Savannah, GA 31421 Weather

What has changed

The Aviation section has been updated for the 00z TAF issuance.

Key messages

- 1) Minor coastal flooding is expected along portions of the South Carolina coast through Saturday.

- 2) Continued risk for rip currents through the weekend.

- 3) Quiet conditions through Saturday with somewhat unsettled and breezy conditions Sunday into Monday.

Discussion

KEY MESSAGE 1: Minor coastal flooding is expected along portions of the South Carolina coast through Saturday.

Astronomical tides will continue to trend lower the rest of this week as we get further away from the Full Moon and perigee. Decent tidal anomalies will stay in place the rest of this week due to persistent and elevated northeast winds. The Friday and Saturday afternoon high tides are forecasted to reach minor coastal flooding thresholds at the Charleston Tide Gauge. Therefore, Coastal Flood Advisories will be needed. The coastal flooding threat should finally end early next week.

KEY MESSAGE 2: Continued risk for rip currents through the weekend.

Ongoing elevated winds, seas and tides will support a high risk for rip currents along the Georgia beaches for Friday. Sightly weaker winds across the Lowcountry beaches will support a moderate risk. Increasing northeast winds and building seas will yield a high risk for all beaches for Saturday. The rip current MOS guidance was a bit marginal for a high risk along the Charleston County beaches, but given gusty northeast winds typically produce rip currents and a nasty longshore current during a weekend, a high risk was favored over a moderate.

Reminder: The local rip current program will end Saturday, October 31 with the afternoon Surf Zone Forecast.

KEY MESSAGE 3: Quiet conditions through Saturday with somewhat unsettled and breezy conditions Sunday into Monday.

Friday and Saturday: Mostly quiet conditions will prevail as high pressure lingers across the area. An isolated shower to two could move inland along the Georgia coast Saturday into Saturday night where weak isentropic ascent and some 850 hPa theta-e pooling are noted. Highs will warm into the lower 80s away from the beaches Friday, but cool to the mid-upper 70s Saturday with increased cloud cover and stronger northeast low- level flow. Breezy conditions are likely at the beaches Saturday afternoon through Saturday night.

Sunday and Monday: The pattern will become somewhat unsettled Sunday and possibly lingering into Monday as a modest southern stream shortwave propagates across the Southeast U.S. and Deep South. Similar to yesterday, there remains considerable uncertainty on how strong this shortwave and any surface reflection will be. The operational GFS is still pretty wet (although drier than yesterday) and looks to be suffering from convective feedback based on how the QPF fields appear, but even its model cross-sections are not showing much in the way of significant deep-layered UVVs associated with the shortwave itself. The drier EC solutions have exhibited the most stable run-to-run consistency over the past few days and that trend was generally favored. Interestingly, the 29/13z NBM cut back significantly on QPF and rain chances from its previous 29/01z run. While the drier trend is supported, even this much drier solution may be too aggressive based on the ensembles. Bottom line, the forecast remains fluid and is open to further adjustments as the weekend gets closer. It will remain breezy at the beaches with gusts as high as 30-35 mph possible.

Aviation

Overall, VFR conditions are expected to mostly prevail at KCHS, KJZI, and KSAV through 00z Saturday. There are concerns for another round of pre-dawn stratus development, mainly at KCHS and KJZI. We have included a TEMPO group for a few hours, ending by around 13z. Thereafter, VFR will quickly return and prevail.

Extended Aviation Outlook: Gusty northeast winds are possible this weekend into Monday with an increased risk for rain impacts Sunday into Monday.

Marine

Tonight: High pressure inland will maintain elevated northeast winds. Though, winds should be the strongest through the evening, then ease somewhat overnight. Likewise, seas will gradually subside. We expect the Small Craft Advisories for the SC waters within 20 nm to end tonight. However, seas should remain high enough (6+ ft) to keep the Small Craft Advisories going for our GA waters.

Friday through Tuesday: Conditions will improve markedly on Friday as the pressure gradient relaxes, bringing an end to the prolonged Small Craft Advisories for the nearshore waters. However, improvement will be short-lived. Restrengthening of the inland wedge to the north this weekend and then the development of a weak coastal trough afterwards will drive northeast gusts back up to 25-30 kt and building seas above 6 ft. Another round of Small Craft Advisories for the nearshore waters could be needed Saturday afternoon potentially into Tuesday. A Small Craft Advisory for the Georgia offshore waters will likely continue through the entire period as 6 ft seas or greater will remain.

Watches, warnings and advisories

GA: High Risk for Rip Currents through Friday evening for GAZ217-219- 239-241. SC: None. MARINE: Small Craft Advisory until 2 AM EDT Friday for AMZ360-362. Small Craft Advisory until 3 PM EDT Friday for AMZ364. Small Craft Advisory until 5 AM EDT Wednesday for AMZ384.