Area Forecast Discussion
Issued by NWS Charleston, SC

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000 FXUS62 KCHS 302255 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 655 PM EDT THU JUN 30 2016 .SYNOPSIS... A stationary front will linger inland through tonight. Atlantic high pressure will remain east of the area as a weak trough of low pressure sits inland through this weekend. By early next week, a nearly stationary front north of the area is expected to align from west to east, while Atlantic high pressure prevails along the Southeast coast. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Convection will gradually end this evening. One last cluster of strong tstms will impact interior Southeast South Carolina over the next 1-2 hours. Isolated severe tstm is still possible, but main focus remains locally heavy rainfall. Adjusted pops per going radar trends. Some redevelopment to showers/tstms is possible over the coastal waters later tonight, some of which may brush the lower South Carolina coast. Adjusted pops slightly to reflect this. Overnight pops will range from 20% inland to 40% along the lower South Carolina coast. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... A pretty typical summer/early July weather pattern will be in place through this weekend. The area will remain near the base of a broad upper level trough and a deep layer ridge over the Atlantic. The latest models are indicating lower mean RH levels for Friday and even Saturday, which should translate to lower afternoon convective coverage. Have nudged pops back a tad for Friday and Saturday afternoons, but still around 40% given some weak upper troughing just north of the area. Convection will be mainly focused by the seabreeze. High temperatures range from the mid 80s at the coast to the lower 90s inland for Friday and a degree or so warmer Saturday. Lows in the lower 70s. By Sunday, deep layer moisture starts to increase but upper heights also rise as the Atlantic ridge builds slowly in from the southeast. Thus, expect afternoon convective coverage to still be pretty typical for this time of year, with pops around 40%, especially just away from the coast. Highs will be hotter in the lower to mid 90s with heat indices of 102 to 106 degrees likely. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... The overall thinking for the long term remains the same though the most recent models runs have trended a bit further south with the nearly stationary front situated to the north. The large subtropical ridge still looks to build in from the east early in the week, with a shortwave progressing into the Appalachians within the zonal flow to the north. Ultimately, how far south this trough can penetrate into the ridge will determine how active the pattern is for Tuesday into Wednesday. The thinking is still that the ridge will remain strong enough to keep the period relatively dry and hot. In fact, chances look good for seeing upper 90s by mid week. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... VFR. Tstms could get close enough to KCHS 00-01z, but think any impacts will remain to the north. Mid-level clouds will linger through the night. Tstms are possible again Friday afternoon. Too far to include a mention attm given uncertainties in timing/coverage this far out. Extended Aviation Outlook: Brief periods of flight restrictions possible with mainly afternoon thunderstorms. Otherwise, VFR will prevail. && .MARINE... Tonight: A light gradient across the waters will maintain south to southwest winds generally under 15 kt. Seas will average 2 to 3 ft through daybreak Friday. Friday through Monday: Atlantic high pressure will prevail across the local waters through at least Monday with no highlights expected. This will result in generally south-southwest flow of 15 knots of less and seas 3 to 4 feet or less. Could see the typical nocturnal surge with winds reaching 15-20 knots in the late night/early morning each day, and then again an increase close to the coast during the afternoon due to the seabreeze. By Tuesday, another upper trough may work toward the area from the west-northwest, resulting in lowering surface pressures over the southeast U.S.. This will increase the pressure gradient across the waters, with southwest winds of 15-20 knots possible and seas 3 to 5 feet. && .TIDES/COASTAL FLOODING... The upcoming Perigee occurs early Friday and the New Moon occurs Independence Day. This scenario will support elevated tides, with shallow coastal flooding possible late this week into early next week. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ ST is the U.S. government's official web portal to all federal, state and local government web resources and services.