376 FXUS62 KCHS 100716 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 316 AM EDT Tue Jun 10 2025 .SYNOPSIS... A cold front will approach the region and stall mid-week. High pressure will prevail late week into the weekend. && .NEAR TERM /THROUGH TONIGHT/... Early this morning: We continue to see the area of showers and thunderstorms slowly sink into the forecast area producing some gusty winds and pockets of moderate to heavy rain. The good news is that the convection is showing signs of weakening as reflectivity values diminish and cloud tops slowly start to warm. We still think the hi-res model solutions are directionally correct in showing this area of showers and storms steadily diminish over the next few hours and eventually go away completely before reaching the coast. Today: Aloft, the forecast area will remain on the east side of the mid/upper level trough axis extending southward out of the Great Lakes region. Model guidance depicts an embedded vort max within the southwest flow that will move along the GA/SC coast and could help to serve as a driver of convection during the day. At the surface, no change as the forecast area sits between Atlantic high pressure and an inland front with a warm, moist, and humid summertime airmass. Current thinking is that the day will start will little to now convection. Then we will see development start in the mid to late morning hours along and south of I-16 and then steadily ride up the coast through the afternoon, associated with the aforementioned shortwave aloft. Therefore, we will highlight the best chances along the coastal corridor where the best forcing and instability will reside. Overall, the near storm environment looks a bit less conducive to strong to severe convection today. MLCAPE values are progged to be a bit less (~1,500 J/kg) as well as DCAPE values (600- 800 J/kg). However, there is still good mid-level flow noted in model soundings, on the order of 30-40 knots. Therefore, there will be the threat of isolated severe thunderstorms capable of producing damaging wind gusts. This is in line with the SPC Day 1 Marginal Risk area that encompasses the entire forecast area. Expect some breezy conditions outside of any storms, with frequent southwesterly gusts into the 15-20 mph range. Temperatures are expected to generally top out in the upper 80s. This evening and tonight: Afternoon convection should diminish starting in the early evening, though some hi-res model solutions suggest there will be some upstream convection that could make a run for our western zones late in the evening. Otherwise, we expect nothing more than isolated coverage through the night. Lows are expected to fall into the low 70s. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... Surface high pressure will reside offshore through late week, while a weak front meanders over the region before largely washing out. Aloft, a trough over the East Coast will continue to lift, allowing ridging to build from the south. Expect daily shower and thunderstorm chances with highest coverage in the afternoon when instability is maximized. No particularly stand- out day for severe weather, but a stronger storm or two will be possible each day, especially where boundary interactions occur. Highs will peak in the upper 80s to around 90. Lows on average will be in the 70-75F range, with some spots dipping into the upper 60s inland. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... Mid level ridging will largely persist over the Southeast into the weekend and early next week, although a couple weak disturbances could pass through the region. Surface high pressure will reside offshore while a front possibly approaches later in the period. Forecast is pretty much on repeat with showers and thunderstorms possible each day, with coverage peaking during the daytime hours. Heat indices start creeping back up, reaching 100-105 in many spots. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... The 06z TAF period begins with VFR conditions at KCHS, KJZI, and KSAV. The first thing to watch is a broken line of thunderstorms that is slowly sinking southward and into southeast GA and southeast SC. However, current thinking is that this area of showers and storms will gradually dissipate over the next few hours and will not be a concern for the TAF sites. We will continue to monitor the need for amendments. Attention then turns to the afternoon and another potential round of showers and thunderstorms. We have added in VCTS at KSAV starting at 18z, 20z at KCHS, and 21z at KJZI. Direct impacts are certainly possible, but confidence is low at this point. If the terminals are directly impacted, there could be a brief period of MVFR or IFR conditions as well as gusty winds. Extended Aviation Forecast: Diurnally driven showers and thunderstorms could bring temporary flight restrictions through the week, mainly in the afternoon hours. && .MARINE... Today and tonight: Similar to the last few days, we expect elevated southwesterly flow across the local waters today and through the evening. However, speeds look to be a little weaker with not quite as much gustiness. The forecast advertises winds peaking at 15-20 knots in the Charleston County waters and Charleston Harbor, likely just below Small Craft Advisory thresholds. Seas should generally average 2-4 feet through the period. Also, it is worth noting that thunderstorms are expected along the coast and could move out into the coastal waters at times, producing strong wind gusts. Wednesday through Sunday: Marine conditions are expected to stay below Small Craft Advisory criteria through the period. Southerly flow will persist with speeds 15 knots or less. Seas will average 2- 3 feet. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...BSH SHORT TERM...ETM LONG TERM...ETM AVIATION...BSH/ETM MARINE...BSH/ETM