textproduct: Charleston

WHAT HAS CHANGED

The Aviation section has been updated.

KEY MESSAGES

- 1) Increasing chances for showers and thunderstorms this weekend, though no hazardous weather is anticipated at this time.

DISCUSSION

KEY MESSAGE 1: Increasing chances for showers and thunderstorms this weekend, though no hazardous weather is anticipated at this time.

Aloft, a ridge will remain centered across the Atlantic, placing the local area along its western periphery, while a series of h5 vort energy ripples across the Deep South and Southeast through the weekend. At the sfc, a weak stationary front remains draped across the Carolinas this afternoon, remaining just north and inland to the local area through the day prior to departing to the north/northeast Saturday and Sunday. Southerly onshore flow and abundant sunshine south of this feature likely results in deep moisture advecting across the local area with PWATs averaging between 1.5-2.0 inches while sfc temps peak in the upper 80s/lower 90s each afternoon. Instability appears sufficient for few to scattered shower and thunderstorm activity to develop along a daily sea breeze circulation, becoming more numerous in coverage across inland areas (west of I-95) during peak afternoon heating into early evening hours. Deep-layered shear remains modest, suggesting unorganized shower/thunderstorm activity, but a few stronger thunderstorms can not be ruled out across the far interior, perhaps with h5 vort energy and an inland progressing sea breeze promoting some enhancement to convection within an environment displaying approximately 20-25 kt of 0-6 km Bulk Shear. Some hires guidance suggests a cluster and/or unorganized line of convection attempting to reach the far interior this evening, but likely trending in an eroding/weaker state as instability wanes with the loss of daytime heating. Regardless, gusty winds and lightning remain the primary concern with thunderstorms through the weekend, although there is some indication of locally heavy downpours with activity away from the coast Saturday and Sunday afternoon/evenings as well. Some locations west of I-95 could see rainfall amounts exceeding 1 inch by the end of the weekend.

Next week, warm and moist conditions persist as the upper ridge retrogrades back to the west toward the Southeast United States. This should bring a more summer-like pattern locally with diurnally driven convection each day, starting along sea breeze circulations, the spreading across inland areas during afternoon into early evening hours.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

00Z TAFs: VFR should prevail through about 18Z Saturday. Shallow ground fog is possible around daybreak Saturday, but confidence is too low to include in the TAFs. A few showers and/or isolated thunderstorm could impact the TAF sites with the sea breeze Saturday afternoon. We added PROB30 at all of the TAF sites to account for this. They may need to be changed to TEMPO groups in later TAFs.

Extended Aviation Outlook: TEMPO flight restrictions possible with showers and thunderstorms at CHS/JZI/SAV terminals each afternoon this weekend and early next week.

MARINE

Tonight: Sfc high pressure will remain the dominant weather feature across the western Atlantic while a stalled front is positioned north and inland of local waters. The setup will favor conditions that remain well below Small Craft Advisory levels. Southerly winds around 10-15 kt are anticipated, although a few gusts up to 20 kt are possible across the offshore Georgia waters. Seas will generally average between 3-4 ft, although could build to 5 ft beyond 30 nm from the coast.

Saturday through Tuesday: Conditions are forecast to remain below Small Craft Advisory criteria through early next week. High pressure to the east will drive onshore ESE flow each day, with wind speeds mostly topping out in the 10-15 knot range. Each afternoon and evening there could be some local enhancement along the land/sea interface with the diurnal sea breeze. Seas will average 2-4 feet through the period.

Rip Currents: A modest easterly swell around 3ft/9s and sea breeze influences each afternoon will keep the rip current risk in the moderate category through at least Sunday.

CHS WATCHES/WARNINGS/ADVISORIES

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