Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
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031 FXUS62 KCHS 150113 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 913 PM EDT Fri Jun 14 2024 .SYNOPSIS... A stationary front will meander just off the coast through the end of the week. A weak cold front will drop into the region early this weekend before high pressure builds in from the north. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Quiet and warm conditions will prevail tonight. The boundary layer is beginning to decouple inland as expected and variable winds should encompass much of the area through daybreak Saturday. Lows from the upper 60s/lower 70s inland to the mid- upper 70s at the beaches and Downtown Charleston look on track. No changes were needed for the late evening update. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/... Saturday: The mid-level trough offshore will move away as time progresses. Meanwhile, ridging and High pressure will gradually build over the Southeast. At the surface, a weak cold front will be located just to our north at daybreak. It`s expected to slowly shift south during the day and weaken, likely stalling around the Savannah River during the evening and overnight hours. Moisture increases around the front, with PWATs possibly rising to 1.75 by late afternoon. The combination of the increasing moisture, lift from the front, and a robust afternoon sea breeze could generate isolated to maybe scattered convection in the afternoon. Generally, the synoptic models and long range CAMs line up with this. However, the limiting factors will be dry air in the mid-levels and not much instability. This is why we maintained the slight chance POPs and didn`t go any higher. Any remnant convection should shift towards the coast during the evening, then offshore overnight. Highs will be in the mid to upper 90s for most areas, except cooler at the beaches. Heat indices will also be in the lower 100s. Overnight lows will be in the lower to mid 70s. Sunday: The mid-levels will consist of a broad 593 dam High hovering over the Southeast. At the surface, a stationary front should be located over our GA counties in the morning. It`s expected to shift south and dissipate in the afternoon as High pressure to our north and northeast tries to build into our area. Plenty of moisture will remain across our area as PWATs should reach or exceed 1.75". Likewise, models indicate there should be enough moisture and lift near the front to generate isolated to scattered convection. We have chance POPs across most our our area, with slight chance POPs generally across the Charleston Tri-County. Though, it`s possible we may need to lower POPs more if dry air moves in from the north, limiting instability and overall convection. Highs will again reach into the low to mid 90s away from the immediate coast. Lows will be in the upper 60s far inland to the mid 70s along the immediate coast. Monday: A broad 595 dam mid-level High will be centered over VA and the Carolinas. Broad surface High pressure will be located off the Mid- Atlantic coast, with its periphery stretching into our region. This will bring drier air into our area in the form of lower PWATs, possibly below 1", and dewpoints in the 60s inland, and the lower 70s at the beaches. Strong subsidence should limit isolated convection to just our GA coast. But even this forecast may be overdone and need to be lowered due to almost no instability and drier model trends. Temperatures will range from the mid 90s far inland, to the upper 80s at the beaches. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... Mid-level High pressure initially to our north Monday night will gradually shift into New England by Wednesday, followed by gradually lowering heights over our region. Surface High pressure in the Atlantic should persist, at times reaching into our area. Convection looks to be limited to the coastal waters or the immediate coast through Wednesday, followed by more coverage over land areas Thursday and Friday. Temperatures are forecast to be right around normal. && .AVIATION /01Z SATURDAY THROUGH WEDNESDAY/... 15/00z TAF Discussion: KCHS/KJZI/KSAV: VFR through 16/00z. There could be a little shallow ground fog that develops at any of the terminals early Saturday morning, but no major impacts are expected. Isolated showers/tstms associated with an approaching cold front could make a run for KCHS and KJZI mid-late afternoon, but confidence on impacts is too low to include a mention of VCTS or TSRA for now. Extended Aviation Outlook: Mainly VFR. There will be low probabilities of brief flight restrictions due to convection each afternoon/evening. && .MARINE... Tonight: Winds will veer to the southwest overnight with speeds less than 10 kt. Seas will average 2-3 ft. Saturday through Wednesday: Generally tranquil marine conditions are expected through the middle of next week, with sustained winds mostly 15 kt or less. Seas should average 2-4 ft. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$