206 FXUS62 KCHS 210228 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 1028 PM EDT MON JUN 20 2016 .SYNOPSIS... High pressure will gradually shift east through Friday while a trough of low pressure develops inland. A cold front will stall over the area Saturday before dissipating by early next week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Late this evening: No change to the going forecast. Continues to look like a very quiet night with high pressure in control. Skies should be mostly clear, with just a few mid/high clouds streaming in from the north around the prominent upper ridge. Temperatures are still expected to fall into the low to mid 60s away from the coast, with the coolest values in the typical cool spots. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... An expansive upper ridge will flatten out over the central and eastern United States during the period while surface high pressure shifts into the western Atlantic. Low-level thickness advection combined with downslope flow and mostly sunny skies will yield steadily increasing high temperatures. By Thursday we expect highs in the mid to upper 90s. Fairly deep offshore flow and deep mixing should maintain rain-free conditions and somewhat below- average dewpoints. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... Hot temps in the mid/upper 90s will continue through at least Friday. Maintained slight chance pops only across northern/inland counties, although the capped environment provided but the upper ridge could prevent any thunderstorm development for yet another day. Then, a cold front is still expected to advance into the region Saturday, although the position/strength of the upper ridge suggests that this front will enter the region in a weakening/slowing fashion and will likely stall/dissipate Sunday/Monday. Accordingly, raised temps into the lower to mid 90s Saturday, and near normal lower 90s should become common Sunday/Monday. While details regarding pops remain uncertain, the general pattern favors at least isolated/scattered thunderstorms Saturday through Monday. In fact, the dissipating stationary front could serve to focus higher dewpoints/greater instability over the region, and we could return to a more active convective regime especially starting early next week. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... VFR through 00z Wednesday. Winds will start out southwest on Tuesday and will then become more southerly with the sea breeze. Some gusts to around 20 kt will be possible in the mid to late afternoon hours. Extended Aviation Outlook: Mainly VFR. && .MARINE... Tonight: The low-level flow gradually turn southerly as high pressure shifts south of the area. There are signals that weak nocturnal surging will occur early Tuesday in response to the formation of a weak lee-side through. Should see winds top out at around 15 kt Charleston County waters with 10-15 kt elsewhere. Seas will average 2-3 ft nearshore waters and 3-4 ft offshore waters. Tuesday through Friday: A decent gradient will exist between Atlantic high pressure and a developing lee trough inland. Wind speeds will frequently be 15-20 kt with some higher gusts though we currently have conditions just below Small Craft Advisory criteria. Saturday, a cold front could push into the waters before stalling, initially turning sub-Small Craft Advisory winds toward the W/NW then pushing winds to the E/NE. Forecast uncertainly increases this weekend due to uncertain timing/progress of the cold front. Rip Currents: There is a moderate risk for rip currents on Tuesday due to 2-3 ft 9 sec swell, a robust afternoon sea breeze and astronomical factors. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...BSH SHORT TERM...JRL LONG TERM...SPR AVIATION...BSH/JRL MARINE...ST/JRL