textproduct: Charleston

WHAT HAS CHANGED

The Aviation section was updated for the 00Z TAF issuance.

KEY MESSAGES

- 1) Gradual increase in rain chances this week.

- 2) Afternoon heat index values may climb into the 100 to 105 degree range across the region Friday through Sunday.

DISCUSSION

KEY MESSAGE 1: Gradual increase in rain chances this week.

A building upper ridge axis Tuesday into Wednesday will maintain fairly dry weather, especially given a relatively dry boundary layer from high pressure centered to the north. Isolated showers or tstms are possible in the afternoon across inland areas, mainly Tuesday. Thursday into Friday, low level moisture will increase as the surface high shifts east. The upper ridge will weaken, allowing an increase in shortwave energy moving through. We'll likely see considerably more active diurnal convection Thursday into Friday. A cold front is expected to approach over the weekend, likely resulting in numerous to widespread showers and thunderstorms during the daytime hours.

KEY MESSAGE 2: Afternoon heat index values may climb into the 100 to 105 degree range across the region Friday through Sunday.

As surface ridging situates itself across the southeastern CONUS, near to above average temperatures will be apparent late this week into the weekend. Expect temperatures to climb into the mid to upper 90s on Thursday through Sunday. This combined with increasing humidity levels could yield afternoon heat index values ranging between 100 to 105 degrees (esp. along the coastline). Thus, Heat Advisories could be possible on Friday and Saturday for portions of the region, however afternoon heat index values (as of right now) do not meet threshold criteria. This will continue to be monitored over the next several days.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

VFR conditions will prevail at CHS/JZI/SAV terminals through 00Z Wednesday.

Extended Aviation Outlook: VFR conditions are expected to prevail at CHS/JZI/SAV terminals. However, brief flight restrictions are possible with afternoon showers and/or thunderstorms on Thursday and Friday.

MARINE

Through tonight: Light southeasterly winds at 5 to 10 kt will persist as a backdoor cold front gradually approaches the local waters from the north. Seas will range from 1 to 3 ft.

Tuesday through Friday: Marine conditions will remain on the quiet side through the end of the week. A weak cold front will attempt to approach the local waters on Tuesday. Thereafter, high pressure will dominate through the remainder of the week. Expect a typical summertime pattern with the modest surge of winds along the coastline as the afternoon sea breeze tracks inland.

CHS WATCHES/WARNINGS/ADVISORIES

GA...None. SC...None. MARINE...None.