350 FXUS62 KCHS 170635 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 235 AM EDT Thu Apr 17 2025 .SYNOPSIS... High pressure will build over the region and remain the primary feature through the weekend and into early next week. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... Tonight: Aloft, a large trough will shift further off the Northeast Coast while a broad trough expands across the Southeast United States. At the sfc, high pressure will linger across the local area, eventually becoming more centered off the Mid-Atlantic coast by daybreak. Light/calm winds under clear skies will continue to support a strong radiational cooling setup for the night. In general, temps should dip into the lower 40s inland, coolest across parts of the Francis Marion Forest. Temps should remain in the low- mid 50s closer to the coast. && .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/... Upper level ridging pushes eastward across the Ohio River Valley Thursday, allowing quiet conditions to continue across our area. Will see highs during this time approach seasonal norms, as temperatures rise into the upper 70s to lower 80s. Above normal temperatures then return heading into the weekend with the aid of plentiful sunshine and S/SE winds. Currently have highs in the mid to upper 80s, with perhaps a few of our interior GA counties approaching 90 degrees. Otherwise, look for overnight lows to remain on the milder side, as temperatures only fall into the 50s to lower 60s. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... Upper level ridging begins to degrade by Sunday as a trough develops across the central CONUS. Despite there being an increase in cloud cover, still expect highs to warm into the mid to upper 80s. Otherwise, look for rain chances to return early next week as the aforementioned trough nudges closer to the region. Mainly have isolated PoPs (<20%) Monday afternoon for our interior SC/GA counties. Given the diurnal nature of these showers, do not expect to see much in the way of severe weather - rather, just some rumbles of thunder. Better forcing arrives Tuesday ahead of an advancing cold front. Nonetheless, still only looking at scattered coverage, with showers then lingering into Wednesday as the front stalls. In regard to temperatures, expect afternoon highs in the 80s and overnight lows in the 60s to remain common. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... VFR conditions will prevail at KCHS/KJZI/KSAV terminals through 06Z Friday. Extended Aviation Outlook: Prevailing VFR. && .MARINE... Tonight: Quiet conditions are expected across the region as high pressure overhead becomes more centered off the Mid-Atlantic coast by daybreak. The pressure gradient will be very weak across local waters as a result, with southwest winds peaking around 10 kt or less becoming more west late. Seas will range between 1-2 ft. Friday through Monday: High pressure strengthens overhead through the weekend, allowing tranquil marine conditions to prevail, with S/SE winds between 10 to 15 kts and seas averaging 2 to 4 ft. Gusts along the direct coastline and the Charleston Harbor could surge each afternoon to around 20 knots due to the afternoon sea breeze. && .FIRE WEATHER... For Thursday, another round of relative humidity values around 25 percent is expected. The best chance for values around or below 25 percent will be interior southeast GA. However, winds will not be a concern with speeds 10 mph or less in most areas. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM... SHORT TERM...SST LONG TERM...SST AVIATION...DPB/SST MARINE...