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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1257 AM CDT Sun Sep 21 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF SOUTHWEST/SOUTH-CENTRAL KANSAS...WESTERN/CENTRAL OKLAHOMA...AND THE EASTERN TEXAS/OKLAHOMA PANHANDLES... ...SUMMARY... Scattered severe thunderstorms will be possible on Monday across portions of the central and southern High Plains. ...Synopsis... On Monday, a mid-level trough will move from the upper Midwest/Missouri Valley to the Great Lakes/Ohio Valley during the period. Farther west, a more complicated pattern will develop as a ridge builds into the Pacific Northwest. As this ridge builds, a mid-level jet streak will be shunted south across the central Rockies. This will deepen a mid-level low with a closed circulation likely developing across the central High Plains region by 12Z Tuesday. In addition, a closed low will persist off the southern California coast for much of the period. High pressure will be present across much of the western CONUS with weak lee troughing along the central and southern High Plains. The surface pattern will be somewhat less defined farther east with a weak remnant front likely through the Upper Midwest to the western Great Lakes. High pressure will dominate areas east of the Appalachians. ...Central Plains... Moderate to strong instability will develop by Monday afternoon in the wake of a morning MCS across Oklahoma/Kansas. Forecast soundings show a strongly capped airmass across Kansas/Oklahoma and given the relatively weak forcing amid modest height falls, do not expect much thunderstorm development until after 00Z. After this time, the mid-level trough will start to overspread the Plains with a strengthening low-level jet potentially approaching 50 knots. Cooling temperatures aloft and strong isentropic ascent should result in thunderstorm development after sunset Monday evening. Seep mid-level lapse rates and strengthening effective shear (40 to 50 knots) will support the potential for supercells with some hail threat. As upscale growth continues, the severe wind threat should increase and continue into the overnight period into portions of central/northern Oklahoma. ...NE/IA to Lake Michigan... Diurnal thunderstorm development is possible along a diffuse frontal zone from Nebraska to southern Wisconsin. Modest lapse rates and moderate instability along this zone will support some multicells capable of some hail or damaging wind gusts. However, mostly weak deep-layer shear (20 knots) and weak upper forcing should keep the overall threat along this zone relatively isolated. ...Tennessee Valley to the eastern Great Lakes... A weak mid-level shortwave trough is forecast to move through the Ohio Valley on Monday with moderate instability forecast ahead of it. An uncapped airmass and some moderate upper-level support in a broader zone of weak, but persistent isentropic ascent should support scattered thunderstorm development. Lapse rates will be poor, but modest effective shear amid 30 to 35 knots of mid-level flow may support some organized multicells capable of damaging wind gusts Monday afternoon/evening. ..Bentley.. 09/21/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Sun Sep 21 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTHERN PLAINS INTO THE OZARKS...MID MS VALLEY...OH VALLEY...AND SOUTHERN GREAT LAKES...AND ALSO FROM NORTHEAST NE/SOUTHEAST SD INTO SOUTHERN MN/NORTHERN IA... ...SUMMARY... Isolated severe thunderstorms are possible later today across parts of the southern Plains into the Ozarks, mid Mississippi Valley, Ohio Valley, and southern Great Lakes. A few strong to severe thunderstorms are also possible from the mid Missouri Valley into southern Minnesota and northern Iowa. ...Synopsis... A broad mid/upper-level trough will cover much of the central/eastern CONUS later today, with several embedded vorticity maxima expected to move across parts of the Great Plains into the Midwest and Ohio Valley. Modest midlevel flow atop a sufficiently moist and unstable environment will support some potential for strong to locally severe storms across a relatively large area. Localized corridors of somewhat greater severe threat may evolve where deep-layer shear is enhanced by one of the embedded midlevel shortwaves, as well as where midlevel flow veers to west-northwesterly across parts of the mid MO Valley and southern Plains. ...Parts of TX into southern OK... Extensive overnight convection is expected to leave a residual outflow boundary that will be located somewhere in the vicinity of north TX/southern OK by afternoon. While some midlevel warming is expected across the southern Plains through the day, relatively strong heating, and the potential influence of an MCV that may evolve from overnight convection, will support isolated to widely scattered storm development this afternoon/evening near the outflow boundary, and potentially southward along a diffuse dryline into northwest/west-central TX. Moderate buoyancy and 35-50 kt of effective shear within the northwesterly flow regime across parts of north TX into southern OK will conditionally support splitting supercells capable of producing hail and localized severe gusts. There is some uncertainty regarding the placement of the boundary by afternoon and the magnitude of any MCV-related enhancement to deep-layer shear and storm coverage, but greater probabilities may be needed if confidence increases in development of multiple supercells and/or an organized cluster within this regime. ...Northeast NE/southeast SD into southern MN/northern IA... A compact mid/upper-level low will move southeastward from eastern ND into MN later today. This low and the attendant shortwave trough will aid in the development of isolated to widely scattered storms by late afternoon or early evening from southwest MN into adjacent southeast SD, northeast NE, and northwest IA, in the vicinity of a weak surface boundary. Relatively cool temperatures aloft, moderate buoyancy, and effective shear of 25-35 kt will support strong multicells and perhaps a couple splitting supercells. Large hail is expected to the primary hazard, though localized strong gusts will also be possible with the strongest storms. ...Eastern KS into MO... A cluster of elevated convection will likely be ongoing at the start of the period across central/eastern KS. This cluster and possibly an attendant MCV may encounter an environment across parts of MO that is recovering from a separate area of overnight convection near the Ozarks. While background midlevel flow will only support effective shear of 20-25 kt, any MCV-related enhancement to the flow would result in sufficient deep-layer shear for somewhat more organized storms. If sufficient destabilization can occur, then a few modestly organized cells or clusters may evolve this afternoon and evening, accompanied by a threat for localized damaging wind and perhaps some hail. ...Parts of the Ohio Valley and Great Lakes... Modest deep-layer southwesterly flow will overspread parts of the southern Great Lakes and Ohio Valley later today, in advance of the midlevel shortwave trough moving across the upper MS Valley. Scattered thunderstorm development is expected across the region, within a moderately unstable and weakly capped environment. Midlevel lapse rates and deep-layer shear are expected to remain relatively weak, but steepening low-level lapse rates will result in potential for cells/clusters capable of locally damaging wind this afternoon into the early evening. There is also some potential for a storm cluster or loosely organized MCS to develop across the lower MO/mid MS Valley and move toward parts of the southern Great Lakes later tonight. ..Dean/Halbert.. 09/21/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Sun Sep 21 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTHERN PLAINS INTO THE OZARKS...MID MS VALLEY...OH VALLEY...AND SOUTHERN GREAT LAKES...AND ALSO FROM NORTHEAST NE/SOUTHEAST SD INTO SOUTHERN MN/NORTHERN IA... ...SUMMARY... Isolated severe thunderstorms are possible later today across parts of the southern Plains into the Ozarks, mid Mississippi Valley, Ohio Valley, and southern Great Lakes. A few strong to severe thunderstorms are also possible from the mid Missouri Valley into southern Minnesota and northern Iowa. ...Synopsis... A broad mid/upper-level trough will cover much of the central/eastern CONUS later today, with several embedded vorticity maxima expected to move across parts of the Great Plains into the Midwest and Ohio Valley. Modest midlevel flow atop a sufficiently moist and unstable environment will support some potential for strong to locally severe storms across a relatively large area. Localized corridors of somewhat greater severe threat may evolve where deep-layer shear is enhanced by one of the embedded midlevel shortwaves, as well as where midlevel flow veers to west-northwesterly across parts of the mid MO Valley and southern Plains. ...Parts of TX into southern OK... Extensive overnight convection is expected to leave a residual outflow boundary that will be located somewhere in the vicinity of north TX/southern OK by afternoon. While some midlevel warming is expected across the southern Plains through the day, relatively strong heating, and the potential influence of an MCV that may evolve from overnight convection, will support isolated to widely scattered storm development this afternoon/evening near the outflow boundary, and potentially southward along a diffuse dryline into northwest/west-central TX. Moderate buoyancy and 35-50 kt of effective shear within the northwesterly flow regime across parts of north TX into southern OK will conditionally support splitting supercells capable of producing hail and localized severe gusts. There is some uncertainty regarding the placement of the boundary by afternoon and the magnitude of any MCV-related enhancement to deep-layer shear and storm coverage, but greater probabilities may be needed if confidence increases in development of multiple supercells and/or an organized cluster within this regime. ...Northeast NE/southeast SD into southern MN/northern IA... A compact mid/upper-level low will move southeastward from eastern ND into MN later today. This low and the attendant shortwave trough will aid in the development of isolated to widely scattered storms by late afternoon or early evening from southwest MN into adjacent southeast SD, northeast NE, and northwest IA, in the vicinity of a weak surface boundary. Relatively cool temperatures aloft, moderate buoyancy, and effective shear of 25-35 kt will support strong multicells and perhaps a couple splitting supercells. Large hail is expected to the primary hazard, though localized strong gusts will also be possible with the strongest storms. ...Eastern KS into MO... A cluster of elevated convection will likely be ongoing at the start of the period across central/eastern KS. This cluster and possibly an attendant MCV may encounter an environment across parts of MO that is recovering from a separate area of overnight convection near the Ozarks. While background midlevel flow will only support effective shear of 20-25 kt, any MCV-related enhancement to the flow would result in sufficient deep-layer shear for somewhat more organized storms. If sufficient destabilization can occur, then a few modestly organized cells or clusters may evolve this afternoon and evening, accompanied by a threat for localized damaging wind and perhaps some hail. ...Parts of the Ohio Valley and Great Lakes... Modest deep-layer southwesterly flow will overspread parts of the southern Great Lakes and Ohio Valley later today, in advance of the midlevel shortwave trough moving across the upper MS Valley. Scattered thunderstorm development is expected across the region, within a moderately unstable and weakly capped environment. Midlevel lapse rates and deep-layer shear are expected to remain relatively weak, but steepening low-level lapse rates will result in potential for cells/clusters capable of locally damaging wind this afternoon into the early evening. There is also some potential for a storm cluster or loosely organized MCS to develop across the lower MO/mid MS Valley and move toward parts of the southern Great Lakes later tonight. ..Dean/Halbert.. 09/21/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Sun Sep 21 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTHERN PLAINS INTO THE OZARKS...MID MS VALLEY...OH VALLEY...AND SOUTHERN GREAT LAKES...AND ALSO FROM NORTHEAST NE/SOUTHEAST SD INTO SOUTHERN MN/NORTHERN IA... ...SUMMARY... Isolated severe thunderstorms are possible later today across parts of the southern Plains into the Ozarks, mid Mississippi Valley, Ohio Valley, and southern Great Lakes. A few strong to severe thunderstorms are also possible from the mid Missouri Valley into southern Minnesota and northern Iowa. ...Synopsis... A broad mid/upper-level trough will cover much of the central/eastern CONUS later today, with several embedded vorticity maxima expected to move across parts of the Great Plains into the Midwest and Ohio Valley. Modest midlevel flow atop a sufficiently moist and unstable environment will support some potential for strong to locally severe storms across a relatively large area. Localized corridors of somewhat greater severe threat may evolve where deep-layer shear is enhanced by one of the embedded midlevel shortwaves, as well as where midlevel flow veers to west-northwesterly across parts of the mid MO Valley and southern Plains. ...Parts of TX into southern OK... Extensive overnight convection is expected to leave a residual outflow boundary that will be located somewhere in the vicinity of north TX/southern OK by afternoon. While some midlevel warming is expected across the southern Plains through the day, relatively strong heating, and the potential influence of an MCV that may evolve from overnight convection, will support isolated to widely scattered storm development this afternoon/evening near the outflow boundary, and potentially southward along a diffuse dryline into northwest/west-central TX. Moderate buoyancy and 35-50 kt of effective shear within the northwesterly flow regime across parts of north TX into southern OK will conditionally support splitting supercells capable of producing hail and localized severe gusts. There is some uncertainty regarding the placement of the boundary by afternoon and the magnitude of any MCV-related enhancement to deep-layer shear and storm coverage, but greater probabilities may be needed if confidence increases in development of multiple supercells and/or an organized cluster within this regime. ...Northeast NE/southeast SD into southern MN/northern IA... A compact mid/upper-level low will move southeastward from eastern ND into MN later today. This low and the attendant shortwave trough will aid in the development of isolated to widely scattered storms by late afternoon or early evening from southwest MN into adjacent southeast SD, northeast NE, and northwest IA, in the vicinity of a weak surface boundary. Relatively cool temperatures aloft, moderate buoyancy, and effective shear of 25-35 kt will support strong multicells and perhaps a couple splitting supercells. Large hail is expected to the primary hazard, though localized strong gusts will also be possible with the strongest storms. ...Eastern KS into MO... A cluster of elevated convection will likely be ongoing at the start of the period across central/eastern KS. This cluster and possibly an attendant MCV may encounter an environment across parts of MO that is recovering from a separate area of overnight convection near the Ozarks. While background midlevel flow will only support effective shear of 20-25 kt, any MCV-related enhancement to the flow would result in sufficient deep-layer shear for somewhat more organized storms. If sufficient destabilization can occur, then a few modestly organized cells or clusters may evolve this afternoon and evening, accompanied by a threat for localized damaging wind and perhaps some hail. ...Parts of the Ohio Valley and Great Lakes... Modest deep-layer southwesterly flow will overspread parts of the southern Great Lakes and Ohio Valley later today, in advance of the midlevel shortwave trough moving across the upper MS Valley. Scattered thunderstorm development is expected across the region, within a moderately unstable and weakly capped environment. Midlevel lapse rates and deep-layer shear are expected to remain relatively weak, but steepening low-level lapse rates will result in potential for cells/clusters capable of locally damaging wind this afternoon into the early evening. There is also some potential for a storm cluster or loosely organized MCS to develop across the lower MO/mid MS Valley and move toward parts of the southern Great Lakes later tonight. ..Dean/Halbert.. 09/21/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Sun Sep 21 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTHERN PLAINS INTO THE OZARKS...MID MS VALLEY...OH VALLEY...AND SOUTHERN GREAT LAKES...AND ALSO FROM NORTHEAST NE/SOUTHEAST SD INTO SOUTHERN MN/NORTHERN IA... ...SUMMARY... Isolated severe thunderstorms are possible later today across parts of the southern Plains into the Ozarks, mid Mississippi Valley, Ohio Valley, and southern Great Lakes. A few strong to severe thunderstorms are also possible from the mid Missouri Valley into southern Minnesota and northern Iowa. ...Synopsis... A broad mid/upper-level trough will cover much of the central/eastern CONUS later today, with several embedded vorticity maxima expected to move across parts of the Great Plains into the Midwest and Ohio Valley. Modest midlevel flow atop a sufficiently moist and unstable environment will support some potential for strong to locally severe storms across a relatively large area. Localized corridors of somewhat greater severe threat may evolve where deep-layer shear is enhanced by one of the embedded midlevel shortwaves, as well as where midlevel flow veers to west-northwesterly across parts of the mid MO Valley and southern Plains. ...Parts of TX into southern OK... Extensive overnight convection is expected to leave a residual outflow boundary that will be located somewhere in the vicinity of north TX/southern OK by afternoon. While some midlevel warming is expected across the southern Plains through the day, relatively strong heating, and the potential influence of an MCV that may evolve from overnight convection, will support isolated to widely scattered storm development this afternoon/evening near the outflow boundary, and potentially southward along a diffuse dryline into northwest/west-central TX. Moderate buoyancy and 35-50 kt of effective shear within the northwesterly flow regime across parts of north TX into southern OK will conditionally support splitting supercells capable of producing hail and localized severe gusts. There is some uncertainty regarding the placement of the boundary by afternoon and the magnitude of any MCV-related enhancement to deep-layer shear and storm coverage, but greater probabilities may be needed if confidence increases in development of multiple supercells and/or an organized cluster within this regime. ...Northeast NE/southeast SD into southern MN/northern IA... A compact mid/upper-level low will move southeastward from eastern ND into MN later today. This low and the attendant shortwave trough will aid in the development of isolated to widely scattered storms by late afternoon or early evening from southwest MN into adjacent southeast SD, northeast NE, and northwest IA, in the vicinity of a weak surface boundary. Relatively cool temperatures aloft, moderate buoyancy, and effective shear of 25-35 kt will support strong multicells and perhaps a couple splitting supercells. Large hail is expected to the primary hazard, though localized strong gusts will also be possible with the strongest storms. ...Eastern KS into MO... A cluster of elevated convection will likely be ongoing at the start of the period across central/eastern KS. This cluster and possibly an attendant MCV may encounter an environment across parts of MO that is recovering from a separate area of overnight convection near the Ozarks. While background midlevel flow will only support effective shear of 20-25 kt, any MCV-related enhancement to the flow would result in sufficient deep-layer shear for somewhat more organized storms. If sufficient destabilization can occur, then a few modestly organized cells or clusters may evolve this afternoon and evening, accompanied by a threat for localized damaging wind and perhaps some hail. ...Parts of the Ohio Valley and Great Lakes... Modest deep-layer southwesterly flow will overspread parts of the southern Great Lakes and Ohio Valley later today, in advance of the midlevel shortwave trough moving across the upper MS Valley. Scattered thunderstorm development is expected across the region, within a moderately unstable and weakly capped environment. Midlevel lapse rates and deep-layer shear are expected to remain relatively weak, but steepening low-level lapse rates will result in potential for cells/clusters capable of locally damaging wind this afternoon into the early evening. There is also some potential for a storm cluster or loosely organized MCS to develop across the lower MO/mid MS Valley and move toward parts of the southern Great Lakes later tonight. ..Dean/Halbert.. 09/21/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Sun Sep 21 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTHERN PLAINS INTO THE OZARKS...MID MS VALLEY...OH VALLEY...AND SOUTHERN GREAT LAKES...AND ALSO FROM NORTHEAST NE/SOUTHEAST SD INTO SOUTHERN MN/NORTHERN IA... ...SUMMARY... Isolated severe thunderstorms are possible later today across parts of the southern Plains into the Ozarks, mid Mississippi Valley, Ohio Valley, and southern Great Lakes. A few strong to severe thunderstorms are also possible from the mid Missouri Valley into southern Minnesota and northern Iowa. ...Synopsis... A broad mid/upper-level trough will cover much of the central/eastern CONUS later today, with several embedded vorticity maxima expected to move across parts of the Great Plains into the Midwest and Ohio Valley. Modest midlevel flow atop a sufficiently moist and unstable environment will support some potential for strong to locally severe storms across a relatively large area. Localized corridors of somewhat greater severe threat may evolve where deep-layer shear is enhanced by one of the embedded midlevel shortwaves, as well as where midlevel flow veers to west-northwesterly across parts of the mid MO Valley and southern Plains. ...Parts of TX into southern OK... Extensive overnight convection is expected to leave a residual outflow boundary that will be located somewhere in the vicinity of north TX/southern OK by afternoon. While some midlevel warming is expected across the southern Plains through the day, relatively strong heating, and the potential influence of an MCV that may evolve from overnight convection, will support isolated to widely scattered storm development this afternoon/evening near the outflow boundary, and potentially southward along a diffuse dryline into northwest/west-central TX. Moderate buoyancy and 35-50 kt of effective shear within the northwesterly flow regime across parts of north TX into southern OK will conditionally support splitting supercells capable of producing hail and localized severe gusts. There is some uncertainty regarding the placement of the boundary by afternoon and the magnitude of any MCV-related enhancement to deep-layer shear and storm coverage, but greater probabilities may be needed if confidence increases in development of multiple supercells and/or an organized cluster within this regime. ...Northeast NE/southeast SD into southern MN/northern IA... A compact mid/upper-level low will move southeastward from eastern ND into MN later today. This low and the attendant shortwave trough will aid in the development of isolated to widely scattered storms by late afternoon or early evening from southwest MN into adjacent southeast SD, northeast NE, and northwest IA, in the vicinity of a weak surface boundary. Relatively cool temperatures aloft, moderate buoyancy, and effective shear of 25-35 kt will support strong multicells and perhaps a couple splitting supercells. Large hail is expected to the primary hazard, though localized strong gusts will also be possible with the strongest storms. ...Eastern KS into MO... A cluster of elevated convection will likely be ongoing at the start of the period across central/eastern KS. This cluster and possibly an attendant MCV may encounter an environment across parts of MO that is recovering from a separate area of overnight convection near the Ozarks. While background midlevel flow will only support effective shear of 20-25 kt, any MCV-related enhancement to the flow would result in sufficient deep-layer shear for somewhat more organized storms. If sufficient destabilization can occur, then a few modestly organized cells or clusters may evolve this afternoon and evening, accompanied by a threat for localized damaging wind and perhaps some hail. ...Parts of the Ohio Valley and Great Lakes... Modest deep-layer southwesterly flow will overspread parts of the southern Great Lakes and Ohio Valley later today, in advance of the midlevel shortwave trough moving across the upper MS Valley. Scattered thunderstorm development is expected across the region, within a moderately unstable and weakly capped environment. Midlevel lapse rates and deep-layer shear are expected to remain relatively weak, but steepening low-level lapse rates will result in potential for cells/clusters capable of locally damaging wind this afternoon into the early evening. There is also some potential for a storm cluster or loosely organized MCS to develop across the lower MO/mid MS Valley and move toward parts of the southern Great Lakes later tonight. ..Dean/Halbert.. 09/21/2025 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1247 AM CDT Sun Sep 21 2025 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... A progressive mid-level trough is forecast to traverse the northern Rockies on Monday, bringing a cold front to the northern and central Great Plains. However, there is no appreciable overlap between receptive fuels, strong surface winds, low relative humidity, or the occurrence of dry thunderstorms across the continental U.S. to support fire-weather highlights at this time. ..Halbert.. 09/21/2025 ...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 1247 AM CDT Sun Sep 21 2025 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... A progressive mid-level trough is forecast to traverse the northern Rockies on Monday, bringing a cold front to the northern and central Great Plains. However, there is no appreciable overlap between receptive fuels, strong surface winds, low relative humidity, or the occurrence of dry thunderstorms across the continental U.S. to support fire-weather highlights at this time. ..Halbert.. 09/21/2025 ...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 1247 AM CDT Sun Sep 21 2025 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... A progressive mid-level trough is forecast to traverse the northern Rockies on Monday, bringing a cold front to the northern and central Great Plains. However, there is no appreciable overlap between receptive fuels, strong surface winds, low relative humidity, or the occurrence of dry thunderstorms across the continental U.S. to support fire-weather highlights at this time. ..Halbert.. 09/21/2025 ...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 1247 AM CDT Sun Sep 21 2025 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... A progressive mid-level trough is forecast to traverse the northern Rockies on Monday, bringing a cold front to the northern and central Great Plains. However, there is no appreciable overlap between receptive fuels, strong surface winds, low relative humidity, or the occurrence of dry thunderstorms across the continental U.S. to support fire-weather highlights at this time. ..Halbert.. 09/21/2025 ...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 1247 AM CDT Sun Sep 21 2025 Valid 221200Z - 231200Z ...NO CRITICAL AREAS... ...Synopsis... A progressive mid-level trough is forecast to traverse the northern Rockies on Monday, bringing a cold front to the northern and central Great Plains. However, there is no appreciable overlap between receptive fuels, strong surface winds, low relative humidity, or the occurrence of dry thunderstorms across the continental U.S. to support fire-weather highlights at this time. ..Halbert.. 09/21/2025 ...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 1246 AM CDT Sun Sep 21 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Generally weak surface winds across the continental U.S., and higher relative humidity and precipitation across the few localized regions of higher winds, will result in minimal fire-weather concerns today. ...North Cascades into the Columbia Basin... Winds in the Cascade gaps and into the Columbia Basin are still forecast to gust as high as 20 MPH. While these winds could impact existing fires across the area, relative humidity is not forecast to get below 30% in large part due to cloud cover and precipitation. Therefore, fire-weather highlights have been withheld at this time. ..Halbert.. 09/21/2025 ...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 1246 AM CDT Sun Sep 21 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Generally weak surface winds across the continental U.S., and higher relative humidity and precipitation across the few localized regions of higher winds, will result in minimal fire-weather concerns today. ...North Cascades into the Columbia Basin... Winds in the Cascade gaps and into the Columbia Basin are still forecast to gust as high as 20 MPH. While these winds could impact existing fires across the area, relative humidity is not forecast to get below 30% in large part due to cloud cover and precipitation. Therefore, fire-weather highlights have been withheld at this time. ..Halbert.. 09/21/2025 ...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 1246 AM CDT Sun Sep 21 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Generally weak surface winds across the continental U.S., and higher relative humidity and precipitation across the few localized regions of higher winds, will result in minimal fire-weather concerns today. ...North Cascades into the Columbia Basin... Winds in the Cascade gaps and into the Columbia Basin are still forecast to gust as high as 20 MPH. While these winds could impact existing fires across the area, relative humidity is not forecast to get below 30% in large part due to cloud cover and precipitation. Therefore, fire-weather highlights have been withheld at this time. ..Halbert.. 09/21/2025 ...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 1246 AM CDT Sun Sep 21 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Generally weak surface winds across the continental U.S., and higher relative humidity and precipitation across the few localized regions of higher winds, will result in minimal fire-weather concerns today. ...North Cascades into the Columbia Basin... Winds in the Cascade gaps and into the Columbia Basin are still forecast to gust as high as 20 MPH. While these winds could impact existing fires across the area, relative humidity is not forecast to get below 30% in large part due to cloud cover and precipitation. Therefore, fire-weather highlights have been withheld at this time. ..Halbert.. 09/21/2025 ...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 1246 AM CDT Sun Sep 21 2025 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Generally weak surface winds across the continental U.S., and higher relative humidity and precipitation across the few localized regions of higher winds, will result in minimal fire-weather concerns today. ...North Cascades into the Columbia Basin... Winds in the Cascade gaps and into the Columbia Basin are still forecast to gust as high as 20 MPH. While these winds could impact existing fires across the area, relative humidity is not forecast to get below 30% in large part due to cloud cover and precipitation. Therefore, fire-weather highlights have been withheld at this time. ..Halbert.. 09/21/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

875
ABPZ20 KNHC 210521
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 PM PDT Sat Sep 20 2025

For the eastern and central North Pacific east of 180 longitude:

Off the Coast of Southern Mexico (EP97):
A broad area of low pressure located a couple of hundred miles south
of the southern coast of Mexico continues to show signs of
organization. Environmental conditions are favorable for additional
development, and a tropical depression or tropical storm is expected
to form within the next day or so, while the system moves
west-northwestward at 5 to 10 mph, roughly parallel to the coast of
southern and southwestern Mexico. Locally heavy rainfall is
possible along portions of the coast of southern and southwestern
Mexico through Monday. For additional information, including gale
warnings, please see the High Seas Forecasts issued by the National
Weather Service.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 7 days...high...90 percent.

&&
High Seas Forecasts issued by the National Weather Service
can be found under AWIPS header NFDHSFEPI, WMO header FZPN02
KWBC, and on the web at ocean.weather.gov/shtml/NFDHSFEPI.php

$$
Forecaster Jelsema

MD 2107 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF NORTHEASTERN OKLAHOMA AND ADJACENT PORTIONS OF THE GREAT PLAINS
Mesoscale Discussion 2107 NWS Storm Prediction Center Norman OK 0902 PM CDT Sat Sep 20 2025 Areas affected...parts of northeastern Oklahoma and adjacent portions of the Great Plains Concerning...Severe potential...Watch unlikely Valid 210202Z - 210400Z Probability of Watch Issuance...5 percent SUMMARY...Lingering strong thunderstorm activity may pose a continuing risk for a localized downburst or two through 10-11 PM CDT. DISCUSSION...Vigorous convective development persists in an evolving, but still not particularly organized, cluster near and northwest through north of Tulsa. Much of the stronger convection is being forced above the eastward propagating portion of an expanding cold pool at the surface, near a stalled, remnant surface frontal zone, along which low-level moisture is maximized and may be contributing to CAPE in excess of 2000 J/kg. This convection will probably gradually consolidate with a smaller immediate downstream cluster supported by lift associated with warm advection along the boundary. This is occurring in the presence of westerly deep-layer ambient mean flow on the order of 10-15 kt, with negligible deep-layer shear. However, lower/mid-tropospheric thermodynamic profiles may be unsaturated enough to contribute to a continuing risk for another strong downburst or two through late evening. ..Kerr/Bunting.. 09/21/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TSA... LAT...LON 36909590 36689502 36209455 35939481 35829521 35889565 36019602 36499658 36909590 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Sat Sep 20 2025 Valid 210100Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTH-CENTRAL PLAINS... ...SUMMARY... Scattered strong to locally severe thunderstorms remain possible across parts of the south-central Plains this evening. ...South-central Plains... A few strong to locally severe storms are ongoing this evening from the TX Panhandle into western/northern OK. Moderate buoyancy remains in place across areas that have not been convectively overturned, while deep-layer shear is marginally sufficient for briefly organized storms capable of isolated severe gusts and hail. Enhanced SRH is still in place near a remnant outflow across northeast OK (as noted on the KINX VWP), and there still a window of opportunity for a supercell or two within this regime, which could pose a threat of a brief tornado and large hail. Some clustering is possible later this evening across the eastern TX Panhandle into western OK, and also across parts of the Ozarks, associated with separate branches of a modest nocturnal low-level jet. Some severe threat could persist into late evening, before convection becomes increasingly elevated overnight. ...Mid MS Valley into lower MI... A storm cluster across western lower MI has recently produced strong gusts, with other isolated strong storms noted from western IN into IL. Isolated strong storms may persist into late evening across this region within a modestly unstable environment, though a gradual weakening trend is expected with time. ...Parts of KS overnight... Guidance generally suggests that convection will increase overnight and spread eastward from northwest into central KS. MUCAPE near/above 1000 J/kg could support a few strong storms, but generally weak effective shear and modest midlevel lapse rates are expected to limit the organized severe threat. ..Dean.. 09/21/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Sat Sep 20 2025 Valid 210100Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTH-CENTRAL PLAINS... ...SUMMARY... Scattered strong to locally severe thunderstorms remain possible across parts of the south-central Plains this evening. ...South-central Plains... A few strong to locally severe storms are ongoing this evening from the TX Panhandle into western/northern OK. Moderate buoyancy remains in place across areas that have not been convectively overturned, while deep-layer shear is marginally sufficient for briefly organized storms capable of isolated severe gusts and hail. Enhanced SRH is still in place near a remnant outflow across northeast OK (as noted on the KINX VWP), and there still a window of opportunity for a supercell or two within this regime, which could pose a threat of a brief tornado and large hail. Some clustering is possible later this evening across the eastern TX Panhandle into western OK, and also across parts of the Ozarks, associated with separate branches of a modest nocturnal low-level jet. Some severe threat could persist into late evening, before convection becomes increasingly elevated overnight. ...Mid MS Valley into lower MI... A storm cluster across western lower MI has recently produced strong gusts, with other isolated strong storms noted from western IN into IL. Isolated strong storms may persist into late evening across this region within a modestly unstable environment, though a gradual weakening trend is expected with time. ...Parts of KS overnight... Guidance generally suggests that convection will increase overnight and spread eastward from northwest into central KS. MUCAPE near/above 1000 J/kg could support a few strong storms, but generally weak effective shear and modest midlevel lapse rates are expected to limit the organized severe threat. ..Dean.. 09/21/2025 Read more