textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

NBM continues trending lower on PoPs for Sunday.

Confidence continues to increase regarding the potential for a few severe storms Monday afternoon and evening.

KEY MESSAGES

1. Dry through the weekend before daily shower and thunderstorm chances return next week. Severe storms are possible Monday afternoon and evening with damaging winds being the main hazard.

DISCUSSION

Key message 1: Dry through the weekend before daily shower and thunderstorm chances return next week. Severe storms are possible Monday afternoon and evening with damaging winds being the main hazard.

Surface high pressure remains over the Carolinas and northeast Georgia through the weekend keeping lower humidity and dry conditions around. The NBM continues to back off on PoPs Sunday afternoon and evening and this matches the latest CAM trends showing dry conditions lingering over the GSP CWA. It will be cooler today with highs running near normal to just below normal. Warmer and above normal highs return Sunday to kick off the first official day of summer as low-level SW'ly flow gradually strengthens ahead of an approaching cold front.

The cold front approaches out of the W/NW on Monday before tracking across the area Monday night into Tuesday. A line of storms looks to develop ahead of the front Monday afternoon and evening per the 12Z CAMs that already go out through Monday evening. With guidance depicting 20-25 kts of deep layer shear in place ahead of the front and 1,500-2,000 J/kg of SBCAPE developing during peak heating hours, strong to severe storms will be possible. The Day 3 SPC Outlook showing a Marginal risk across the entire GSP CWA appears warranted. Damaging winds will be the main hazard with any severe storms that develop. Timing for severe on Monday looks to be from roughly 2 PM to 10 PM per the 12Z NAMNest but this is subject to change as the rest of the high-res guidance begins to fully capture the event. Breezy SW winds can also be expected ahead of the front on Monday, ranging from 20 to 30 mph (well below advisory criteria).

A more diurnal convective pattern returns for the rest of the week behind the front with highs each afternoon ending up near normal to just above normal.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

At KCLT and elsewhere: Dry and VFR through the 18Z TAF period. Winds will pick up out of the WSW/SW east of the mountains this afternoon while winds at KAVL remain VRB. Winds will go calm to light and VRB this evening into Sunday morning before picking up out of the S/SW by early Sunday afternoon. Cirrus will continue streaming overhead through late this evening before gradually thinning overnight. Thin cirrus will stick around through Sunday with some cumulus possibly developing during peak heating hours.

Outlook: Dry and VFR through at least Sunday night before shower and thunderstorms, as well as associated restrictions, return ahead of cold front Monday into Tuesday. Daily chances for showers and thunderstorms will continue behind the front the rest of the week.

GSP WATCHES/WARNINGS/ADVISORIES

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