textproduct: Charleston

WHAT HAS CHANGED

Updated Key Messages to remove strong thunderstorm potential this evening. Updated the Aviation Section for the 00Z TAF issuance.

KEY MESSAGES

- 1) Hot and humid conditions will persist through much of the week.

- 2) Typical summertime convection returns this week.

DISCUSSION

KEY MESSAGE 1: Hot and humid conditions will persist through much of the week.

Upper ridging will remain entrenched across the Southeast, supporting above normal temperatures through the week. Highs will generally peak in the mid to upper 90s, and combined with elevated humidity, it will feel even hotter. Heat indices over 100F are expected each afternoon, with areas closer to the coast generally in the 105-110F range. Overnight low temperatures could remain near record-high minimum values through much of the week (see Climate Section below), providing little relief from the daytime heat. Additional Heat Advisories will be possible, especially in the first part of the week. Forecast trends will continue to be monitored to determine where Heat Advisories could become needed on a day-to-day basis.

It's worth noting that with showers and thunderstorms back in the forecast, any convection that develops would limit the duration where heat indices reach the 108+ criteria. Regardless, this extended stretch of hot and humid conditions will bring a risk of heat-related impacts, especially to those more vulnerable to heat or those without adequate cooling/hydration.

KEY MESSAGE 2: Typical summertime convection returns this week.

A more typical summertime convective pattern is expected this week, with daily shower and thunderstorm chances. Coverage will be highest in the afternoon and early evenings, before dwindling after sunset with loss of insolation. Environment favors mainly pulse-type convection, however isolated strong to severe storms are possible with damaging wind gusts as the primary hazard. This jives with some of the AI/MLP guidance as well. Locally heavy rainfall is possible in any storms with PWats near or over 2", but flooding risk looks low especially given the hot and dry conditions of late.

AVIATION /00Z MONDAY THROUGH FRIDAY/

VFR conditions are expected to prevail for CHS/JZI/SAV terminals through 00Z Tuesday. Southerly winds could gust upwards to 15-20 kt at CHS/JZI terminals with a Monday afternoon sea breeze. There is also a risk for an afternoon thunderstorm, mainly at CHS and SAV terminals Monday afternoon, but confidence in timing/occurrence is too low to mention in the latest TAF issuance.

Extended Aviation Outlook: Brief flight restrictions are possible in afternoon showers/thunderstorms this week.

MARINE

Through Tonight: High pressure will support southerly winds between 10 to 15 kts, with occasional gusts up to 20 kts. Wave heights are forecast to favor 3 ft, increasing to 3-4 ft overnight.

Monday through Friday: A fairly typical summertime pattern on tap for this week. Southwest winds in the morning will back more to the south for the afternoon and evenings. Speeds are forecast to stay below Small Craft Advisory criteria through the period, however gusts in the low 20 kt range are possible, especially in the afternoon and evenings. Seas will average 2-4 feet.

Rip Currents: The combination of gusty onshore winds, along with increasing swell of 9 or 10 seconds will generate a Moderate Risk of rip currents at the Charleston County beaches Tuesday.

CLIMATE

Record High Temperatures:

July 5: KSAV: 100/1902

July 7: KCHS: 99/1954

July 10: KCHS: 100/1986 KCXM: 99/1986

Record High Minimum Temperatures:

July 5: KCHS: 78/2017 KCXM: 82/2016 KSAV: 78/2016

July 6: KCHS: 79/1990 KCXM: 82/2024 KSAV: 78/2024

July 7: KCHS: 80/2017 KCXM: 82/2022 KSAV: 80/1883

July 8: KCXM: 83/2016 KSAV: 80/1990

July 9: KCHS: 80/1998 KSAV: 80/1883

July 10: KCHS: 81/1986 KCXM: 82/1986

July 11: KCHS: 80/2016 KCXM: 82/2016

CHS WATCHES/WARNINGS/ADVISORIES

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