AFD_CHS

FXUS62 KCHS 030644 AFDCHS

Area Forecast Discussion National Weather Service Charleston SC 244 AM EDT Fri Apr 3 2026

.WHAT HAS CHANGED...

Key messages have been updated to reflect ongoing warm weather and precipitation chances this weekend and again with a cold front arriving early next week. The Aviation Section has been updated for the 06Z TAF issuance. The Marine Section has been updated for latest trends in Small Craft Advisory potential early next week.

.KEY MESSAGES...

- 1) Warm temperatures will continue, with mostly isolated to scattered

showers and thunderstorms possible through Saturday.

- 2) A cold front could bring increased rain chances late this weekend

into early next week.

.DISCUSSION...

KEY MESSAGE 1: Warm temperatures will continue, with mostly isolated to scattered showers and thunderstorms possible through Saturday.

Strong mid-lvl ridging centered across the western Atlantic will continue to extend across the Southeast United States, setting up the stage for warm temperatures to continue today and through late weekend. At the sfc, the Atlantic high will remain the dominant weather feature as well, but subtle coastal troughing along its western periphery should shift onshore, helping produce scattered showers and thunderstorms today and to a lessor extent Saturday. Greatest chances for precip should occur along/west of I-95 today where/when moisture is deeper (PWATs 1.5 inches/sfc dewpts mid 60s). There is even some indication in hires guidance that convection could become numerous across the far interior early/mid afternoon during peak diurnal heating. Latest HREF guidance indicated a 20-40% probability of 0.25 inch rainfall accumulation west of I-95, but most locations in this noted area should see rainfall amounts in the 0.1 to 0.25 inch range. On Saturday, coastal troughing is noticeably less pronounced and the axis of deeper moisture shifts just inland of the local area, but a few showers/isolated thunderstorms can not be ruled out with warm temps in place. Afternoon highs should peak in the low-mid 80s both days, warmest inland of the coastal corridor.

KEY MESSAGE 2: A cold front could bring increased rain chances late this weekend into early next week along with 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 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 chances for any rain remain below 20% in the morning before increasing throughout the afternoon as the front moves towards the area.

While wind fields do look to gradually increase, probabilities for 1000 J/kg of SBCAPE in the NBM remain below 20%, which looks to be fairly representative from the few 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. In regard to precipitation amounts, overall moisture with this system still remains rather meager, with most guidance supporting accumulations less than 0.5 inch. 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.

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...

VFR conditions are expected at CHS/JZI/SAV terminals through 06Z Saturday. Brief MIFG is possible prior to daybreak, highest chance at SAV, but impacts appear minimal. TEMPO MVFR conditions are possible with shower and/or thunderstorm activity associated with weak coastal troughing during late morning/early afternoon hours. For now, a PROB30 group has been introduced for thunderstorms/MVFR vsbys at the SAV terminal between 15-20Z today, where greater precip chances are anticipated prior to activity shifting further inland this afternoon.

Extended Aviation Outlook: VFR conditions should prevail at CHS/JZI/SAV terminals Saturday, although can not rule out an isolated shower/thunderstorm impacting the terminals during afternoon hours. Higher chances for flight restrictions arrive Sunday afternoon into early Monday due to showers/thunderstorms associated with a passing cold front. Gusty northerly winds should also occur post fropa Monday.

.MARINE...

Today and Tonight: Weak coastal troughing along western periphery of Atlantic high pressure should drift onshore early morning, producing a few showers across coastal waters through about noon. East- southeast winds in the 10-15 kt are expected across local waters. Seas should generally range between 3-5 ft, although a few 6 ft seas could approach the outer GA waters early morning, the duration and impact do not appear sufficient for a Small Craft Advisory.

Extended Marine: Atlantic high pressure will prevail this weekend, supporting winds/seas that remain below Small Craft Advisory levels across local waters. A cold front will then approach from the west Sunday, then shift across coastal waters late Sunday into early Monday, producing gusty northerly winds and building seas as cold air advection occurs early week. Small Craft Advisories should be needed across a majority of coastal waters Monday, and could persist with an enhanced pressure gradient leading to stronger winds and building seas into the middle of next week.

.CHS WATCHES/WARNINGS/ADVISORIES...

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

APT/DPB