557 FXUS62 KGSP 112344 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 744 PM EDT Wed Jun 11 2025 .SYNOPSIS... Seasonably hot and humid weather returns Thursday with numerous showers and storms each afternoon and evening through the weekend. && .NEAR TERM /THROUGH THURSDAY/... As of 600 PM EDT Wednesday: An pronounced outflow boundary drifting northwestward from convection over the Midlands is just entering the SE edge of the CWFA. Based on the vis imagery, cannot rule out an isoalted shower or thunderstorm along the boundary in the lower Piedmont early this evening. The HRRR still favors a few cells firing south of Charlotte. But with limited sbCAPE to work with, don`t expect too much activity this evening. So PoPs look on track. Otherwise, no major changes with this update. Continued influence of sfc high pressure should promote fairly efficient radiational cooling tonight, depending on influences from cloud cover, with seasonal lows falling into the low to upper 60s. Otherwise, a broad upper trof over New England will continue to lift NE into the Canadian Maritimes. What`s left of an attendant cold front will linger just to our south and east with drier post- frontal air filtering across much of the region. Heights will rise in the wake of the departing upper trof with increasing subsidence. This should keep us mostly dry thru tomorrow morning, with the po- tential for an isolated shower or t-storm across the far southern and eastern reaches of our area in the vicinity of the stalled frontal bndy. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... As of 230 PM EDT Wednesday: The short-term period will feature fairly typical summertime weather as the region is sandwiched between a closed-low trough largely detached from the westerlies over the middle Mississippi River Valley and a seasonal subtropical ridge over the Atlantic. On Friday, the upper-level pattern supports shortwave ridging over the area, suggesting that the trough to our west will be unable to provide appreciable forcing to the area. Nevertheless, with little inhibition, favorable profiles imply enough instability via typical diurnal heating to result in above-normal shower and thunderstorm coverage areawide. Modest southwesterly flow through the column supports weak shear, continued weak moisture advection, fairly moist profiles, and shallow lapse rates. These parameters are not conducive to a notable severe thunderstorm threat, though they could support very isolated damaging wet microbursts, typical for this time of year. PWs will be approaching 2.00" across the Piedmont, especially across our eastern zones, with flow vectors supporting slow-moving or even training cells. Therefore, there is also an isolated excessive rain/flash-flood threat, but absent appreciable forcing or focused moisture flux, this threat isn`t significant enough to present a noteworthy concern. On Saturday, the aforementioned upper low opens up and deamplifies over the Ohio Valley as it begins to be absorbed into the westerlies. The proximity of this trough will be close enough to aid in convective forcing, especially across our western zones, with categorical PoPs forecasted over the mountains Saturday afternoon and likely PoPs east. Its proximity will also increase bulk shear, with guidance in decent agreement that values will approach 25kts over the mountains, otherwise, the profile changes little from Friday. While shear values might support a bit more convective organization and a slightly higher damaging wind gust threat, it appears the more prevalent impact will be heavy rainfall given continued elevated PWs and Corfidi vectors supporting slow storm-motion and possible cell training. This once again presents an isolated flash-flood threat not unusual for this time of year. Expect near-normal temperatures both Friday and Saturday, but humidity will be quite uncomfortable with dewpoints in the lower 70s across the Piedmont and near 70 in the mountain valleys. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... As of 230 PM EDT Wednesday: The shortwave trough influencing our weather in the short term is expected to cross the area later Sunday into Sunday night, with decent agreement across the guidance. As such, above-normal diurnal PoPs continue to be expected on Sunday with the column perhaps a bit more moist compared to Saturday. Lapse rates will be poor with SBCAPE values perhaps a bit lower on Sunday compared to Saturday. Bulk shear values below 15 kts also appear to be likely. Therefore, Sunday is expected to remain quite unsettled but as in prior days, we lack an appreciable severe weather trigger. Once again, elevated PWs and poor storm motion vectors suggest areas of heavy rain and isolated flash-flooding cannot be ruled out. Overall, however, model guidance agrees that we lack the targeted support necessary for a notable threat. Temperatures and humidity values remain similar to Saturday. By Monday afternoon, the shortwave should be east of the area, resulting in a more westerly mean flow. However, yet another shortwave trough is quickly approaching the area from the west so we are certainly on a wash-rinse-repeat cycle with categorical PoPs west and likely PoPs east. No significant changes in the severe or heavy-rain parameters and the subsequent threats are currently forecast. The westerly flow may support a slight uptick in high temperatures to slightly above normal. Unfortunately, humidity values will remain uncomfortable if not oppressive. Heading into the middle of the work week next week, there really is very little change in the overall pattern. The aforementioned shortwave will slowly propagate east Tuesday into Wednesday, but the guidance disagrees on exactly when the trough axis will finally pass east of our area. Nevertheless, Tuesday and Wednesday will continue the persistent weather story of above-normal PoPs, especially along and west of I-85, with no significant severe thunderstorm or flash-flood threat. There is general agreement that behind this shortwave, ridging will exert a greater influence on our pattern, especially by later next week. As a result, a slight increase in max temperatures is expected on Wednesday that will likely persist beyond the current day 7. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... At KCLT and elsewhere: Generally VFR tonight, however, guidance is hinting at some low stratus and possibly some patchy fog forming before daybreak Thursday, as moisture increases from the south. Confidence remains low, so will go with few-sct low clouds in the Upstate and at KCLT, and some MVFR vsby at KAVL. Whatever clouds may form should scatter out quickly as they will be shallow. By early aftn, a return of fairly decent coverage of diurnal showers and thunderstorms across the region. Have PROB30 for TSRA at all sites, starting at 18z in the Upstate and KAVL, then as coverage expands north and east, start at 21z at KCLT and KHKY. Winds will be light, generally favoring a S/SW direction. Outlook: Mainly diurnal showers and thunderstorms are expected each aftn/evening thru the weekend and early next week. There will be potential for late night and early morning fog and low stratus restrictions each day. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...JMP NEAR TERM...ARK/JPT SHORT TERM...JMP LONG TERM...JMP AVIATION...ARK