textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Lowered dewpoints on Tuesday afternoon compared to the previous forecast, to account for stronger and deeper mixing depicted in recent model guidance.

Updated the aviation forecast to reflect the recent 00Z TAF issuance.

KEY MESSAGES

1. Low-end fire danger conditions expected Tuesday afternoons. 2. Clear skies and seasonable temperatures persist into next weekend.

DISCUSSION

Key message 1: Low-end fire danger conditions expected Tuesday afternoons.

Daytime mixing should be a little less pronounced tomorrow, as the low pressure center pulls farther northeast and low-level flow weakens in response. Forecast soundings also exhibit more prominent subsidence atop the PBL, which should further inhibit deep mixing. Some degree of a dewpoint drop and another breezy afternoon are nonetheless expected, but RH values should crash less than on Monday, and wind gusts should be lower, and less frequent. By Wednesday, the complete loss of strong low-level CAA and an even stronger subsidence inversion should reduce fire danger concerns even further.

Key message 2: Clear skies and seasonable temperatures persist into next weekend.

The synoptic pattern still looks like it will evolve into an omega- like blocking pattern through the middle of the week. As an upper low off the Atlantic coast retreats northeastward on Tuesday and Wednesday and heights build over the central CONUS, stationary upper troughing will become established east of the area, before the ridge slowly builds into the Carolinas over the weekend.

For our part, we can expect mostly-clear skies, with temperatures slowly but steadily trending warmer through the week. Highs may be a solid category above normal by Thursday (which for this time of year, is still in the mid 70s!). Long-range ensembles have begun to form an unsteady consensus for a weak reinforcing cold front to arrive Friday or Friday night, driving temperatures back below normal going into the weekend. As usual at this timescale, confidence is only moderate.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

At KCLT and elsewhere: VFR conditions will prevail at all terminals through the TAF period. Light northerly winds will continue overnight with several locations likely becoming calm with light northeast winds returning during the day on Tuesday.

Outlook: Dry, VFR conditions persist through the week, and into next weekend. Patchy mountain valley fog and low stratus may be possible each morning.

GSP WATCHES/WARNINGS/ADVISORIES

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