FXUS62 KCHS 141825 AFDCHS
Area Forecast Discussion National Weather Service Charleston SC 125 PM EST Sat Feb 14 2026
.WHAT HAS CHANGED...
The dew point values this afternoon have been lowered to match current observations. The risk for severe thunderstorms on Sunday afternoon has marginally increased. The Aviation Section has been updated to reflect the 18Z TAFs. Small Craft Advisory issued for all nearshore waters Sunday afternoon into Monday.
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.KEY MESSAGES...
- 1) A storm system will move through Sunday and Sunday night,
bringing widespread rain and perhaps a few severe thunderstorms.
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.DISCUSSION...
KEY MESSAGE 1: A storm system will move through Sunday and Sunday night, bringing widespread rain and perhaps a few severe thunderstorms.
A southern stream shortwave will move into western Alabama around daybreak Sunday, then off the Southeast coast late Sunday night. An associated surface low will move through GA and SC late Sunday afternoon through Sunday night, with dry high pressure building in from the west on Monday.
0-6 km wind will become SW and strengthen to 40-50 kt late tonight, bringing deep moisture to the area. Precipitable Water values are expected to reach approximately 1.4" by Sunday afternoon. Widespread mid and high clouds are expected to overspread the area late tonight into Sunday, with stratocu also increasing in coverage through the day. Only pockets of sunshine are anticipated on Sunday, limiting diabatic heating. However, strong low-level warm advection should allow temperatures to rise into the low to mid 70s across southeast GA (upper 60s in southern SC). Model soundings depict relatively warm air aloft which will limit surface-based instability. Most guidance shows no more than 100-200 J/kg CAPE Sunday afternoon. If more sunshine is able break through the clouds, CAPE could get closer to 500 J/kg across inland GA and SC.
A few showers may move through in the morning as a weak inverted trough lifts north from the Atlantic, though most areas are expected to be mostly dry until early afternoon. A fairly widespread area of showers should move into central SC/GA early in the afternoon, then through the local forecast area late Sunday afternoon through evening. The greatest chance for thunderstorms will be late afternoon through early evening. Rain could linger until close to daybreak Sunday across coastal areas, then clear out by mid- morning Monday. Guidance is still in pretty good agreement that total rainfall amounts will range from 0.50-0.75" across the area.
There is a chance that a few strong or severe thunderstorms could occur Sunday afternoon or evening, mainly across southeast GA and far inland SC. Some of the Convection-Allowing Models (CAMs) depict a relatively discrete line of thunderstorms moving in from the west mid afternoon Sunday, though others show a more broken or decaying band of convection by the time it gets this far east. As convection gets closer to the SC coast, it is expected to encounter a pronounced stable marine layer which should cause rapid weakening. We are still not particularly impressed with the severe thunderstorm risk given the meager instability. However, 0-3 km helicity of 350-500 m2/s2 and 50-60 kt of bulk shear could support a few damaging wind gusts or isolated tornadoes in pockets of greater buoyancy. The Storm Prediction Center (SPC) expanded the Marginal Risk of severe thunderstorms farther north, now encompassing Jasper, Hampton, Allendale, and the western part of Colleton County in addition to southeast GA.
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.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR will prevail at KCHS/KJZI/KSAV through the 18Z TAF period. Clouds will increase overnight tonight ahead of an approaching low pressure system. Rain chances increase near the end of the 18Z TAF period.
Extended Aviation Outlook: The potential for flight restrictions will increase Sunday night as an area of low pressure moves into the region.
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.MARINE...
High pressure will remain across the marine zones today, then gradually fading tonight. An area of low pressure will approach from the west on Sunday, resulting in a pinched gradient by Sunday afternoon. Winds gusts are forecast to strengthen to around 25 kts across all waters outside of the Charleston Harbor. A Small Craft Advisory is in effect for all waters (outside the Charleston Harbor) from Sunday afternoon into Monday. A band of showers and thunderstorms should develop along and ahead of a cold front late Sunday afternoon and evening. It is possible that some storm segments will require Special Marine Warnings due to gusty winds.
Conditions across the marine zones should begin to improve as the low departs on Monday. Gusty winds and elevated seas will yield SCA conditions across the 20 to 60 nm offshore GA waters and the Charleston County nearshore waters through Monday afternoon. High pressure will build over the region late Monday and remain through mid-week.
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.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None. SC...None. MARINE...Small Craft Advisory from 1 PM Sunday to 1 PM EST Monday for
AMZ350-374. Small Craft Advisory from 1 PM Sunday to 7 AM EST Monday for AMZ352. Small Craft Advisory from 1 PM to 9 PM EST Sunday for AMZ354.
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CPM/JRL