textproduct: Charleston

WHAT HAS CHANGED

All sections have been updated.

KEY MESSAGES

- 1) Quiet conditions continue with somewhat unsettled weather possible Sunday into Monday.

DISCUSSION

KEY MESSAGE 1: Quiet conditions continue with somewhat unsettled weather possible Sunday into Monday.

Tonight: Aloft, h500 heights will continue to fall as shortwaves move through the flow into the overnight period. At the surface, a wedge of high pressure will continue to shift into the northeast, with a coastal trough just offshore. The resulting increased surface pressure gradient is creating the occasional gusty winds, especially closer to the coast. Though, they are expected to ease a bit overnight. The coastal trough will push light showers ashore over southeast Georgia overnight. Though, there remains some uncertainty on just how far inland the showers are able to get before dissipating. Either way, we continue to have chance POPs mainly south of I-16. Any precipitation amounts will remain light, with totals by sunrise Sunday expected to remain under a quarter of an inch.

Extended: High pressure will remain the primary feature across the region through early next week. The high will be centered near the Mid Atlantic and southern New England Sunday into Monday before drifting eastward over the Atlantic Tuesday into the middle of the week. A coastal trough is expected to develop just off the GA/SC coast and provide sufficient convergence to generate showers. This shower activity will likely favor the GA coast Sunday into Monday. The shower potential will then gradually spread to the entire coast Tuesday into Wednesday as the parent high slips to the east and allows the trough to attempt to push onshore. Any rainfall that does occur shouldn't be particularly impactful, with most places likely only seeing a few hundredths of an inch.

The gradient will remain sufficiently tight to drive elevated northeast flow Sunday through Tuesday. Gusts into the 20-25 mph range are expected, especially along the coast each afternoon and evening.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

00Z TAFs:

CHS/JZI: Both sites are expected to remain rain-free. However, the concern is how far ceilings drop overnight. Observations around the area indicate SCT-BKN 4,000 ft ceilings. Though, MOS expects VFR to prevail. There is enough concern that we introduced SCT025. But it's certainly possible both sites could go MVFR with short notice overnight. If so, ceilings will rise back to VFR in the morning hours as ENE winds increase and become gusty. These winds are expected to ease late in the TAF time period.

SAV: MVFR ceilings are being observed at this site along with nearby sites. This is due to light scattered showers moving onshore well to the south. While these showers could briefly approach or bring brief impacts overnight, confidence was not high enough to include SHRA or VCSH in the current TAF. Though, MVFR is expected to prevail overnight. Ceilings will rise back to VFR in the morning hours as the light shower threat dissipates, and ENE winds increase and become gusty. These winds are expected to ease late in the TAF time period.

Extended aviation: Breezy northeast winds will continue late Sunday through Monday. Rain chances will increase Sunday into early next week which could bring the potential for periodic flight restrictions.

MARINE

Tonight: Winds across the Charleston Harbor have eased a few hours earlier than expected, so we dropped the Small Craft Advisory for that location. The remaining Small Craft Advisories are still in effect. Otherwise, behind the front that pushed through earlier, breezy northeasterly winds have been moved in producing gusts of 25-30 kts across our local waters. Expect seas 6-7 ft in the nearshore zones and 7-8 ft in the offshore zones.

Sunday through Thursday: The overall setup will continue to feature high pressure centered off to the north with a pinched gradient across the local waters. This will drive continued northeast flow through the remainder of the weekend and early next week. 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 11 PM EDT this evening for AMZ340. Small Craft Advisory until 7 AM EDT Wednesday for AMZ360-362- 364. Small Craft Advisory until 7 AM EDT Thursday for AMZ384.