textproduct: Charleston

WHAT HAS CHANGED

The Aviation Section has been updated for the 18Z TAF issuance.

KEY MESSAGES

- 1) Gradual increase in rain chances early and late week.

DISCUSSION

KEY MESSAGE 1: Gradual increase in rain chances early and late week.

Aloft, mid-upper lvl ridging will weaken and retreat south today as a trough slowly makes way across the Eastern CONUS. At the sfc, high pressure extending across the western Atlantic will slowly retreat further offshore, in advance of a backdoor cold front attempting to reach the local area on Tuesday. The pattern suggests a few showers and/or isolated thunderstorms developing across interior Georgia this afternoon, mainly where weak h5 vort energy traverses along the western periphery of the Atlantic high. On Tuesday, the backdoor front appears to weaken/dissipate before reaching the South Santee River, but instability and deepening moisture associated with a southerly flow favor an uptick in shower and thunderstorm coverage during afternoon hours, perhaps most focused along and west of an inland moving sea breeze.

Heading into the second half of the week, a more typical summer-like pattern is in place under and/or along the edge of high pressure. Diurnally driven/sea breeze convection is possible starting Thursday with sufficient instability and moisture supporting few to scattered pulse type showers/thunderstorms each afternoon through late week. Some guidance suggests longwave troughing extending across parts of the Midwest into the Northeast late week with another weak sfc front attempting to approach the Southeast, which could support slightly higher shower and thunderstorm coverage across the local area this weekend. However, the threat for severe or hazardous weather remains low at this time.

AVIATION /18Z MONDAY THROUGH SATURDAY/

VFR conditions will prevail at CHS/JZI/SAV terminals through 18Z Tuesday.

Extended Aviation Outlook: VFR conditions are expected to prevail at CHS/JZI/SAV terminals. However, brief flight restrictions are possible with afternoon showers/tstms Tuesday, then again Thursday/Friday afternoon.

MARINE

Today and Tonight: Light southerly winds along the western periphery of Atlantic high pressure are expected, with wind speeds topping out in the 10-15 kt range (highest along the land/sea interface where a sea breeze occurs). Seas will range between 2-3 ft today, largest beyond 20 nm from the coast, then should subside about 1 ft during the night.

Tuesday through Friday: Conditions will remain below Small Craft Advisory criteria through the period. A weak cold front will attempt to approach the marine waters on Tuesday. High pressure will dominate thereafter through the remainder of the week. Winds will generally be out of the S, with a typical summertime pattern of a surge in gusts along the coast with the afternoon sea breeze.

CHS WATCHES/WARNINGS/ADVISORIES

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