784 FXUS62 KGSP 160003 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 803 PM EDT Tue Jul 15 2025 .SYNOPSIS... Daily thunderstorm chances continue through the week and into the weekend. A few storms could produce damaging wind gusts and localized flash flooding. Hot and humid conditions stick around through most of the week. && .NEAR TERM /THROUGH WEDNESDAY/... As of 752 PM EDT Tuesday: No major changes to the forecast this evening. Convection is ongoing across the NC Foothills and parts of the SC Upstate, but is running on fumes at this point between the loss of strong daytime heating and an increasingly stabilized environment, and so notable convection shouldn`t persist for much longer. Synoptic setup remains unchanged, with a the periphery of the Bermuda High extending from the west Atlantic into the Carolinas, and significant PWs of 2-2.2" across much of the area...so the threat of localized flash flooding remains with any continuing activity. Overnight, PoPs continue to decrease...but cannot rule out a pop- up shower or thunderstorm given the moist environment. Evening guidance has become increasingly insistent upon the development of low stratus and patchy fog after midnight, most focused along the Blue Ridge Escarpment...and areas that received significant rainfall this afternoon. Coverage should be sparse enough that a DFA shouldn`t be necessary. For Wednesday, the surface high continues to migrate further west, bringing more of a S/SW surface wind and enhancing advection of moisture into the area. The location of the high could help to direct activity westward...and indeed the evening runs of the operational CAMs as well as the RRFS both favor areas west of I-26 for convection overall and support delayed initiation into the mid/late afternoon. Temperatures look to remain in the low 90s (mid 90s further south) with the heat index increasing into the upper 90s. A few locations in the southern zones could see HI of 100-103 today, but remains below any Heat Advisory criteria. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... As of 1145 AM EDT Tuesday: The rest of the work week should be more of the same...typical hot and humid summertime with mainly diurnal storms both days...as a westward extension of the Atlantic subtropical ridge keeps us insulated from whatever happens with the system moving westward along/off the northern Gulf Coast. The forecast will feature an above-climo precip probability over the area, particularly the mountains, where differential heating will provide a focus for convection. The usual isolated pulse-severe storm threats will apply, and heavy rain could also be a problem. Fcst soundings show deep warm cloud depths and slow-moving storms, but the precipitable water will not be quite as high as the past few days, so the flash flood potential looks marginal for now. Temps will continue to run 3-5 degrees above normal, but the apparent temps over the Piedmont should stay below Advisory criteria Thursday and Friday. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... As of 1225 PM EDT Tuesday: The latest model blend suggests the big story this weekend and into early next week will be the heat, as part of the Atlantic subtropical ridge breaks off and moves slowly west across the Deep South. In spite of nothing to suppress the deep convection, temps will remain on the order of five degrees above normal, while tropical moisture remains in place, keeping the dewpoints in the lower 70s. This combination is forecast to push the apparent temps up into the Advisory range each day from Saturday onward across the lower Piedmont and the Charlotte metro area/western Piedmont, even with mixing down the dewpoint from the NBM by a couple of degrees. Note that none of this is out of the ordinary for July. Confidence is marginal at this point anyway, because there is much on the mesoscale that could derail this potential, such as the weak upper wave moving past to our north on Saturday and then a more active convective regime Sunday into Tuesday as the upper high to our south oozes farther west and flattens more, possibly bringing the MCS track farther south to where it would affect the western Carolinas more directly. It`s not until Monday/Tuesday when we keep precip chances going round the clock, though, because of a better signal for something going on aloft to sustain the convection overnight. Through the period, pulse severe storms and isolated flash flooding will be possible each day, which is also more or less typical for July. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... At KCLT and elsewhere: Midsummer pattern continues with ongoing convection across the terminal forecast area expected to wind down in the next 1-2 hours. In its wake, lingering moisture will result in widespread MVFR ceilings overnight, pockmarked with areas of IFR that appear most likely to develop across the NC Foothills (which makes KHKY the most likely to see this materialize). After daybreak, restrictions will gradually scatter out through morning and we`ll jump right back into another summertime day...with PROB30s for afternoon/evening convection again Wednesday. Coverage appears lower than today, and timing may be delayed compared to the typical ~18-20z onset. 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...None. SC...None. && $$ SYNOPSIS...CP NEAR TERM...CP/MPR SHORT TERM...PM LONG TERM...PM AVIATION...MPR