Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
637 FXUS62 KCHS 142323 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 723 PM EDT Mon Jul 14 2025 .SYNOPSIS... Atlantic high pressure will prevail into the upcoming weekend. && .NEAR TERM /THROUGH TUESDAY/... SPC mesoanalysis indicates that the CWA has CIN values between 50-75 J/kg following widespread thunderstorms this afternoon and evening. Isolated to scattered showers and thunderstorms may develop along newer outflow boundaries until late this evening. The rest of the night should remain dry. The forecast update will align hourly temperatures with recent observations, showing large areas of rain-cooled temps in the mid 70s. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... Tuesday: A weakening TUTT will be approaching Florida with dry air located on the northwest flank. PWATs drop to less than 1.5", with 2"+ PWATs on either side. Surface convergence from Monday will have moved further inland over GA on Tuesday with a sea breeze forecast to move inland during the afternoon. The lower PWAT air will likely limit convection slightly, but the overall extent of coverage should still be at least chance. High temperatures will also be lower on Tuesday as 1000/ 850 mb thicknesses fall to 1415 m (or about 10 m cooler than Monday) due to the undercutting TUTT. Wednesday - Thursday: Another TUTT will break off and approach the region Wednesday allowing thunderstorms to continue both days. Storm motions Wednesday are forecast to be around 10 kt, but increase to near 20 kt by Thursday as the TUTT moves overhead and elongates the wind field slightly. This means the greatest chance for locally heavy rainfall will be on Wednesday, with slightly lower chances on Thursday due to increased storm motion. High temperatures will be near climo or in the lower 90s. && .LONG TERM /FRIDAY THROUGH MONDAY/... The TUTT that was near the area on Thursday will cross Florida Saturday keeping afternoon thunderstorm chances in the forecast through the weekend. High temperatures will also remain near climo/ slightly above climo as low level thicknesses slowly recover. Max heat index values each afternoon will be near or just below advisory criteria (108 F). && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... Prior to the 0Z TAFs, a few remnant showers were drifting around KSAV, with little to no impact expected. These showers should dissipate by 1Z. The rest of the night, terminals should remain dry with light winds. Sea breeze convection is forecast to develop across KCHS and KJZI between 16-19Z. The KCHS and KJZI TAFs will feature TEMPOs to highlight -TSRA, restricting visibility to MVFR. Coverage around KSAV appears too low to mention of this time. Extended Aviation Outlook (Tuesday through Saturday): 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 hours. && .MARINE... This Afternoon and Tonight: Expect generally northeast to east- northeast flow at 5 to 10 kt to prevail through tonight. This flow pattern will generally be driven by the circulation around the developing low pressure off the Florida coastline. It could become a bit gusty in the 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 and seas will be 1 to 2 ft. Showers and thunderstorms will develop over the coastal waters tonight and increase in coverage closer to daybreak. Otherwise, no marine concerns expected. Tuesday through Saturday: A TUTT will be located just off of the SC coast through the extended while at the surface Bermuda high pressure will be in control. For the marine zones, this will translate to each afternoon featuring wind gusts peaking 15 to 20 kt due to an inland advancing sea breeze. Seas through the period will be 2-4 ft. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...NED SHORT TERM...Haines LONG TERM...Haines AVIATION...NED MARINE...Dennis/Haines