley. Increasing warm/moist advection associated with a low-level jet should eventually support weak MUCAPE and isolated thunderstorm potential across parts of eastern KS into MO and central IL late tonight/early Sunday morning. With MUCAPE forecast to remain generally less than 750 J/kg, the potential for severe hail with elevated convection appears low even though deep-layer shear will be strong. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Sat Dec 27 2025 Valid 272000Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...20z Update... The previous forecast remains on track with no changes required. Latest high-res guidance continues to show limited thunderstorm potential until around/after 06z tonight across portions of northeast KS into northern MO and western IL. See the previous discussion below for additional details. ..Moore.. 12/27/2025 .PREV DISCUSSION... /ISSUED 1016 AM CST Sat Dec 27 2025/ ...Synopsis and Discussion... A large-scale upper trough with multiple embedded perturbations will move eastward from the western CONUS across much of the Plains through the period. While cold mid-level temperatures will accompany this upper trough, meager low-level moisture and cool surface temperatures should generally limit instability and the potential for lightning with any convective showers that can develop this afternoon across the Great Basin/Rockies. Low-level moisture will gradually return northward through tonight across the lower/mid MS Valley and lower OH Valley ahead of a strong cold front and deepening surface low over the central Plains and mid MO Valley. Increasing warm/moist advection associated with a low-level jet should eventually support weak MUCAPE and isolated thunderstorm potential across parts of eastern KS into MO and central IL late tonight/early Sunday morning. With MUCAPE forecast to remain generally less than 750 J/kg, the potential for severe hail with elevated convection appears low even though deep-layer shear will be strong. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Sat Dec 27 2025 Valid 272000Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...20z Update... The previous forecast remains on track with no changes required. Latest high-res guidance continues to show limited thunderstorm potential until around/after 06z tonight across portions of northeast KS into northern MO and western IL. See the previous discussion below for additional details. ..Moore.. 12/27/2025 .PREV DISCUSSION... /ISSUED 1016 AM CST Sat Dec 27 2025/ ...Synopsis and Discussion... A large-scale upper trough with multiple embedded perturbations will move eastward from the western CONUS across much of the Plains through the period. While cold mid-level temperatures will accompany this upper trough, meager low-level moisture and cool surface temperatures should generally limit instability and the potential for lightning with any convective showers that can develop this afternoon across the Great Basin/Rockies. Low-level moisture will gradually return northward through tonight across the lower/mid MS Valley and lower OH Valley ahead of a strong cold front and deepening surface low over the central Plains and mid MO Valley. Increasing warm/moist advection associated with a low-level jet should eventually support weak MUCAPE and isolated thunderstorm potential across parts of eastern KS into MO and central IL late tonight/early Sunday morning. With MUCAPE forecast to remain generally less than 750 J/kg, the potential for severe hail with elevated convection appears low even though deep-layer shear will be strong. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0119 PM CST Sat Dec 27 2025 Valid 291200Z - 301200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. Monday through Monday night. ...Discussion... Models indicate that large-scale mid-level ridging will be maintained across British Columbia and the Pacific Northwest into portions of the Canadian Prairies and U.S. Great Plains Monday through Monday night, but with little further amplification. At the same time, some further amplification of large-scale downstream troughing may continue, as a surface cold intrusion noses through the northwestern Gulf Basin. However, the primary embedded short wave perturbation and associated lower/mid-tropospheric cyclone are generally forecast to progress northeast and east of the lower Great Lakes region, toward the Canadian Maritimes. In the wake of a secondary developing surface low, across parts of northern New England into the lower St. Lawrence Valley, the leading edge of the cold air is forecast to rapidly spread east/southeast of the Appalachians and well offshore of much of the Atlantic Seaboard by late Monday night. Along this frontal zone, models do indicate the lingering presence of weak, elevated instability across parts of Deep South Texas, the northeastern Gulf coast vicinity, and the northern Mid Atlantic into New England early through midday Monday. However, the extent to which forcing for ascent remains supportive of convection capable of producing lightning remains unclear, and thunderstorm probabilities will be maintained at less than 10 percent. ..Kerr.. 12/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0119 PM CST Sat Dec 27 2025 Valid 291200Z - 301200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. Monday through Monday night. ...Discussion... Models indicate that large-scale mid-level ridging will be maintained across British Columbia and the Pacific Northwest into portions of the Canadian Prairies and U.S. Great Plains Monday through Monday night, but with little further amplification. At the same time, some further amplification of large-scale downstream troughing may continue, as a surface cold intrusion noses through the northwestern Gulf Basin. However, the primary embedded short wave perturbation and associated lower/mid-tropospheric cyclone are generally forecast to progress northeast and east of the lower Great Lakes region, toward the Canadian Maritimes. In the wake of a secondary developing surface low, across parts of northern New England into the lower St. Lawrence Valley, the leading edge of the cold air is forecast to rapidly spread east/southeast of the Appalachians and well offshore of much of the Atlantic Seaboard by late Monday night. Along this frontal zone, models do indicate the lingering presence of weak, elevated instability across parts of Deep South Texas, the northeastern Gulf coast vicinity, and the northern Mid Atlantic into New England early through midday Monday. However, the extent to which forcing for ascent remains supportive of convection capable of producing lightning remains unclear, and thunderstorm probabilities will be maintained at less than 10 percent. ..Kerr.. 12/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0119 PM CST Sat Dec 27 2025 Valid 291200Z - 301200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. Monday through Monday night. ...Discussion... Models indicate that large-scale mid-level ridging will be maintained across British Columbia and the Pacific Northwest into portions of the Canadian Prairies and U.S. Great Plains Monday through Monday night, but with little further amplification. At the same time, some further amplification of large-scale downstream troughing may continue, as a surface cold intrusion noses through the northwestern Gulf Basin. However, the primary embedded short wave perturbation and associated lower/mid-tropospheric cyclone are generally forecast to progress northeast and east of the lower Great Lakes region, toward the Canadian Maritimes. In the wake of a secondary developing surface low, across parts of northern New England into the lower St. Lawrence Valley, the leading edge of the cold air is forecast to rapidly spread east/southeast of the Appalachians and well offshore of much of the Atlantic Seaboard by late Monday night. Along this frontal zone, models do indicate the lingering presence of weak, elevated instability across parts of Deep South Texas, the northeastern Gulf coast vicinity, and the northern Mid Atlantic into New England early through midday Monday. However, the extent to which forcing for ascent remains supportive of convection capable of producing lightning remains unclear, and thunderstorm probabilities will be maintained at less than 10 percent. ..Kerr.. 12/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0119 PM CST Sat Dec 27 2025 Valid 291200Z - 301200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. Monday through Monday night. ...Discussion... Models indicate that large-scale mid-level ridging will be maintained across British Columbia and the Pacific Northwest into portions of the Canadian Prairies and U.S. Great Plains Monday through Monday night, but with little further amplification. At the same time, some further amplification of large-scale downstream troughing may continue, as a surface cold intrusion noses through the northwestern Gulf Basin. However, the primary embedded short wave perturbation and associated lower/mid-tropospheric cyclone are generally forecast to progress northeast and east of the lower Great Lakes region, toward the Canadian Maritimes. In the wake of a secondary developing surface low, across parts of northern New England into the lower St. Lawrence Valley, the leading edge of the cold air is forecast to rapidly spread east/southeast of the Appalachians and well offshore of much of the Atlantic Seaboard by late Monday night. Along this frontal zone, models do indicate the lingering presence of weak, elevated instability across parts of Deep South Texas, the northeastern Gulf coast vicinity, and the northern Mid Atlantic into New England early through midday Monday. However, the extent to which forcing for ascent remains supportive of convection capable of producing lightning remains unclear, and thunderstorm probabilities will be maintained at less than 10 percent. ..Kerr.. 12/27/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0100 PM CST Sat Dec 27 2025 Valid 281200Z - 291200Z A strong surface cold front will rapidly move across the Southern Plains on Sunday, ushering in a much dryer and colder airmass. Westerly winds ahead of the front may support locally elevated fire weather conditions during the late morning or early afternoon across the region. In the wake of the front, strong/gusty northerly winds between 20 and 30 mph (with gusts approaching 50 mph) will usher in the aforementioned very dry continental airmass. Although the post-frontal airmass will be colder than the pre-frontal airmass, pockets of sunshine may slow the rate at which temperatures fall during the afternoon. Thus, despite the cooler post-frontal airmass, relative humidity should continue to fall during the afternoon as the dryer air takes hold. Given the ability of the Southern Plains fire environment to overproduce the past few days, especially across portions of the Texas Panhandle, have opted to go ahead and expand the elevated risk area from West Texas north and east into the southeast part of the Texas Panhandle and most of western and central Oklahoma. The expectation is that relative humidity will be lower than currently forecast and the very strong, gusty northerly post-frontal winds will be sufficient to offset the slightly higher relative humidity. ..Marsh.. 12/27/2025 .PREV DISCUSSION... /ISSUED 1128 PM CST Fri Dec 26 2025/ ...Synopsis... An upper-level trough over the central/northern High Plains will shift east into the Great Lakes and Ohio Valley region throughout the day. At the surface, an area of low pressure will track from the central Great Plains to the Great Lakes region. In its wake, a cold front will sweep across much of the central CONUS, replacing near record warmth with more seasonal temperatures. Model guidance suggests there could be a window of up to a few hours supporting Elevated fire-weather conditions associated with the pre/post cold front passage, mainly across portions of the southern High Plains. Pre-frontal residual dry air and diurnally driven winds should be present ahead of the front by early afternoon. Then, temperatures should remain above the minimum thresholds behind the front for another 2-3 hours amid gusty northwest winds despite rising RH values. Therefore, Elevated highlights have been introduced for a small portion of West Texas and far southeast New Mexico, confined to areas where fuels appear most receptive. The frontal passage may at least temporarily exacerbate any ongoing fires across the region as well. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0100 PM CST Sat Dec 27 2025 Valid 281200Z - 291200Z A strong surface cold front will rapidly move across the Southern Plains on Sunday, ushering in a much dryer and colder airmass. Westerly winds ahead of the front may support locally elevated fire weather conditions during the late morning or early afternoon across the region. In the wake of the front, strong/gusty northerly winds between 20 and 30 mph (with gusts approaching 50 mph) will usher in the aforementioned very dry continental airmass. Although the post-frontal airmass will be colder than the pre-frontal airmass, pockets of sunshine may slow the rate at which temperatures fall during the afternoon. Thus, despite the cooler post-frontal airmass, relative humidity should continue to fall during the afternoon as the dryer air takes hold. Given the ability of the Southern Plains fire environment to overproduce the past few days, especially across portions of the Texas Panhandle, have opted to go ahead and expand the elevated risk area from West Texas north and east into the southeast part of the Texas Panhandle and most of western and central Oklahoma. The expectation is that relative humidity will be lower than currently forecast and the very strong, gusty northerly post-frontal winds will be sufficient to offset the slightly higher relative humidity. ..Marsh.. 12/27/2025 .PREV DISCUSSION... /ISSUED 1128 PM CST Fri Dec 26 2025/ ...Synopsis... An upper-level trough over the central/northern High Plains will shift east into the Great Lakes and Ohio Valley region throughout the day. At the surface, an area of low pressure will track from the central Great Plains to the Great Lakes region. In its wake, a cold front will sweep across much of the central CONUS, replacing near record warmth with more seasonal temperatures. Model guidance suggests there could be a window of up to a few hours supporting Elevated fire-weather conditions associated with the pre/post cold front passage, mainly across portions of the southern High Plains. Pre-frontal residual dry air and diurnally driven winds should be present ahead of the front by early afternoon. Then, temperatures should remain above the minimum thresholds behind the front for another 2-3 hours amid gusty northwest winds despite rising RH values. Therefore, Elevated highlights have been introduced for a small portion of West Texas and far southeast New Mexico, confined to areas where fuels appear most receptive. The frontal passage may at least temporarily exacerbate any ongoing fires across the region as well. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0100 PM CST Sat Dec 27 2025 Valid 281200Z - 291200Z A strong surface cold front will rapidly move across the Southern Plains on Sunday, ushering in a much dryer and colder airmass. Westerly winds ahead of the front may support locally elevated fire weather conditions during the late morning or early afternoon across the region. In the wake of the front, strong/gusty northerly winds between 20 and 30 mph (with gusts approaching 50 mph) will usher in the aforementioned very dry continental airmass. Although the post-frontal airmass will be colder than the pre-frontal airmass, pockets of sunshine may slow the rate at which temperatures fall during the afternoon. Thus, despite the cooler post-frontal airmass, relative humidity should continue to fall during the afternoon as the dryer air takes hold. Given the ability of the Southern Plains fire environment to overproduce the past few days, especially across portions of the Texas Panhandle, have opted to go ahead and expand the elevated risk area from West Texas north and east into the southeast part of the Texas Panhandle and most of western and central Oklahoma. The expectation is that relative humidity will be lower than currently forecast and the very strong, gusty northerly post-frontal winds will be sufficient to offset the slightly higher relative humidity. ..Marsh.. 12/27/2025 .PREV DISCUSSION... /ISSUED 1128 PM CST Fri Dec 26 2025/ ...Synopsis... An upper-level trough over the central/northern High Plains will shift east into the Great Lakes and Ohio Valley region throughout the day. At the surface, an area of low pressure will track from the central Great Plains to the Great Lakes region. In its wake, a cold front will sweep across much of the central CONUS, replacing near record warmth with more seasonal temperatures. Model guidance suggests there could be a window of up to a few hours supporting Elevated fire-weather conditions associated with the pre/post cold front passage, mainly across portions of the southern High Plains. Pre-frontal residual dry air and diurnally driven winds should be present ahead of the front by early afternoon. Then, temperatures should remain above the minimum thresholds behind the front for another 2-3 hours amid gusty northwest winds despite rising RH values. Therefore, Elevated highlights have been introduced for a small portion of West Texas and far southeast New Mexico, confined to areas where fuels appear most receptive. The frontal passage may at least temporarily exacerbate any ongoing fires across the region as well. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0100 PM CST Sat Dec 27 2025 Valid 281200Z - 291200Z A strong surface cold front will rapidly move across the Southern Plains on Sunday, ushering in a much dryer and colder airmass. Westerly winds ahead of the front may support locally elevated fire weather conditions during the late morning or early afternoon across the region. In the wake of the front, strong/gusty northerly winds between 20 and 30 mph (with gusts approaching 50 mph) will usher in the aforementioned very dry continental airmass. Although the post-frontal airmass will be colder than the pre-frontal airmass, pockets of sunshine may slow the rate at which temperatures fall during the afternoon. Thus, despite the cooler post-frontal airmass, relative humidity should continue to fall during the afternoon as the dryer air takes hold. Given the ability of the Southern Plains fire environment to overproduce the past few days, especially across portions of the Texas Panhandle, have opted to go ahead and expand the elevated risk area from West Texas north and east into the southeast part of the Texas Panhandle and most of western and central Oklahoma. The expectation is that relative humidity will be lower than currently forecast and the very strong, gusty northerly post-frontal winds will be sufficient to offset the slightly higher relative humidity. ..Marsh.. 12/27/2025 .PREV DISCUSSION... /ISSUED 1128 PM CST Fri Dec 26 2025/ ...Synopsis... An upper-level trough over the central/northern High Plains will shift east into the Great Lakes and Ohio Valley region throughout the day. At the surface, an area of low pressure will track from the central Great Plains to the Great Lakes region. In its wake, a cold front will sweep across much of the central CONUS, replacing near record warmth with more seasonal temperatures. Model guidance suggests there could be a window of up to a few hours supporting Elevated fire-weather conditions associated with the pre/post cold front passage, mainly across portions of the southern High Plains. Pre-frontal residual dry air and diurnally driven winds should be present ahead of the front by early afternoon. Then, temperatures should remain above the minimum thresholds behind the front for another 2-3 hours amid gusty northwest winds despite rising RH values. Therefore, Elevated highlights have been introduced for a small portion of West Texas and far southeast New Mexico, confined to areas where fuels appear most receptive. The frontal passage may at least temporarily exacerbate any ongoing fires across the region as well. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1154 AM CST Sat Dec 27 2025 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY AFTERNOON AND EVENING ACROSS PARTS OF EAST CENTRAL AND SOUTHEAST MISSOURI...ADJACENT NORTHEASTERN ARKANSAS AND NORTHWESTERN TENNESSEE...CENTRAL AND SOUTHERN ILLINOIS...INDIANA...WESTERN OHIO AND ADJACENT SOUTHERN LOWER MICHIGAN...WESTERN AND NORTHERN KENTUCKY... CORRECTED FOR TYPOS ...SUMMARY... Strong thunderstorms may develop across parts of the middle Mississippi Valley Sunday afternoon, accompanied by at least some risk for severe weather while spreading into the lower Ohio Valley through Sunday evening. This may include potential for a tornado or two across parts of central Illinois into north central Indiana. Otherwise, potentially damaging wind gusts appear the primary severe threat. ...Discussion... Much of the interior U.S. remains anomalously warm, as westerlies across the Pacific into western North America undergo amplification. Later today through Sunday, models indicate that this will include mid/upper ridging building inland across British Columbia and the Pacific Northwest, through the Canadian/northern U.S. Rockies and adjacent Prairies/northern Great Plains. Downstream, it appears that a pair of short wave troughs will come in phase while migrating across and east of the Rockies, and provide support for strong cyclogenesis. By late Sunday night, guidance generally indicates that the center of a deep, occluding surface low will reach the Lake Huron/Georgian Bay vicinity, with a strong trailing cold front advancing through the western slopes of the Appalachians and northwestern Gulf/Gulf coast region. ...Middle Mississippi/Ohio Valley... There remains notable spread within/among the various model output concerning the evolution of the developing surface cyclone across the lower Missouri Valley through Great Lakes region, including timing of periods of more rapid deepening Sunday through Sunday night. This could substantially impact the location, timing and extent of any associated thunderstorm development and accompanying severe weather potential. In general, it does appear that the pre-frontal warm sector will be relatively moist, with surface dew points near/above 60F likely as far north as a developing warm front, east of the deepening surface low, across parts of middle Mississippi Valley into southern Great Lakes region by Sunday afternoon. Convection allowing guidance and other model output suggest that forcing for ascent along the warm front, near and east of the low, may be the focus for highest thunderstorm probabilities through the period. However, based on forecast soundings, relatively warm mid-level temperatures will tend to minimize CAPE, and the risk for severe hail and wind with convection rooted above the cool/stable boundary layer appears negligible. Relatively warm air aloft appears likely to be problematic within the surface warm sector as well, particularly given forecast weaker mid/upper forcing for ascent. However, there does appear a consensus in model output that a corridor of weak pre-cold frontal boundary-layer destabilization could develop by early Sunday afternoon across parts of south central/east central Missouri into central Illinois. Coincident with strengthening deep-layer wind fields/shear and perhaps a period of glancing mid/upper support for upward vertical motion, there may be a window of opportunity for strong thunderstorm development, which could spread just ahead of the front into the Ohio Valley before diminishing Sunday evening. Based on forecast soundings, low-level hodographs to the east-southeast of the deepening cyclone may become conducive to low-topped supercells posing the risk for a tornado or two across parts of central Illinois into north central Indiana late Sunday afternoon. Otherwise, low-level hodographs, trending more linear along the cold front to the southwest, will generally support a narrow line of convection with potential mix down 40-50 kt mean flow in the lowest 3 to 6 km. Once thunderstorm development wanes, the potential for convectively enhanced gusts will diminish, but strong wind gusts associated with the cold frontal passage are likely through much of the remainder of the Ohio and Mississippi Valleys. ..Kerr.. 12/27/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1154 AM CST Sat Dec 27 2025 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY AFTERNOON AND EVENING ACROSS PARTS OF EAST CENTRAL AND SOUTHEAST MISSOURI...ADJACENT NORTHEASTERN ARKANSAS AND NORTHWESTERN TENNESSEE...CENTRAL AND SOUTHERN ILLINOIS...INDIANA...WESTERN OHIO AND ADJACENT SOUTHERN LOWER MICHIGAN...WESTERN AND NORTHERN KENTUCKY... CORRECTED FOR TYPOS ...SUMMARY... Strong thunderstorms may develop across parts of the middle Mississippi Valley Sunday afternoon, accompanied by at least some risk for severe weather while spreading into the lower Ohio Valley through Sunday evening. This may include potential for a tornado or two across parts of central Illinois into north central Indiana. Otherwise, potentially damaging wind gusts appear the primary severe threat. ...Discussion... Much of the interior U.S. remains anomalously warm, as westerlies across the Pacific into western North America undergo amplification. Later today through Sunday, models indicate that this will include mid/upper ridging building inland across British Columbia and the Pacific Northwest, through the Canadian/northern U.S. Rockies and adjacent Prairies/northern Great Plains. Downstream, it appears that a pair of short wave troughs will come in phase while migrating across and east of the Rockies, and provide support for strong cyclogenesis. By late Sunday night, guidance generally indicates that the center of a deep, occluding surface low will reach the Lake Huron/Georgian Bay vicinity, with a strong trailing cold front advancing through the western slopes of the Appalachians and northwestern Gulf/Gulf coast region. ...Middle Mississippi/Ohio Valley... There remains notable spread within/among the various model output concerning the evolution of the developing surface cyclone across the lower Missouri Valley through Great Lakes region, including timing of periods of more rapid deepening Sunday through Sunday night. This could substantially impact the location, timing and extent of any associated thunderstorm development and accompanying severe weather potential. In general, it does appear that the pre-frontal warm sector will be relatively moist, with surface dew points near/above 60F likely as far north as a developing warm front, east of the deepening surface low, across parts of middle Mississippi Valley into southern Great Lakes region by Sunday afternoon. Convection allowing guidance and other model output suggest that forcing for ascent along the warm front, near and east of the low, may be the focus for highest thunderstorm probabilities through the period. However, based on forecast soundings, relatively warm mid-level temperatures will tend to minimize CAPE, and the risk for severe hail and wind with convection rooted above the cool/stable boundary layer appears negligible. Relatively warm air aloft appears likely to be problematic within the surface warm sector as well, particularly given forecast weaker mid/upper forcing for ascent. However, there does appear a consensus in model output that a corridor of weak pre-cold frontal boundary-layer destabilization could develop by early Sunday afternoon across parts of south central/east central Missouri into central Illinois. Coincident with strengthening deep-layer wind fields/shear and perhaps a period of glancing mid/upper support for upward vertical motion, there may be a window of opportunity for strong thunderstorm development, which could spread just ahead of the front into the Ohio Valley before diminishing Sunday evening. Based on forecast soundings, low-level hodographs to the east-southeast of the deepening cyclone may become conducive to low-topped supercells posing the risk for a tornado or two across parts of central Illinois into north central Indiana late Sunday afternoon. Otherwise, low-level hodographs, trending more linear along the cold front to the southwest, will generally support a narrow line of convection with potential mix down 40-50 kt mean flow in the lowest 3 to 6 km. Once thunderstorm development wanes, the potential for convectively enhanced gusts will diminish, but strong wind gusts associated with the cold frontal passage are likely through much of the remainder of the Ohio and Mississippi Valleys. ..Kerr.. 12/27/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1154 AM CST Sat Dec 27 2025 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY AFTERNOON AND EVENING ACROSS PARTS OF EAST CENTRAL AND SOUTHEAST MISSOURI...ADJACENT NORTHEASTERN ARKANSAS AND NORTHWESTERN TENNESSEE...CENTRAL AND SOUTHERN ILLINOIS...INDIANA...WESTERN OHIO AND ADJACENT SOUTHERN LOWER MICHIGAN...WESTERN AND NORTHERN KENTUCKY... CORRECTED FOR TYPOS ...SUMMARY... Strong thunderstorms may develop across parts of the middle Mississippi Valley Sunday afternoon, accompanied by at least some risk for severe weather while spreading into the lower Ohio Valley through Sunday evening. This may include potential for a tornado or two across parts of central Illinois into north central Indiana. Otherwise, potentially damaging wind gusts appear the primary severe threat. ...Discussion... Much of the interior U.S. remains anomalously warm, as westerlies across the Pacific into western North America undergo amplification. Later today through Sunday, models indicate that this will include mid/upper ridging building inland across British Columbia and the Pacific Northwest, through the Canadian/northern U.S. Rockies and adjacent Prairies/northern Great Plains. Downstream, it appears that a pair of short wave troughs will come in phase while migrating across and east of the Rockies, and provide support for strong cyclogenesis. By late Sunday night, guidance generally indicates that the center of a deep, occluding surface low will reach the Lake Huron/Georgian Bay vicinity, with a strong trailing cold front advancing through the western slopes of the Appalachians and northwestern Gulf/Gulf coast region. ...Middle Mississippi/Ohio Valley... There remains notable spread within/among the various model output concerning the evolution of the developing surface cyclone across the lower Missouri Valley through Great Lakes region, including timing of periods of more rapid deepening Sunday through Sunday night. This could substantially impact the location, timing and extent of any associated thunderstorm development and accompanying severe weather potential. In general, it does appear that the pre-frontal warm sector will be relatively moist, with surface dew points near/above 60F likely as far north as a developing warm front, east of the deepening surface low, across parts of middle Mississippi Valley into southern Great Lakes region by Sunday afternoon. Convection allowing guidance and other model output suggest that forcing for ascent along the warm front, near and east of the low, may be the focus for highest thunderstorm probabilities through the period. However, based on forecast soundings, relatively warm mid-level temperatures will tend to minimize CAPE, and the risk for severe hail and wind with convection rooted above the cool/stable boundary layer appears negligible. Relatively warm air aloft appears likely to be problematic within the surface warm sector as well, particularly given forecast weaker mid/upper forcing for ascent. However, there does appear a consensus in model output that a corridor of weak pre-cold frontal boundary-layer destabilization could develop by early Sunday afternoon across parts of south central/east central Missouri into central Illinois. Coincident with strengthening deep-layer wind fields/shear and perhaps a period of glancing mid/upper support for upward vertical motion, there may be a window of opportunity for strong thunderstorm development, which could spread just ahead of the front into the Ohio Valley before diminishing Sunday evening. Based on forecast soundings, low-level hodographs to the east-southeast of the deepening cyclone may become conducive to low-topped supercells posing the risk for a tornado or two across parts of central Illinois into north central Indiana late Sunday afternoon. Otherwise, low-level hodographs, trending more linear along the cold front to the southwest, will generally support a narrow line of convection with potential mix down 40-50 kt mean flow in the lowest 3 to 6 km. Once thunderstorm development wanes, the potential for convectively enhanced gusts will diminish, but strong wind gusts associated with the cold frontal passage are likely through much of the remainder of the Ohio and Mississippi Valleys. ..Kerr.. 12/27/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1154 AM CST Sat Dec 27 2025 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY AFTERNOON AND EVENING ACROSS PARTS OF EAST CENTRAL AND SOUTHEAST MISSOURI...ADJACENT NORTHEASTERN ARKANSAS AND NORTHWESTERN TENNESSEE...CENTRAL AND SOUTHERN ILLINOIS...INDIANA...WESTERN OHIO AND ADJACENT SOUTHERN LOWER MICHIGAN...WESTERN AND NORTHERN KENTUCKY... CORRECTED FOR TYPOS ...SUMMARY... Strong thunderstorms may develop across parts of the middle Mississippi Valley Sunday afternoon, accompanied by at least some risk for severe weather while spreading into the lower Ohio Valley through Sunday evening. This may include potential for a tornado or two across parts of central Illinois into north central Indiana. Otherwise, potentially damaging wind gusts appear the primary severe threat. ...Discussion... Much of the interior U.S. remains anomalously warm, as westerlies across the Pacific into western North America undergo amplification. Later today through Sunday, models indicate that this will include mid/upper ridging building inland across British Columbia and the Pacific Northwest, through the Canadian/northern U.S. Rockies and adjacent Prairies/northern Great Plains. Downstream, it appears that a pair of short wave troughs will come in phase while migrating across and east of the Rockies, and provide support for strong cyclogenesis. By late Sunday night, guidance generally indicates that the center of a deep, occluding surface low will reach the Lake Huron/Georgian Bay vicinity, with a strong trailing cold front advancing through the western slopes of the Appalachians and northwestern Gulf/Gulf coast region. ...Middle Mississippi/Ohio Valley... There remains notable spread within/among the various model output concerning the evolution of the developing surface cyclone across the lower Missouri Valley through Great Lakes region, including timing of periods of more rapid deepening Sunday through Sunday night. This could substantially impact the location, timing and extent of any associated thunderstorm development and accompanying severe weather potential. In general, it does appear that the pre-frontal warm sector will be relatively moist, with surface dew points near/above 60F likely as far north as a developing warm front, east of the deepening surface low, across parts of middle Mississippi Valley into southern Great Lakes region by Sunday afternoon. Convection allowing guidance and other model output suggest that forcing for ascent along the warm front, near and east of the low, may be the focus for highest thunderstorm probabilities through the period. However, based on forecast soundings, relatively warm mid-level temperatures will tend to minimize CAPE, and the risk for severe hail and wind with convection rooted above the cool/stable boundary layer appears negligible. Relatively warm air aloft appears likely to be problematic within the surface warm sector as well, particularly given forecast weaker mid/upper forcing for ascent. However, there does appear a consensus in model output that a corridor of weak pre-cold frontal boundary-layer destabilization could develop by early Sunday afternoon across parts of south central/east central Missouri into central Illinois. Coincident with strengthening deep-layer wind fields/shear and perhaps a period of glancing mid/upper support for upward vertical motion, there may be a window of opportunity for strong thunderstorm development, which could spread just ahead of the front into the Ohio Valley before diminishing Sunday evening. Based on forecast soundings, low-level hodographs to the east-southeast of the deepening cyclone may become conducive to low-topped supercells posing the risk for a tornado or two across parts of central Illinois into north central Indiana late Sunday afternoon. Otherwise, low-level hodographs, trending more linear along the cold front to the southwest, will generally support a narrow line of convection with potential mix down 40-50 kt mean flow in the lowest 3 to 6 km. Once thunderstorm development wanes, the potential for convectively enhanced gusts will diminish, but strong wind gusts associated with the cold frontal passage are likely through much of the remainder of the Ohio and Mississippi Valleys. ..Kerr.. 12/27/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1016 AM CST Sat Dec 27 2025 Valid 271630Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis and Discussion... A large-scale upper trough with multiple embedded perturbations will move eastward from the western CONUS across much of the Plains through the period. While cold mid-level temperatures will accompany this upper trough, meager low-level moisture and cool surface temperatures should generally limit instability and the potential for lightning with any convective showers that can develop this afternoon across the Great Basin/Rockies. Low-level moisture will gradually return northward through tonight across the lower/mid MS Valley and lower OH Valley ahead of a strong cold front and deepening surface low over the central Plains and mid MO Valley. Increasing warm/moist advection associated with a low-level jet should eventually support weak MUCAPE and isolated thunderstorm potential across parts of eastern KS into MO and central IL late tonight/early Sunday morning. With MUCAPE forecast to remain generally less than 750 J/kg, the potential for severe hail with elevated convection appears low even though deep-layer shear will be strong. ..Gleason/Wendt.. 12/27/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1016 AM CST Sat Dec 27 2025 Valid 271630Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis and Discussion... A large-scale upper trough with multiple embedded perturbations will move eastward from the western CONUS across much of the Plains through the period. While cold mid-level temperatures will accompany this upper trough, meager low-level moisture and cool surface temperatures should generally limit instability and the potential for lightning with any convective showers that can develop this afternoon across the Great Basin/Rockies. Low-level moisture will gradually return northward through tonight across the lower/mid MS Valley and lower OH Valley ahead of a strong cold front and deepening surface low over the central Plains and mid MO Valley. Increasing warm/moist advection associated with a low-level jet should eventually support weak MUCAPE and isolated thunderstorm potential across parts of eastern KS into MO and central IL late tonight/early Sunday morning. With MUCAPE forecast to remain generally less than 750 J/kg, the potential for severe hail with elevated convection appears low even though deep-layer shear will be strong. ..Gleason/Wendt.. 12/27/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1016 AM CST Sat Dec 27 2025 Valid 271630Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis and Discussion... A large-scale upper trough with multiple embedded perturbations will move eastward from the western CONUS across much of the Plains through the period. While cold mid-level temperatures will accompany this upper trough, meager low-level moisture and cool surface temperatures should generally limit instability and the potential for lightning with any convective showers that can develop this afternoon across the Great Basin/Rockies. Low-level moisture will gradually return northward through tonight across the lower/mid MS Valley and lower OH Valley ahead of a strong cold front and deepening surface low over the central Plains and mid MO Valley. Increasing warm/moist advection associated with a low-level jet should eventually support weak MUCAPE and isolated thunderstorm potential across parts of eastern KS into MO and central IL late tonight/early Sunday morning. With MUCAPE forecast to remain generally less than 750 J/kg, the potential for severe hail with elevated convection appears low even though deep-layer shear will be strong. ..Gleason/Wendt.. 12/27/2025 Read more