textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

PoPs increased by 15-25% for Friday into Friday night.

The aviation discussion was updated for the 18z TAF issuance.

KEY MESSAGES

1. Dry weather with a gradual warming trend expected through most of the work week. Then rain chances may return to the area Friday, with better chances over the weekend.

DISCUSSION

Key message 1: Dry weather with a gradual warming trend expected through most of the work week. Then rain chances may return to the area Friday, with better chances over the weekend.

A stalled nor'easter will continue to meander over the NY/NJ Bight thru Monday, then start to drift NE into New England and weaken Monday night into Tuesday. Dry, stable cyclonic flow on the back side of the low will remain atop the forecast area, keeping temps near normal and skies mostly clear.

Upper ridge builds in from the Plains Wednesday, peaking Thursday over the Southeast. Dry conditions are expected to continue, but temps will warm back above normal, with mid 80s Wed, and mid to upper 80s Thu and Fri across the Piedmont. Models start to diverge on Friday, with a large upper low tracking across the Four Corners region into the Southern Plains and possibly interacting with T.C. Polo in NW Mexico/Southern Plains. The GFS seems to be a fast outlier with the trough and quickly advecting Gulf moisture over the forecast area Friday. The EC and Canadian keep Friday dry, but enough of the medium range ensemble members have PoPs, such that the NBM has now trended back up into the chance range Friday. Having said that, the NBM PoPs seem overdone given the upper ridge still in place and weak return flow. By Saturday, return flow should start to ramp up, as the upper ridge shifts east and the southern stream upper low crosses the Southern Plains. There will be an ~1030 mb sfc high over the eastern Great Lakes or the Northeast that may produce a CAD event over the weekend, with moisture advecting atop the wedge. The NBM has trended cooler Sat and Sun due to potential CAD, with solid chance to likely PoPs.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

At KCLT and elsewhere: VFR conditions with mostly clear skies to continue thru the 18z TAF period. Mtn valley fog is expected again tonight in the usual areas, but like the past few mornings it is not expected to impact KAVL. Otherwise, winds will continue to favor a NWLY to NLY direction thru the period with speeds generally between 5 and 10 kts. KAVL will see 15-20-kt gusts until around 00z.

Outlook: Dry, VFR conditions should persist thru the middle of the week, with the usual mtn valley fog/low stratus possible each morning.

GSP WATCHES/WARNINGS/ADVISORIES

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