263 FXUS62 KCHS 302322 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 722 PM EDT Mon Apr 30 2018 .SYNOPSIS... Surface high pressure centered off the Southeast coast will remain in control through the week. A cold front could impact the area early next week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Although there is air mass modification tonight, given another night of strong radiational cooling and the pattern much of this spring with dry and radiational nights, we have lowered min temps by about 2-4F from the previous forecast. This now supports lows as cool as the middle 40s far inland to the mid and upper 50s along the immediate coast. Otherwise, we have decouple winds quicker this evening than originally planned, as some places are already calm. Previous discussion... The center of large sfc high pressure will slide off the Southeast coast of the U.S. tonight. H5 heights are forecast to increase from the west, with the ridge axis west of the Appalachians. Weather conditions will remain clear and dry. Using a blend of MOS, low temperatures are expected to range from the upper 40s inland to the mid 50s along the coast. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Deep layer subsidence will strengthen over the area as surface high pressure slides further off the coast through the middle of the week. Low level theta-e content will gradually trend upward as trajectories back from onshore to more southerly through the period. Still, too much dry air in the column for there to be any chance of precipitation. Mainly sunny skies will prevail Tuesday and Wednesday, with some flat afternoon cumulus possible inland of the afternoon seabreeze beginning Thursday afternoon. High temps will be near normal Tuesday before trending upward a couple degrees each successive day. Boundary layer decoupling each night will result in diurnal swings of around 30 degrees. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... The area will remain along the western periphery of high pressure centered over the western Atlantic through late weekend. In general, a southerly sfc wind in combination with mostly sunny skies should support high temps in the mid/upper 80s Friday and Saturday with a few locations potentially reaching 90 degrees well inland. Overnight lows should also remain more mild, ranging in the low/mid 60s Friday night and Saturday night. The next best chance of precip should come with a h5 shortwave trough and slow moving cold front Sunday and/or Monday. A slight chance of showers is possible as this feature slowly shifts through the Southeast. A few rumbles of thunder can not be ruled out. Temps should be a few degrees cooler as clouds/precip activity increase and fropa occurs early next week. In general, highs should range in the upper 70s/lower 80s Sunday and Monday. Lows should dip into the lower 60s Sunday night, then upper 50s inland to lower 60s near the coast Monday night. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... VFR at KCHS and KSAV through 00Z Wednesday. Extended Aviation Outlook: VFR conditions will prevail through the rest of the week. && .MARINE... The sea breeze influences have been a little stronger than originally predicted, so we have raised SE'erly winds up to 10-15 kt this evening. Much lighter winds overnight with the center of high pressure atop the area, and local land breeze circulations developing north by late. Seas will average 2-3 ft, highest across the Georgia waters. Previous discussion... Dominate high pressure will remain across the marine zones and surround waters through tonight. Winds may fall below 5 kts across the coastal waters late tonight, favoring a southeast direction. Wave heights between 1-2 feet should be common within 20 NM, 2-3 feet across the outer GA waters. Tuesday through Saturday: High pressure centered off the Southeast coast will bring mainly light winds across the coastal waters through late week. Gusts to around 15 kt are possible near the coast during afternoon seabreeze circulations Thursday through the weekend. No significant swells are expected, and seas will be mainly 2 to 3 ft, with some 4 ft waves beyond 30 nm from shore as we head toward the weekend. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM... SHORT TERM...CEB LONG TERM...DPB AVIATION... MARINE...