Area Forecast Discussion

WHAT HAS CHANGED

All sections updated.

KEY MESSAGES

- 1) A significant, multi-day coastal flooding event will continue this week.

- 2) Strong northeast flow through early week will result in several hazards including rip currents, high surf, and beach erosion.

- 3) Dry conditions will continue through the week before gradually warming up by the end of the week.

DISCUSSION

KEY MESSAGE 1: A significant, multi-day coastal flooding event will continue this week.

Astronomical tides will continue to rise into early this week due to the upcoming full moon (10/26) and the lunar perigee (10/28). Large tidal departures are ongoing, and with an extended period of strong northeast flow this weekend and into next week, departures will increase in magnitude. The combination of the highest astronomical tides of the year and persistent strong northeast flow will result in a multi-day moderate to major coastal flooding event for the entire southeast GA/SC coast.

Monday Morning: The highest tide level of the event is forecast to occur around 8 AM, with 7.9-8.1 ft MLLW forecast at the Charleston Harbor and 10.0-10.2 ft MLLW at Fort Pulaski. A Coastal Flood Warning is in effect for Charleston and Coastal Colleton Counties, as this tide is forecast to reach major flood levels. Elsewhere along the coast a Coastal Flood Advisories are in effect, including Tidal Berkeley.

Rest of This Week: Coastal flooding is forecast to occur with the Tuesday, and Wednesday morning high tide cycles, with minor flooding possible through the end of the week. During these cycles, it is possible that the Charleston Harbor could exceed moderate flood stage. Winds will slightly relax heading into this week, leading to lowering tidal departures. Coastal Flood Advisories will be needed.

KEY MESSAGE 2: Prolonged gusty northeast flow through late week will result in several hazards including rip currents, high surf, and beach erosion.

Rip Currents: Gusty northeast winds, long-period swell, and ongoing wave action will continue to support dangerous rip currents along all southeast SC/GA beaches. A High Risk for rip currents is in place for all area beaches through Tuesday. An enhanced risk of rip currents could continue through the rest of week. Of note: Saturday, October 31 marks the end of the 2026 surf season and the final routine issuance of the Surf Zone Forecast.

High Surf/Beach Erosion: Breaking wave heights will be at their peak early this morning around 4-6 ft, before subsiding below 5 feet by early afternoon, when the High Surf Advisory for the entire southeast SC/GA coast is set to expire. Another round of high surf is possible mid-week as the pattern holds, although looks to fall just short of criteria at this time. Additionally, the combination of elevated tides, wave action and the persistent gusty northeast winds will continue to result in beach erosion for the ongoing high surf event, with the most significant impacts occurring around high tide this morning.

KEY MESSAGE 3: Dry conditions will continue through the week before gradually warming up by the end of the week.

A rather persistent synoptic pattern continue through the week, with upper level ridging over the northern Gulf Coast and an upper trough lingering around the Bahamas. At the surface, high pressure centered over New England will dominate through mid- week allowing for a wedge to remain in place across the Carolinas. The wedge of high pressure will weaken slightly mid- week as the upper ridge begins to flatten out and slide east. This will allow for temperatures to return to near normal by the end of the week. The forecast remains rain- free through the week. Our next rainfall possibly arrives by Sunday into early next week as our next pattern change occurs.

AVIATION /06Z MONDAY THROUGH FRIDAY/

VFR Conditions are expected to prevail through the forecast with gusty northeasterly winds persisting during the day. Winds should be slightly lower than the past few days with gusts up to 20 knots possible. Winds should relax tomorrow night to around 5 knots or less.

Extended Aviation Outlook: Breezy north-northeast winds are expected at KCHS/KJZI/KSAV daily through late week. Otherwise, there are no high confidence concerns.

MARINE

Today and Tonight: A tight pressure gradient persists between high pressure wedged inland to the north and weak low pressure struggling to organize well offshore. Although winds and seas are trending downward, hazardous conditions continue. Gale Warnings for the nearshore waters (0-20 nm) have transitioned to Small Craft Advisories, while Gale Warnings remain in effect for the offshore waters (20-60 nm) through this afternoon before transitioning to advisories. The Small Craft Advisory for Charleston Harbor has been cancelled. Seas will peak this morning at 6 to 10 ft nearshore and 10 to 13 ft offshore, followed by a gradual decline this afternoon.

Tuesday through Thursday: The persistent inland high pressure wedge will keep winds and seas elevated across the coastal waters through late week. Outside of the Charleston Harbor, expect widespread Small Craft Advisory conditions featuring north-northeast wind gusts of 25 to 30 kt, nearshore seas of 5 to 8 ft, and offshore seas of 8 to 10 ft (highest across Georgia waters). A brief surge Wednesday evening could produce localized low-end gale gusts, especially across the Georgia waters. However, an upgrade to a Gale Warning for that area looks unlikely at this time.

Friday and Saturday: Marine conditions will improve drastically as the pressure gradient over the waters relaxes, bringing an end to the prolonged stretch of hazardous conditions.

CHS WATCHES / WARNINGS / ADVISORIES

GA...High Risk for Rip Currents through this evening for GAZ217-219-239- 241. High Surf Advisory until 2 PM EDT this afternoon for GAZ217- 219-239-241. Coastal Flood Advisory until 11 AM EDT this morning for GAZ217- 219-239-241. SC...High Risk for Rip Currents through this evening for SCZ148>151. High Surf Advisory until 2 PM EDT this afternoon for SCZ148>151. Coastal Flood Advisory until 11 AM EDT this morning for SCZ148- 151. Coastal Flood Warning until 11 AM EDT this morning for SCZ149- 150. Coastal Flood Advisory from 6 AM to 11 AM EDT this morning for SCZ152. MARINE...Small Craft Advisory until 2 AM EDT Saturday for AMZ360-362- 364. Gale Warning until 2 PM EDT this afternoon for AMZ380-382-384.