Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
314 FXUS62 KCAE 141806 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 206 PM EDT Sat Sep 14 2024 .SYNOPSIS... Generally low chances for rain overnight tonight. There will be a chance of showers and thunderstorms each day through early next week with deep moisture over the region. Low pressure is expected to develop offshore next week, potentially enhancing rain chances. && .NEAR TERM /THROUGH TONIGHT/... Key Message(s): - Mostly cloudy conditions. - Periodic light showers are possible. 10:30 AM Update: A couple areas of light showers are persisting late this morning, namely along the I-26 corridor and along the Savannah River. This activity is slowly drifting south and westward. Radar is showing that these showers are gradually dissipating as well. Expect the shower activity to continue to diminish, but as moisture continues to be fed into the forecast area, at least a slight chance of showers continues throughout the day. Still looking like drier air filters into the northern portions of the forecast area, so have kept PoPs out of there. Otherwise, forecast remains on track from early this morning. See more below. Earl-morning update: Not a whole lot of change in the overall pattern through tonight. Francine remnants will continue to slowly spin over western TN. Closer to SC/GA, a weak surface trough will remain off the coast. Between these systems, and area of high pressure off to the north will keep low level northeasterly wedge wind flow pattern across the region. Through the day, moisture will lift over the surface wedge, keeping a good amount of clouds and some light rain across the region this morning. QPF amounts will continue to be light with any rainfall. May see some drier air moving in across the northern cwa this afternoon, which may help to bring some breaks in the clouds. With a tight pressure gradient between the offshore trough and the ridge of high pressure north of the region, breezy conditions will remain. Winds around 10 mph, with gusts above 20 mph through the period. As for temperatures, readings remain below normal with the expected cloud cover for much of the day. Highs only in the lower 80s. Lows tonight back into the mid to upper 60s. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... Key Message(s): - Potential for subtropical low pressure formation along an offshore frontal boundary. An exceptionally strong H5 high pressure system will be over the Northeast U.S. early nezt week with a frontal boundary extending from the Deep South into the Western Atlantic Ocean. Multiple synoptic and mesoscale models develop a low pressure system along this boundary which might take on subtropical characteristics. These models differ on the strength and trajectory of this surface low which greatly influences the sensible weather for The Midlands and CSRA during this time period. The Eastern and Northern Midlands have the best chance of being impacted by this potential system with a chance of showers and thunderstorms. The best estimate given the uncertainty with the low pressure system development, timing, and trajectory is a slight chance of showers on Sunday followed by a chance of showers and thunderstorms Eastern and Northern Midlands closer the low pressure system`s path on Monday. There is a chance of showers on Tuesday with residual moisture in place after the system moves into the Mid Atlantic region. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... Key Message(s): - Drying trend likely during the middle of the week. - A more uncertain forecast by Friday and Saturday. An unseasonably strong H5 high pressure system weakens during the middle of next week which allows a potential sub tropical low pressure system to lift northward into the Mid Atlantic States. Drier air on the backside of the low pressure system should usher into The Midlands and CSRA Wednesday through Thursday. The pattern becomes more uncertain toward the end of the week with a blocking pattern across the contiguous U.S. Much above normal H5 heights over the Great Lakes region may push the above mentioned but weakening low pressure system back over the Southeast U.S. for a slight chance of showers and thunderstorms. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... MVFR/IFR conditions through the morning hours before vfr conditions return by this afternoon and tonight.. Regional observations at taf locations showing a mixture of mvfr and ifr ceilings. In addition, some light rain/drizzle will remain possible through late morning as Atlantic moisture moves over top of surface wedge conditions. A return to vfr is being indicated by guidance by this afternoon with better mixing and slightly drier air moving into the area, and have trended that direction with all tafs. Once again late tonight around 06z a return of mvfr ceilings should develop. As for winds, easterly winds will remain around 10 knots with gusts up to 18 knots as strong low-level jet will be over the area. EXTENDED AVIATION OUTLOOK...Scattered showers with possible restrictions at times through Monday as moisture pools over the area along a front and low pressure in the southeast. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM... AVIATION...