072 FXUS62 KCHS 042323 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 723 PM EDT Sat Aug 4 2018 .SYNOPSIS... Atlantic high pressure will build into the area tonight and Sunday, before another inland trough develops during the early to middle part of next week. A cold front may approach the area from the north late next week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Convection is showing a more diurnal pattern early this evening with most activity diminishing as we head toward sunset. All high-res guidance is in agreement that once the lingering convection dissipates, we should have dry conditions overnight. Patchy ground fog will be possible in some places, especially where rainfall occurred, but conditions are not particularly favorable for dense fog. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... Sunday and Monday: Aloft, a ridge of high pressure will build over the Southeast United States, becoming centered over the area early next week. At the sfc, high pressure over the western Atlantic will press closer to the coast while a lee trough develops and persists inland. The setup suggests a more typical summertime pattern over Southeast South Carolina and Southeast Georgia to start off the week with chances of showers and/or thunderstorms each day. Although the pattern becomes less favorable for widespread precip, a light onshore wind and inland moving seabreeze should provide the moisture and lifting needed for afternoon convection. SBCAPE ranging between 1500-2500 J/kg and PWATs between 1.5-2.0 inches support scattered showers and thunderstorms during peak heating, a few which could be produce strong wind gusts and/or moderate downpours. Most convection will likely diminish each night with the loss of diurnal heating. Overall highs should peak in the upper 80s near the coast to lower 90s inland. Overnight lows should range in the low/mid 70s away from the immediate coast. Tuesday: The mid/upper ridge of high pressure will gradually weaken aloft while sfc high pressure slowly retreats over the western Atlantic. The pattern suggests a greater potential for showers and thunderstorms as deeper moisture returns over the Southeast United States between the western edge of high pressure offshore and a trough of low pressure passing over the Appalachian Mountains. Scattered showers and thunderstorms remain in the forecast, with the greatest potential expected during the afternoon and evening hours. In general, afternoon highs should peak in the upper 80s near the coast to lower 90s inland. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... Upper level ridging will slide south of the area as troughing develops to our north through the middle of next week. A cold front will progress into the Carolinas by late week, but persistent deep westerly flow will make it difficult for the front to progress all the way into our area. Still, we will remain squarely within the warm/moist airmass ahead of the front, keeping near normal POPs and temps in the forecast through the period. && .AVIATION /23Z SATURDAY THROUGH THURSDAY/... Mainly VFR for the 00Z TAF period. We maintained mention of shallow ground fog at both terminals later tonight given moist soil and calm winds. However, conditions do not appear favorable for much in the way of dense fog. On Sunday, convective potential appears lower than on Saturday due to strengthening high pressure. Extended Aviation Outlook: VFR conditions will prevail at both CHS and SAV terminals into the middle of next week. However, brief flight restrictions are possible with afternoon showers and/or thunderstorms at either terminal each day. && .MARINE... Tonight: Ridging will build into the waters tonight, allowing S to SE winds. Seas will average 2-3 ft. Sunday through Thursday: High pressure will remain the dominant weather feature over the coastal waters early next week. In general, winds speeds will remain at or below 10 kt with winds primarily coming from the south Sunday and Monday before turning more southwest into the middle of the week as sfc high pressure presses closer to the Southeast coast. Winds could also be slightly stronger late morning/early afternoon each day until a seabreeze circulation shifts inland. On Wednesday, the pressure gradient should gradually strengthen between high pressure near the coast and a trough of low pressure approaching from the northwest inland. As a result, south/southwest winds of 10-15 kt should increase up to 15-20 kt by late Wednesday/early Thursday. Seas will range between 2-4 ft during the period, highest beyond 15 nm from the coast in northern South Carolina waters Tuesday night and Wednesday night. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...JRL SHORT TERM... LONG TERM... AVIATION...JRL MARINE...