Marine Weather and Tide Forecast for Summerville, SC

NEAR TERM /THROUGH TONIGHT/
Today: Aloft, a large mid-lvl trough extending across much of the Mid-Atlantic and Northeast will gradually flatten while slowly shifting off the Eastern Seaboard as weak/broad ridging takes place across the Great Plains. The pattern will setup a zonal flow across the Southeast, favoring a dry west-northwest downslope wind across the local area while sfc high pressure spreads across the region behind a front well to the south and offshore. Latest model soundings indicate substantial dry air throughout the day, suggesting any h5 shortwave energy left rounding the departing trough aloft to struggle producing nothing more than a few clouds across the local area this afternoon. Ample sunshine, the dry downslope flow and 1000-850 mb thickness values suggest highs in the mid 80s across Southeast South Carolina and upper 80s to around 90 degrees across Southeast Georgia, warmest south of I-16.

Tonight: High pressure centered across the Mid-Atlantic states will nudge into the area during overnight hours, continuing a dry pattern through the night. Winds are expected to decouple early, leading to light and/or calm winds away from coastal locations for much of the night. This will lead to a favorable radiational cooling setup and low temps that are slightly cooler than previous nights. In general, lows should dip into the upper 50s across the far interior and northern areas in the Francis Marion Forest, but should remain in the mid-upper 60s closer to the coast, and around 70 degrees at the beaches.

SHORT TERM /SATURDAY THROUGH MONDAY/
The area remains within broad upper troughing as a large cutoff low lingers over eastern Canada this weekend. Deep layer westerly/downsloping flow and subsidence keeps a mainly dry forecast in place Saturday, though a very weak front stalled across SE GA could provide for just enough moisture pooling to spawn an afternoon shower or two.
Seasonable temps expected.

Later Saturday night into Sunday will begin an increasingly unsettled period as a weak upper wave moves overhead. A few coastal showers/storms expected Sunday morning as DPVA initiates broad/weak lift locally, with convective activity increasing by the afternoon along and ahead of the sea breeze. The aforementioned weak front remains stalled over/near SE GA, and could bring some moisture pooling/modest convective enhancement north of and along the front, resulting in slightly greater shower/storm coverage expected across the Lowcountry and Savannah River area. Moderate storm motion and lack of substantial shear keeps the overall severe and flooding threat low, but a few back-building storms producing localized heavy rainfall and a wet microburst or two are possible. Otherwise, temps climb a few degrees above normal Sunday afternoon away from the early afternoon storms, with the potential for a few locations across SE GA (south of the weak front) to reach into the mid-90s.

Expect mainly diurnally-driven shower/storm coverage to increase Monday as a shortwave begins to approach from the west. Overall heavy rainfall and severe weather threat is limited by lack of shear and moderate storm motions again on Monday, though the front remaining nearby could result in some focus for storm activity and potential for training again.

LONG TERM /MONDAY NIGHT THROUGH THURSDAY/
Shortwave passes overhead Tuesday. Convective threats require further monitoring as the wave could bring modest shear enhancement and some marginally organized convection is possible ahead of an approaching cold front. PWAT values reach their peak of near 2 inches later in the day Tuesday, and locally heavy rainfall is again possible.

Wednesday begins the trend back toward seasonable convective patterns with scattered afternoon convection expected. Post-frontal CAA is minimal (as is standard this time of year), with weak troughing over the Southeast likely to bring continued seasonable conditions through the end of the workweek.

AVIATION /12Z FRIDAY THROUGH TUESDAY/
VFR conditions will prevail at CHS/JZI/SAV terminals through 12Z Saturday. However, a few wind gusts up to 15-20 kt are possible at CHS/JZI terminals mid afternoon today.

Extended Aviation Outlook: Threat for flight restrictions primarily limited to convection, mainly following a diurnal trend with increasing coverage Sunday through Tuesday.

MARINE
Today and Tonight: Offshore flow will prevail this morning with high pressure spreading across the region behind a cold front well offshore and south of the region. In general, west/northwest winds should be no higher than 10-15 kt. By the afternoon, sfc winds should become more southwest across nearshore South Carolina waters along the Charleston County Coast and in the Charleston Harbor, while turning more east or southeast across remaining waters as a weak sea breeze takes shape along the coast. A few gusts to 20 kt are possible along the Charleston County Coast and in the Charleston Harbor as the sea breeze begins to shift inland this afternoon. High pressure centered north of the region will continue to nudge across local waters tonight, leading to somewhat lighter offshore winds from the west or northwest by around midnight. Seas will generally range between 1-2 ft, although seas could touch 3 ft across far outer Georgia waters this morning.

No significant marine concerns through the holiday weekend and into next week with mainly moderate winds prevailing, and gusty winds developing nearshore with the sea breeze each afternoon.

One note to boaters: Stronger than normal currents can be expected on tidal waterways through the holiday weekend given large tidal ranges as we approach the Perigee on Monday. Early afternoon low tides will be followed by quickly rising water, which has, in the past, resulted in dangerous conditions as area sandbars quickly become submerged.

Rip Currents: The risk for rip currents near Savannah/Tybee Island were borderline Moderate for Saturday. Given it's a holiday weekend, have opted to maintain a Moderate Risk for rip currents along Georgia beaches Saturday.

CHS WATCHES/WARNINGS/ADVISORIES
GA...None.
SC...None.
MARINE...None.