FXUS62 KCHS 071852 AFDCHS
Area Forecast Discussion National Weather Service Charleston SC 152 PM EST Sat Mar 7 2026
.WHAT HAS CHANGED...
All sections have been updated, including mention of dense fog across coastal waters, the 18Z TAF issuance, and a new key message for widespread rainfall Thursday.
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.KEY MESSAGES...
- 1) Patchy to areas of fog possible across Southeast South Carolina and Southeast Georgia tonight into Sunday morning.
- 2) Unseasonably warm temperatures continue through Wednesday, along with increased rain chances.
- 3) A cold front may bring widespread rainfall on Thursday.
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.DISCUSSION...
KEY MESSAGE 1: Patchy to areas of fog possible across Southeast South Carolina and Southeast Georgia tonight into Sunday morning.
High pressure will prevail across the western Atlantic while a front approaches the Southeast early next week, continuing a southerly flow across the local area. Like previous nights, increasing moisture levels under ridging aloft could help set the stage for fog to develop across areas after midnight tonight when condensation pressure deficits are quite favorable. However, there are some mixed signals in regards to fog coverage, including dense fog potential given 1000 mb geostrophic winds appear slightly stronger across the area compared to previous nights. It is possible most cloud formation stays in the form of a low stratus deck at least a few hundred feet off the ground, leaving sfc visibilities above 1 mile through the night for most areas. Locations across Southeast Georgia, mainly along and south of I-16, maintain the greatest risk for areas of dense fog late night through a few hours after daybreak (HREF probabilities of 1/4 mile vsbys between 20-30%). The risk could be most enhanced along coastal GA should sea fog drift onshore overnight.
KEY MESSAGE 2: Unseasonably warm temperatures continue through Wednesday, along with increased rain chances.
Deep-layered high pressure extending across the western Atlantic will prevail across the Southeast United States into the middle of next week. A stalling/dissipating front will be upstream Monday, followed by High pressure in the wester Atlantic Tuesday and Wednesday. This pattern will usher moisture into our area through the middle of next week. Likewise, the NBM generally has slight chance to chance POPs Sunday through Tuesday. Any showers/thunderstorms should be fairly quick moving, leading to low rainfall amounts. No severe weather is expected.
The main story during this time period will continue to be the unseasonably warm temperatures. Highs will range from near 80 degrees to the upper 80s, except cooler temperatures along/near the coast. Wednesday should be the hottest day across our entire area with a few spots across our interior GA counties making a run for the 90 degree mark. Lows each night will generally be in the lower 60s.
KEY MESSAGE 3: A cold front may bring widespread rainfall on Thursday.
The mid-levels will consist of a trough axis roughly over the MS River Valley early Thursday morning. Models vary on its eastward speed and location, but the general consensus has the trough quickly moving over the East Coast later in the day, then off the coast Thursday night. This matters because the energy will be transferred to a cold front, which appears to move through our area on Thursday. There will be a deep plume of moisture ahead of this front. The combination of the moisture and lift may generate widespread showers across our area. Given the unseasonably warm temperatures ahead of the front, there should be enough instability to fire off some thunderstorms. Though, it's too early to determine how strong they will be. Likewise, it's too early to determine rainfall amounts. But any showers/storms appear to be progressive in speed.
High pressure behind the front will bring drier conditions along with a return to seasonal temperatures.
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.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR conditions are expected at CHS/JZI/SAV terminals through at least 00Z Sunday. Latest guidance suggests flight restrictions returning at all terminals tonight, mainly in the form of low stratus overnight and perhaps fog late night. Conditions deteriorate to MVFR at JZI by around 03Z Sunday, then IFR and/or possibly lower at JZI around 05Z Sunday. IFR and/or possibly lower conditions occur at CHS/SAV terminals as well, generally by 08Z Sunday (but could be a few hours prior). IFR conditions should then prevail through about 14Z Sunday. Like previous mornings, any low clouds (or fog) likely lifts/erodes quickly around 14-15Z, with VFR conditions then prevailing through 18Z Sunday.
Extended Aviation Outlook: Low stratus/fog could bring restrictive ceilings and visibilities during the overnight into the early morning hours early next week. Brief flight restrictions are possible due to showers and thunderstorms next week. A cold front should bring flight restrictions on Thursday.
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.MARINE...
Today and Tonight: The main issue will be the continuation of sea fog across nearshore waters this afternoon and potentially overnight. Latest webcams and visible sat imagery indicate sea fog just off local beaches across coastal waters early this afternoon. Conditions have improved sufficiently across nearshore SC waters, but with some restrictions remaining (vsbys 1-3 NM). However, areas south of Tybee Island, GA across nearshore GA waters continue to experience areas of dense sea fog, which has resulted in extending a Dense Fog Advisory across nearshore GA waters into early evening. Guidance does suggest the redevelopment of sea fog (some dense) returning across nearshore waters overnight, and to a lessor degree across the Charleston Harbor, but confidence is somewhat less for all nearshore waters overnight given slightly stronger low-lvl flow across the region. Conditions will continue to be monitored for Dense Fog Advisories across these waters overnight into early daylight hours Sunday. Otherwise, fairly light southeast winds will veer to the south and southwest tonight as the gradient between high pressure centered well offshore and an approaching cold front tightens. The risk for sea fog should persist into early next week.
Sunday through Thursday: High pressure will remain the dominant weather feature across our local waters next week, favoring a south/southwest wind in the 10-15 kt range and seas generally between 2-4 ft, well below Small Craft Advisory thresholds. A cold front will approach late Wednesday, causing winds and seas to increase to Small Craft Advisory levels across all of our ocean zones. Gusts to gale force cannot be ruled out behind the cold front on Thursday.
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.CLIMATE...
Record High Temperatures:
March 7: KCHS: 87/2023 KCXM: 84/2023 KSAV: 86/2023
March 8: KCHS: 86/1974 KCXM: 86/1951 KSAV: 86/1974
March 9: KCHS: 87/1974 KCXM: 84/1974 KSAV: 88/1974
March 10: KCHS: 90/1974 KCXM: 87/1974 KSAV: 91/1974
March 11: KCHS: 85/2015 KCXM: 82/1997 KSAV: 87/2015
Record High Minimum Temperatures:
March 7: KCHS: 63/1992 KCXM: 65/2023 KSAV: 68/1880
March 8: KCHS: 63/2022 KCXM: 65/2022 KSAV: 65/1880
March 9: KCHS: 66/2022 KCXM: 65/2022 KSAV: 65/2022
March 10: KCHS: 64/1974 KCXM: 65/1974 KSAV: 63/1909
March 11: KCHS: 63/2015 KCXM: 64/2016 KSAV: 64/1974
March 12: KCHS: 62/1985 KCXM: 64/1973 KSAV: 65/1973
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.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None. SC...None. MARINE...Dense Fog Advisory until 7 PM EST this evening for AMZ354.
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