Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
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897 FXUS62 KCHS 091712 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 112 PM EDT Tue Jul 9 2024 .SYNOPSIS... A surface trough will remain over inland areas this week while high pressure persists over the western Atlantic. && .NEAR TERM /THROUGH TONIGHT/... Mid level ridge remains across the Southeast today in between a trough to the west and weakening low over the Atlantic that will track westward towards the coast. A trough of low pressure will reside at the surface. 12z KCHS RAOB showed a PWAT of 2.38 inches which is close to the daily max for this date. Should see scattered to numerous showers and thunderstorms develop this afternoon with some upper forcing and deep moisture in place. Severe weather threat is low, but locally heavy rainfall is possible. Rainfall totals of 1-2" are the most likely with isolated totals greater than 3". Temperatures are forecast to reach the lower to mid 90s over the much of the area today. This combined with a surge of slightly higher dewpoints off of the Atlantic (ahead of the surface trough) equates to heat index values around 108. A heat advisory is in effect today from 11 AM to 8 PM. It is worth noting that temperatures have been a bit slower to rise due to lingering cloud cover, so it looks to be a bit more marginal than previously expected. Tonight, expect low temperatures in the mid to upper 70s with winds quickly falling off as the PBL decouples. && .SHORT TERM /WEDNESDAY THROUGH FRIDAY/... The mid-level ridge across the western Atlantic will continue to extend west into the local forecast area on Wednesday. Weak upper vort maxima may rotate through the area, particularly across southeast GA during the afternoon. The sea breeze should spur scattered showers and thunderstorms during the day, with the greatest coverage potentially drifting inland during the afternoon. High temps expected to reach 91-94 degrees while dewpoints remain in the upper 70s. The current forecast shows an area of peak heat indices of 108-111 across southern SC, so we may need another Heat Advisory on Wednesday. A weak cold front is expected to push into the area from the west on Thursday, spreading some drier air across southeast GA. The best moisture and convergence is expected to be across southern SC where we show the highest PoPs. Friday will feature an increase in upper shortwave energy. A weak surface low is forecast to develop across southeast GA, with the greatest moisture and forcing over southern SC. Fairly good coverage of showers and thunderstorms is anticipated, especially in SC. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... A mid-level ridge will gradually build over the eastern United States Saturday through Tuesday. A relatively typical summertime coverage of diurnal showers and thunderstorms expected. Temperatures will steadily increase during the period, with highs in the upper 90s by early next week. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... Mostly VFR is expected through 18z Wednesday. Flight restrictions will be possible if any showers/thunderstorms directly impact the terminals this afternoon or early evening. Precip coverage will diminish overnight. Extended Aviation Outlook: Scattered afternoon showers and thunderstorms may produce brief flight restrictions. && .MARINE... South to southwest winds of 10 kt will persist through tonight. Seas will be 2 to 3 ft. Showers and thunderstorms will also be possible near a surface trough. Wednesday through Sunday: Southerly flow will persist through the period. Conditions will remain below advisory criteria with wind speeds largely in the 10-15 knot range and seas 2-3 feet. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...Heat Advisory until 8 PM EDT this evening for GAZ087-088- 099>101-114>119-137>141. SC...Heat Advisory until 8 PM EDT this evening for SCZ040-042>045- 047>052. MARINE...None. && $$ NEAR TERM...ETM SHORT TERM...JRL LONG TERM...JRL AVIATION...ETM/JRL MARINE...Haines/JRL