textproduct: Charleston

WHAT HAS CHANGED

All Key Messages and sections have been updated.

KEY MESSAGES

- 1) Another round of low clouds and fog are likely this morning with sea fog plaguing the coastal waters. Above normal temperatures to continue today into tonight.

- 2) Unseasonably warm temperatures continue through Wednesday, followed by cooler temperatures to end the week in the wake of a departing cold front.

- 3) Scattered showers and thunderstorms remain possible Tuesday, with additional storms possible Thursday ahead of an advancing cold front.

DISCUSSION

KEY MESSAGE 1: Another round of low clouds and fog are likely this morning with sea fog plaguing the coastal waters. Above normal temperatures to continue today into tonight.

A cold front to the north and northwest is becoming increasingly stationary as it become parallel to the flow aloft. This will keep the entire region in the warm sector with warm/moist conditions prevailing. Shower activity will continue to clear the coast over the next few hours with rain-free conditions prevailing today. Stratus and fog are poised to steadily expand through daybreak within a light wind field and saturated conditions. 1000 hPa condensation pressure deficits are forecast to be the lowest along the lower South Carolina coast arcing back into Colleton, Dorchester and Berkeley Counties. This is likely where the greatest concentration of fog will occur, some of which could become dense. It is possible visibilities 1/4 mile or less could become widespread enough that a Dense Fog Advisory may be needed closer to daybreak, but confidence in this is only medium at this time. Some degree of sea fog offshore could also spread inland along parts of the lower South Carolina coastal counties. Trends are carefully monitored.

The fog and stratus should quickly mix out after daybreak with mostly sunny to partly cloudy skies expected. Low-level thickness schemes support highs in the lower-mid 80s, but should largely peak below record territory despite temperatures running about 15-20 degrees above normal. A robust sea breeze will develop along the coast by early afternoon, but its inland progression will be hampered by a modest westerly flow aloft. Still, a very large thermal gradient will be found across the coastal counties with the beaches likely not getting out of the mid-upper 60s. It will continue warm tonight with lows dropping into the lower 60s. More stratus and fog are possible. A few showers/tstms may also develop early Tuesday morning with the onset of some weak warm air advection/isentropic lift.

KEY MESSAGE 2: Unseasonably warm temperatures continue through Wednesday, followed by cooler temperatures to end the week in the wake of a departing cold front.

Broad ridging holds tight across the southeastern CONUS through Wednesday allowing unseasonably warm temperatures to continue. Highs in the 80s will be common during this time, though areas along the coast will likely stay capped in the upper 70s. As noted in the previous discussion, expect Wednesday to be the hottest day across our entire area, with a few locations across interior Georgia taking a shot at 90 degrees. Otherwise, look for lows to remain mild, as temperatures only fall into the lower 60s.

Upper level flow shifts heading into Thursday as a trough and sfc cold front move in tandem over the Tennessee River Valley and push eastward toward the Atlantic. While an influx of CAA will be present Thursday afternoon, expect more notable impacts to occur Thursday night as lows fall into the 40s to lower 50s. Otherwise, look for near normal highs to prevail Friday, before temperatures gradually warm back into the upper 70s to 80s over the weekend.

KEY MESSAGE 3: Scattered showers and thunderstorms remain possible Tuesday, with additional storms possible Thursday ahead of an advancing cold front.

Isolated to scattered showers remain possible Tuesday morning and afternoon, especially across the Tri-County area. Nonetheless, with coverage and overall moisture lacking, not expecting to see much in the way of significant rainfall. Severe weather is also not anticipated at this time.

Rain chances then return to the forecast Thursday ahead of an advancing cold front. Coverage with this boundary looks to be more widespread, with PoPs currently ranging between 60-80%. With the aid of south/southwesterly flow, should see a decent push of moisture advection across the region. Given the unseasonably warm temperatures ahead of the front, there should also be just enough instability to fire off some thunderstorms, though the timing of FROPA will likely limit the risk of severe weather. Rather, the more likely outcome of this front will entail a few strong thunderstorms capable of producing frequent lightning, brief heavy downpours, and breezy winds. With rainfall amounts ranging between 0.25 - 1.0 inch, should see overall flooding concerns remain low, though drainage issues may still exist in urban or low-lying areas.

AVIATION /06Z MONDAY THROUGH FRIDAY/

09/06z TAF Discussion: KCHS/KJZI/KSAV: IFR to LIFR cigs are poised to fill into the terminal through daybreak with a warm/moist airmass holding in place. Fog is also possible with the best chances for fog impacts occurring at KCHS and KJZI where vsbys could approach airfield minimums at times, especially at KJZI where some sea fog contribution may occur. Fog/stratus should lift quickly after daybreak with VFR conditions returning by 14-15z. VFR will then prevail for the remainder of the 06z TAF period.

Extended Aviation Outlook: Flight restrictions due to low stratus/fog remain possible through mid-week. Brief flight restrictions may occur Tuesday in response to scattered showers and thunderstorms. Otherwise, look for a cold front to bring additional flight restrictions and breezy winds on Thursday.

MARINE

Through Tonight: The risk for sea fog will persist into tonight. Guidance continues to struggle on how widespread any fog will become, which has been an ongoing issue for the past several days. Expect some degree of expansion through daybreak which may yield enough low vsbys to require a Marine Dense Fog Advisory. Fog should linger through the day, although its coverage could diminish as the morning progresses. More fog could redevelop tonight. Otherwise, southerly winds 10 kt or less will persist with some sea breeze enhancement likely (10 kt possibly 10-15 kt) along the beaches and Charleston Harbor this afternoon. Seas will average 2-3 ft nearshore waters and 3-4 ft over the Georgia offshore waters.

Tuesday through Friday: High pressure will be the dominant weather feature across our local waters through the middle of this week. Expect south/southwest wind sustained in the 5-10 kt range and seas 2-4 ft. A cold front will approach from the west late Wednesday, causing winds and seas to increase to Small Craft Advisory levels across all of our ocean zones. The cold front should cross through our waters Thursday, causing winds to veer behind it and further increase. Gusts to gale force are possible across portions of our waters Thursday and Thursday night. High pressure building into the region will lead to improving conditions for the end of the week.

CLIMATE

Record High Temperatures:

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 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

EQUIPMENT

The KCLX radar is scheduled for radome panel replacement March 14-16, 2026. The radar will be down during this time. Users are encouraged to use data from the following nearby radar sites during the maintenance outage:

KCAE - Columbia, SC KLTX - Wilmington, NC KJAX - Jacksonville, FL KVAX - Moody AFB, GA KJGX - Robbins AFB, GA

CHS WATCHES/WARNINGS/ADVISORIES

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