textproduct: Charleston

WHAT HAS CHANGED

The Aviation section updated for the 12Z TAFs and Marine section updated for changes in Small Craft Advisories.

KEY MESSAGES

- 1) Scattered showers and perhaps a few thunderstorms possible Thursday and Friday.

DISCUSSION

KEY MESSAGE 1: Scattered showers and perhaps a few thunderstorms possible Thursday and Friday.

A mid level trough and associated cold front will approach the region late week. The best forcing will pass to the north, but deeper moisture will spread into the area, noted by PWats climbing to over 1.5". Rain chances will increase as a result with scattered showers and perhaps a few thunderstorms possible Thursday and especially Friday. Highest coverage is expected over inland areas. Rainfall amounts look rather unimpressive, with NBM indicating only a 10-25% chance for precip greater than 0.25" in a 24 hour period. Drier air moves back in following fropa later Friday with a dry forecast for the weekend.

Otherwise, temperatures will be on the warmer side of normal this week. Highs are forecast to peak in the low to mid 80s most days.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

Prior to the 12Z TAFs, IR satellite indicated a patch of IFR ceilings over KCHS and KJZI, with MVFR ceilings near KSAV. The TAFs will highlight the potential for restrictive ceilings with TEMPOs this morning through 15Z. VFR conditions expected through the rest of the day.

As temperatures warm into the low 80s today, a weak sea breeze should develop and advance inland. By 15z, the TAFs will feature a east-northeast wind at KJZI with gusts around 20 kts with an east wind at KCHS and KSAV. Wind gusts should end by 22Z, with speeds around 10 kts remaining through the rest of the TAF period.

Late tonight, terminals will see dewpoints in the upper 60s in the wake of the afternoon sea breeze. As winds become light to calm during the pre-dawn hours, patchy fog or ground fog may develop over each terminal. At this time, each TAF will feature MVFR vis in fog after 9Z.

Extended Aviation Outlook: Isolated to scattered shower coverage is expected on Thursday and Friday. Any flight restrictions with the showers will be brief.

MARINE

Today through Tonight: The sfc pattern should generally support northeast winds between 15 to 20 kts across the nearshore waters early this morning. As temperatures over land warm into the low 80s today, a sea breeze should develop and advance inland through this afternoon. Once the sea breeze forms, winds across the nearshore waters should veer gradually from the east-northeast and subside to around 10 to 15 kts. As a result, wave heights should begin the day between 5 to 6 ft across the nearshore, decreasing to 4 to 5 ft this afternoon. Small Craft Advisories are scheduled to end over the GA nearshore waters this afternoon. The outer GA waters should continue to see periods of 6 ft seas today into tonight. The 6 ft seas over the outer GA waters should end tonight.

Wednesday through Sunday: Wind and sea conditions should remain below Small Craft Advisory criteria through the period. A weak pressure gradient will provide SE winds between 5 to 10 kts on Wednesday. As a result, seas will decrease to 3 to 4 ft across the marine zones. A weak cold front will approach the waters on Thursday into Thursday night. Winds should turn from the southwest, with speeds generally less than 10 kts. Sfc high pressure will build across the area late this week into this weekend. Given a weak pressure gradient, winds should remain less than 15 kts with seas between 3 to 5 ft.

CHS WATCHES/WARNINGS/ADVISORIES

GA...None. SC...None. MARINE...Small Craft Advisory until 7 PM EST this evening for AMZ364. Small Craft Advisory until 7 AM EST Wednesday for AMZ384.