


Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
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592 FXUS62 KCHS 111755 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 155 PM EDT Fri Jul 11 2025 .SYNOPSIS... Weak high pressure will extend across the area into early next week. A surface front may sag into the area during the middle of next week. && .NEAR TERM /THROUGH TONIGHT/... This afternoon: Aloft the region will be under the influence of ridging across the western Atlantic while high pressure dominates at the surface. SPC Mesoanalysis shows a moist and unstable environment across the region, especially across southeast GA where ML CAPE values are around 2000 J/kg and PWAT values are pushing 2 inches. CAMs highlight southeast GA as the highlight of this afternoon, with numerous showers and thunderstorms possible. Coverage will likely be significantly less than yesterday, given the absence of large scale forcing aloft. Storms today will likely initiate off of the inland pushing sea breeze and any other outflow boundaries. While a severe thunderstorm cannot be ruled out, the main threat for this afternoon will be heavy rainfall and flooding. Several locations across the region have seen 4 to 6 inches of rain over the last two days and the ground is quite wet. The HREF highlights southeastern GA with a 50% probability of 1" or more and a 10% probability of 3" or more. Flooding of low lying and poor drainage areas is possible, especially over areas that have seen a lot of recent rainfall. Overnight: Any precipitation will diminish in the early overnight hours, with low temperatures dropping into the 70s. && .SHORT TERM /SATURDAY THROUGH MONDAY/... A weak upper-lvl ridge will slowly build across the Gulf Coast this weekend into early next week. Simultaneously, a broad ridge will remain off the East Coast as rich moisture continues to advect into the region with PWAT values ~2.0 inches through early next week. This will be more than enough moisture to spark up some showers and thunderstorms each afternoon as the sea breeze pushes inland. Expect temperatures to be in the low to mid 90s on Saturday, with mid to upper 90s on Sunday and Monday. Heat index values be in the 100 to the 106 degree range, specifically on Sunday and Monday. As of right now, these values remain under Heat Advisory Criteria (108F), however we will continue to be monitor these values over the next couple days. With these temperatures and dewpoints in the the low to mid 70s, moderate instability should develop and it`s possible to see strong to severe thunderstorms each afternoon. Overnight lows will remain mild and only dip into the low to mid 70s (with warmer temperatures closer to the beaches). && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... This current pattern will be slow to change as this weak upper-lvl ridge eventually begins to break down in the middle part of next week. Recent guidance suggests a weak surface trough, or front, could settle across the region with storm activity gradually increasing by the end of the week. Temperatures will remain near normal for this time of the year. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... The 18Z TAF period will initialize with VFR at KCHS/KJZI/KSAV, with a TEMPO included at KCHS for some lingering MVFR cigs over the next couple of hours. Showers and thunderstorms are forecast this afternoon, with the greatest chance of impacts at KSAV where a TEMPO is included from 21Z to 00Z. Otherwise direct impacts are uncertain so VCTS has been maintained at KCHS/KJZI. VFR will then prevail through the overnight period. Extended Aviation Outlook: VFR will mainly prevail throughout the period, however brief flight restrictions are possible within showers and thunderstorms that develop in the afternoon and/or evening. && .MARINE... Through Tonight: High pressure will dominate across the marine waters, yielding southerly winds generally 10 to 15 knots. Some gusts along the direct coastline could approach 20 knots this afternoon in association with the afternoon sea breeze. Overnight winds will remain elevated as high pressure builds into the region, with winds around 15 knots with gusts to around 20 knots. Seas will average 2-4 ft through tonight. Saturday through Tuesday: Expect generally south-southwesterly winds at 5 to 10 kt to prevail throughout the period. It could become a bit gusty each afternoon with gusts up to 15 to 20 kt as the seabreeze pushes inland (gusts strongest across the immediate coastline and the Charleston Harbor). Southeasterly swell will continue to mix into the local waters over the weekend. Seas will be 2 to 3 ft, then decrease to 1 to 2 ft on Monday. Otherwise, no marine concerns expected. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...CPM SHORT TERM...Dennis LONG TERM...Dennis AVIATION...CPM/Dennis MARINE...CPM/Dennis