textproduct: Charleston

WHAT HAS CHANGED

Update key message 1.

KEY MESSAGES

- 1) Minor to moderate coastal flooding possible during the Wednesday evening high tide cycle along the South Carolina and Georgia coast.

- 2) Hot and humid conditions are expected to return to the area late this week through early next week. Heat Advisories could be needed.

DISCUSSION

KEY MESSAGE 1: Minor to moderate coastal flooding possible during the Wednesday evening high tide cycle along the South Carolina and Georgia coast.

High astronomical tides associated with Monday's lunar perigee and today's New Moon will continue, with a 6.46 ft MLLW Wednesday evening in the Charleston Harbor. Peak water levels of 7.4-7.6 ft MLLW are forecast for Wednesday evening's high tide. At Fort Pulaski the high tide is forecast to peak near 9.5 ft MLLW (Minor Flooding). Another Coastal Flood Advisory is expected Wednesday evening as well. If heavy rainfall were to occur near or during the time of the evening high tide cycle, flooding concerns would increase as total water levels would similarly increase.

In the absence of strong tidal departures on Thursday, coastal flood issues are not anticipated.

KEY MESSAGE 2: Hot and humid conditions are expected to return to the area late this week through early next week. Heat Advisories could be needed.

Mid and upper level ridging is expected to build back across the Southeast later this week and persist through the weekend. Widespread low to mid 90s return to the forecast starting Thursday and extend through the weekend and into early next week. The low- level flow pattern around the subtropical high will help to drive elevated dewpoints across the region as well. This combination of highs in the low to mid 90s and dewpoints in the mid to upper 70s will yield elevated heat indices each day, especially along the coastal corridor. Heat index values of 105-110 degrees will be possible along the coast each day, and Heat Advisories could be needed.

AVIATION /02Z WEDNESDAY THROUGH SUNDAY/

0Z TAFs: A shower or two may pass by the terminals through mid- evening. Forecast soundings and MOS indicate that some restrictive ceilings may develop during the pre-dawn hours, TAFs will indicate MVFR ceilings at this time. Conditions should return to VFR once mixing begins by 14Z Weds morning. Given a coastal low nearby, warm and humid conditions, thunderstorms are possible Wed afternoon and evening along a sea breeze. The TAFs will feature PROB30 at KCHS and KJZI between 18-21Z and a TEMPO from 18-21Z.

Extended Aviation Outlook: Shower and thunderstorm coverage is expected to diminish across the region beginning Wednesday evening. Low chances of thunderstorm impacts are expected through the weekend.

MARINE

Tonight through Sunday: Quiet conditions with relatively light flow and seas around 2 feet will prevail across the local waters through Wednesday night as a weak boundary sits in the vicinity. By Thursday, this boundary will wash out and the subtropical high to the east will increasingly take control. This change will bring southwest flow to the region, turning more southerly each afternoon and evening with the sea breeze. Winds will be stronger during this time, with 10-15 knots and gusts up to 20 knots along the land/sea interface. Over the weekend, the gradient is expected to strengthen between an inland trough and the high to the east. This will produce stronger southwest to south flow, with speeds getting more into the 15-20 knot range and an increasing chance of gusts up to 25 knots, mainly for the SC coast and Charleston Harbor. We could even need some short duration Small Craft Advisories over the weekend.

CHS WATCHES/WARNINGS/ADVISORIES

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