textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Warming trend continues for next week.

KEY MESSAGES

1. Rain chances and cooler temperatures continue into the weekend. Isolated flash flooding and a strong storm or two are possible across the area each day through Saturday. 2. A return to seasonably hot conditions and typical coverage of afternoon and evening showers and storms is expected starting Sunday and continuing through early to mid next week.

DISCUSSION

Key message 1: Rain chances and cooler temperatures continue into the weekend. Isolated flash flooding and a strong storm or two are possible across the area each day through Saturday.

The CWA remains in between two ridges with a trough located to the north through at least the weekend. The southern most edge of the trough swings across the Tennessee and Ohio Valley. Depending on how far south it dips, could increase or decrease the shower and thunderstorm activity across the area, especially over the mountains. Either way, it's a return to normal diurnally driven convection and showers through the weekend. Expecting shower and thunderstorm activity to mainly be across the mountains (60-90%) and a lower chance (20-40%) east of the mountains through Sunday. Though not outlooked, an isolated strong storm is possible each day. Additionally, temperatures remain below-normal for August through at least Sunday as high pressure remains east of the Carolinas.

Key message 2: A return to seasonably hot conditions and typical coverage of afternoon and evening showers and storms is expected starting Sunday and continuing through early to mid next week.

Through Sunday into next week, a large upper trough moves east into New England, which help push the high pressure southward. At the same time, the ridge is forecasted to move southwest creating typical hot summer conditions with upper 80s and 90s. Convection across next week is still uncertain as some models show a placement of a frontal boundary and some saying this boundary won't dip down into the area. Model guidance suggest that a front may sag south into the Ohio Valley, but confidence is low. A southern shift of this front may impact daily thunderstorm chances with the area residing on the northern fringe of the Bermuda high. This would also result in a wet pattern that would continue further into the week as bouts of convection make runs at the area from the Ohio Valley. For now, the forecast reflects typical summer PoPs with the best shower and thunderstorm chances being over the mountains. The main risks from theses daily storms are heavy rain and localized flooding.

AVIATION /18Z THURSDAY THROUGH TUESDAY/

At KCLT and elsewhere: TSRA possible again through this evening, but confidence remains lower, so a PROB30 at all sites continue. BR and low stratus could return overnight at most terminals, especially where rain fell. TEMPO for KAVL and KHKY for 1SM vsby. Light to calm winds overnight and lightly pick up out of the SW Friday. Another round of scattered TSRA so PROB30 at KCLT for Friday. VCSH for KAVL at the end of the forecast period. BKN/SCT cigs should remain VFR for Friday.

Outlook: Scattered showers and thunderstorms, with associated flight restrictions, are expected through early next week. Patchy fog and low stratus are possible each morning, especially in the mtn valleys and anywhere that received significant rainfall the previous day/evening.

GSP WATCHES/WARNINGS/ADVISORIES

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