textproduct: Charleston

WHAT HAS CHANGED

The Coastal Flooding Key Message was removed. All sections were updated.

KEY MESSAGES

- 1) Breezy conditions with somewhat unsettled weather possible today into Monday. Mild temperatures expected through midweek, then a cold front should bring at least scattered showers on Thursday.

DISCUSSION

KEY MESSAGE 1: Breezy conditions with somewhat unsettled weather possible today into Monday. Mild temperatures expected through midweek, then a cold front should bring at least scattered showers on Thursday.

Through Tonight: The risk for patchy showers will linger into tonight as waves of weak isentropic ascent atop the inland wedge and subtle coastal trough offshore persists. The risk for anything measurable looks highest at the coast. Lows tonight will range from the mid-upper 50s well inland to the mid-upper 60s at the beaches. Breezy conditions will linger at the beaches.

This Week: A weak coastal trough is expected to set up along the SC/GA coastline on Monday, however most shower activity associated with the coastal trough should remain offshore. Some shower activity along the GA coastline cannot be ruled out, and some slight chance PoPs are in the forecast for Monday afternoon. Otherwise, surface high pressure will remain the dominant synoptic feature across the region Monday into Tuesday before shifting offshore into Wednesday. Aloft, a mid-level trough will trek towards the southeastern states early in the week, pushing into New England late week. A surface cold front associated with this upper level feature will push across the local forecast area late week.

Generally quiet weather is expected through midweek, with temperatures warming into the lower 80s by midweek. Breezy northeasterly wind gusts (20 to 25 mph) will continue as a pinched pressure gradient prevails overhead. Forecast details late in the week have lower confidence as there is model differences in the timing and the location of the moisture axis associated with the passing cold front. The current forecast features slight chance to chance showers on Thursday.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

01/18z TAFs: KCHS/KJZI/KSAV: VFR through 02/18z. Some patches of very light showers will lurk around the terminals through much of the period, but no meaningful impacts are expected. Gusty winds will persist for the rest of the afternoon, diminish a bit overnight, then become gusty again after daybreak Monday.

Extended Aviation Outlook: Breezy NE wind gusts around 20 to 25 mph will continue through Tuesday. Rain chances increase late in the week.

MARINE

Through Tonight: A pinched gradient between inland high pressure and a coastal trough offshore will keep northeast winds 20-25 kt with gusts to 30 kt in place over the nearshore and offshore waters through tonight. Seas will average 4-7 ft nearshore waters and 7-9 ft offshore waters. Small Craft Advisories remain in effect. For Charleston Harbor, Winds have been around 20 kt with gusts as high as 30 kt for much of the day. Winds are forecast to relax somewhat this evening, likely settling back down into the 15-20 kt range. Waves 2 ft will subside to 1-2 ft. Small Craft Advisory continues for the Harbor until 7 PM.

Monday through Thursday: Frequent gusts into the 25-30 knot range are expected into Monday, along with seas in the 5-7 ft range. These conditions will support an extended period of Small Craft Advisories. Winds should gradually diminish Tuesday into Wednesday as the gradient relaxes. However, seas will remain elevated enough to keep the advisories going through Tuesday night. By Wednesday night and Thursday, winds will diminish even more as a cold front approaches from the west.

CHS WATCHES/WARNINGS/ADVISORIES

GA...None. SC...None. MARINE...Small Craft Advisory until 7 PM EST this evening for AMZ340. Small Craft Advisory until 7 AM EST Wednesday for AMZ360-362- 364. Small Craft Advisory until 7 AM EST Thursday for AMZ384.