textproduct: Charleston

WHAT HAS CHANGED

All Key Messages and sections were updated.

KEY MESSAGES

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

Water levels in Charleston Harbor could approach minor flood stage Saturday morning. One last Coastal Flood Advisory could be needed for Charleston and Coastal Colleton Counties.

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

The rip current risk increases to high for all beaches by Saturday, as increased northeasterly winds and seas become more widespread.

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.

Saturday: The ridge aloft begins to break down as a wedge of high pressure meanders towards the northeast coast, setting up a coastal trough just offshore. Expect winds to become gusty inland to breezy along the coast throughout the day, with areas along the coast likely seeing gusts of 25 to 30 mph during the afternoon, possibly as high as 35 mph down near Darien. While temperatures will be a touch cooler than today, normal to above normal temperatures remain expected with highs in the mid 70s to lower 80s, warmest across southeast Georgia. With low to mid level moisture increasing throughout the day, partly cloudy skies will become mostly cloudy. Can't rule out some scattered light showers near Darien, GA Saturday afternoon into the early evening hours, though the rest of the area looks to remain dry for any outdoor activities.

Lake Moultrie: As breezy winds develop Saturday morning, there is a brief window shortly after sunrise where winds on Lake Moultrie may briefly gust to near 25 knot. Confidence is not high enough for a Lake Wind Advisory, but something to keep an eye on.

Sunday: As the surface high begins to slowly decrease in strength, gusty to breezy conditions remain across the area for Sunday, with highs in the mid 70s. Models continue to show mostly dry conditions for Sunday as the shortwaves look very weak and isolated, with the coastal trough likely keeping rainfall chances just offshore. The exception remains for areas near Darien, GA as the coastal trough extends onto land, though amounts look to remain light under a quarter of an inch.

Monday and Tuesday: The center of the surface high pressure to our north begins to shift out into the Atlantic, with the coastal trough remaining just offshore of our local waters. Combined with increasing low-level moisture and a weak slow moving shortwave, chances for light scattered showers will build across the region Monday morning into the early overnight hours on Tuesday. Otherwise, expect simlar conditions to continue, with gusty northeast winds and afternoon highs in the mid 70s for Monday, rising into the upper 70s to lower 80s on Tuesday. The forecast is currently calling for low chances for light rain on Tuesday, though that is a bit uncertain as forecast solutions begin to diverge on Tuesday.

Wednesday and Thursday: Forecast guidance is handling the longwave trough and associated surface low pressure that they have moving towards the eastwards from the central CONUS with various solutions, leading to lowered confidence in the forecast. General concensus is for the longwave trough to continue shifting eastwards Wednesday into Thursday, though some models have it becoming a closed off low and others are more progressive, which should bring some chances for rain. The track of the surface low looks to remain north of the area, with the associated cold front aiding rainfall chances.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

30/18z TAFs: KCHS/KJZI/KSAV: VFR through 31/18z. Gusty winds will develop after daybreak Saturday at all three terminals.

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

MARINE

Restrengthening of the inland wedge to the north overnight with the development of a weak coastal trough will drive northeast wind gusts back up to 25-30 kt, with building seas above 6 ft. Small Craft Advisories have been issued for the Charleston Harbor and all near-shore (out to 20nm) zones, starting Saturday morning. The offshore (20-60nm) waters from Savannah to Altamaha sound will continue their advisories. Wave heights will build overnight to become 7 to 9 ft in the offshore (20-60nm out) zones, and into the 5 to 8 ft range in the nearshore zones. With high pressure lingering into the mid-week, northeast winds will remain breezy during the day and gusty overnight, keeping wave heights in the 5 to 8 ft range into Wednesday morning.

CHS WATCHES/WARNINGS/ADVISORIES

GA...High Risk for Rip Currents through Saturday evening for GAZ217-219- 239-241. SC...High Risk for Rip Currents from Saturday morning through Saturday evening for SCZ148>151. MARINE...Small Craft Advisory from 8 AM to 8 PM EDT Saturday for AMZ340. Small Craft Advisory from 8 AM Saturday to 7 AM EDT Wednesday for AMZ360-362-364. Small Craft Advisory until 7 AM EDT Wednesday for AMZ384.