FXUS62 KCHS 242310 AFDCHS
Area Forecast Discussion National Weather Service Charleston SC 710 PM EDT Fri Apr 24 2026
.WHAT HAS CHANGED...
The Aviation Section was updated for the 00Z TAFs.
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.KEY MESSAGES...
- 1) Above normal temperatures with low relative humidity inland
today. Isolated showers possible along the sea breeze over the South Carolina Lowcountry this afternoon.
- 2) A cold front will provide some much needed rainfall across
southeast Georgia and the South Carolina Lowcountry this weekend.
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.DISCUSSION...
KEY MESSAGE 1: Above normal temperatures with low relative humidity inland today. Isolated showers possible along the sea breeze over the South Carolina Lowcountry this afternoon.
Quiet conditions continue to prevail across the region with latest observations showing mostly sunny skies and temperatures in the low to mid 80s. As noted in the previous discussion, still expect dewpoints to fall into the 40s to 50 inland, resulting in relative humidity values below 30 percent. Given the lack of rainfall, these values combined with dry fuels may promote worsening fire danger conditions this afternoon, primarily inland of I-95. Thus, we encourage folks to exercise caution with any activity heat may cause a spark and to heed any local burn bans.
High-res CAMs continue to suggest that isolated areas of convection may be possible this afternoon along the advancing sea breeze. That being said, sounding profiles still remain quite dry even with SBCAPE values near 500 J/kg - so rainfall totals will likely only equate to a few hundredths if any. Given that confidence in exact location remains low, have opted to only carry some slight chance PoPs across portions of inland South Carolina during the mid to late afternoon. Nonetheless, any convection that does develop should quickly dissipate with the loss of heating near sunset.
KEY MESSAGE 2: A cold front will provide some much needed rainfall across southeast Georgia and the South Carolina Lowcountry this weekend.
The mid-levels will consist of a positively tilted shortwave passing to our north Saturday night into Sunday, then shifting offshore Sunday night. At the surface, a cold front will approach from the northwest Saturday. It'll move southeast, through our area Saturday night into early Sunday morning, then shift well offshore and to our south by later Sunday. Ahead of the front will be a decent plume of moisture. PWATs should rise to around 1.5" Saturday night, which is above normal for this time of year per SPC Sounding Climatology for CHS. The combination of lift and moisture will generate isolated to scattered showers Saturday late afternoon and evening, increasing to scattered to numerous showers Saturday night. Scattered coverage should persist into Sunday, followed by drying conditions Sunday evening and overnight. Instability remains limited both days, so isolated to scattered thunderstorms are possible. But the severe threat is low. As for rainfall amounts, even though any rainfall will be beneficial, this system is not expected to significantly alleviate ongoing drought conditions. QPF amounts were trended slightly lower, so storm total amounts should be 0.1-0.25", with locally higher amounts. The NBM now has a 50% probability or lower of storm total rainfall exceeding 0.25".
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.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
24/00Z TAFs: VFR conditions expected to prevail for KCHS/KJZI/KSAV. A large wildfire burning over southern Georgia continues to produce some smoke, however most of this smoke is traveling out over the Atlantic and away from the KSAV. Therefore, vsbys were left at 10SM for KSAV, however confidence in the smoke/vsby forecast is low.
Extended Aviation Outlook: A cold front with scattered showers/thunderstorms could bring occasional impacts to the terminals late Saturday into Sunday.
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.MARINE...
High pressure will remain centered over the western Atlantic today and tonight. The pressure gradient will remain generally weak, south winds between 10 to 15 kts. Some enhancement in the winds may occur along the coast this afternoon as the sea breeze moves onshore. Wave heights are forecast to remain around 2 ft within 20 NM and 3 ft between 20-60 NM.
A cold front will approach from the northwest Saturday. It'll move southeast, through our waters Saturday night into early Sunday morning, then shift well offshore and to our south by later Sunday. High pressure will then build in from the north Sunday night, bringing a brief surge of NE winds into early Monday. Conditions could approach Small Craft Advisory levels during this time period, mainly due to wind gusts. Winds and seas trend lower Monday as the pressure gradient weakens.
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.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None. SC...None. MARINE...None.
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Dennis