textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Flash flood potential is increasing for isolated locations east of the I-77 corridor.

Temperatures are trending slightly cooler for next week.

KEY MESSAGES

1. Another round of showers and thunderstorms for the area through this evening. A few storms may be severe, producing damaging wind gusts, locally heavy rainfall and isolated flash flooding. 2. Drier weather returns Sunday through early next week, with afternoon shower and thunderstorm chances returning by midweek.

DISCUSSION

Key message 1: Another round of showers and thunderstorms for the area through this evening. A few storms may be severe, producing damaging wind gusts, locally heavy rainfall and isolated flash flooding.

An upper trough swings a weak cold front through the TN/Ohio Valley and makes a run for the Carolinas tonight. Ahead of it, showers and thunderstorms make a return for another round of convective fun that may linger into the overnight hours. Destabilization is helping to fuel showers and thunderstorms already ongoing in the Upstate. A Severe Thunderstorm Watch has been issued for a portion of the Upstate, mainly along and south/east of I-85 and a portion of the NC Piedmont through 9 PM. the main area of concern for the severe threat still remains along and east of I-77, which includes the Charlotte Metro, and counties in SC to the south of I-85. For this the Storm Prediction Center has issued a Slight risk (threat level 2 of 5), mainly for damaging winds. Given the higher moisture amounts ahead of the front, a small risk for locally heavy rainfall and flash flooding is possible, especially for urban areas and locations that received rainfall this morning. Model guidance seems to hint at the greater potential for heavy rainfall and flash flooding is east of I-77, especially just east of Charlotte. Current guidance depicts 2-3 inch/hour rain rates so cannot rule out the potential for flash flooding. It depends on where these storms setup and how much destabilization can occur over the next few hours. Model guidance is not in consensus with timing or coverage, but given the location of the front and anticipated arrival, expect the potential severe threat to ramp up from now through 9 PM. Could have a few lingering storms as the front moves in, but looking at shower chances quickly dropping off throughout the night. Regardless of the exact locations and timing, always remember to have multiple ways to get a warning. If you are outdoors and hear thunder or see lightning, seek shelter and never drive through flooded roadways.

Key message 2: Drier weather returns Sunday through early next week, with afternoon shower and thunderstorm chances returning by midweek.

Behind the front, drier and somewhat cooler air moves into the area by Sunday, shunting rain chances for a a few days. As a surface high migrates eastward over the Midwest and into the northeast portion of the country, reduced moisture and air from the north contribute to a welcomed break in heat as temperatures look to dip into the 80s for most of the area through the end the forecast period. As the high moves offshore by midweek, moisture slowly starts to return and increases rain chances once again. Mostly expecting the typical summertime afternoon shower and thunderstorm activity to resume. Overall, calmer and slightly cooler weather ahead.

AVIATION /18Z FRIDAY THROUGH WEDNESDAY/

At KCLT and elsewhere: SHRA and TSRA for all terminals with the higher confidence being at KCLT. A TEMPO for KCLT 21z-01z for TSRA and a PROB30 01z-04z for any lingering TSRA. PROB30 for all other sites for TSRA through 00z. Patchy BR/FG possible at all sites overnight, with highest confidence at KAVL, hence a TEMPO for 1/2SM FG from 09z-13z. After a front moves through, expect quick improvement Saturday morning into the afternoon. Winds remain VRB/light outside of any TSRA, with a light NW direction Saturday.

Outlook: Quieter weather returns after Saturday. Mountain valley fog and low stratus is possible each morning.

GSP WATCHES/WARNINGS/ADVISORIES

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