SPC Dec 18, 2024 1300 UTC Day 1 Convective Outlook
SPC 1300Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0651 AM CST Wed Dec 18 2024 Valid 181300Z - 191200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE TENNESSEE VALLEY REGION... ...SUMMARY... Isolated damaging wind gusts and a brief tornado are possible into early afternoon across parts of the Tennessee Valley region. ...Synopsis... A continuing progressive pattern aloft will be dominated by two main shortwave troughs: a trailing perturbation now over the coastal Pacific Northwest, and a positively tilted one apparent in moisture- channel imagery near a DBQ-STJ-P28-DHT axis. The
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
Hydrologic Outlook issued December 16 at 3:41PM PST by NWS Seattle WA
ESFSEW An atmospheric river will impact the region Tuesday and Wednesday, bringing potentially significant rainfall that could drive some rivers in western Washington into flood stage. There is still a fair amount of uncertainty regarding river flooding mid-week, but the latest rainfall forecast shows 3 to 5 inches over the Olympic Peninsula with snow levels as high as 7000 to 8000 feet. The northern and central Cascades will also see heavy rainfall during this period, with up to 4 inches of liquid forecast through Wednesday. The Skokomish River is currently forecast to enter moderate flood stage by Wednesday, and other
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
Hydrologic Outlook issued December 16 at 4:11AM PST by NWS Seattle WA
ESFSEW An atmospheric river will impact the region Tuesday and Wednesday, bringing potentially significant rainfall that could drive some rivers in western Washington into flood stage. There is still a fair amount of uncertainty regarding river flooding mid-week, but the latest rainfall forecast shows 4 to 7 inches over the Olympic Peninsula with snow levels as high as 7000 to 8000 feet. Forecast models show large variability in the forecast, with as much as 8 inches or higher over the Olympics in less than 36 hours. The northern and central Cascades will also see heavy rainfall during this period, with