920 FXUS62 KCHS 111125 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 725 AM EDT Sun Aug 11 2019 .SYNOPSIS... A front will remain stalled over or just south of the area through Monday. Drier high pressure will briefly build from the north on Tuesday, then another front will drop into the area late Wednesday and linger into Saturday. && .NEAR TERM /THROUGH TONIGHT/... Today: While high pressure settles over the northern Mid Atlc region, a poorly defined surface front is forecast to drift over the northern half of the forecast area in SC through mid afternoon, prior to mingling with the GA sea breeze corridor later today and early this evening. The main result of this boundary will be an enhancement of low level moisture convergence and a late day flux of Atlc moisture which is something we have not seen in a while with the offshore flow and pinned sea breezes. Reliable CAMs suggest showers/tstms will initially develop in the axis of the surface trough bisecting the area W-E along/north of I-16 in GA and then across coastal SC. The weaker cap is over SC zones and convective initiation may occur as early at 16Z-17Z in this area. Coverage of convective rains will expand inland and southward during the afternoon with scattered to occasionally numerous showers and tstms. A few stronger tstms are likely with very heavy rainfall, gusty winds and frequent lightning strikes. Inspection of the elevated environment gives mixed signals with some drier air advecting in from the northwest and some decent DCAPEs. Mid level instability looks rather unremarkable over much of SC and only a bit better inland from I-95 in GA. We think chances of severe weather are low with a couple isolated wet downburst wind events not out of the question. The risk of locally heavy downpours looks decent and we will watch for any tstms pinned along coastal areas as high tide approaches late in the afternoon. In GA, very hot weather will be extended today with heat indices approaching heat advisory criteria to the south of I-16 and especially along the coast. Highs should not reach Saturday's levels however dew points will be more elevated. Tonight: The weak front should push south of the area late and showers and storms are expected to diminish late evening with mainly coastal convection in GA possible toward daybreak on Mon. We will need to further access fog potential for some patchy mention inland zones as well, especially if soils were moistened under a weak northeast flow overnight. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... Deep layered ridging briefly builds over the area Monday into Tuesday with slightly drier air filtering in from the northwest. Convective coverage will be considerably lower and mainly focused along southern areas where deeper moisture coincides with weak low-level convergence. High temps will be in the low to mid 90s both days, but slightly lower dewpoints should preclude the need for Heat Advisories. The upper ridge will flatten on Wednesday and a cold front will approach the area late in the day from the northwest. Hot temperatures are expected with highs in the mid to upper 90s. Subsidence will limit convective development during the morning and early afternoon, then a substantial increase in coverage is expected late in the day as the front approaches and the sea breeze comes into play. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... The cold front will stall over the area Wednesday night and linger into Saturday. Deep tropical moisture will continue to overspread the area, likely resulting in a wet pattern with scattered to numerous showers and tstms much of the period. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... VFR conditions this morning. Showers and tstms are expected to develop this afternoon and early evening as a weak front drops south over the coastal corridor, interacting with the developing sea breeze and enhancement convergence of moisture. Flight restrictions associated with tstms are possible at both terminals. Later tonight, patchy low clouds and fog are possible but the current potential is too low for TAF inclusions. Extended Aviation Outlook: Brief flight restrictions in scattered showers and thunderstorms, mainly during the afternoon hours. && .MARINE... Conditions appear to be favorable for waterspouts later this morning and we will access the potential as sunrise approaches. A weak front dropping through the area will result in light and variable winds early on, then become onshore later this afternoon. There should be some modest 10-15 kt surges later today and early this evening but the flow will generally remain on the light side through tonight outside of deep convection. Showers and tstms are possible through tonight with potential for heavy rains and dangerous lightning strikes. Seas will mainly be in the 1-3 ft range, 2 ft or so on average. Winds will fluctuate between SW and SE, generally at or below 15 kt. A slight surge is expected late Wednesday into Thursday as a cold front approaches the waters. A moderate sea breeze will develop each afternoon along the coast. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM... SHORT TERM...JRL LONG TERM...JRL AVIATION... MARINE...