SPC Dec 18, 2024 Day 4-8 Severe Weather Outlook
Day 4-8 Outlook Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0339 AM CST Wed Dec 18 2024 Valid 211200Z - 261200Z ...DISCUSSION... Strong surface high pressure and a dearth of boundary-layer moisture will preclude severe thunderstorm potential on Days 4-5/Sat-Sun. By Day 6/Mon, medium range forecast guidance shows a series of upper shortwave troughs shifting east from the Rockies to the MS Valley through Day 8/Wed (Christmas Day). In response, lee troughing/surface low developing is expected over parts of the southern Plains. Increasing southerly low-level flow will support modest northward transport of Gulf moisture across parts of
SPC Dec 17, 2024 Day 4-8 Severe Weather Outlook
Day 4-8 Outlook Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0333 AM CST Tue Dec 17 2024 Valid 201200Z - 251200Z ...DISCUSSION... Strong surface high pressure over the central U.S. and a prior cold front intruding into the southern Gulf of Mexico will result in a dearth of boundary layer moisture across much of the CONUS through at least Day 6/Sun. As a result, thunderstorm chances will be low. Toward the end of the period, some forecast guidance suggests lee troughing will allow southeasterly low-level flow to bring modest Gulf moisture northward across TX. This may result
SPC Dec 17, 2024 0830 UTC Day 3 Severe Thunderstorm Outlook
SPC 0830Z Day 3 Outlook Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0152 AM CST Tue Dec 17 2024 Valid 191200Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Thursday. ...Synopsis... An upper trough extending along the Atlantic coast into the eastern Gulf of Mexico will shift east across FL and moving offshore early in the forecast period. Meanwhile, a shortwave trough over the northern/central Plains will deepen and pivot east, maintaining a mean upper trough over the eastern U.S. through the period. A surface cold front will be located over
SPC Dec 16, 2024 2000 UTC Day 1 Convective Outlook
SPC 2000Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0200 PM CST Mon Dec 16 2024 Valid 162000Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE ARK-LA-TEX AND LOWER TO MID MISSISSIPPI VALLEY... ...SUMMARY... Isolated strong to severe thunderstorms with mainly a damaging wind threat may occur today across parts of the ArkLaTex into western Tennessee and vicinity. Some hail may also occur. ...20Z Update... The previous forecast remains on track. Only minor adjustments to the lines have been made for this Day 1 outlook update. A cold
SPC Dec 16, 2024 1300 UTC Day 1 Convective Outlook
SPC 1300Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0624 AM CST Mon Dec 16 2024 Valid 161300Z - 171200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...Synopsis/Discussion... A progressive mid/upper-level pattern will persist, with the most important feature being a trough now apparent in moisture-channel imagery from a low over southeastern MB, across western MN, eastern NE, central KS, and the TX Panhandle. The main/northern part of this trough is forecast to weaken and move across the Upper Great Lakes today. A weaker, positively tilted, basal vorticity
SPC Dec 16, 2024 Day 4-8 Severe Weather Outlook
Day 4-8 Outlook Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0347 AM CST Mon Dec 16 2024 Valid 191200Z - 241200Z ...DISCUSSION... Medium range guidance is in fairly good agreement that an amplified but progressive upper level pattern will overspread the CONUS during the Day 4-8 period. A shortwave trough over the northern Plains early on Day 4/Thu will deepen and spread east over the eastern half of the CONUS through Day 6 or 7/Sat or Sun. Meanwhile, an amplified upper ridge will build over the western states and spread east into the Plains during this same
SPC Dec 16, 2024 0830 UTC Day 3 Severe Thunderstorm Outlook
SPC 0830Z Day 3 Outlook Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0203 AM CST Mon Dec 16 2024 Valid 181200Z - 191200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are possible from the lower Ohio Valley southwest into northeast/central Texas, as well as across the Florida Peninsula and Georgia coast on Wednesday. Severe thunderstorms are not expected. ...Synopsis... An upper trough will migrate across the eastern half of the CONUS on Wednesday. Boundary-layer moisture will remain modest across the southeast U.S., ahead of a southeast-advancing cold front extending from southern OH southwest to western TN and
SPC Dec 15, 2024 2000 UTC Day 1 Convective Outlook
SPC 2000Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CST Sun Dec 15 2024 Valid 152000Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NORTH TEXAS TO THE OZARKS... ...SUMMARY... Isolated severe hail, strong/gusty winds, and perhaps a tornado may occur tonight through early Monday morning from parts of north Texas to the Ozarks. ...20Z Update... The previous forecast (see below) remains on track, and no changes were needed with this update. The latest guidance indicates some potential for embedded/loosely organized cells tracking northeastward across southeast MO
SPC Dec 15, 2024 1300 UTC Day 1 Convective Outlook
SPC 1300Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0624 AM CST Sun Dec 15 2024 Valid 151300Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF NORTH TEXAS TO THE OZARKS... ...SUMMARY... Isolated hail near severe limits is possible tonight from portions of north Texas to the Ozarks. ...Synopsis... In mid/upper levels, a low-amplitude longwave pattern will remain in place over the CONUS, with progressive shortwave to synoptic troughs traversing the prevailing westerlies. The leading trough -- currently anchored by a closed low near the northern IL/IN border --
SPC Dec 15, 2024 Day 4-8 Severe Weather Outlook
Day 4-8 Outlook Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0312 AM CST Sun Dec 15 2024 Valid 181200Z - 231200Z ...DISCUSSION... A surface cold front will move south and east across the eastern and southeastern U.S. on Day 4/Wed, moving offshore the Gulf and Atlantic coasts by early Day 5/Thu. Showers and thunderstorms are possible near the cold front across parts of the Southeast and Mid-Atlantic vicinity on Day 4/Wed. However, weak instability and only modest vertical shear is expected to limit severe thunderstorm potential. After Day 4/Wed, a mean upper level trough will persist over