353 FXUS62 KCHS 060034 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 734 PM EST Fri Mar 5 2021 .SYNOPSIS... High pressure will prevail this weekend and through much of next week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Tonight: Aloft, a zonal flow will prevail during the first half of the night with high cirrus clouds associated with the left front quadrant of a passing h25 jet spreading across the region from the west. Although a light northeast sfc wind will be in place, high clouds will likely limit overall cooling potential early tonight, and even more so after midnight when mid-clouds arrive with an h5 shortwave rounding the southern base of a broad mid/upper lvl trough positioned across the Northeast United States. Despite a fair amount of moisture arriving in the mid-upper lvls along with mid-lvl forcing and upper-lvl divergence in place, model soundings along with the most recent chs sounding indicate a significant amount of dry air from the sfc to the 500mb lvl, which will likely keep all areas dry through the overnight period. In general, low temps should range in the low/mid 40s away from the coast with a few upper 30s possible across northern parts of Berkeley County. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... High pressure will remain the dominant feature over the weekend and early next week. Dry weather is expected, with the possible exception being on Saturday when a few showers could brush the far southeast Georgia coast as a weak system passes well to the south. The main forecast concern for the period is the potential for frost or a freeze each morning. Favorable radiational cooling under clear skies and light winds will allow temperatures to fall into the low/mid 30s across most locations inland of the beaches. These temperatures are supportive of frost development, however relative humidity values are a bit low. Opted to maintain patchy frost in the forecast for now, but coverage could certainly be higher if conditions trend more favorably. In addition, freezing temperatures are possible across the far interior. Freeze Watches and/or Warnings could be needed. High temperatures will remain unseasonably cool as well, generally peaking in the mid to upper 50s over the weekend, then around 60/low 60s on Monday. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... Models are in excellent agreement for the long term forecast. They keep high pressure off the coast, with it's periphery stretching into the Southeast U.S. Dry conditions with moderating temperatures are expected. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... VFR conditions will prevail at both CHS and SAV terminals through 00Z Sunday. Extended Aviation Outlook: VFR. && .MARINE... Tonight: High pressure will persist across local waters late this evening and through the overnight period behind a cold front positioned south of the area. In general, east-northeast winds will average no higher than 10-15 kt early tonight, but are anticipated to increase slightly after midnight with the approach of a h5 shortwave from the west. Fair cold air advection across the waters will be in place, but 1000 mb geostrophic flow is rather limited (15- 25 kt). Given the setup, expect winds to turn northeast after midnight with a slight surge in wind speeds gusting up to 15-20 kt at times. Seas should range between 2-3 ft across nearshore waters and around 4 ft across offshore Georgia waters. Saturday through Wednesday: Elevated northeast to north winds are expected over the weekend, especially Saturday night into Sunday morning with strong pressure rises and cold air advection. The best chance for Small Craft Advisories will be across the outer Georgia waters for 25 kt wind gusts. Opted to hold off on issuance as conditions appear marginal at this time. Winds and seas will improve early next week as high pressure moves over the area and the pressure gradient relaxes. No additional marine headlines are expected. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...DPB SHORT TERM... LONG TERM... AVIATION...DPB MARINE...DPB