Marine Weather and Tide Forecast for McClellanville, SC

NEAR TERM /THROUGH TONIGHT/
Patchy fog/mist and any low stratus early this morning should burn off within an hour or two of sunrise as daytime heating gets underway and southerly winds pick up. Mid-upper ridging centered around the Florida Peninsula and The Bahamas will maintain southwesterly flow aloft (and a healthy supply of high clouds) over the forecast area through tonight. Near the surface, high pressure off the coast of South Carolina will maintain southerly low-level flow off the Atlantic. Despite low-level moisture streaming off of the warming ocean waters, with nearshore water temps now in the mid- upper 60s, dry air from above the boundary layer will keep dew points in check as forecast soundings depict extremely dry air between 850mb up through about 400mb. Thermals due to solar heating will help to both develop scattered cumulus clouds while also mixing this dry air down and knocking dew points below 60F by late morning away from the coast. However, with highs forecast to reach the middle 80s inland, expect a sea breeze to develop and slide inland through this afternoon and evening, raising dew points in its wake for tonight.

High clouds will continue streaming overhead tonight and lower in height somewhat. A slow-moving cold front will take its time crossing the Appalachians tonight, keeping any precip chances well west of the area. Otherwise, patchy fog and low stratus will be possible, although a stronger LLJ should keep winds a bit more elevated tonight, precluding more widespread fog concerns.

SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/
Rain chances will increase later in the day Tuesday ahead of a cold front. This front will stall over the area through the short term period, allowing an axis of Gulf moisture to stream in and PWATs increasing to 1-1.5". With this warm, moist airmass some instability will lead to thunderstorms Tuesday PM. At the same time, shear will increase aloft to around 30-40 kts. These values would suggest some isolated storm organization may be possible late Tuesday afternoon into the evening. Some stronger storms could produce damaging wind gusts, so our inland counties have been placed in a marginal risk (threat 1 of 5) for severe weather. Rain coverage will generally increase into Tuesday night as a shortwave passes overhead and forcing increases, but the loss of daytime heating should inhibit most thunder. Another wave of energy will move through Wednesday afternoon along with increased moisture, increasing rain/storm coverage. Some heavier showers may be possible. Rainfall totals through the period could be ~0.5-1" with the majority of meaningful rainfall expected Wednesday afternoon. The coast will receive less rain due to more stable marine air from the sea breeze. Highs in the 80s and lows in the 60s.

LONG TERM /WEDNESDAY THROUGH SUNDAY/
The stationary front may linger through late Thursday before dissipating. Friday may be the driest day of the period as, while showers and storms will remain possible during the day, the nighttime should be mostly dry. Another cold front will approach for the weekend with increasing shower/storm chances and cooler weather after its passage. Highs in the 80s and lows in the 60s until the cold front moves through and temps could drop 5-10 degrees.

AVIATION /12Z MONDAY THROUGH FRIDAY/
Early AM fog/mist lingering at LBT should burn off within the next 1-2 hours. Otherwise surface high pressure off the SE coast will maintain S-SW winds, which will pick up a bit as mixing gets underway. A sea breeze will back winds to the S at the coastal terminals this afternoon and bump speeds up.
Otherwise a VFR day across the terminals through the TAF period with scattered fair-weather cumulus in the 3.5-5kft layer. Potential for fog development late tonight at CRE given SW flow across the intracoastal waterway, but confidence is low at this point.

Extended Outlook...Moderate confidence in VFR through early Wednesday, with a possibility of fog/stratus each morning.
Increasing rain chances could bring periodic restrictions beginning on Wednesday and continuing through Friday as a cold front stalls and wavers over the area.

MARINE
Through Tonight... High pressure off the South Carolina coast will maintain south-southwesterly winds over the waters through tonight.
5-10 kt winds this morning will increase to 10-15 kts with gusts up to 20 kts nearshore this afternoon as the sea breeze circulation ramps up and pushes inland. Seas around 1-2 ft this morning increase to 2-3 feet this afternoon, resulting from a combination of persistent 2 ft southeasterly 7-8 sec swell and 1-2 ft southerly wind waves.

Tuesday through Friday... Winds generally AOB 10 kts through the period. A stalled front in the area will cause winds to be SW to SE before it dissipates late Thursday, SW flow building in. Seas generally 2-3 ft with a predominant SE swell at 8-9 seconds.

ILM WATCHES/WARNINGS/ADVISORIES
NC...None.
SC...None.
MARINE...None.