Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
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987 FXUS62 KCAE 241619 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 1219 PM EDT Mon Jun 24 2024 .SYNOPSIS... Above normal temperatures are expected to continue for the next several days. Isolated to scattered showers and thunderstorms should occur each afternoon and evening, with better rain chances likely toward the end of the work week. && .NEAR TERM /THROUGH TONIGHT/... KEY MESSAGES: -Max heat indices around 105F today. -Scattered afternoon storms in eastern area. Marginal risk for severe weather with damaging wind gusts primary threat. Weak and diffuse surface boundary continues to move through the area with a few showers in the Pee Dee and the southern CSRA. Expect the boundary to slow this afternoon with some additional convective activity possible mainly along and south of I-20 this afternoon. With dry air in the mid and upper levels thunderstorms which develop could contain strong and gusty winds. Heat also remains a concern as winds behind the boundary are turning northwesterly adding downsloping to the mix. This has pushed temperatures in the central and western Midlands up several degrees in the past hour with readings in the low to mid 90s already. Although the temperatures are quickly rising the dewpoints are also falling with dewpoints in the western Midlands falling into the mid and upper 60s. This combination will continue to result in heat index values mainly between 100 and 105 however a few locations in the eastern Midlands may be slightly higher for a brief time. Convection will diminish with sunset and with drier air over the area expect gradually clearing skies with mostly clear conditions by daybreak. High temperatures this afternoon will be in the upper 90s with low tonight falling into the low to mid 70s. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... KEY MESSAGES: -Hot conditions continue. Max heat indices 100-105, slightly drier conditions in the north Midlands. -Widely scattered to scattered afternoon thunderstorms mainly in the southeast Midlands. Upper level ridge building again as long wave trough axis off the coast. Deep moisture will shift east of the area. A weak frontal boundary will be across near the southeast Midlands in the afternoon. Drier air is expected to advect into the SC Piedmont and north Midlands where precipitable water is expected around 1.00 inch. In the east, precipitable water above 1.5-1.8 inch or a little higher. Temperatures will rise into the upper 90s during the afternoon with relatively strong subsidence over much of the area. Weaker capping in the east at least early in the afternoon. The air mass remains dry above 3km which should limit convective coverage overall. The CAM models are suggesting scattered thunderstorms will focus near the frontal boundary/trough in the southeast Midlands and coastal Plain. Low level convergence will be the main forcing for convection, possibly enhanced by the sea breeze. Showers will be more limited into the central Midlands. Overall, expect the heat index range from 100-105 across the region. Overnight lows continue to range in the low to mid 70s. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... KEY MESSAGES: -Hot conditions continue. Max heat indices up to 107. -Widely scattered to scattered afternoon thunderstorms each day. An upper level trough will move from the Mississippi Valley into the Carolinas and Georgia by Thursday. The diffuse boundary/front remains near the region Wednesday so continued threat of scattered afternoon thunderstorms mainly in the southeast Midlands/CSRA. Lower pops west. There may be stronger dynamics for thunderstorms Thursday afternoon as the GFS/ECMWF show short wave trough moving through the area. Weak front/boundary near the area. Overall shear not that strong. But soundings show weaker capping, moderate instability and more pronounced inverted V, suggesting wind threat. NBM pops suggesting scattered thunderstorms. With higher chance rain, temps a tad cooler. The ensembles continue to show the strong upper ridge building into the area over the weekend and remaining through early next week. Relatively high confidence for continued hot temperatures, above normal, upper 90s to near 100 degrees. Lower confidence on convective coverage. The NBM suggests scattered coverage at most and mainly diurnally driven. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... VFR conditions expected through the TAF period. Weak frontal boundary continue to move through the region with a few showers north and south of the terminals. Chances of showers and thunderstorms at any terminal remain too low to mention however the highest potential remains at OGB. As the boundary moves east of the area winds will veer to westerly with some gusts to 15 mph through this evening. With sunset convection will end and with drier air moving into the area do not expect fog development Tuesday morning. EXTENDED AVIATION OUTLOOK...Increasing chances for afternoon scattered showers and thunderstorms and associated restrictions Tuesday through Friday. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$