Area Forecast Discussion
Issued by NWS Greer, SC
Issued by NWS Greer, SC
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991 FXUS62 KGSP 301750 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 150 PM EDT Thu May 30 2024 .SYNOPSIS... Dry high pressure to our north will keep temperatures a bit below normal through the end of the week. Once the high moves off to our east Saturday night, we should see a slow warm up with a return of the mainly afternoon and evening showers and thunderstorms typical of late spring and early summer. && .NEAR TERM /THROUGH FRIDAY/... As of 130 PM: Expecting another uneventful near term period. Omega block will continue although the whole pattern will progress slowly eastward thru Friday. This will bring us out from under the trough and more under the influence of the ridge and attendant dry sfc high expanding out of the Ohio Valley. A few cumulus again are seen in the shallow unstable layer beneath the inversion aloft, still too undeveloped for mentionable PoPs. The high will tighten the gradient, amplifying winds slightly in the Piedmont late tonight and turning them toward the NE. Dewpoints will dip further overnight, so no fog expected again Fri morning; mins will be 5-7 degrees below normal. Expect fewer cumulus Fri with deeper/stronger subsidence aloft and the sfc drying. Max temps overall will be a few below normal--perhaps trending a degree or two cooler in our eastern zones, and a degree or two warmer in our southwest compared to today, reflecting the thickness pattern. Minimum RH Friday will be quite low for the end of May, below 30 percent in the Piedmont northeast of I-26. Winds however look to mix out to just a few mph by the time the RH bottoms out, so not anticipating wildfire danger. && .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/... As of 1247 AM EDT Thursday: The first part of the weekend still looks relatively quiet as a mid/upper ridge builds in further Friday night, which finally brings a center of sfc high pressure down over the Carolinas on Saturday morning. Once the ridge axis crosses overhead and moves toward the coast on Saturday, the high gets pushed offshore and the moisture will start to move back up from the Gulf of Mexico. Think that Saturday afternoon should be rain-free at this time, with temps returning to normal. However, Saturday night there will be a small chance that showers could move in from the southwest or develop over the southern mountains in the light southerly upslope flow overnight. Some of the guidance is more aggressive with bringing some precip in from the west, perhaps because of some sort of loosely organized convective system developing closer to a cold front to our west Saturday afternoon/evening and then making a run at the mountains. Prefer to keep the precip probs low over the mtns until we get a better sense for that potential in the HREF. && .LONG TERM /SUNDAY THROUGH THURSDAY/... As of 243 AM EDT Thursday: The medium range continues to look like a return to summer-like mainly diurnal showers and thunderstorms beginning Sunday. The upper pattern should feature a flattened nearly-zonal flow, but with several weak waves running through it, the strongest of which may dampen as it moves past to the north on Sunday. The suggestion in some of the guidance is that a remnant weak cold front will get strung out west-east across the region in the wake of this wave, and that would act as a focus for more storms as moisture remains pooled over the region for the rest of the period. Meanwhile, other convectively-induced waves could move along and across the region on any given day. Precip probs a bit above climo seem appropriate, with a peak in the mid/late afternoon each day. The details are too sketchy for anything else for now. Not yet buying the GFS and its closed low over the region by mid-week. So, we will keep to the plan of temps gradually rising above climo and eventually reaching mid/upper 80s with increasing humidity as we work through the week. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... At KCLT and elsewhere: VFR. Once again FEW-SCT cumulus will be seen this aftn around the region at 050-070, but no precip expected. Light, generally northerly winds will exhibit some variability especially at the SC sites. Upper trough remains over the NE CONUS, and as this feature shifts east dry sfc high will build more effectively into the area tonight. Jet streak upstream of main trough axis may introduce some cirrus, but low levels remain dry. Sfc high will enhance gradient and basically bring in a dry backdoor front, suggesting winds veer to NE and pick up a bit in the wee hours Fri morning. Can`t entirely rule out some fog in a few mountain valleys, although chance at KAVL looks minimal. Outlook: VFR conditions and dry weather through Saturday. Shower and thunderstorm chances return by the end of the weekend and into next week. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...PM NEAR TERM...Wimberley SHORT TERM...PM LONG TERM...PM AVIATION...Wimberley