Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
936 FXUS62 KCAE 170056 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 856 PM EDT Mon Sep 16 2024 .SYNOPSIS... Low pressure moving onshore will spread rain along with breezy conditions across mainly the central and north Midlands through tonight. Locally heavy rain possible in the north Midlands and Pee Dee tonight. The low pressure area will continue to weaken and remain across the western Carolinas through Wednesday. Linger showers and seasonable temperatures expected through midweek. Drier weather expected by the weekend. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Key Message(s): - Former PTC8 moving through the area tonight - Heavy rainfall expected for the next hour or two across the northern Midlands, with light rain thereafter Former PTC8 is pushing through the area as I type this, with heavy rainfall moving into the upstate and foothills of the Appalachians. The majority of the area is simply blanketed with low clouds, and dry air wrapping around the backside of this system is helping to reinforce an already sharp precip gradient across our northern FA. WV imagery reveals dry air wrapping around the backside of the system which will help to shut off rainfall gradually over the next several hours as the center moves more into the upstate. Subsidence & mid-level dry air should lock clouds in place across the area, keeping temps in the low 60s overnight. If there are areas that do see sustained clear skies, especially across the CSRA where winds are lighter, expect temps to dip into the 50s tonight given widespread dewpoints below 60. A low-end Flash Flood threat does remain in place across Lancaster county for the next few hours as the rain pivots, but generally any issues should be confined to flood prone locations. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... Key Message(s): - Lingering showers both days more likely focused in the north Midlands and Piedmont - Cooler than normal temperatures in the north Midlands/Piedmont Tuesday then warming Wednesday Vertically stacked/slowly filling mature low pressure system will be near the area, probably in the western Carolinas into Wednesday. Lingering diurnally driven showers expected to focus in the Piedmont and north Midlands Tuesday where moisture and lift more evident. In-situ shallow wedge conditions with isentropic lift expected in the SC Upstate into the Piedmont/extreme north Midlands with ridge to the north extending into the western Carolinas and surface low/front across the Midlands. Drier air may advect into the southern Midlands/CSRA but in general expect precipitable water values to remain above 1.5 inches. Upper low remains over the area Wednesday, moving slowly east. There may be an increase in moisture in weak south 850mb flow. Coupled with short waves rotating around low, lift appears sufficient for scattered showers mainly in the afternoon as diabatic heating increases leading to weak instability. Isolated thunderstorms possible mainly Wednesday with weak instability noted. Stayed near the NBM mean temps. Wide range of temperatures Tuesday with mid 70s north to mid 80s south. Temperatures warmer Wednesday into the low to mid 80s across the area. Overnight lows both nights in the low to mid 60s. && .LONG TERM /THURSDAY THROUGH SUNDAY/... Key Message(s): -Trending drier for the weekend. Model ensembles in pretty good agreement with upper trough taking on positive tilt and moving to the SC coast by late Friday into the weekend. Moisture becoming more limited and surface high building into the area. Diurnally driven showers expected to be more isolated and focused near the coast. Temperatures appear seasonable then maybe slightly cooler than normal by next week. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... Widespread MVFR conditions expected through the night into mid morning with IFR cigs expected at CAE/CUB before improving again after daybreak. Remnants of former PTC 8 continue to move through the Pee Dee region with most of the rain remaining north of the terminals. Widespread MVFR cigs to start the period with IFR cigs expected to develop at CAE/CUB by 05z, less confidence at OGB so will include a tempo group there. IFR cigs not expected to reach AGS/DNL and there could be a few hours of low VFR cigs at AGS/DNL as the edge of the MVFR cigs will be around the CSRA. Cigs should gradually improve through the late morning hours Tuesday and eventually return to VFR at AGS/DNL by 15z and by 20z-21z elsewhere. Winds have shifted around to the northwest and will gradually shift more westerly towards morning and will remain a bit gusty overnight. EXTENDED AVIATION OUTLOOK...Drier air will push into the region this week lowering rain chances. However lingering moisture leaves the door open for early morning restrictions. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...Flood Watch until 8 AM EDT Tuesday for SCZ115. GA...None. && $$