FXUS62 KCHS 040635 AFDCHS
Area Forecast Discussion National Weather Service Charleston SC 235 AM EDT Sat Apr 4 2026
.WHAT HAS CHANGED...
Rain chances for today have lowered slightly. Key Message 2 was added to address the rip current threat on Sunday. The Aviation Section was updated for the 06Z TAF issuance.
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.KEY MESSAGES...
- 1) Warm temperatures and minimal rain chances today.
- 2) Moderate risk for rip currents for all area beaches on
Sunday.
- 3) A cold front will bring increased rain chances Sunday
afternoon into Monday morning, followed by cooler temperatures.
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.DISCUSSION...
KEY MESSAGE 1: Warm temperatures and minimal rain chances today.
At the surface high pressure centered over Bermuda will build into the region from the east, yielding an onshore flow in the lower levels. Aloft, southwesterly flow will dominate as a mid-level trough treks eastward across the Midwestern states. There are very low chances that the onshore flow in the morning hours could result in a weak shower impacting the coastal counties early this morning, especially along Charleston County where the NAM and the HRRR show some weak showers developing. Confidence levels in these showers developing is very low, so the forecast does not explicitly include rain at this time. A progressive sea breeze is expected today, pushing inland of I-95 around noon/1 PM. Any shower/tstorm activity in the afternoon will be across inland locations. Temperatures this afternoon will once again reach into the low 80s, with some mid 80s across inland SE GA.
KEY MESSAGE 2: Moderate risk for rip currents for all area beaches on Sunday.
With onshore flow and steady waves, there is a low risk for rip currents at all area beaches for today. For Sunday, increasing swells with 3 to 4 foot breaker waves and winds out of the south- southwest will result in a moderate risk for rip currents at all beaches.
KEY MESSAGE 3: A cold front will bring increased rain chances Sunday afternoon into Monday morning, followed by cooler temperatures.
A broad mid-level trough accompanied by a cold front at the surface will move across the eastern U.S. late this weekend into early next week, bringing a chance for light rain and ushering in cooler temperatures. However, before the front arrives, expect temperatures to remain well above-normal given low-level temperature fields above the 90th percentile per the Ensemble Situational Awareness Tables (ESATs), resulting in afternoon highs in the lower to mid 80s across the region, though areas along the coast will likely stay in the upper 70s. Can't fully rule out some weak and isolated showers during the morning and afternoon given the on-going warm-air advection at 850mb, though a peek at a few of the long-range high resolution convection allowing models are suggesting a dry forecast for the morning hours.
While wind fields do look to gradually increase, probabilities for 1000 J/kg of SBCAPE in the NBM have risen slightly into the 20-30% range, which looks to be remain representative from the deterministic MUCAPE profiles for Sunday afternoon. This looks to keep the threat for severe weather on the lower end, with the various AI/ML output similarly suggesting a low threat for severe weather, highest across Charleston and Berkeley counties where SPC has placed a Marginal Risk (Level 1 out of 5). In regard to precipitation amounts, despite overall moisture being plentiful with ESATs showing precipitable water values AOA 1.5" and above the 90th percentile wrt climatology, the forcing mechanism from this system looks to be fairly weak. Thus, most guidance only supports accumulations less than 0.5 inch, though most will likely see less than a 0.25 inches. Thus, do not expect to see any significant improvements to the ongoing drought conditions at this time.
Notably cooler temperatures look to return Monday in the wake of FROPA, with afternoon highs in the upper 60s to 70s continuing into the middle of next week. A secondary mid-level wave may dive across the southeast CONUS late Monday into Tuesday, resulting in a weak low pressure and additional rain chances. However, model certainty with this feature remains poor, making it difficult to put too much confidence behind any one solution just yet.
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.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
Prevailing VFR through the 06Z TAF period at KCHS/KJZI/KSAV. Some shallow ground could develop near KSAV just before daybreak and possibly allow for a brief period of MVFR vsbys, but no significant impacts are expected. There is a low threat of some weak showers impacting KCHS/KJZI this morning, however confidence levels were too low to include mention at this time. This afternoon the main focus for any precipitation is west of the terminals.
Extended Aviation Outlook: There will be increased chances for flight restrictions associated with FROPA Sunday into early Monday.
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.MARINE...
Through tonight: Conditions across the marine zones will remain sub-Small Craft Advisory criteria through the period.
Sunday through Thursday: A cold front will then approach from the west-northwest on Sunday, moving through the waters Sunday night with scattered showers and thunderstorms. Expect a surge in winds and seas behind the front early morning Monday, which will likely necessitate the need for Small Craft Advisories across most of our coastal waters throughout portions of the day. Surface high pressure builds to our north Tuesday and could persist into the later half of next week, leading to a period of breezy winds and hazardous seas.
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.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None. SC...None. MARINE...None.
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APT/CPM