


Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
437 FXUS62 KCHS 140538 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 138 AM EDT Mon Jul 14 2025 .SYNOPSIS... Atlantic high pressure will prevail into the upcoming weekend. && .NEAR TERM /THROUGH TONIGHT/... Today: Aloft, the upper ridge will be centered near the FL panhandle and will extend into northern and western portions of GA and the Carolinas. Also of note is the upper low just north of the Bahamas and off the east coast of Florida. The forecast area will sit between these features which will yield deep layer north to northeast flow which is certainly not common. At the surface, the developing lows off the east coast of FL will drive the flow across the forecast area. Current thinking is that the result of this northeast to easterly flow will result in a more progressive sea breeze than we have seen the past few days with the primary convergence zone setting up along and west of the I-95 corridor. There is general agreement in the hi-res model solutions that the best convective coverage will set up this afternoon in this area. Also of note, this zone along and west of I-95 will be where the deepest moisture will reside with precipitable water values of 2 inches or higher. Coincident with this, some relatively drier air will work in from the east with precipitable water values approximately 1.7-1.9 inches along and just inland of the southeast SC coast. Once again, the severe threat does not look particularly noteworthy with middling DCAPE values and certainly no support for anything organized. But, the standard summertime disclaimer applies in that where boundary interactions occur and enhance updrafts there could be an isolated strong to marginally severe storm. Locally heavy rain will be possible in this area along and west of I-95 where the best moisture and storm coverage is expected. A quick 1-2 inches will be possible in areas directly impacted by storms but we do not anticipate any significant flooding threat at this time. Highs are forecast to mostly reach the low 90s along and east of I-95, with mid to upper 90s west of I-95. We have again lowered dewpoints a bit from the raw NBM by blending in the NBM10, which seems to have worked out well yesterday and yielded some more realistic heat index values. So for today we expect to see heat indices max out around 105, and we should stay below Heat Advisory criteria. Tonight: Afternoon convection should gradually shift further inland and off to the southwest through the evening. The rest of the overnight should be dry for land areas, though we will likely see increasing coverage over the coastal waters which could draw close to the coast by daybreak. Look for lows in the low to mid 70s inland and upper 70s along the coast. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... On Tuesday, the area will remain sandwiched between a weak upper ridge over the northern Gulf Coast states and an expansive upper ridge across the central and western Atlantic. Wednesday into Thursday, the Atlantic ridge will expand into the Southeast. And increase in mid-level subsidence during this period should reduce the coverage of diurnal convection, though with ample moisture and instability plus an active sea breeze, we should still see scattered showers and tstms each day. Temps will be near normal and heat indices are currently forecast to fall short of Heat Advisory criteria. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... Deep layered ridging will persist into the upcoming weekend. Fairly typical July weather will continue with mainly scattered diurnal convection each day. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... The 06z TAF period begins with VFR conditions at KCHS, KJZI, and KSAV. Overall, it does not appear that there are any significant concerns for fog and stratus through day break. Then for afternoon and evening thunderstorm potential, the focus for storms is expected to be further inland today. This means that thunderstorm activity should remain inland of KCHS and KJZI. KSAV will have a better chance of at least seeing a storm in the vicinity and we have maintained VCTS starting at 21z. Extended Aviation Outlook: VFR will mainly prevail throughout the period, however brief flight restrictions are possible within showers and thunderstorms that develop in the afternoon and/or evening hours. && .MARINE... Today and tonight: The flow pattern across the local waters will largely be driven by circulation around the developing area of low pressure off the east coast of FL. This setup will drive northeast to east-northeast flow, which could turn more east or east-southeast for portions of the waters at times. Wind speeds will remain on the weaker side, perhaps as high as 10-15 knot at times. Seas should average around 2 feet through the period. Thunderstorms do not appear to be as big of a threat this afternoon and evening as most of the activity is expected to remain inland of the coast. Moderate southerly winds will continue Tuesday through Friday. Speeds will generally be no higher than 15 kt and seas will run 2-4 ft. A decent sea breeze should occur each afternoon along the coast, with a few gusts in Charleston Harbor approaching 20 kt. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM...BSH SHORT TERM...JRL LONG TERM...JRL AVIATION...BSH/JRL MARINE...BSH/JRL