Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
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386 FXUS62 KCHS 160206 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 1006 PM EDT Sat Jun 15 2024 .SYNOPSIS... A weak cold front will linger over the area this weekend before slowly lifting back northward early next week. High pressure will then ridge in from offshore mid to late next week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Per radar data, surface boundary appears to snake from upper Charleston County over through Jenkins County. Still some instability out there around 500 J/Kg MLCAPE particularly across the northern part of the forecast area, although convective inhibition continues to build with boundary layer cooling. But some modest showers continue to percolate at this hour especially around the Charleston and Berkeley counties area. Boundary will slowly sag southward and/or stall across the southern part of the area overnight while upper level ridging and surface high pressure build over the region. Ongoing convection will eventually run its course but may take a few more hours yet to do so. We have tweaked pops/weather accordingly. Lows will generally range from the lower 70s far inland to the mid 70s along the immediate coast. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... Sunday: Aloft, a strong mid-upper lvl ridge will prevail, remaining centered over the Southeast United States. At the sfc, high pressure centered across New England will slowly build south across the Southeast, nudging a cold front into the region that eventually stalls across the local area. Much of the area should remain rain- free, but sufficient moisture and instability should support few to scattered showers and thunderstorms during the afternoon into early evening, mainly away from the coast. Conditions will remain warm as well, with high temps in the low-mid 90s, warmest inland. Overnight lows will also remain mild, generally in the upper 60s/lower 70s inland to mid-upper 70s near the coast. Monday and Tuesday: Aloft, the pattern will remain similar with a ridge of high pressure elongated across the Northeast to Southeast United States that results in large scale subsidence locally. At the sfc, a stalled front will become more diffuse and/or lift back north of the area early week before high pressure builds across the region from the Atlantic by Tuesday. There are some hints of weak coastal troughing developing along the southern periphery of the ridge just off the Southeast Coast, which could result in some showers and/or thunderstorms across coastal areas, mainly south of Beaufort, SC and into southeast Georgia each afternoon/evening. High temps in the upper 80s nearshore to lower 90s inland Monday should trend a degree or two cooler on Tuesday with an onshore flow in place. Overnight lows will range in the mid-upper 60s well inland to low-mid 70s closer to the coast Monday night. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... Upper ridging shifts north mid-to-late week, with height falls aloft leading to diminishing upper subsidence. At the surface, high pressure migrates off the Northeast coast and toward a more seasonable Bermuda High location. Expect the forecast to trend back toward a more summer-like precip pattern, with scattered afternoon thunderstorms along and inland of the sea breeze and lesser storm activity overnight. Temps remain within a few degrees of normal. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... 00Z TAFs: Mainly VFR. Still some isolated diminishing convection across the tri-county area and recent radar trends suggest diminishing shower activity might drift into the KCHS and KJZI areas over the next few hours. Holding off on including precip at those TAF sites for now but will amend as needed. Quiet overnight into Sunday morning although some guidance suggest there could be some lower cloud cover streaming off the Atlantic into the coastal areas. Will see. Isolated to scattered convection is possible again Sunday afternoon although chances are too low to include in the forecasts for now. Extended Aviation Outlook: Mainly VFR at KCHS/KJZI/KSAV terminals, but there will be low probabilities for brief flight restrictions due to showers and/or thunderstorms impacting the terminals each afternoon/evening. Highest chances for flight restrictions should occur at the KSAV terminal. && .MARINE... Tonight: A weak cold front is expected to move south through our waters late, possibly stalling near the SC/GA line around daybreak Sunday. Sustained winds from the S or SE in the evening will veer overnight, becoming E by daybreak Sunday. Seas should average 2-3 ft. Sunday through Wednesday: The pressure gradient will remain fairly weak through Monday as a front becomes nearly stationary across the area and begins to deteriorate. However, a modest uptick in wind speeds (especially near the coast) and gradually building seas is anticipated early into the middle of next week as the pressure gradient is somewhat enhanced by high pressure extending across the area from the north and perhaps weak coastal troughing occurring along its southern base along the Southeast Coast. During this time, east-northeast winds could gust to 15-20 kt with seas building upwards to 3-5 ft, largest across offshore GA waters. Southeast swell is anticipated to increase during the second half of next week, which could prompt Small Craft Advisories for 6 ft seas. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...Adam SHORT TERM...DPB LONG TERM...DPB AVIATION...Adam/DPB MARINE...DPB