FXUS62 KCHS 112328 AFDCHS
Area Forecast Discussion National Weather Service Charleston SC 728 PM EDT Wed Mar 11 2026
.WHAT HAS CHANGED...
The aviation section was updated for the 00z TAFs.
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.KEY MESSAGES...
- 1) Record to near record warmth through tonight.
- 2) As a cold front passes through the region, expect showers
and thunderstorms tomorrow morning through the afternoon.
- 3) Chances for rain return late weekend into early next week,
followed by notably cooler temperatures Monday night into midweek.
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.DISCUSSION...
KEY MESSAGE 1: Record to near record warmth through tonight.
High pressure centered over the western Atlantic will dominate across the region through the remainder of today, both aloft and at the surface. Off to the west a cold front will approach the southeastern states, progged to push through the region tomorrow. Pinched between the approaching cold front and the offshore high pressure, southerly winds will approach gusts of 15 to even 20 mph this afternoon. As of noon temperatures have reached into the low to mid 80s, with conditions expected to warm into the upper 80s to around 90 this afternoon. These high temperatures will challenge the record high temperatures at all three of the local climate sites (KCHS, KSAV, KCXM). See the Climate Section for more details. A robust sea breeze has developed as of noon and will work its way inland through the afternoon hours. This will yield a tight temperature gradient across the coastal counties, with significantly cooler conditions at area beaches.
Tonight a low level jet will strengthen across the region, ahead of the approaching cold front. This will result in the atmosphere remaining mixed through the overnight period. Temperatures are only expected to dip into the mid to even upper 60s, challenging the record high minimum temperatures at our local climate sites (additional details in the Climate Section).
KEY MESSAGE 2: Showers and thunderstorms likely Thursday as a cold front moves through.
As an upper-lvl trough traverses eastward from the Great Lakes towards the Atlantic Seaboard, an associated cold front will pass through the region tomorrow. Expect plenty of moisture to be available with PWATs peaking from 1.2 to 1.4 inches by the early afternoon. Scattered showers and thunderstorms will likely be ongoing ahead of the front tomorrow morning and expected to persist into the afternoon. An ample amount of shear will be present on the order of 50-60 kts as these showers and thunderstorms pass through the region, indicating a few thunderstorms could become severe (mainly because of wind gusts). However, with the lack of instability and poor lapse rates, the severe threat remains rather low tomorrow. Consistent with the other guidance, recent models continue to suggest the front pushing through the region rather quickly and forecasted to be offshore by the evening. This system should be progressive given the widespread severe (D2) and extreme (D3) drought and flooding is not anticipated with this event. Average rainfall amounts range from 0.25-0.75 inches, with NBM probs of 12 hr precip. > 1 inch of only 20-30%.
Other than showers and thunderstorms, winds could be rather breezy tomorrow with gusts up to 25-30 mph possible. A Lake Wind Advisory has been issued for Lake Moultrie tomorrow from 10AM to 8PM to account for the gustier winds present. Expect a significant drop in temperatures after the front passes through with Thurs. night/Fri. morn. lows falling into the upper 30s to mid 40s (a good 20+ degrees cooler than the previous nights).
KEY MESSAGE 3: Chances for rain return late weekend into early next week, followed by notably cooler temperatures Monday night into midweek.
The next opportunity for rain arrives Sunday as a warm front passes through the region, followed by additional chances on Monday with a trailing cold front. Of greater significance may be cooler temps. on Monday night and Tuesday night behind the cold front, when lows could fall into the 30s across interior South Carolina and Georgia. This will need to be monitored for potential frost/freeze impacts as growing season has begun. NBM currently has a 30-40% chance for minimum temps. less than 32F, mainly Tuesday night into Wednesday morning.
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.AVIATION /00Z THURSDAY THROUGH MONDAY/...
00Z TAF: Winds will remain on the breezy side this evening and into the morning hours out ahead of an approaching cold front, with a period of low-level wind shear expected at both KCHS and KJZI from 03-08Z. Areas of showers with embedded isolated thunderstorms will build ahead of the front Thursday morning, but given the spatially isolated nature have left mention of thunder out of this set of TAFs though did keep prevailing showers. The front will bring a quick shift in winds from southwesterly in the morning to northwesterly in the afternoon and northerly by the late afternoon, with winds remaining breezy with gusts in the 24-28kt range.
Extended Aviation Outlook: Restrictive ceilings are possible in showers and thunderstorms that persist into tomorrow evening.
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.MARINE...
Through Tonight: High pressure centered across the western Atlantic will prevail over the marine waters. A cold front approaching from the west will yield a pinched pressure gradient, with southerly gusts around 15 knots. A sea breeze surge will enhance the winds along the coastline and in the Charleston Harbor this afternoon. Gusts along the coastline and in the Charleston Harbor could approach 20 knots this afternoon, however conditions appear to stay just below Small Craft Advisory levels in the harbor. Winds will remain elevated overnight as the cold front approaches, with Small Craft Advisories beginning tonight and early tomorrow morning across portions of the waters.
Thursday through Monday: Expect winds and seas to increase ahead of an approaching cold front, and then continue to increase behind the front as it pushes offshore Thursday afternoon. Therefore, Small Craft Advisories have been hoisted for all coastal waters outside of the Charleston Harbor. Conditions will peak Thursday evening into Thursday night. There remains a low-end potential for gusts to gale force (mainly across the outer Georgia waters). 13Z NBM continues to highlight a 30% chance of gusts exceeding 34 kts Thursday night, however this duration seems fairly short (less than 3 hours). Therefore, holding off on a Gale Warning at this time. Afterwards, marine conditions should vastly improve on Friday, however the Small Craft Advisory for the outer Georgia waters could linger into Friday afternoon if elevated seas persist. The next period of concern will be on Monday ahead of another cold front and additional advisories could be possible.
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.CLIMATE...
Record High Temperatures:
March 11: KCHS: 85/2015 KCXM: 82/1997 KSAV: 87/2015
Record High Minimum Temperatures:
March 11: KCHS: 63/2015 KCXM: 64/2016 KSAV: 64/1974
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.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
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.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None. SC...Lake Wind Advisory from 10 AM to 8 PM EDT Thursday for SCZ045. MARINE...Small Craft Advisory from 6 AM Thursday to 11 AM EDT Friday
for AMZ350. Small Craft Advisory from 2 PM Thursday to 8 AM EDT Friday for AMZ352-354. Small Craft Advisory from midnight tonight to 8 PM EDT Friday for AMZ374.
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APT/CPM/Dennis