Area Forecast Discussion
Issued by NWS Greer, SC
Issued by NWS Greer, SC
169 FXUS62 KGSP 142349 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 749 PM EDT Mon Jul 14 2025 .SYNOPSIS... A typically active mid-summer week is ahead as daily thunderstorm chances continue. A few storms could produce damaging wind gusts and localized flash flooding. Daily high temperatures will trend back to around the normal mid-July mugginess Tuesday through Thursday. && .NEAR TERM /THROUGH TUESDAY/... As of 745 PM EDT Monday: Convection remains fairly isolated across much of the forecast area this evening with the highest coverage of convection confined to an outflow boundary pushing northwestward across the eastern SC Upstate and the NC Piedmont this evening. Another weaker outflow boundary is currently pushing across the northern SC Upstate. Could see coverage blossom further over the eastern half of the CWA over the next half hour or so as the two outflow boundaries collide. The environment isn`t quite as robust as the previous few, with sfc-based CAPE still only ranging from the 1500-2500 J/kg range. Still cannot entirely rule out an isolated wet microburst pulse severe storm, mainly over the eastern half of the CWA, but confidence is low with DCAPE values only up to 800-900 J/kg currently. The profiles show more moisture than yesterday, so there`s an uptick in heavy rain potential, but the better chances of flooding rain are definitely east and northeast of the forecast area. Most likely, the convection will have a diurnal tendency and will weaken after sunset, but it is worth mentioning the HRRR that appears to keep some sort of weak boundary across the area east of the mtns that is a focus for convection through the late evening and early morning hours. The fcst hasn`t been changed much in that regard, and still holds onto a swath of precip chances mainly over the western Piedmont and nrn Upstate past midnight. Confidence is fairly low because we are stuck in weak flow aloft in between the ridge to the south and the short wave that has lifted out to the northeast. Because of the deep warm cloud depth, high precipitable water, and weak flow late tonight, there`s a sneaky flash flood potential over the western Piedmont late late tonight if we can get convection to develop, which the CAMs are not altogether excited about. Otherwise, there`s more of an indication of mtn valley fog and low stratus compared to the weekend. Low temps will be seasonally warm. For Tuesday, the guidance shows better coverage of deep convection that gets an earlier start. We will be under an expanding flat upper anticyclone, so the trigger will be differential heating over the higher terrain, which all the CAMs are showing. Storms would eventually work their way off the Escarpment and down across the Piedmont along cold pools and outflow boundaries thru the afternoon. Profiles are not especially favorable for severe storms. High temps will be a few degrees cooler because of the early start, more clouds, and more numerous storms. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... As of 1215 PM Monday: The mean pattern atop the region changes little through the period, continued southerly flow around Bermuda high pressure, with the wwd extent of the upper ridge axis lingering over the area. The synoptic scale feature of interest is the wwd moving inverted trough evolving into the gulf on Wednesday. There exists the ongoing probability of tapping into tropical moisture as richer PWATs are progged to blossom nwd within reinforced southerly llvl flow. The trend of becoming slight less hot will continue but with sfc dwpts nudging higher it will still feel quite muggy. With the deep layered ridge axis poking further wwd into the cwfa on Thursday, the llvl flow will continue to veer to a more SW direction, perhaps resulting in diurnally enhanced deep convective chances trending back toward the mid-July climo, given the richer than typical moisture, storms will probably become numerous again. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... As of 115 PM Monday: Expecting to heat back above to above normal temperatures through the period with Piedmont solid middle 90s possible by Sunday. Also over the weekend, there is the ongoing chance of experiencing apparent temperatures in the lower 100s each afternoon. The upper ridge axis centered offshore to start off the period translates wwd to atop the SE CONUS through Sunday with the southern edge of the westerlies and perhaps a llvl baroclinic zone encroaching our northern tier. Despite the upper ridge positioning, daily thunderstorm chances will remain above climo with an ongoing risk localized flash flooding with in the lingering weak flow regime. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... At KCLT and elsewhere: VFR through tonight outside of isolated convection. Maintained a PROB30 for TSRA and associated restrictions at KCLT as convection is closest to this terminal as of 00Z. Went with dry conditions elsewhere as convection has struggled to hold together outside of KCLT. Could see mountain valley fog and/or low stratus develop again overnight into daybreak Tuesday. Confidence on fog/low stratus reaching KAVL remains very low. Confidence is a bit higher for KHKY as the terminal has seen cig and vsby restrictions develop the last few mornings. Winds will generally be calm to light and VRB through early Tuesday morning. Better TSRA chances return tomorrow late afternoon and evening so have PROB30s across all terminals to account for activity. VFR will once again prevail Tuesday outside of convection and morning fog/stratus. Wind direction will gradually turn SE`ly Tuesday morning into early Tuesday afternoon. Outlook: Typical summertime weather is expected this week with scattered to numerous thunderstorms each afternoon/evening. Fog and/or low stratus are possible each morning, especially across the mountain valleys. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...CSH NEAR TERM...AR/PM SHORT TERM...CSH LONG TERM...CSH AVIATION...AR