textproduct: Charleston

WHAT HAS CHANGED

Aviation section and Key Message 1.

KEY MESSAGES

- 1) Increased chances for showers and thunderstorms through early next week.

DISCUSSION

KEY MESSAGE 1: Increased chances for showers and thunderstorms through early next week.

The boundary layer is stabilizing with the loss of diabatic heating. The brunt of the diurnal convection today has been across inland southeast GA. Modest boundary layer CAPE remains in place over the area. A potent upper vort is progged to lift northeast through the area overnight, potentially triggering new convection farther east of today's activity. PoPs taper off later this evening, then show an increase over southern SC later tonight.

On Sunday, conditions are not expected to change, with comparable temperatures and moisture content. The sea breeze will again be the focus for the initial thunderstorms, then coverage should expand across inland areas. Locally heavy rainfall is possible generally along and west of I-95.

Next week, warm and moist conditions persist as the upper ridge shifts back towards the southeast United States, which should support a more summer-like pattern with diurnally driven convection each day, initially along a sea breeze before expanding across inland areas mid-late afternoon into evening hours. Temps will remain above normal, with daily highs in the upper 80s/lower 90s and overnight lows only in the mid 60s to mid 70s, possibly resulting in record high minimum temperatures.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

In general, VFR conditions expected through Sunday. However, we anticipate fairly widespread coverage of showers and tstms early Sunday afternoon, with the potential for brief visibility reductions at KCHS/KZJI/KSAV terminals. Fairly robust SSE winds anticipated later Sunday afternoon due to a strengthening sea breeze.

Extended Aviation Outlook: Brief flight restrictions possible within showers and thunderstorms.

MARINE

This Afternoon and Tonight: Onshore flow will prevail along the western periphery of Atlantic high pressure, with some local enhancement to southeasterly winds (~15 kt) along the land/sea interface today, including the Charleston Harbor. Southerly winds in the 10-15 kt range are likely overnight. Seas will generally range between 3-4 ft, although could slightly build about a ft during the night.

Sunday through Thursday: Conditions are forecast to remain below Small Craft Advisory criteria through at least the middle of next week, with daily chances for showers and thunderstorms. High pressure to the east will drive onshore ESE flow each day, with wind speeds averaging 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/8s and sea breeze influences each afternoon will keep the rip current risk in the moderate category at all area beaches through Monday.

CHS WATCHES/WARNINGS/ADVISORIES

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