Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
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208 FXUS62 KCHS 082358 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 758 PM EDT Sat Jun 8 2024 .SYNOPSIS... High pressure will prevail through the weekend, followed by a cold front moving through the area on Monday. The pattern is expected to turn more unsettled mid to late next week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... Tonight: A quiet and relatively nice night is in store for early June. Surface high pressure centered southeast of the area will continue to weaken as a broad upper level trough builds over the eastern and southeastern states. Expect winds to become light south-southwest with mostly clear skies, except for cirrus. Despite temperatures being above normal earlier today, the relatively dry low levels will allow temperatures to fall close to seasonal normals, in the mid to upper 60s west of I-95 and lower 70s close to the coast. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... Sunday: The mid-levels will initially consist of High pressure in the northeast Gulf of Mexico and Low pressure north of the Great Lakes region. The High will weaken as time progresses, while the Low strengthens and forms a trough along the East Coast. At the surface, weak High pressure will initially be over the region in the morning. A cold front will approach from the northwest overnight, possibly making it to our northernmost counties by daybreak Monday. The High will bring our area mainly dry conditions into the afternoon. The combination of low-level thickness values, mostly sunny skies, and a sea breeze limited mainly to the coast will support high temperatures just short of record values. Highs should peak in the mid to upper 90s, except cooler at the beaches. However, dew points will be in the upper 50s to lower 60s away from the immediate coast, which will equate to heat indices at or just short of 100 degrees across our area. Moisture increases during the evening and overnight ahead of the front. The models point towards isolated convection, but disagree on the location. Therefore, we kept slight chance POPs closest to the front. While, SPC did put the northernmost portion of our area under a Marginal Risk for severe storms late at night, we feel like this may be overdone at this point. Low temperatures will remain mild, falling into the low 70s far inland and the mid/upper 70s near the coast. Monday: The mid-levels will consist of a positively tilted trough amplifying over the East Coast. At the surface, a cold front located over our northernmost counties at daybreak will slowly shift southeast during the day, likely becoming located offshore to our southeast by late at night. There will be a plume of moisture ahead of the front, with PWATs peaking around 2". Temperatures will few cooler compared to Sunday, with highs ranging from the upper 80s across our northernmost tier, to the mid 90s near the Altamaha River. Lift from the front and the sea breeze will combine with the moisture to generate afternoon convection. It appears the highest instability is along our GA coast, where MLCAPEs could reach 1,500 J/kg. Shear increases there, with DCAPEs possibly exceeding 1,000 J/kg. So a few marginally severe thunderstorms with damaging winds cannot be ruled out. We`ll also need to monitor the front, sea breeze, and boundary interactions as there is the concern backbuilding storms could lead to locally heavy rainfall, mainly along our GA coast. This will need to be refined with future updates. For now, we have chance POPs in the afternoon and evening. But models are showing hints that strong convection could persist through the night, especially closer to our entire coast. Low temperatures will range from the mid 60s far inland to the lower 70s near the coast. Tuesday: The positively tilted trough prevails over the East Coast. Meanwhile, a stationary front will meander just off our coast. Additionally, High pressure will be centered to our northwest. There is some uncertainty regarding whether moisture associated with the front will combined with the afternoon sea breeze to bring our area unsettled conditions, or if drier air from the High will overspread enough of our area to limit convection. We have chance POPs along the coast, especially our GA coast. But the models hint at it being drier as opposed to wetter. Highs will peak in the upper 80s to lower 90s. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... The general pattern is for a large, unorganized area of Low pressure to potentially develop somewhere in the Gulf of Mexico. Most models indicate that at least some of the deep layer/tropical moisture associated with this feature could spread northeastward toward our region, especially mid to late next week. We will continue to monitor the potential for locally heavy rainfall, but it remains too early to determine QPF/rainfall totals. Temperatures should be near to slightly below normal. && .AVIATION /23Z SATURDAY THROUGH THURSDAY/... Tonight: VFR conditions will prevail at KCHS, KJZI, and KSAV with light sse winds of 5-10 mph, becoming variable to southwest 5 mph or less later tonight into Sunday morning. Extended Aviation Outlook: VFR through Sunday night. The chance for convection and periodic flight restrictions increases Monday through Thursday. && .MARINE... Tonight: No changes were made to the previous forecast. The latest observations shows mostly southeast winds of 5 to 15 knots across the waters. Winds are expected to drop a little more tonight to 5 to 10 knots most areas, with seas 3 feet or less. Extended Marine: A cold front will approach from the northwest Sunday night, slowly moving through our waters on Monday, then meandering to our southeast Monday night through the middle of next week. Winds will initially surge Sunday night, but stay below Small Craft Advisory criteria. && .CLIMATE... Record High Temperatures June 9: KCHS: 99/1986 && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...RFM SHORT TERM...RFM LONG TERM... AVIATION...RFM MARINE...RFM