textproduct: Charleston

WHAT HAS CHANGED

The Aviation Section has been updated for the 00Z TAF issuance.

KEY MESSAGES

- 1) Temperatures are expected to rise through the weekend, likely approaching triple digits on Sunday. Heat Advisories could be needed this weekend and into early next week.

DISCUSSION

KEY MESSAGE 1: Temperatures are expected to rise through the weekend, likely approaching triple digits on Sunday. Heat Advisories could be needed this weekend and into early next week.

The primary weather concern through the weekend and into early next week continues to be building heat and humidity. High temperatures are forecast to steadily warm into the weekend. Mid 90s are expected across the entire forecast area Saturday, followed by upper 90s and possibly even triple digits on Sunday. Monday should then bring mid to upper 90s to the area. Also of note, low temperatures will rise each night as well, providing no significant relief from the daytime heat. Sunday highs could approach daily records, and record high minimums will also be in play. See the Climate section below for additional details.

Rising temperatures will be accompanied by increasing humidity thanks to dewpoints well into the 70s each afternoon. This combination will yield increasingly uncomfortable heat index values starting Saturday and continuing through Monday. For Saturday, heat index values are forecast to rise into the 100-105 degree range across the entire area with pockets of 105-110 possible along the coast. Then for Sunday and Monday, the footprint of heat index values into the 108-112 degree range is expected to increase, especially along the coast. At this time, it appears the best chance for meeting Heat Advisory criteria (108-112) will come Sunday and Monday primarily for the coastal counties. There could even be pockets of heat index values higher than 112 degrees and the need for Excessive Heat Watches/Warnings can't be completely ruled out.

The potential for thunderstorm development Sunday and Monday could complicate things a bit as the presence of storms could prevent some areas from reaching peak heating and heat index potential. This prevents forecast confidence from being too high this far out. Regardless, very hot and humid conditions are expected.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

VFR conditions are expected to prevail at CHS/JZI/SAV terminals through 16Z Friday. The risk for a shower or thunderstorm increases Friday afternoon along and/or ahead of an inland moving sea breeze. PROB30 groups for 4SM -TSRA have been introduced at CHS between 17-22Z Friday and at SAV between 19-23Z Friday where greater chances of precip are forecast. JZI could experience a shower or thunderstorm for a shorter period Friday afternoon, but confidence is too low to include in the latest TAF issuance. South winds gusting up to 15-20 kt are possible during peak heating hours Friday, primarily at CHS/JZI when the sea breeze shifts through.

Extended Aviation Outlook: Mostly VFR.

MARINE

Through Tonight: Southeast flow this evening will gradually turn more southerly and southwesterly through the overnight. Wind speeds should mostly peak in the 10-15 kt range. Seas will average around 2 ft.

Friday through Tuesday: Overall, a pretty standard summertime pattern is expected across the local waters. Some enhanced flow with wind gusts up to around 25 knots will be possible Saturday afternoon and evening across the Charleston County waters. A similar surge could occur Tuesday as well. Conditions could become marginally supportive of needing a Small Craft Advisory. Otherwise, the strongest flow will occur during the afternoon and evening periods with the sea breeze circulation along the land/sea interface.

CLIMATE

Record High Temperatures:

June 28: KCHS: 99/1998 KSAV: 100/1998

Record High Minimum Temperatures:

June 27: KCHS: 77/2015

June 28: KCHS: 78/2013 KCXM: 81/1998 KSAV: 80/1880

June 29: KCHS: 79/1977 KSAV: 80/1885

June 30: KSAV: 79/1880

CHS WATCHES/WARNINGS/ADVISORIES

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