


Area Forecast Discussion
Issued by NWS Greer, SC
Issued by NWS Greer, SC
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555 FXUS62 KGSP 020010 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 810 PM EDT Tue Jul 1 2025 .SYNOPSIS... A cold front crosses the mountains tonight then becoming stationary across Georgia and the Carolinas continuing the chance of showers and storms mainly for the Piedmont on Wednesday. Another cold front drops south from the Great Lakes on Thursday with drier weather for the Independence Day holiday weekend. Temperatures remain typical for the summertime season through the beginning of next week. && .NEAR TERM /THROUGH WEDNESDAY/... As of 155 PM: An upper trough and cold front move into the area tonight and stall or only slowly move south of the area by Wednesday. Convection already ongoing across the area and will become more widespread than the past few days. Mesoanalysis shows the atmos has become very unstable despite only moderate to weak mid level lapse rates. Bulk shear, while higher than the past few days, remains less then 20 kts, and DCAPE values are moderate across portions of the area. All this to say that isolated severe downbursts will be possible where storms can grow tall enough, but there could be some weak organization given the slightly stronger shear. PW values remain very high as well. Although storms will have more movement than the past few days, locally excessive rainfall is possible given the greater storm coverage and the potential for training and back-building cells. Convection diminishes by late evening or early overnight, but isolated showers could continue. Low clouds and patchy fog expected once again by morning. Lows will be a little above normal. Scattered to numerous convection is expected to develop on Wednesday with the stalled or slowly moving trough/front. However, better coverage flips from the past few days and will be greater along the I-77 corridor becoming more scattered across the mountains. At least moderate instability and around 20 kts of bulk shear will combine with a rebound in DCAPE and sfc delta theta-e to create the potential for an isolated damaging downburst. Higher PW values are shunted off to the east and faster moving cells will limit heavy rain potential. Highs will be a couple of degrees below normal. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... As of 100 PM Tuesday: An upper trough axis will exit off the East Coast Thursday, as a large ridge builds in across the center of the CONUS. A cold front should finish pushing thru the area, with lingering showers and storms possible Wednesday evening in the southeast part of the forecast area. PoPs should taper off by daybreak Thursday. With the ridge building in and dry air advecting in from the NW, Thursday and Friday (Independence Day) look dry. Cannot rule out a stray shower or general tstm along some of the highest ridgetops of the NC mountains, but otherwise should be dry. Temps will warm to slightly above normal, with highs mainly in the lower to mid 90s in the Piedmont and mid to upper 80s in the lower mountain valleys. Lows in 60s mountains and upper 60s to lower 70s Piedmont. The dewpts are expected to mix out enough to keep heat indices close to the ambient temps. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... As of 130 PM Tuesday: Relatively dry weather continues into the weekend, as an upper ridge slides from the Mid-MS Valley east to the Mid-Atlantic. This will keep the forecast area fairly suppressed. But with strong mid-summer heating each day, a gradual increase in mainly mountain convection is expected Saturday thru Monday. The medium range guidance is becoming a little more bullish on developing a weak tropical low along a stalled frontal boundary invof FL over the weekend. This disturbance is likely to remain shunted south of the forecast area, but may drift NE into the Atlantic. There is a lot of uncertainty on that, as it depends on exactly where along the front it develops and how long the upper ridge can hold on over the Mid-Atlantic. The ridge is expected to weaken/shift east late in the weekend thru early next week, as shortwave energy carves a flat trough over the Upper Midwest. Overall, this should allow for a return to near-climo diurnal PoPs by next Tuesday. Temps will continue to be slightly above normal thru the period. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... At KCLT and elsewhere: Ongoing convection across the area has led to an extended period of TEMPOs for TSRA and associated restrictions through 02Z-03Z. Winds generally out of the southwest, but direction may become variable and gustier with any direct hit from thunderstorms. Lingering showers will be possible going into the overnight hours with convective debris still hanging out. Model guidance continue to keen in on low stratus and possible fog developing just before daybreak. Placed a prevailing IFR cig at all sites, with MVFR vsby at KAND/KHKY/KAVL due to either mountain valley enhancement or close proximity to bodies of water. Any restrictions that develop should scatter out by mid-morning with daytime heating and mixing commencing. Another round of convection is possible at the Piedmont terminals and placed a PROB30 for TSRA and associated restrictions between 18Z Wednesday - 00Z Thursday. Winds will remain southwesterly through most of the forecast period before a cold front advances through the area by the very end of the period or slightly after, leading to a wind shift out of the northwest by Wednesday evening. KAVL will maintain a northwesterly wind with possible low-end gusts through the period. Outlook: Convection continues Wed evening. Drier air moving in Thursday is expected to inhibit diurnal convection into the weekend, with at most isolated activity expected each day. Fog and/or low stratus possible each morning in the usual mountain valleys, as well as near lakes and rivers, and where significant rain fell the day before. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...DEO NEAR TERM...RWH SHORT TERM...ARK LONG TERM...ARK AVIATION...CAC