Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
970 FXUS62 KCAE 171745 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 145 PM EDT Tue Sep 17 2024 .SYNOPSIS... An upper level low pressure system will move slowly east across the area through Thursday. This will lead to scattered showers and seasonable temperatures. High pressure will build into the area from New England over the weekend into early next week with dry and seasonable temperatures expected. && .NEAR TERM /THROUGH TONIGHT/... Key Message(s): -Light showers move into the western portions of the area overnight. Upper low continues to spin over the Upstate this afternoon, which has kept cloud cover over much of the area. These clouds have led to a sharp temperature gradient across the forecast area, with low 70s north and mid 80s south. Latest guidance indicates that this low is forecast to meander eastward later this evening and overnight, bringing a chance of rain showers (15-30%) back to the western portions of the forecast area tonight into early tomorrow morning. Any showers that due occur are anticipated to be on the lighter side. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... Key Message(s): - Scattered showers and seasonable temperatures. Upper level low over the Upstate SC will move slowly east during the period. By Thursday afternoon the long wave trough axis should be along the Carolina coast. Precipitable water increases to 1.75-1.95 inches especially across the north Midlands and Pee Dee through Thursday night. Models show short wave triggers rotating around the upper low, with the strongest short wave Wednesday morning through the afternoon. Warm advection ahead of the trough should provide additional lift. Instability appears weak with HREF cape less than 1000 J/kg. Can`t rule out isolated thunderstorms especially in the east Midlands Wednesday afternoon. Otherwise, expect scattered showers and seasonable temperatures in the low to mid 80s. Persistence with lows in the low to mid to mid 60s Wednesday night. With the trough near the Coastal Plain Thursday afternoon, enough low-level moisture/weak instability for scattered showers and thunderstorms especially in the east Midlands and Pee Dee as weak short wave troughs rotate through. High temps again in the low to mid 80s. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Key Message(s): -Trending drier for the weekend into early next week with seasonable temperatures Ensembles are in pretty good agreement with long wave trough along the Eastern Seaboard with ridge in the southern Plains slowly flattening and building to the east. Surface high building southwest from New England across the Carolinas into Georgia. The period appears dry with seasonable temperatures in the upper 70s to mid 80s for high temps. As the upper ridge to the west flattens, increase in some mid and high clouds at times. && .AVIATION /18Z TUESDAY THROUGH SATURDAY/... VFR conditions for much of the TAF period, with MVFR cigs possible near daybreak. Scattered VFR cumulus clouds are being noted on satellite with bases around 4-5 kft. Expect these to hang around until sunset. Upper low then shifts eastward, bringing lower ceilings back to the area. There is some uncertainty on how far east the low cloud shield makes it, however. Therefore, have some MVFR cigs at CAE and CUB starting at 10z, but uncertainty is too high at AGS, DNL, and OGB to include for now. Winds are expected to be from the west to southwest, with gusts around 15 kts through about 00z before diminishing for the rest of the TAF period. EXTENDED AVIATION OUTLOOK...A lack of forcing will limit rain chances over the region this week. Lingering low-level moisture may support early morning restrictions through Friday. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$