Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
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273 FXUS62 KCHS 281450 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 1050 AM EDT Tue May 28 2024 .SYNOPSIS... A cold front will stall near the coast today. High pressure will return for the second half of the week. && .NEAR TERM /THROUGH TONIGHT/... Isolated showers have dissipated, so we lowered POPs for the next few hours. However, we`re still anticipating slight chance POPs for a small portion of our area later this afternoon. Otherwise, the foundation of the forecast remains solid. Rest of Today: The cold front has pushed through our land areas and is roughly located along the coast. This is confirmed with NW winds and dew points dropping, at least away from the beaches. Even though the front will stall along the coast, we`re still expected a weak sea breeze circulation to remain pinned to the coast later this afternoon. There may just enough convergence and lingering moisture near/behind the sea breeze itself to support isolated showers/tstms for a few hours this afternoon, mainly in the upper parts of Charleston County and far eastern Berkeley County where near term guidance shows a small pocket of marginal 850 hPa theta-e, K-indices rising 30-35C and dewpoints pooling back into the lower 70s. Slight chance POPs remain highlighted in this area mid-late afternoon. Elsewhere, considerably drier air advecting in from the west and northwest will make it very difficult for anything more than clouds to form. Even though low- level thicknesses drop a bit behind the front, a modest downslope flow developing downwind of the Southern Appalachians will tend to counteract and cooling influences. Highs look to peak in the lower 90s almost all the way to the beaches, but lower dewpoints will make it feel a bit less sticky and humid compared to the past few days. Tonight: High pressure will build in from the west overnight as a stalled front begins to push farther offshore. The gradient between these two features will likely keep a bit of wind going through the night, but clear skies and low dewpoints will promote at least some degree of modest radiational cooling. Lows will range from the lower 60s well inland to the lower 70s at the beaches. A northwest wind across Lake Moultrie will likely keep areas immediately downwind of the lake (i.e. Bonneau and Moncks Corner) a bit warmer given water temperatures are in the upper 70s/lower 80s. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... Surface trough develops over the region on Wednesday, before high pressure builds Wednesday night and pushes a secondary front offshore. High pressure remains the dominant surface feature through late week. Aloft, broad troughing persists over the eastern U.S., until a shortwave dives across the mid- Atlantic and eventually shifts offshore. Not much in the way of forcing or moisture for convection, so rain chances remain pretty low through the period. Highs near 90 on Wednesday return to the mid 80s for Thursday and Friday. Lows span the 60s. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... Surface high pressure initially centered over the mid-Atlantic will transition offshore and persist into early next week. Aloft, ridging will shift across the Southeast on Saturday before a series of weak disturbances possibly pass through. No stand-out day for precip at this point, with rain chances just in the 20-30% range. Temperatures will be within a few degrees of climo through the period. && .AVIATION /15Z TUESDAY THROUGH SATURDAY/... 28/12z TAF Discussion: KCHS/KJZI/KSAV: VFR through 29/12z. There is a risk for isolated showers/tstms to develop north of KCHS and KJZI for a few hours this afternoon near the intersection of a weak sea breeze and a stationary front. Right now, it appears any such convection should remain far enough to the north of both terminals to not cause any issues. No mention of VCTS will be included for the 12z TAF cycle. Extended Aviation Outlook: VFR. && .MARINE... Through Tonight: Winds will back more southerly this afternoon as a cold front stalls near the coast and a weak sea breeze develops near the beaches. Winds will remain less than 15 kt with seas 2-3 ft. Winds will finally turn west and eventually northwest tonight as the front finally begins to push farther offshore. Again, speeds will remain less than 15 kt with seas 2-3 ft. Wednesday through Sunday: No marine concerns anticipated midweek through the weekend. Secondary front passes through Wednesday night with high pressure the main feature for Thursday and beyond. Wind speeds average less than 15 knots. Seas 1-2 feet initially build to 2-4 feet over the weekend. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE...