textproduct: Charleston

WHAT HAS CHANGED

The Aviation Section has been updated for the 12Z TAF issuance.

KEY MESSAGES

- 1) A cold front should bring scattered showers and thunderstorms to the region Thursday into early Friday.

DISCUSSION

KEY MESSAGE 1: A cold front should bring scattered showers and thunderstorms to the region Thursday into early Friday.

High pressure will build across the Southeast United states this week, eventually becoming centered off the Mid-Atlantic Coast. Aloft a zonal pattern will transition to a modest ridging pattern mid- week, and with ample sunshine during the next few days will result in a warming trend prior to the arrival of a cold front Thursday. High temperatures could approach the mid-upper 80s inland to around 90 degrees across parts of Southeast Georgia by Wednesday. The position of the sfc high offshore favors a light southerly flow across the Southeast United States in advance of the arriving front, helping advect deeper moisture (PWATs ~2.0 inches) across the local area as large scale troughing advances across the Midwest/Great Lakes region and forces the cold front toward the Southeast Coast during the second half of the week. Although timing of the front will play a key factor in the overall intensity of convection developing prior to and during fropa on Thursday, some guidance supports modest instability and shear in the local area while a favorable quadrant of a h25 jet passes to the northwest inland. Should peak instability/shear coincide with timing of fropa, the risk for stronger thunderstorm activity could increase, especially if occurring near peak diurnal heating Thursday afternoon. Regardless, the speed of the system/front appears to be on the slightly more progressive side, which should limit precip amounts and the risk for flooding locally, especially outside thunderstorm activity. The bulk of precip activity should push offshore Thursday night into early Friday.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

VFR conditions are expected at CHS/JZI/SAV terminals through 12Z Monday.

Extended Aviation Outlook: VFR conditions expected through Wednesday. Flight restrictions are possible at CHS/JZI/SAV terminals with scattered showers and thunderstorms associated with a passing cold front Thursday.

MARINE

A brief period of 25 kt gusts or 6 ft seas is possible late Wednesday night through Thursday as southerly flow strengthens ahead of a cold front. The greatest chance of eventually needing Small Craft Advisories will be across the Charleston County nearshore waters and the GA offshore waters.

CHS WATCHES/WARNINGS/ADVISORIES

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