Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
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286 FXUS62 KCHS 211807 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 207 PM EDT Sat Sep 21 2024 .SYNOPSIS... High pressure across the region will prevail through early next week. A weak cold front may approach from the west around the middle of next week. && .NEAR TERM /THROUGH TONIGHT/... Rest of Today: Aloft, a trough is shifting eastward across the western Atlantic while a ridge centered across Texas extends further east across the Deep South and into the Southeast United States. At the sfc, High pressure remains across the Southeast United States, but is showing signs of drifting off the Mid- Atlantic coast. The pattern is bringing mostly dry weather with fair weather cumulus. Highs are on track to peak in the low to mid 80s closer to the coast, and the upper 80s inland. A few areas could top out near 90 degrees across far inland zones of Southeast Georgia. Tonight: Dry conditions will prevail with sfc high pressure settled across the local area and mid-lvl ridging extending from the west aloft. Although a bit of cirrus could move across the region, conditions should favor another decent radiational cooling night with light/calm winds for much of the night for areas away from the coast. Low-lvl moisture is a bit lacking, so fog is generally not anticipated. Overnight lows should range in the mid 60s inland to upper 60s/lower 70s near the beaches. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... The synoptic pattern will remain largely unchanged through the period with a large upper ridge across the Deep South, slowly progressing eastward with time. Broad surface high pressure will remain over the eastern CONUS and extreme western Atlantic providing subsidence and generally quiet weather conditions through the period. Mostly sunny skies are expected each day through Tuesday. Any potential for convection will be largely suppressed due to relatively dry air aloft and the lack of significant forcing mechanisms. No mentionable rainfall chances have been included during this period. Temperatures will be mild/slightly above normal through the period due to the ridge aloft with highs in the upper 80s/low 90s each day. Sunday and Monday night will feature lows in the upper 60s inland and lower 70s near the coast. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... The long-term forecast features increasing chances for showers and perhaps a few thunderstorms. The region will see a slight uptick in moisture as the upper ridge axis shifts offshore Wednesday. Slight chance POPs return Wednesday evening with peak rain chances anticipated to occur later in the week as an upper trough and cold front approach. Temperatures will start mild with highs in the upper 80s initially and trending cooler into the lower 80s by next weekend. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... 18z TAFs: VFR. Extended Aviation Outlook: VFR conditions expected to prevail. && .MARINE... Today and Tonight: A modest pressure gradient is prevailing between High pressure inland and a weak trough well south of our area. This synoptic setup is yielding 10-15 kt NE winds with a few gusts up to 20 kt. Winds will gradually veer and ease overnight as the pressure gradient lowers. Seas will generally range between 2-4 ft across the nearshore waters and 4-5 ft across the offshore Georgia waters during the day, but should subside about a foot during the night. Sunday through Wednesday: As high pressure begins to migrate offshore, winds will shift out of the east/southeast around 10 kt or less. Seas will average 2-3 ft within 20 nm and 3-4 ft for the GA waters from 20-60 nm. Rip Currents: Onshore winds approaching 10-15 kt, 2 ft swell near 10 seconds along with local RCMOS model data favor a Moderate Risk for rip currents along Georgia beaches today. && .TIDES/COASTAL FLOODING... Positive tidal anomalies and high astronomical tides from the recent full moon will lead to elevated tides through the weekend. Although the astronomical high tides are lowering, coastal flooding is expected with each daytime high tide cycle along the Charleston and Colleton County coasts. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM... SHORT TERM...BRM LONG TERM...BRM AVIATION...BRM MARINE...BRM