Severe Storms

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0402 PM CST Tue Jan 21 2025 Valid 231200Z - 291200Z ...Day 3/Thursday - Southern California... A shortwave trough will advance southeastward from the Four Corners region into the southern Plains, while a midlevel ridge gradually deamplifies over the West Coast. As a result, surface high pressure will persist across the Intermountain West, favoring dry/windy offshore flow across much of southern CA. Sustained surface winds of 20+ mph (with higher gusts) will coincide with single-digit to lower teens RH into Day 3/Thursday afternoon. Given very dry fuels, critical fire-weather conditions are expected. The pressure gradient will weaken substantially by Day 4/Friday, though dry conditions will persist -- with locally breezy/gusty winds still possible over terrain-favored areas. By Day 5/Saturday, onshore flow and the potential for rain will overspread southern CA, reducing the overall fire-weather risk. ...Southwest and Southern Plains... On Day 3/Thursday, dry/breezy conditions are expected across portions of southern/central AZ -- along the southern periphery of the expansive surface high pressure. While elevated fire-weather conditions are possible, critical conditions are not currently expected. On Day 4/Friday, dry/breezy pre-frontal conditions will develop across the southern Plains, as westerly flow strengthens across the southern Rockies. Current indications are that marginal fuels will keep any fire-weather concerns localized. Dry/windy conditions are once again expected across the Southwest on Day 5/Saturday -- ahead of a strong midlevel trough moving across the southern Great Basin. However, fuels do not appear supportive of Critical probabilities at this time. ..Weinman.. 01/21/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 0049 CONCERNING HEAVY SNOW FOR SOUTHERN JEFFERSON AND NORTHERN LEWIS COUNTIES DOWNSTREAM OF LAKE ONTARIO
Mesoscale Discussion 0049 NWS Storm Prediction Center Norman OK 1028 AM CST Tue Jan 21 2025 Areas affected...Southern Jefferson and northern Lewis counties downstream of Lake Ontario Concerning...Heavy snow Valid 211628Z - 212230Z SUMMARY...Heavy lake-effect snow to continue downstream of Lake Ontario to continue for another 10 to 12 hours. Snowfall rates of 2+ inches per hour expected. DISCUSSION...A strong lake-effect snow band which developed yesterday evening and slowly shifted north has now stalled over the same location since around 10Z this morning with snowfall rates in excess of 2 inches per hour. Forecast soundings show a similar wind direction and EL depth which should support similar intensity through at least 00Z. After this time, winds become more erratic and the depth of the convective layer will become more shallow which will likely result in a weaker, more erratic snow band. However, until that time, 2+ inch per hour snowfall rates are expected to persist through the afternoon and into the early evening across the same area across southern Jefferson and northern Lewis counties. ..Bentley.. 01/21/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BUF... LAT...LON 43947628 44037579 44007543 43897536 43767560 43717592 43697613 43707625 43847635 43947628 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0158 PM CST Tue Jan 21 2025 Valid 221200Z - 231200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... The Critical highlights were expanded to the Malibu Coast vicinity, and nudged westward toward the coast in southern Orange County and San Diego County with this update. For both areas, the latest high-resolution guidance is in good agreement, depicting 20+ mph sustained east-northeasterly surface winds (with higher gusts) amid single-digit to lower teens RH. The strongest winds are currently expected Wednesday night into Day 3/Thursday. For additional details, see the previous discussion below. ..Weinman.. 01/21/2025 .PREV DISCUSSION... /ISSUED 0157 AM CST Tue Jan 21 2025/ ...Synopsis... A surface pressure gradient will persist across southern California, with some strengthening of the gradient likely by late Wednesday afternoon as another in a series of mid-level troughs overspread the Great Basin tomorrow (Wednesday). Another day of offshore flow capable of supporting rapid wildfire spread is expected. By afternoon peak heating, widespread sustained 20-30 mph wind speeds are likely, along with RH dropping to at least the 10-15 percent range. Locally higher wind speeds/gusts are also likely in terrain-favoring areas. Anywhere from the Ventura Valley region to the Laguna Mountains may experience the aforementioned meteorological surface conditions, necessitating the introduction of Critical fire weather highlights this outlook. ...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 0158 PM CST Tue Jan 21 2025 Valid 221200Z - 231200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... The Critical highlights were expanded to the Malibu Coast vicinity, and nudged westward toward the coast in southern Orange County and San Diego County with this update. For both areas, the latest high-resolution guidance is in good agreement, depicting 20+ mph sustained east-northeasterly surface winds (with higher gusts) amid single-digit to lower teens RH. The strongest winds are currently expected Wednesday night into Day 3/Thursday. For additional details, see the previous discussion below. ..Weinman.. 01/21/2025 .PREV DISCUSSION... /ISSUED 0157 AM CST Tue Jan 21 2025/ ...Synopsis... A surface pressure gradient will persist across southern California, with some strengthening of the gradient likely by late Wednesday afternoon as another in a series of mid-level troughs overspread the Great Basin tomorrow (Wednesday). Another day of offshore flow capable of supporting rapid wildfire spread is expected. By afternoon peak heating, widespread sustained 20-30 mph wind speeds are likely, along with RH dropping to at least the 10-15 percent range. Locally higher wind speeds/gusts are also likely in terrain-favoring areas. Anywhere from the Ventura Valley region to the Laguna Mountains may experience the aforementioned meteorological surface conditions, necessitating the introduction of Critical fire weather highlights this outlook. ...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 0158 PM CST Tue Jan 21 2025 Valid 221200Z - 231200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... The Critical highlights were expanded to the Malibu Coast vicinity, and nudged westward toward the coast in southern Orange County and San Diego County with this update. For both areas, the latest high-resolution guidance is in good agreement, depicting 20+ mph sustained east-northeasterly surface winds (with higher gusts) amid single-digit to lower teens RH. The strongest winds are currently expected Wednesday night into Day 3/Thursday. For additional details, see the previous discussion below. ..Weinman.. 01/21/2025 .PREV DISCUSSION... /ISSUED 0157 AM CST Tue Jan 21 2025/ ...Synopsis... A surface pressure gradient will persist across southern California, with some strengthening of the gradient likely by late Wednesday afternoon as another in a series of mid-level troughs overspread the Great Basin tomorrow (Wednesday). Another day of offshore flow capable of supporting rapid wildfire spread is expected. By afternoon peak heating, widespread sustained 20-30 mph wind speeds are likely, along with RH dropping to at least the 10-15 percent range. Locally higher wind speeds/gusts are also likely in terrain-favoring areas. Anywhere from the Ventura Valley region to the Laguna Mountains may experience the aforementioned meteorological surface conditions, necessitating the introduction of Critical fire weather highlights this outlook. ...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 0158 PM CST Tue Jan 21 2025 Valid 221200Z - 231200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... The Critical highlights were expanded to the Malibu Coast vicinity, and nudged westward toward the coast in southern Orange County and San Diego County with this update. For both areas, the latest high-resolution guidance is in good agreement, depicting 20+ mph sustained east-northeasterly surface winds (with higher gusts) amid single-digit to lower teens RH. The strongest winds are currently expected Wednesday night into Day 3/Thursday. For additional details, see the previous discussion below. ..Weinman.. 01/21/2025 .PREV DISCUSSION... /ISSUED 0157 AM CST Tue Jan 21 2025/ ...Synopsis... A surface pressure gradient will persist across southern California, with some strengthening of the gradient likely by late Wednesday afternoon as another in a series of mid-level troughs overspread the Great Basin tomorrow (Wednesday). Another day of offshore flow capable of supporting rapid wildfire spread is expected. By afternoon peak heating, widespread sustained 20-30 mph wind speeds are likely, along with RH dropping to at least the 10-15 percent range. Locally higher wind speeds/gusts are also likely in terrain-favoring areas. Anywhere from the Ventura Valley region to the Laguna Mountains may experience the aforementioned meteorological surface conditions, necessitating the introduction of Critical fire weather highlights this outlook. ...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 0158 PM CST Tue Jan 21 2025 Valid 221200Z - 231200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... The Critical highlights were expanded to the Malibu Coast vicinity, and nudged westward toward the coast in southern Orange County and San Diego County with this update. For both areas, the latest high-resolution guidance is in good agreement, depicting 20+ mph sustained east-northeasterly surface winds (with higher gusts) amid single-digit to lower teens RH. The strongest winds are currently expected Wednesday night into Day 3/Thursday. For additional details, see the previous discussion below. ..Weinman.. 01/21/2025 .PREV DISCUSSION... /ISSUED 0157 AM CST Tue Jan 21 2025/ ...Synopsis... A surface pressure gradient will persist across southern California, with some strengthening of the gradient likely by late Wednesday afternoon as another in a series of mid-level troughs overspread the Great Basin tomorrow (Wednesday). Another day of offshore flow capable of supporting rapid wildfire spread is expected. By afternoon peak heating, widespread sustained 20-30 mph wind speeds are likely, along with RH dropping to at least the 10-15 percent range. Locally higher wind speeds/gusts are also likely in terrain-favoring areas. Anywhere from the Ventura Valley region to the Laguna Mountains may experience the aforementioned meteorological surface conditions, necessitating the introduction of Critical fire weather highlights this outlook. ...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 0158 PM CST Tue Jan 21 2025 Valid 221200Z - 231200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... The Critical highlights were expanded to the Malibu Coast vicinity, and nudged westward toward the coast in southern Orange County and San Diego County with this update. For both areas, the latest high-resolution guidance is in good agreement, depicting 20+ mph sustained east-northeasterly surface winds (with higher gusts) amid single-digit to lower teens RH. The strongest winds are currently expected Wednesday night into Day 3/Thursday. For additional details, see the previous discussion below. ..Weinman.. 01/21/2025 .PREV DISCUSSION... /ISSUED 0157 AM CST Tue Jan 21 2025/ ...Synopsis... A surface pressure gradient will persist across southern California, with some strengthening of the gradient likely by late Wednesday afternoon as another in a series of mid-level troughs overspread the Great Basin tomorrow (Wednesday). Another day of offshore flow capable of supporting rapid wildfire spread is expected. By afternoon peak heating, widespread sustained 20-30 mph wind speeds are likely, along with RH dropping to at least the 10-15 percent range. Locally higher wind speeds/gusts are also likely in terrain-favoring areas. Anywhere from the Ventura Valley region to the Laguna Mountains may experience the aforementioned meteorological surface conditions, necessitating the introduction of Critical fire weather highlights this outlook. ...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 0158 PM CST Tue Jan 21 2025 Valid 221200Z - 231200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... The Critical highlights were expanded to the Malibu Coast vicinity, and nudged westward toward the coast in southern Orange County and San Diego County with this update. For both areas, the latest high-resolution guidance is in good agreement, depicting 20+ mph sustained east-northeasterly surface winds (with higher gusts) amid single-digit to lower teens RH. The strongest winds are currently expected Wednesday night into Day 3/Thursday. For additional details, see the previous discussion below. ..Weinman.. 01/21/2025 .PREV DISCUSSION... /ISSUED 0157 AM CST Tue Jan 21 2025/ ...Synopsis... A surface pressure gradient will persist across southern California, with some strengthening of the gradient likely by late Wednesday afternoon as another in a series of mid-level troughs overspread the Great Basin tomorrow (Wednesday). Another day of offshore flow capable of supporting rapid wildfire spread is expected. By afternoon peak heating, widespread sustained 20-30 mph wind speeds are likely, along with RH dropping to at least the 10-15 percent range. Locally higher wind speeds/gusts are also likely in terrain-favoring areas. Anywhere from the Ventura Valley region to the Laguna Mountains may experience the aforementioned meteorological surface conditions, necessitating the introduction of Critical fire weather highlights this outlook. ...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 0158 PM CST Tue Jan 21 2025 Valid 221200Z - 231200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... The Critical highlights were expanded to the Malibu Coast vicinity, and nudged westward toward the coast in southern Orange County and San Diego County with this update. For both areas, the latest high-resolution guidance is in good agreement, depicting 20+ mph sustained east-northeasterly surface winds (with higher gusts) amid single-digit to lower teens RH. The strongest winds are currently expected Wednesday night into Day 3/Thursday. For additional details, see the previous discussion below. ..Weinman.. 01/21/2025 .PREV DISCUSSION... /ISSUED 0157 AM CST Tue Jan 21 2025/ ...Synopsis... A surface pressure gradient will persist across southern California, with some strengthening of the gradient likely by late Wednesday afternoon as another in a series of mid-level troughs overspread the Great Basin tomorrow (Wednesday). Another day of offshore flow capable of supporting rapid wildfire spread is expected. By afternoon peak heating, widespread sustained 20-30 mph wind speeds are likely, along with RH dropping to at least the 10-15 percent range. Locally higher wind speeds/gusts are also likely in terrain-favoring areas. Anywhere from the Ventura Valley region to the Laguna Mountains may experience the aforementioned meteorological surface conditions, necessitating the introduction of Critical fire weather highlights this outlook. ...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 0158 PM CST Tue Jan 21 2025 Valid 221200Z - 231200Z ...CRITICAL FIRE WEATHER AREA FOR MUCH OF SOUTHERN CALIFORNIA... The Critical highlights were expanded to the Malibu Coast vicinity, and nudged westward toward the coast in southern Orange County and San Diego County with this update. For both areas, the latest high-resolution guidance is in good agreement, depicting 20+ mph sustained east-northeasterly surface winds (with higher gusts) amid single-digit to lower teens RH. The strongest winds are currently expected Wednesday night into Day 3/Thursday. For additional details, see the previous discussion below. ..Weinman.. 01/21/2025 .PREV DISCUSSION... /ISSUED 0157 AM CST Tue Jan 21 2025/ ...Synopsis... A surface pressure gradient will persist across southern California, with some strengthening of the gradient likely by late Wednesday afternoon as another in a series of mid-level troughs overspread the Great Basin tomorrow (Wednesday). Another day of offshore flow capable of supporting rapid wildfire spread is expected. By afternoon peak heating, widespread sustained 20-30 mph wind speeds are likely, along with RH dropping to at least the 10-15 percent range. Locally higher wind speeds/gusts are also likely in terrain-favoring areas. Anywhere from the Ventura Valley region to the Laguna Mountains may experience the aforementioned meteorological surface conditions, necessitating the introduction of Critical fire weather highlights this outlook. ...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 0132 PM CST Tue Jan 21 2025 Valid 212000Z - 221200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. through tonight. ...20z... No changes were made. Widespread winter precipitation is ongoing along the Gulf Coast. High pressure over the interior of the central CONUS will continue to support very cold, dry and stable conditions with offshore flow. This will negate sufficient buoyancy for thunderstorm potential. See the prior outlook for more info. ..Lyons.. 01/21/2025 .PREV DISCUSSION... /ISSUED 1012 AM CST Tue Jan 21 2025/ ...Synopsis... Expansive high pressure associated with a polar airmass is in place across is in place east of Rockies. This high, which is currently centered over eastern OK/western AR, is expected to shift eastward/northeastward throughout the day, ending the period over the Ohio Valley. Associated cold, dry, and stable conditions will preclude thunderstorm development. A similar environment is anticipated across the western CONUS, with high pressure and associated stability dominating the sensible weather. A deepening surface low will continue to shift eastward across the Gulf of Mexico, with strong warm-air advection throughout its warm sector contributing to a broad precipitation field across the Gulf Coast. A few lightning flashes were observed over Acadia Parish in south-central LA over the past hour, but these flashes were most likely created by the self-initiated upward leader process. Given the continuing windy conditions and potential for mixed-phase hydrometeors at low levels, some additional self-initiated flashes are possible throughout the period. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0132 PM CST Tue Jan 21 2025 Valid 212000Z - 221200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. through tonight. ...20z... No changes were made. Widespread winter precipitation is ongoing along the Gulf Coast. High pressure over the interior of the central CONUS will continue to support very cold, dry and stable conditions with offshore flow. This will negate sufficient buoyancy for thunderstorm potential. See the prior outlook for more info. ..Lyons.. 01/21/2025 .PREV DISCUSSION... /ISSUED 1012 AM CST Tue Jan 21 2025/ ...Synopsis... Expansive high pressure associated with a polar airmass is in place across is in place east of Rockies. This high, which is currently centered over eastern OK/western AR, is expected to shift eastward/northeastward throughout the day, ending the period over the Ohio Valley. Associated cold, dry, and stable conditions will preclude thunderstorm development. A similar environment is anticipated across the western CONUS, with high pressure and associated stability dominating the sensible weather. A deepening surface low will continue to shift eastward across the Gulf of Mexico, with strong warm-air advection throughout its warm sector contributing to a broad precipitation field across the Gulf Coast. A few lightning flashes were observed over Acadia Parish in south-central LA over the past hour, but these flashes were most likely created by the self-initiated upward leader process. Given the continuing windy conditions and potential for mixed-phase hydrometeors at low levels, some additional self-initiated flashes are possible throughout the period. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0132 PM CST Tue Jan 21 2025 Valid 212000Z - 221200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. through tonight. ...20z... No changes were made. Widespread winter precipitation is ongoing along the Gulf Coast. High pressure over the interior of the central CONUS will continue to support very cold, dry and stable conditions with offshore flow. This will negate sufficient buoyancy for thunderstorm potential. See the prior outlook for more info. ..Lyons.. 01/21/2025 .PREV DISCUSSION... /ISSUED 1012 AM CST Tue Jan 21 2025/ ...Synopsis... Expansive high pressure associated with a polar airmass is in place across is in place east of Rockies. This high, which is currently centered over eastern OK/western AR, is expected to shift eastward/northeastward throughout the day, ending the period over the Ohio Valley. Associated cold, dry, and stable conditions will preclude thunderstorm development. A similar environment is anticipated across the western CONUS, with high pressure and associated stability dominating the sensible weather. A deepening surface low will continue to shift eastward across the Gulf of Mexico, with strong warm-air advection throughout its warm sector contributing to a broad precipitation field across the Gulf Coast. A few lightning flashes were observed over Acadia Parish in south-central LA over the past hour, but these flashes were most likely created by the self-initiated upward leader process. Given the continuing windy conditions and potential for mixed-phase hydrometeors at low levels, some additional self-initiated flashes are possible throughout the period. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0132 PM CST Tue Jan 21 2025 Valid 212000Z - 221200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. through tonight. ...20z... No changes were made. Widespread winter precipitation is ongoing along the Gulf Coast. High pressure over the interior of the central CONUS will continue to support very cold, dry and stable conditions with offshore flow. This will negate sufficient buoyancy for thunderstorm potential. See the prior outlook for more info. ..Lyons.. 01/21/2025 .PREV DISCUSSION... /ISSUED 1012 AM CST Tue Jan 21 2025/ ...Synopsis... Expansive high pressure associated with a polar airmass is in place across is in place east of Rockies. This high, which is currently centered over eastern OK/western AR, is expected to shift eastward/northeastward throughout the day, ending the period over the Ohio Valley. Associated cold, dry, and stable conditions will preclude thunderstorm development. A similar environment is anticipated across the western CONUS, with high pressure and associated stability dominating the sensible weather. A deepening surface low will continue to shift eastward across the Gulf of Mexico, with strong warm-air advection throughout its warm sector contributing to a broad precipitation field across the Gulf Coast. A few lightning flashes were observed over Acadia Parish in south-central LA over the past hour, but these flashes were most likely created by the self-initiated upward leader process. Given the continuing windy conditions and potential for mixed-phase hydrometeors at low levels, some additional self-initiated flashes are possible throughout the period. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0132 PM CST Tue Jan 21 2025 Valid 212000Z - 221200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. through tonight. ...20z... No changes were made. Widespread winter precipitation is ongoing along the Gulf Coast. High pressure over the interior of the central CONUS will continue to support very cold, dry and stable conditions with offshore flow. This will negate sufficient buoyancy for thunderstorm potential. See the prior outlook for more info. ..Lyons.. 01/21/2025 .PREV DISCUSSION... /ISSUED 1012 AM CST Tue Jan 21 2025/ ...Synopsis... Expansive high pressure associated with a polar airmass is in place across is in place east of Rockies. This high, which is currently centered over eastern OK/western AR, is expected to shift eastward/northeastward throughout the day, ending the period over the Ohio Valley. Associated cold, dry, and stable conditions will preclude thunderstorm development. A similar environment is anticipated across the western CONUS, with high pressure and associated stability dominating the sensible weather. A deepening surface low will continue to shift eastward across the Gulf of Mexico, with strong warm-air advection throughout its warm sector contributing to a broad precipitation field across the Gulf Coast. A few lightning flashes were observed over Acadia Parish in south-central LA over the past hour, but these flashes were most likely created by the self-initiated upward leader process. Given the continuing windy conditions and potential for mixed-phase hydrometeors at low levels, some additional self-initiated flashes are possible throughout the period. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0132 PM CST Tue Jan 21 2025 Valid 212000Z - 221200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. through tonight. ...20z... No changes were made. Widespread winter precipitation is ongoing along the Gulf Coast. High pressure over the interior of the central CONUS will continue to support very cold, dry and stable conditions with offshore flow. This will negate sufficient buoyancy for thunderstorm potential. See the prior outlook for more info. ..Lyons.. 01/21/2025 .PREV DISCUSSION... /ISSUED 1012 AM CST Tue Jan 21 2025/ ...Synopsis... Expansive high pressure associated with a polar airmass is in place across is in place east of Rockies. This high, which is currently centered over eastern OK/western AR, is expected to shift eastward/northeastward throughout the day, ending the period over the Ohio Valley. Associated cold, dry, and stable conditions will preclude thunderstorm development. A similar environment is anticipated across the western CONUS, with high pressure and associated stability dominating the sensible weather. A deepening surface low will continue to shift eastward across the Gulf of Mexico, with strong warm-air advection throughout its warm sector contributing to a broad precipitation field across the Gulf Coast. A few lightning flashes were observed over Acadia Parish in south-central LA over the past hour, but these flashes were most likely created by the self-initiated upward leader process. Given the continuing windy conditions and potential for mixed-phase hydrometeors at low levels, some additional self-initiated flashes are possible throughout the period. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0132 PM CST Tue Jan 21 2025 Valid 212000Z - 221200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. through tonight. ...20z... No changes were made. Widespread winter precipitation is ongoing along the Gulf Coast. High pressure over the interior of the central CONUS will continue to support very cold, dry and stable conditions with offshore flow. This will negate sufficient buoyancy for thunderstorm potential. See the prior outlook for more info. ..Lyons.. 01/21/2025 .PREV DISCUSSION... /ISSUED 1012 AM CST Tue Jan 21 2025/ ...Synopsis... Expansive high pressure associated with a polar airmass is in place across is in place east of Rockies. This high, which is currently centered over eastern OK/western AR, is expected to shift eastward/northeastward throughout the day, ending the period over the Ohio Valley. Associated cold, dry, and stable conditions will preclude thunderstorm development. A similar environment is anticipated across the western CONUS, with high pressure and associated stability dominating the sensible weather. A deepening surface low will continue to shift eastward across the Gulf of Mexico, with strong warm-air advection throughout its warm sector contributing to a broad precipitation field across the Gulf Coast. A few lightning flashes were observed over Acadia Parish in south-central LA over the past hour, but these flashes were most likely created by the self-initiated upward leader process. Given the continuing windy conditions and potential for mixed-phase hydrometeors at low levels, some additional self-initiated flashes are possible throughout the period. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0132 PM CST Tue Jan 21 2025 Valid 212000Z - 221200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. through tonight. ...20z... No changes were made. Widespread winter precipitation is ongoing along the Gulf Coast. High pressure over the interior of the central CONUS will continue to support very cold, dry and stable conditions with offshore flow. This will negate sufficient buoyancy for thunderstorm potential. See the prior outlook for more info. ..Lyons.. 01/21/2025 .PREV DISCUSSION... /ISSUED 1012 AM CST Tue Jan 21 2025/ ...Synopsis... Expansive high pressure associated with a polar airmass is in place across is in place east of Rockies. This high, which is currently centered over eastern OK/western AR, is expected to shift eastward/northeastward throughout the day, ending the period over the Ohio Valley. Associated cold, dry, and stable conditions will preclude thunderstorm development. A similar environment is anticipated across the western CONUS, with high pressure and associated stability dominating the sensible weather. A deepening surface low will continue to shift eastward across the Gulf of Mexico, with strong warm-air advection throughout its warm sector contributing to a broad precipitation field across the Gulf Coast. A few lightning flashes were observed over Acadia Parish in south-central LA over the past hour, but these flashes were most likely created by the self-initiated upward leader process. Given the continuing windy conditions and potential for mixed-phase hydrometeors at low levels, some additional self-initiated flashes are possible throughout the period. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 1248 PM CST Tue Jan 21 2025 Valid 231200Z - 241200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are not forecast on Thursday. ...Synopsis... A large mid/upper-level trough will persist from the south-central Great Plains into the eastern CONUS on Thursday, as multiple embedded shortwaves move southeastward through the larger-scale trough. Generally dry and stable conditions in the wake of a significant cold intrusion should continue to limit thunderstorm potential through the period. ..Dean.. 01/21/2025 Read more