Marine Weather and Tide Forecast for Tybee Island, GA

NEAR TERM /THROUGH TONIGHT/
Today: No significant changes were made to the early morning update. The region will remain between deep layer ridging to the southeast and broad mid/upper level troughing to the west.
Ample moisture, average afternoon CAPE values of 1000-2000 J/Kg, and weak upper level short waves are expected to produce scattered to numerous showers and thunderstorms, mainly centered around peak afternoon heating. The potential for severe storms is again too low to mention. However, there is the potential for a strong storm or two, especially where outflow boundaries collide with each other or with the late afternoon seabreeze.
With 2+ inch PWs, along with the potential for some training of storms, locally heavy rainfall will be possible again today, especially closer to the coast from roughly Beaufort, SC to south of Savannah, GA. High temperatures near to slightly above normal in the upper 80s to lower 90s.

Tonight: Convection should reduce in coverage after sunset.
However, isolated showers may linger through at least midnight, with weak upper forcing and ample moisture/instability. Lows in the lower to mid 70s inland, and the mid to upper 70s closer to the coast.

SHORT TERM /SUNDAY THROUGH TUESDAY/
Daily chances for showers and thunderstorms continue as the surface Atlantic high pressure remains off to our east, and an upper level high is parked off to our south-southeast. While this won't lead to constant rain, highest probabilities and spatial coverage for rain are expected through the late morning and into the afternoon hours as instability builds, with chances decreasing into the overnight hours as instability wanes. While severe weather can't be entirely ruled out given 1-2 J of MUCAPE, the lack of strong forcing and weak mid-upper level flow will keep such activity isolated at best. This is further validated by various AI/ML models, as well as the SPC keeping chances for severe weather below 5%. With precipitable water remaining above 1.75", locally heavy rainfall can't be ruled out.

As for temperatures, they are expected to slowly increase into the beginning of the week given the persistent pattern underneath the aforementioned upper level high. Both the NAEFs and ECMWF ensemble situational awareness tables (ESATs) continue to show the region remaining near/above the 90th percentile of climatology with respect to geopotential heights from 850mb up to 200 mb per the NAEFS and ECMWF, resulting in afternoon highs on Sunday in the upper 80s to lower 90s and lower to mid 90s on Monday and Tuesday, while those near the coast remain in the mid/upper 80s. Heat index values in the mid 90s to lower 100s are also expected, possibly as high as mid 100s on Monday and Tuesday if dewpoints rise into the upper 70s.

LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/
The aforementioned pattern continues while the upper level ridge begins to slowly build westward as a weak trough moves into the northeast Thursday into Friday. Daily chances for showers and thunderstorms continue, with temperatures remaining in the lower to mid 90s. Currently have heat indices largely remaining below Heat Advisory criteria of 108 degrees F, but that will need to be closely monitored.

AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
12Z TAFs: VFR are expected to prevail all sites through this morning. By afternoon, scattered to numerous showers and thunderstorms could produce periodic MVFR CIGs . Wind gusts around 20 knots possible from late morning into mid afternoon.
Convection is expected to decrease in coverage after sunset this evening, with a return to VFR conditions generally after 01z.

Extended Aviation Forecast: Brief flight restrictions are possible in showers and thunderstorms each day, mainly in the afternoon.

MARINE
Today through Tonight: No significant changes were made with the early morning update. Although winds will gust to near 20 knots today, winds/seas are not expected to reach SCA levels during this period. Deep layer high pressure will remain southeast of the waters with deep layer troughing well inland/west of the waters. This will keep south-southwest winds of 10-15 knots in place, gusting to near 20 knots during the afternoon as the seabreeze develops, but likely stays close to the coast. Seas generally 2-3 feet within 10 nm of the coast, and 3 to 4 feet beyond 10 nm.

Sunday through Thursday: Typical summertime conditions will prevail over the waters with high pressure centered offshore of the Southeast States. A broad, southerly wind regime can be expected with winds generally averaging 15 kt or less, except a bit higher along the land/sea interface and Charleston Harbor each afternoon with the sea breeze. Seas will remain 4 ft or less through the period.

Rip Currents: An easterly swell surge will arrive along the Charleston County beaches today and all remaining beaches for Sunday. This coupled with locally breezy conditions near the afternoon sea breeze will support a moderate rip current risk for the Charleston County beaches Saturday and for all beaches Sunday.

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