textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

The Aviation Discussion was updated.

KEY MESSAGES

1. Dry and hot conditions through Sunday. Daily shower and thunderstorm chances return next week.

DISCUSSION

Key message 1: Dry and hot conditions through Sunday. Daily shower and thunderstorm chances return next week.

A compact shortwave trough is currently sliding across New England while a notably stronger trough drops across the Pacific Northwest and into the Northern Rockies. Farther south, a weak closed upper low is spinning over the Southern Plains with broad upper ridging extending across the southeast states. At the surface, residual dry air remains in place across much of the region with only weak southwest return flow. Dewpoints in the upper 50s to low 60s and a lack of deep-layer moisture will continue to preclude the development of traditional diurnal summer pulse convection. Heading into tomorrow, the synoptic pattern begins to evolve as the Southern Plains upper low opens into a shortwave trough as it lifts across the Mississippi Valley. This will in turn foster more pronounced southwest flow and deeper moisture return extending from the Gulf into much of the Deep South and Georgia. The best moisture will still remain to our southwest, but a few isolated showers could graze the far southwest mountains.

The pattern finally returns to a more typical summer regime by the start of next week with upper ridging centered to our south and east. This allows for persistent southwest return flow into the area with deep-layer moisture finally recovering. This will also be working in concert with several passing shortwave troughs across the Ohio Valley. Daily chances for diurnal showers and thunderstorms will return with the highest chances over the mountains. As with any summer storms, isolated damaging downbursts and locally heavy rain cannot be ruled out with any storm, but organized severe weather or widespread flooding are not anticipated. Temperatures will also increase late week into the low to potentially mid 90s as heights rise in response to a digging trough across the Great Plains. Heat indices will remain well below advisory criteria, but we may see our first near 100 degree readings across far southern reaches of the area.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

At KCLT and elsewhere: Expect dry, VFR conditions to continue thru the 00z TAF period. Sct to bkn high cirrus will continue to stream overhead from the west thru most of the period, with sct cumulus likely developing over the NC mtns again tomorrow afternoon. There's a decent chance of some patchy mtn valley fog/low stratus developing again Sunday morning over the usual areas, but it's not expected to reach KAVL. Winds will become light later tonight and could be VRB and/or calm at times. Otherwise, they will pick up again from the SW tomorrow aftn with speeds between 5 and 10 kts.

Outlook: Diurnal convection and associated restrictions return Monday and continue thru next week. Mountain valley fog and low stratus will be possible each morning.

GSP WATCHES/WARNINGS/ADVISORIES

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