textproduct: Charleston

WHAT HAS CHANGED

All sections have been updated.

KEY MESSAGES

- 1) Below normal temperatures this week as high pressure prevails and a powerful nor'easter meanders off the Mid- Atlantic coast.

- 2) Risk for high surf will end this morning along much of the Georgia coast. High risk for rip currents for all beaches through this evening.

DISCUSSION

KEY MESSAGE 1: Below normal temperatures this week as high pressure prevails and a powerful nor'easter meanders off the Mid-Atlantic coast.

Tonight, the large circulation around the nor'easter located off the NC coast will supply SE GA and the SC Lowcountry with deep dry air. As a result, clear sky will remain across the forecast area tonight. In addition, north winds are forecast to decrease to around 5 mph. Given clear sky and light north winds, the forecast will favor the cooler MOS, indicating low temperature Tuesday morning between the low to mid 40s inland to around 50 near the beaches.

Tuesday through late week: High pressure will extend across the region this week. Meanwhile, a nor'easter will spin off the Mid- Atlantic coast through mid week before lifting northeast further away from the area. Deep dry air will remain in place, with LREF indicating PWats around or below the 10th percentile. This will lead to a rain-free forecast through the week. Despite plenty of sunshine, temperatures will lean on the cooler side of normal. Highs generally average in the low to mid 70s. Lows will fall into the mid to upper 40s across most interior locations. Gusty winds could develop late this week into the weekend as models depict a coastal trough developing while high pressure strengthens inland.

KEY MESSAGE 2: Risk for high surf will end this morning along much of the Georgia coast. High risk for rip currents for all beaches through this evening.

Latest lifeguard reports from Tybee and Kiawah indicated a surf height between 1-2 ft. More recently, Grays Reef buoy prior to high tide this afternoon was observing seas around 6 ft with a dominate wave period of 14 sec. Surf cams indicate a wave period between 12- 14 sec, however, heights nearing high tide appeared below 5 ft. The High Surf Advisory for the GA coast will end at 2 PM. However, long period swells will provide some larger breakers, around 4 ft, along the Charleston County beaches this afternoon and evening.

Rip Currents: Today: The combination of gusty winds and elevated, lingering swell will support a high risk for rip currents at all beaches through this evening.

Tuesday: Strong and gusty N winds at daybreak will ease during the morning and into the afternoon. Wave heights will be subsiding during this time period. However, the distant nor'easter will be generating a 4-5 ft NE wave at 12-13 seconds just offshore. We have a High Risk of rip currents for the Georgia beaches, with a Moderate Risk for South Carolina beaches.

Wednesday: The risk will lower for our SC beaches as the waves subside. Along the Georgia coast, conditions will remain supportive of a Moderate Risk. An elevated risk of rip currents could persist through late week and into the weekend.

AVIATION /18Z MONDAY THROUGH SATURDAY/

18Z TAFs: VFR. North winds wind gusts between 15-20 kts should remain until early this evening. North winds around 5 kts will likely continue tonight. After sunrise Tuesday, north winds should strengthen to 10 to 15 kts with gusts near 20 kts possible, strongest over KJZI.

Extended Aviation Outlook: VFR. Gusty winds could return late week into the weekend.

MARINE

Through Tonight: The marine zones will remain between a ridge of high pressure along the Appalachians and a nor'easter off the NC coast. The pressure pattern is forecast to support northeast winds between 15-20 kts with gusts around 25 kts across the nearshore and outer waters. Gusty winds should keep seas elevated between 5 to 7 ft across the nearshore and up to 10 across portions of the outer GA waters. Small Craft Advisories will continue for all marine zones outside the CHS Harbor tonight.

Tuesday through Thursday: A nor'easter will spin off the Mid- Atlantic coast through mid week before lifting northeast further away from the area. Conditions will remain supportive of Small Craft Advisories for all coastal waters outside of the Charleston Harbor through Wednesday morning. Later Wednesday into Thursday, winds should settle into the 10-15 knot range. Seas will also subside, but 6+ footers will likely maintain an Advisory for the outer Georgia waters.

Friday into the weekend: Marine conditions look to deteriorate again late week into the weekend as high pressure strengthens inland and a coastal trough develops offshore. Winds and seas will increase as a result, with Small Craft Advisories and even Gale Watches/Warnings possible.

CHS WATCHES/WARNINGS/ADVISORIES

GA...High Risk for Rip Currents through Tuesday evening for GAZ217-219- 239-241. SC...High Risk for Rip Currents until 8 PM EDT this evening for SCZ148>151. MARINE...Small Craft Advisory until 2 PM EDT Wednesday for AMZ360-362. Small Craft Advisory until 6 PM EDT Wednesday for AMZ364. Small Craft Advisory until 6 AM EDT Saturday for AMZ384.