


Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
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723 FXUS62 KCHS 021904 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 304 PM EDT Wed Jul 2 2025 .SYNOPSIS... A cold front is expected to move into the area today and could then linger along or just off the coast through the weekend. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... As of mid afternoon, visible satellite and sfc observations indicated that a sea breeze was advancing inland across the coastal counties as a cold front was pushing from the Carolina Foothills. SPC mesoanalysis indicated a band of 2 to 2.1 inches between the sea breeze and cold front. In addition, SBCAPE values between the two boundaries is expected to build between 2500-3000 J/kg late this afternoon and evening. High resolution guidance indicates that clusters of thunderstorms will initial develop near the sea breeze this afternoon, then coverage should increase as the cold front nears from the west. These storms are forecast to have slow motions, generally remaining around 10 mph, or propagate on outflow boundaries. Given the deep moisture and slow storm motions, heavy rainfall will be a concern for these storms. In fact, the 12Z HREF indicate high probabilities for 3"/3hr to 10-30% with 1"/3hr increasing to 50-70%. Flooding of low-lying areas or other poor drainage areas will remain a concern through this afternoon into early this evening, especially along the I-95 corridor. Deep convection across SE GA/SC should dissipate late this evening, some shower activity may linger over the adjacent Atlantic waters late tonight. Low temperatures are forecast to range from near 70 inland to the mid to upper 70s along the coast. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/... The surface front is expected to remain stalled along the coast on Thursday. Weak shortwave energy will be moving off the coast in the morning, with mainly weak NVA over the area. PWs will remain fairly high, particularly along the coast, with slightly drier air moving into inland areas. Close to 2000 J/kg CAPE expected to develop during the afternoon with highs in the low 90s and dewpoints in the mid 70s. Scattered showers and tstms expected to develop in the afternoon with the greatest coverage closer to the coast mid to late afternoon. Quite a bit of coverage could continue into the early to mid evening including locally heavy rainfall and numerous cloud to ground lightning strikes. Slightly drier air will overspread the area on Friday with the surface front a bit farther off the coast. However, there should still be a moderate sea breeze in the afternoon and enough instability to support scattered showers and thunderstorms, mainly in the afternoon/evening. Slightly drier high pressure will move into inland SC on Saturday. However, a potential tropical or subtropical low may develop well off the SC/GA coast and start moving northwest. This could bring increasing coverage of showers and tstms to coastal areas later in the day though the confidence is very low due to large model uncertainties. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... The main concern for this period continues to be the possibility that low pressure will develop off the SC/GA coast and then move NW or N toward the area. NHC currently has a 40% chance for tropical cyclone formation in the next 7 days. The 12Z GFS and ECMWF are showing increasing chances of development. Even if tropical development doesn`t occur, Saturday night through Sunday could be relatively wet, particularly along the coast. Upper ridging heading into the middle of next week should bring increasing temperatures and heat indices. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... 18Z TAFs: Clusters of thunderstorms will initial develop near the sea breeze this afternoon, then coverage should increase as the cold front nears from the west. These storms are forecast to have slow motions, generally remaining around 10 mph, or propagate on outflow boundaries. KCHS and KSAV TAFs will feature TEMPOs from 19-23Z for TSRA. Convection should decrease as it crosses west of the sea breeze later this evening. The rest of the night should feature VFR conditions and south winds between 5 to 10 kts. Extended Aviation Outlook: Brief flight restrictions will be possible with isolated to scattered afternoon showers and thunderstorms through the weekend and into early next week. && .MARINE... Tonight, the sfc pattern should yield southerly winds generally between 10-15 kts. This evening, a slight gradient pinch may yield a period of gusts around 20 kts late this evening. Seas are forecast to range between 2 to 3 ft. Winds/seas expected to remain below advisory criteria Thursday through Sunday. The only caveat is the possibility of a tropical or subtropical low developing off the GA/SC coast on Saturday that could affect the waters Saturday night into Sunday. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...NED SHORT TERM...JRL LONG TERM...JRL AVIATION...JRL MARINE...JRL