Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
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849 FXUS62 KCHS 070012 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 812 PM EDT Thu Jun 6 2024 .SYNOPSIS... A cold front will approach from the northwest tonight and move through Friday morning. High pressure returns for the weekend, then another cold front will move through Monday. High pressure will build back in behind the front. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Tonight: A few showers/thunderstorms could develop across far western most zones early this evening, where strong heating during the day (highs in the low-mid 90s) along with broad h5 shortwave energy advancing eastward across the region has led to SBCAPE in the 1500-2500 J/kg range locally. Strong low-lvl lapse rates around 8 C/km and DCAPE values upwards to 1000-1200 J/kg also suggests a brief window for a thunderstorm or two to produce strong wind gusts, but any activity should gradually wane after sunset within a weakly sheared environment. There should be a lull in precip activity mid-late evening before the focus of additional shower/thunderstorm activity occurs as a cold front approaches the region overnight. Some hi-res guidance suggests shower/thunderstorm redevelopment to occur along/east of the I-95 corridor after midnight, with the bulk of precip activity drifting eastward and eventually off the coast by daybreak Friday as the cold front nears. Shear remains weak during this time frame and the severe weather threat is anticipated to be low, but modest instability (SBCAPE around 1500-2000 J/kg) could support loosely organized showers/thunderstorms capable of producing strong wind gusts. With increasing cloud cover and a southerly flow in place ahead of the front, low temps will remain quiet mild with mid/upper 70s along near the coast and low 70s inland. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... An elongated axis of upper level low pressure will build across the Northern Plains/Great Lakes and New England region during the first part of the near term with low amplitude troughing pressing down through the Mid Atlantic and southeast states. Surface boundary is still looking to gradually slip down through the region during the course of day Friday and will knock temperatures down a few degrees from where we have been the last few. But the more noticeable impact will be lower dewpoint/drier air gradually spreading into the southeast region through the course of the day. Precip chances look minimal, although there could be a few pop-up showers along the boundary Friday afternoon particularly across parts of southeast Georgia where higher dewpoint air/instability is expected to reside - although that will depend on just where the boundary ends up at that time. With drier air/minimal instability across the region, Saturday and Sunday look quiet at this juncture. But temperatures will continue to run warm/above normal through the weekend with highs warming into the lower to middle 90s each day...a good 5 to 10 degrees above normal for early June. Overnight lows through the period will range through the 60s overall, to the lower/middle 70s along the coast. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... Low amplitude ridging is looking spread out along the Gulf Coast region through the first part of next week with warmer/higher dewpoint air again edging back through the southeast states. Along with several weak disturbances rippling through the region, daytime shower/thunderstorm chances are looking to return during the first half of the week. A stronger/better organized upper level trough may advance through the Gulf Coast and southeast region during the middle and latter half of next week bringing higher precip chances, although longer term guidance solutions do show a fair amount of spread during that time frame. Temperatures will continue to run above normal through the period overall, but we could see a bit of a cooldown mid to late week...depending on how the pattern evolves. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... VFR conditions are expected at CHS/JZI/SAV terminals through 00Z Saturday. However, there is a chance for a few showers/thunderstorms to develop late tonight and impact the terminals, with CHS/JZI seeing the better chances of occurrence and reducing cigs/vsbys to MVFR levels or possibly lower if directly impacted. At this time, confidence remains too low to include mention of thunderstorms in the latest TAF issuance. Extended Aviation Outlook: Overall VFR conditions will prevail through the period. && .MARINE... Tonight: Winds will surge slightly as a cold front approaches from the west overnight. A somewhat enhanced pressure gradient should yield south-southeast winds upwards to 15-20 kt, strongest across South Carolina waters and the CHS Harbor. Seas should also build up to 3-4 ft. Friday through Monday: Southerly flow early Friday will veer westerly Friday night and northerly on Saturday behind a cold front. However, the pattern quickly reverts back to the typical southerly/ southwesterly flow later in the weekend into early next week. Winds will continue to run 15 knots or less with seas 3 feet or less. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...DPB SHORT TERM...Adam LONG TERM...Adam AVIATION...Adam/CPM MARINE...Adam/DPB