textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

The aviation discussion was updated for the upcoming 12Z TAF issuance.

KEY MESSAGES

1. Dry weather with more comfortable humidity returns to the region today and continues through Tuesday. Daily shower and thunderstorm chances return Wednesday and continue through the rest of the week.

DISCUSSION

Key message 1: Dry weather with more comfortable humidity returns to the region today and continues through Tuesday. Daily shower and thunderstorm chances return Wednesday and continue through the rest of the week.

A deep upper trough is pivoting to a negative tilt over the OH Valley to the Mid-Atlantic today, and will close off into a large upper low over the Great Lakes. This will keep a relatively dry, NWLY mid-upper flow atop the CWFA thru Monday. A sfc cold front will cross the area early this morning, ushering in much lower dewpts, as downslope and deep mixing help bring dewpts down into the 50s to lower 60s across the area. Temps will top out near normal, but it should feel nice compared to the normal humidity for late August. The dry air will keep the air mass stable, so a dry fcst is on tap. This will continue thru Monday, as little change in pattern expected.

Then, Tuesday will be the beginning of a transition toward higher humidity and a gradual return of diurnal convection chances. latest guidance keeps Tuesday largely dry, then isolated to scattered convection will be possible late Wednesday aftn thru Wednesday evening, as a weak warm front brings higher dewpts in from the south and east. An upper trough digs into the Mid-MS Valley on Thursday and brings an associated cold front toward the forecast area. Guidance is in pretty good agreement on more widespread convective coverage, and NBM already has likely PoPs across most of the area. Scattered diurnal convection looks to continue Friday and into next weekend, as the front stalls out in the area and keeps warm and humid conditions in place. Overall, temps will be near to slightly above normal from Wednesday onward.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

At KCLT and elsewhere: Patchy fog and low stratus has formed early this morning, but should quickly burn off within an hour or two of sunrise, as dry air and mixing picks up. As drier air spreads across the region today, no deep convection is expected, with just some high-based Cu. Winds become N to NW mid to late morning, with low-end gusts at KAVL. KAND will see a westerly wind. Light wind and mainly some Ci overnight should allow for mountain valley fog to form. Will go with MVFR vsby and sct low clouds at KAVL for now.

Outlook: No significant chance of convection until Wednesday with an even better chance on Thursday. Mountain valley fog and low stratus is possible each morning.

GSP WATCHES/WARNINGS/ADVISORIES

GA...None. NC...None. SC...None.