textproduct: Charleston

WHAT HAS CHANGED

Updated Key Message #1 and the Aviation section for the 06Z TAFs.

KEY MESSAGES

- 1) Periodic showers and thunderstorms are expected to continue this week within a persistent summertime pattern.

DISCUSSION

KEY MESSAGE 1: Periodic showers and thunderstorms are expected to continue this week within a persistent summertime pattern.

Today: As weak shortwave energy tracks through moist southwesterly flow, scattered showers and thunderstorms should persist through this afternoon. The severe threat remains quite limited, however a few rumbles of thunder and brief heavy downpours will be reasonable within stronger thunderstorms. The highest PoPs will be located across far southeast Georgia as pockets of partial sunshine could support SBCAPE values ~1000 J/kg. Extensive cloud cover should limit daytime heating with afternoon highs remaining in the mid to upper 80s, with a few inland locations struggling to reach into the low 80s. Activity should gradually diminish this evening, although a few showers and thunderstorms could linger into the overnight period. Conditions will remain warm and humid overnight with lows mainly in the low to mid 70s.

Thursday and Friday: A relative lull precipitation is expect on Thursday morning as the initial disturbance exits and weak ridging briefly develops aloft. Clear skies combined with strengthening southwesterly flow will yield afternoon temperatures in the low to mid 90s. Heat index values could approach 100 to 105 degrees in some locations.

Another round of showers and thunderstorms will likely begin on Thursday afternoon as anomalously high moisture from Potential Tropical Cyclone (PTC) One will slowly migrate into the region. This should result in numerous to widespread showers and thunderstorms though Friday evening. Severe threat remains limited at this time, however cannot rule out an couple isolated storms becoming strong to severe as instability increases out ahead of an advancing cold front. Localized flooding of poor-drainage and low-lying areas will be possible, especially where storms repeatedly track over the same locations.

Saturday and Sunday: The aforementioned front should slide offshore on Saturday morning as a few showers and thunderstorms linger near the coastline. Thereafter, the typical summertime pattern will dominate the forecast as the daily chances for showers and thunderstorms initiating along the afternoon seabreeze return. However, it's important to note that coverage should be much less than Thursday and Friday. Otherwise, afternoon highs will warm into the upper 80s to low 90s.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

Occasional light rain will continue overnight, then the best upper forcing will move offshore Wednesday morning. Although there remains a chance for brief MVFR ceilings overnight, the models have backed off on the probability, and we removed mention from the 06Z TAFs. Convective coverage on Wednesday looks fairly low, but the greatest chance will be at KSAV. Gusty SW winds expected to develop by mid-morning.

Extended Aviation Outlook: VFR conditions should largely prevail through the weekend, with brief periods of flight restrictions possible with any shower and thunderstorm throughout the week.

MARINE

Today: Breezy southwesterly winds should prevail across the local waters with some a few gusts reaching up to 22-24 kts esp. along the land-sea interface as the afternoon seabreeze pushes inland. Showers and thunderstorms will remain possible through the evening, however convection should gradually decrease overnight.

Thursday through Saturday: The pressure gradient should gradually tighten ahead of an advancing cold front on Thursday with southwesterly winds increasing through overnight into Friday morning. Seas will also build from 2-4ft on Thursday night to 4-7 ft by Friday afternoon across the South Carolina waters. The Georgia waters will likely only build to 3-5 ft (maybe some 6 footers in the offshore waters). Therefore, Small Craft Advisories will likely be needed on Thursday evening into Friday night for elevated winds and seas. As the aforementioned cold front pushes offshore on Saturday morning, expect marine conditions to gradually improve throughout Saturday.

CLIMATE

Record High Minimum Temperatures:

June 18: KCHS: 78/2015 KCXM: 81/1998

June 19: KCHS: 79/2025 KCXM: 81/2025 KSAV: 79/1881

June 22: KCHS: 79/2018 KSAV: 78/1937

June 23: KCHS: 78/2024 KCXM: 82/1998 KSAV: 77/2017

CHS WATCHES/WARNINGS/ADVISORIES

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