Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
580 FXUS62 KCHS 100014 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 814 PM EDT Sun Aug 9 2026 .WHAT HAS CHANGED... Key Message 2 was updated for latest trends. The Aviation Section has been updated for the 00Z TAF issuance. && .KEY MESSAGES... - 1) Typical summertime storm activity will continue through early this week. - 2) Hot and humid conditions will return this week. && .DISCUSSION... KEY MESSAGE 1: Typical summertime storm activity will continue through early this week. The Bermuda high will remain in control of our forecast for the next day or two as it slowly flattens out across Florida. This will continue to bring a more summerlike pattern to the area as we remain on the northwestern periphery of the ridge. Expect the seabreeze to be the main surface driver for afternoon showers and thunderstorms. Isolated to scattered storms should develop by mid-afternoon Monday with the progression of the seabreeze. PWATS will remain around 2 inches and with slightly increased moisture throughout the column Monday we could see a little better coverage than today. As always a strong to severe storm cannot be ruled out with damaging winds the primary threat as well as some locally heavy rainfall. However, conditions are not necessarily favorable for a more widespread concern at this time. Tuesday through Thursday, the upper ridge will shift westward and build over the deep south. A series of shortwaves are expected to progress through the northwesterly flow Tuesday through Thursday leading to slightly increased showers and storms during the afternoon. This will be especially true for inland areas Wednesday and Thursday. Given the increased coverage, warmer temperatures and maybe some drier air in the mid levels advecting in some increased potential for a strong to severe storm looks likely Wednesday and Thursday. This has even been noted in some of the longer range machine learning guidance highlighting increased potential for damaging wind gusts across interior South Carolina on Wednesday. Just something to watch as things may get a little more active later in the week. KEY MESSAGE 2: Hot and humid conditions will return this week. Expect highs to warm into the low 90s for most locations Monday, with perhaps a few areas flirting with the mid 90s as a coastal trough enhances WAA across the region. Dewpoints during this time look to remain in the mid to upper 70s, which should result in heat indices up to 105 degrees. A more pronounced heat wave is expected to arrive mid week. High temperatures each day are expected to peak in the lower to mid 90s, with chances for upper 90s by the end of the week, putting a few of our daily record highs and record minimum highs at jeopardy (more in the climate section below). Inland areas (especially those well west of the I-95 corridor) will likely see enough surface mixing to limit dew points to the mid 70s, while those along the coast could see dew points linger in the upper 70s to lower 80s. Combined with the aforementioned temperatures in the mid to upper 90s, expect heat index values between 105-112 degrees to be common along the coast through Wednesday. These values look to further increase by the end of the week as upper level ridging amplifies overhead - which could yield heat index values up to 115 degrees. Thus, expect some Heat Advisories to be issued during the upcoming week, though some Extreme Heat Warnings may also not be out of the question. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... VFR conditions are expected to prevail at CHS/JZI/SAV terminals through 00Z Tuesday. There is a risk for a few showers and/or thunderstorms impacting the terminals during Monday afternoon hours, with highest probabilities at CHS, but confidence remains too low to include TEMPO or PROB30 groups with MVFR restrictions for the latest TAF issuance. Extended Aviation Outlook: Periodic flight restrictions are expected in showers and thunderstorms through next week. && .MARINE... Tonight through Thursday: Atlantic high pressure will be the dominant synoptic feature this week, keeping winds out of the south-southwest. Light to moderate winds prevail on Monday, though gusty winds are expected along the land/sea interface during the afternoon hours as the sea breeze moves onshore. Coastal troughing sets up overnight into Tuesday and continues throughout the week, keeping winds breezy with gusts into the teens to lower 20s. Seas look to remain largely in the 2-3 ft range, though 4 foot waves will be possible at times in the South Carolina waters from 20-60nm offshore. Small Craft Advisories currently look unlikely, but will be something to monitor. Coastal Flooding: While elevated tidal cycles are expected next week due to the upcoming perigee and new moon, the south-southwesterly surface flow should keep tidal departures low, limiting the overall coastal flood threat. && .CLIMATE... Record High Temperatures: August 11: KCHS: 98/1968 KCXM: 97/1954 KSAV: 100/2011 August 12: KCHS: 98/1957 KCXM: 98/1998 KSAV: 100/1999 August 13: KCHS: 100/1995 KCXM: 98/1913 KSAV: 98/2010 Record High Minimum Temperatures: August 10: KCHS: 80/2007 KCXM: 83/2007 KSAV: 79/2024 August 11: KCHS: 79/1983 KCXM: 82/2021 KSAV: 78/1878 August 12: KCHS: 79/1999 KCXM: 83/2021 KSAV: 80/1878 August 13: KCHS: 81/2023 KCXM: 83/2023 KSAV: 81/2023 August 14: KCHS: 80/2023 KCXM: 83/2023 KSAV: 80/2023 && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$