textproduct: Charleston

WHAT HAS CHANGED

The Aviation Section was updated for the 00Z TAFs and Key Messages have been updated.

KEY MESSAGES

- 1) A cold front will provide some much needed rainfall across southeast Georgia and the South Carolina Lowcountry this weekend.

DISCUSSION

KEY MESSAGE 1: 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".

AVIATION /02Z 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.

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.

CHS WATCHES/WARNINGS/ADVISORIES

GA...None. SC...None. MARINE...None.