Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
577 FXUS62 KCAE 160016 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 816 PM EDT Sun Sep 15 2024 .SYNOPSIS... High pressure extending into the region from the north will weaken as a low pressure area offshore moves toward the Carolina coast tonight into Monday. Breezy conditions and scattered to numerous showers are expected through Monday night. Moisture will remain high across the area through mid week with scattered mainly diurnally driven showers and thunderstorms. Lower chance of rain late week as drier air moves into the area. Temperatures cooler than normal early in the week then expect a warming trend. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... Key Message(s): - Breezy conditions continue through tonight. - Rain chances gradually increase overnight, mainly for the eastern and northern portions of the forecast area. Well, PTC8 has developed off the coast of SC and is influencing our weather currently and through the near term period. Though there is a change in the status of this area of low pressure, our expected impacts won`t change much from the previous forecast. Isolated showers are pushing through the area right now, with a more solid area of rain shifting westward towards Clarendon/Lee/Sumter counties over the next several hours. Clouds are expected to really be thick across the eastern FA, with coverage decreasing westward. Additionally, strong surface high pressure remains in place to our north. With PTC8 developing and the pressure gradient continuing to intensify expect gusty winds to continue through much of the night tonight. A Lake Wind Advisory has been issued for the eastern half of the area beginning at 2am to account for this as winds are expected to gust 35-45 mph on area lakes tonight and into Monday. Expect lows tonight in the upper 60s and lower 70s. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... Key Message(s): - Locally heavy rain possible in the Pee Dee Region Monday and Monday night - Gusty north winds 20 to 30 mph Monday. Monday and Monday night...Low pressure, currently offshore of SC along a stalled frontal boundary is expected to move onshore sometime Monday. Expect 18z models to have a better handle on the overall development/track with data from NHC reconnaissance mission. Notice large spread in track guidance/timing of low moving onshore, but ensembles appear to favor north coast SC and coastal NC. Although steering flow weak, latest water vapor shows a robust short wave over southeast GA/SC, which should nudge coastal low to the north. Model guidance in general suggest a weak low pressure system with some tropical characteristics. As the low moves toward the coast tonight, moisture flux/warm advection will increase primarily across the north coast SC/Pee Dee and eastern North Carolina. Precipitable water will increase likely to values above 2.00-2.25 inches in the Pee Dee. So locally heavy rain possible in that region with up to 3.00 inches. Elsewhere, qpf amounts expected to much lower. Continued a large range in pops from slight chance/chance in the CSRA, to likely in the Pee Dee. Possible sharp precipitation gradient across the area. Strong pressure gradient across the area although ridge to the north will be weakening as the low moves toward the coast, but expect gusty north winds Monday to around 30 mph possible, especially in the morning to midday. Temperatures will be cooler in the north Midlands with highs mainly in the mid 70s. Near 80 degrees in the CSRA where showers will be more limited. Stayed near the NBM mean. Lows in the low to mid 60s with showers lifting to the north. Tuesday and Tuesday night...Moisture could linger across the region for Tuesday as the low pulls away from the forecast area. A few showers will be possible but overall rain chances are lower as the deepest moisture shifts north. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Key Message(s): - Drier weather expected for mid-week - Forecast uncertainty increases for late week As a surface low moves north of the forecast area by mid-week, relatively dry air is expected to wrap around the system and move into the forecast area. However, GEFS appears to be more moist than ECMWF/GEPS ensembles through the week. Uncertainty with regards to temps/precip. Appears blocking pattern aloft may set up with upper low remaining over the southeastern States, leading to cooler temps and higher chance of rain each day. Kept low pops through the period with mainly widely scattered diurnally driven convection with overall weak forcing. Temps near the NBM mean with warmest temps/above normal Thursday, otherwise seasonal values. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... VFR conditions expected through around midnight before transitioning to MVFR as low level stratus clouds return. Breezy northeast winds persist with the increased pressure gradient between the surface high to our north and the developing potential tropical storm offshore which NHC has begun issuing advisories on. Winds around 10 to 12 knots with gusts to 20 knots expected overnight before increasing further Some isolated showers across the Midlands this evening may impact CAE/CUB so including VCSH for a few hours there, otherwise the terminals are expected to remain rain free overnight. Expect cigs to remain in the MVFR range through the day Monday with possible IFR cigs during the afternoon as the low off shore moves inland across northeast SC toward the Charlotte Metro area. CAE/CUB could see some vsby restrictions in rain so included a tempo group for that although there is some uncertainty in the exact track and where the sharp gradient in rain ends up. EXTENDED AVIATION OUTLOOK...Scattered showers with possible restrictions at times through Monday night with low pressure moving across the Carolinas. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...Lake Wind Advisory from 2 AM Monday to 2 AM EDT Tuesday for SCZ016-020>022-027>029-031-037-038-115-116-135>137. GA...None. && $$