


Area Forecast Discussion
Issued by NWS Greer, SC
Issued by NWS Greer, SC
615 FXUS62 KGSP 181755 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 155 PM EDT Fri Jul 18 2025 .SYNOPSIS... Daily mainly afternoon and evening shower and thunderstorm chances continue through the start of next week. A few storms could produce damaging wind gusts and localized flash flooding. A weak cold front slowly crosses our area from the north Monday night and Tuesday. This front will temporarily bring temperatures closer to normal into mid week. && .NEAR TERM /THROUGH SATURDAY/... As of 140 PM Friday: A 597 dam anticyclone will drift westward over FL tonight, keeping the jet stream to our north. A quasi-stationary front draped across the Ohio Valley to the Mid-Atlantic Coast is expect to nudge slightly further north of the forecast area thru Saturday. Diurnal convection is kicking off like usual across the high terrain, and should remain most numerous over the NC mountains. A west-southwesterly steering flow will try to carry some activity east across the northern NC Foothills and NW Piedmont. Areas along and north of I-40 have the highest DCAPE and MLCAPE in the forecast area per latest SPC mesoanalysis, and marginal effective shear around 25 kt could help storms organize around outflows into multicell clusters. So there may be a few severe storms producing damaging wind gusts. Locally heavy rainfall will also be possible where storms manage to anchor or train. Activity should be much more isolated in nature across the lower Piedmont along and south of I-85. Temps are on track, but dewpts are mixing out a little more than expected, with even some gustiness seen in the early aftn METARs. The Mesonet obs notwithstanding, it looks like the Heat Advisory criteria will struggle to be met this aftn. Tonight, convection should wane, with a few stray showers possible into the overnight. Mountain valley fog will be likely, but otherwise, skies become mostly clear. Lows will be a category or so above normal. Saturday looks to be almost a carbon copy of today, with only subtle changes in the air mass and overall flow. Given the mixing occurring today, have blended in the NBM 10th percentile dewpts to lower them a few deg during peak heating. This keeps heat indices mostly below 105 degrees. There may be a need for another Heat Advisory for Mecklenburg, Cabarrus, and Union; but confidence is too low and will hold off until the current advisory expires and reassess. Greenwood, Abbeville, and Elbert are also close to 105 heat index, so may need one if confidence increases. Otherwise, similar trend of timing and coverage of diurnal convection. Also, similar environment for a few strong pulse storms and isolated flash flood threat (again mainly NC mountains and I-40 corridor east). && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... As of 1205 PM EDT Friday: Mid level ridging will slide slowly westward through the short range period, but will act to keep hot and humid conditions in place regardless. Highs both Sunday and Monday will be 3-4 degrees above normal with high dewpoints leading to heat indices near advisory criteria in our southern and eastern areas. Showers and thunderstorms will develop each afternoon and evening. Pops will be pretty high in the mountains with lower pops in the Piedmont. Overall, pretty typical conditions for late July. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... As of 1210 PM EDT Friday: Mid level ridging briefly pushing west will allow a weak cold front to impact the area Tuesday with slightly less hot temperatures, i.e. near normal. The ridge will rebuild through the rest of the week, so highs will climb back to several degrees above normal after Tuesday. Pops will be the highest with the front on Tuesday and then slowly get lower through the week. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... At KCLT and elsewhere: Another round of afternoon/evening thunderstorms is expected, especially across the mountains and adjacent foothills where a TEMPO will be carried for KAVL and KHKY. Elsewhere, coverage is expected to be lower with just a PROB30s being carried. More mountain valley fog is expected again tonight with some impacts across the foothills also possible. Otherwise, the rest of the area should remain VFR. Saturday looks very similar to today, with convection firing toward the end of the 18z TAF period. Have a PROB30 for KCLT for 21z Sat to 00z Sun. Outlook: Thunderstorm chances each afternoon/evening. Low stratus or fog are possible each morning in mountain/river valleys. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...Heat Advisory until 7 PM EDT this evening for NCZ071-072-082. SC...None. && $$ SYNOPSIS...DEO NEAR TERM...ARK SHORT TERM...SCW LONG TERM...SCW AVIATION...ARK