SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0953 AM CST Tue Jan 20 2026 Valid 201630Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not forecast across the U.S. today or tonight. ...Discussion... A prominent longwave trough will remain entrenched from the Rockies to the western Atlantic, with a general prevalence of cold/dry continental trajectories and surface high pressure over the eastern third of the CONUS. Airmass modification will occur with a modest increase in low-level moisture toward coastal Texas tonight. However, instability is expected to remain too limited to support thunderstorms through tonight. ..Guyer/Lyons.. 01/20/2026 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0953 AM CST Tue Jan 20 2026 Valid 201630Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not forecast across the U.S. today or tonight. ...Discussion... A prominent longwave trough will remain entrenched from the Rockies to the western Atlantic, with a general prevalence of cold/dry continental trajectories and surface high pressure over the eastern third of the CONUS. Airmass modification will occur with a modest increase in low-level moisture toward coastal Texas tonight. However, instability is expected to remain too limited to support thunderstorms through tonight. ..Guyer/Lyons.. 01/20/2026 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0953 AM CST Tue Jan 20 2026 Valid 201630Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not forecast across the U.S. today or tonight. ...Discussion... A prominent longwave trough will remain entrenched from the Rockies to the western Atlantic, with a general prevalence of cold/dry continental trajectories and surface high pressure over the eastern third of the CONUS. Airmass modification will occur with a modest increase in low-level moisture toward coastal Texas tonight. However, instability is expected to remain too limited to support thunderstorms through tonight. ..Guyer/Lyons.. 01/20/2026 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0953 AM CST Tue Jan 20 2026 Valid 201630Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not forecast across the U.S. today or tonight. ...Discussion... A prominent longwave trough will remain entrenched from the Rockies to the western Atlantic, with a general prevalence of cold/dry continental trajectories and surface high pressure over the eastern third of the CONUS. Airmass modification will occur with a modest increase in low-level moisture toward coastal Texas tonight. However, instability is expected to remain too limited to support thunderstorms through tonight. ..Guyer/Lyons.. 01/20/2026 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0953 AM CST Tue Jan 20 2026 Valid 201630Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not forecast across the U.S. today or tonight. ...Discussion... A prominent longwave trough will remain entrenched from the Rockies to the western Atlantic, with a general prevalence of cold/dry continental trajectories and surface high pressure over the eastern third of the CONUS. Airmass modification will occur with a modest increase in low-level moisture toward coastal Texas tonight. However, instability is expected to remain too limited to support thunderstorms through tonight. ..Guyer/Lyons.. 01/20/2026 Read more

MD 0030 CONCERNING HEAVY SNOW FOR EASTERN SHORE OF LAKE ONTARIO INTO THE TUG HILL PLATEAU
Mesoscale Discussion 0030 NWS Storm Prediction Center Norman OK 0522 AM CST Tue Jan 20 2026 Areas affected...Eastern shore of Lake Ontario into the Tug Hill Plateau Concerning...Heavy snow Valid 201122Z - 201615Z SUMMARY...A heavy lake-effect snow band will continue through the morning, with rates of 2-4 inches/hour possible in the most intense portions of the band. DISCUSSION...A well-established lake-effect snow band is ongoing from Lake Ontario into parts of the Tug Hill Plateau this morning. While some north-south oscillations will be possible as a minor midlevel shortwave trough approaches from the west, this band is expected to persist through the morning. A favorably long fetch off of Lake Ontario and a relatively deep convective boundary layer will continue to favor very heavy snow rates within the most intense portions of the band. Short-term guidance indicates that midlevel temperatures will reach a minimum (-32 to -33 C at 700 mb) by mid/late morning, and snow rates of 2-4 inches/hour will continue to be possible through this time frame. Some warming aloft and modest lowering of equilibrium levels is eventually expected in the wake of the approaching shortwave trough, but the favorable fetch will help to maintain this band through much of the day. ..Dean.. 01/20/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ALY...BGM...BUF... LAT...LON 43977635 44047581 44027529 43777512 43597509 43477539 43437602 43467629 43547644 43977635 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0648 AM CST Tue Jan 20 2026 Valid 201300Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not forecast across the U.S. today or tonight. ...Synopsis and Discussion... With large-scale upper troughing persisting over central/eastern Canada and the CONUS today, expansive surface high pressure in place across the MS/OH Valleys and eastern states will shift gradually eastward as weak surface lee troughing/low development occurs across the central High Plains. Modest low-level moisture will advance slightly inland across parts of deep south into coastal/east TX, but instability is expected to remain too limited to support thunderstorms through the end of the period. ..Gleason/Dean.. 01/20/2026 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0648 AM CST Tue Jan 20 2026 Valid 201300Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not forecast across the U.S. today or tonight. ...Synopsis and Discussion... With large-scale upper troughing persisting over central/eastern Canada and the CONUS today, expansive surface high pressure in place across the MS/OH Valleys and eastern states will shift gradually eastward as weak surface lee troughing/low development occurs across the central High Plains. Modest low-level moisture will advance slightly inland across parts of deep south into coastal/east TX, but instability is expected to remain too limited to support thunderstorms through the end of the period. ..Gleason/Dean.. 01/20/2026 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0648 AM CST Tue Jan 20 2026 Valid 201300Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not forecast across the U.S. today or tonight. ...Synopsis and Discussion... With large-scale upper troughing persisting over central/eastern Canada and the CONUS today, expansive surface high pressure in place across the MS/OH Valleys and eastern states will shift gradually eastward as weak surface lee troughing/low development occurs across the central High Plains. Modest low-level moisture will advance slightly inland across parts of deep south into coastal/east TX, but instability is expected to remain too limited to support thunderstorms through the end of the period. ..Gleason/Dean.. 01/20/2026 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0648 AM CST Tue Jan 20 2026 Valid 201300Z - 211200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not forecast across the U.S. today or tonight. ...Synopsis and Discussion... With large-scale upper troughing persisting over central/eastern Canada and the CONUS today, expansive surface high pressure in place across the MS/OH Valleys and eastern states will shift gradually eastward as weak surface lee troughing/low development occurs across the central High Plains. Modest low-level moisture will advance slightly inland across parts of deep south into coastal/east TX, but instability is expected to remain too limited to support thunderstorms through the end of the period. ..Gleason/Dean.. 01/20/2026 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0252 AM CST Tue Jan 20 2026 Valid 231200Z - 281200Z ...DISCUSSION... An arctic airmass will settle across much of the CONUS east of the Rockies on Days 4-5/Fri-Sat. Resulting strong high pressure and cold/dry/stable conditions will persist over much of the country throughout the period. However, some thunderstorm potential could develop across portions of the Gulf Coast states/Southeast on Days 4-6/Fri-Sun as a surface cold front progresses east/southeast. Modified Gulf moisture will be in place near the immediate Gulf Coast. Warm advection in the low-levels could result in isolated thunderstorms near or just to the cool side of the cold front Friday afternoon across parts of TX, spreading east/northeast across the Southeast through Saturday and early Sunday. Instability should remain weak as better moisture remains offshore, and due to convection becoming undercut by the cold front. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0252 AM CST Tue Jan 20 2026 Valid 231200Z - 281200Z ...DISCUSSION... An arctic airmass will settle across much of the CONUS east of the Rockies on Days 4-5/Fri-Sat. Resulting strong high pressure and cold/dry/stable conditions will persist over much of the country throughout the period. However, some thunderstorm potential could develop across portions of the Gulf Coast states/Southeast on Days 4-6/Fri-Sun as a surface cold front progresses east/southeast. Modified Gulf moisture will be in place near the immediate Gulf Coast. Warm advection in the low-levels could result in isolated thunderstorms near or just to the cool side of the cold front Friday afternoon across parts of TX, spreading east/northeast across the Southeast through Saturday and early Sunday. Instability should remain weak as better moisture remains offshore, and due to convection becoming undercut by the cold front. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0252 AM CST Tue Jan 20 2026 Valid 231200Z - 281200Z ...DISCUSSION... An arctic airmass will settle across much of the CONUS east of the Rockies on Days 4-5/Fri-Sat. Resulting strong high pressure and cold/dry/stable conditions will persist over much of the country throughout the period. However, some thunderstorm potential could develop across portions of the Gulf Coast states/Southeast on Days 4-6/Fri-Sun as a surface cold front progresses east/southeast. Modified Gulf moisture will be in place near the immediate Gulf Coast. Warm advection in the low-levels could result in isolated thunderstorms near or just to the cool side of the cold front Friday afternoon across parts of TX, spreading east/northeast across the Southeast through Saturday and early Sunday. Instability should remain weak as better moisture remains offshore, and due to convection becoming undercut by the cold front. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0145 AM CST Tue Jan 20 2026 Valid 221200Z - 231200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Synopsis... An upper shortwave trough/low near the CA coast will develop east toward southern CA/northern Baja by Friday morning. As this occurs, upper flow over the eastern half of the CONUS will become flatter/quasi-zonal. At the surface, arctic high pressure will build over the Canadian Prairies and begin to slide southward into the Plains, ushering in a very cold airmass. Forecast guidance varies in the location of an arctic cold front by the end of the period, but the expectation is that by early Friday morning, the front will be located somewhere near central OK to the Red River, and stretch eastward toward the Mid-South. Modified Gulf moisture will be located well south of the front from central/southern TX toward the central Gulf Coast. Isolated convection may develop near or to the cool side of the cold front late Thursday night/early Friday morning across north TX/southern OK within warm advection around 850 mb. However, instability is expected to be very minor and lighting is not expected. Further south in better low-level moisture, forcing for ascent will be limited and warm midlevel temperatures will preclude destabilization. ..Leitman.. 01/20/2026 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0145 AM CST Tue Jan 20 2026 Valid 221200Z - 231200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Synopsis... An upper shortwave trough/low near the CA coast will develop east toward southern CA/northern Baja by Friday morning. As this occurs, upper flow over the eastern half of the CONUS will become flatter/quasi-zonal. At the surface, arctic high pressure will build over the Canadian Prairies and begin to slide southward into the Plains, ushering in a very cold airmass. Forecast guidance varies in the location of an arctic cold front by the end of the period, but the expectation is that by early Friday morning, the front will be located somewhere near central OK to the Red River, and stretch eastward toward the Mid-South. Modified Gulf moisture will be located well south of the front from central/southern TX toward the central Gulf Coast. Isolated convection may develop near or to the cool side of the cold front late Thursday night/early Friday morning across north TX/southern OK within warm advection around 850 mb. However, instability is expected to be very minor and lighting is not expected. Further south in better low-level moisture, forcing for ascent will be limited and warm midlevel temperatures will preclude destabilization. ..Leitman.. 01/20/2026 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0145 AM CST Tue Jan 20 2026 Valid 221200Z - 231200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not expected on Thursday. ...Synopsis... An upper shortwave trough/low near the CA coast will develop east toward southern CA/northern Baja by Friday morning. As this occurs, upper flow over the eastern half of the CONUS will become flatter/quasi-zonal. At the surface, arctic high pressure will build over the Canadian Prairies and begin to slide southward into the Plains, ushering in a very cold airmass. Forecast guidance varies in the location of an arctic cold front by the end of the period, but the expectation is that by early Friday morning, the front will be located somewhere near central OK to the Red River, and stretch eastward toward the Mid-South. Modified Gulf moisture will be located well south of the front from central/southern TX toward the central Gulf Coast. Isolated convection may develop near or to the cool side of the cold front late Thursday night/early Friday morning across north TX/southern OK within warm advection around 850 mb. However, instability is expected to be very minor and lighting is not expected. Further south in better low-level moisture, forcing for ascent will be limited and warm midlevel temperatures will preclude destabilization. ..Leitman.. 01/20/2026 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0145 AM CST Tue Jan 20 2026 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Fire-weather concerns are minimal on Wednesday, as a cold air mass begins to infiltrate the central U.S. ..Weinman.. 01/20/2026 ...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 0145 AM CST Tue Jan 20 2026 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Fire-weather concerns are minimal on Wednesday, as a cold air mass begins to infiltrate the central U.S. ..Weinman.. 01/20/2026 ...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 0145 AM CST Tue Jan 20 2026 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Fire-weather concerns are minimal on Wednesday, as a cold air mass begins to infiltrate the central U.S. ..Weinman.. 01/20/2026 ...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 0145 AM CST Tue Jan 20 2026 Valid 201200Z - 211200Z ...Synopsis... A low-amplitude shortwave trough and accompanying speed maximum will cross the central Rockies during the afternoon, while an attendant surface low tracks south-southeastward along the northern/central High Plains. Related downslope flow will yield 10-15 percent RH across much of the central High Plains, where around 20 mph sustained northwesterly surface winds (with higher gusts) are expected. These dry/windy conditions will favor elevated to locally critical fire-weather conditions over northeastern CO, southwestern NE, and northwest KS. A separate corridor of elevated fire-weather conditions is expected in the lee of the Sangre de Cristo Mountains in southern CO, with locally critical conditions possible within the gap flow areas. Between these two corridors, recent snowfall should limit fire-weather concerns. Elsewhere, modestly breezy northeasterly surface winds are expected amid a dry antecedent air mass across parts of the western and central FL Peninsula, where locally elevated fire-weather conditions are possible. ..Weinman.. 01/20/2026 ...Please see www.spc.noaa.gov/fire for graphic product... Read more