textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

No major changes.

KEY MESSAGES

1. Much cooler today with below normal highs expected. Showers will continue to blossom through early this morning, mainly west of I-77. A low-end flood threat will persist through the early morning hours with this activity. 2. Drier conditions return Monday night, persisting through mid-week. A cold front will bring rain chances back towards the end of the week. Above normal temperatures return for the rest of the week.

DISCUSSION

Key message 1: Much cooler today with below normal highs expected. Showers will continue to blossom through early this morning, mainly west of I-77. A low-end flood threat will persist through the early morning hours with this activity.

A wedge-like pattern will remain in place today thanks to high pressure building in from the northeast. Easterly 850 mb flow has allowed scattered showers to develop overnight, mainly west of I-77. Shower activity will continue to blossom through the early morning hours while remaining mostly west of I-77. Weak shear will continue to lead to slow movement of showers which will keep the low-end flood threat around through at least the early morning hours. Mainly isolated nuisance to minor flooding is possible but cannot entirely rule out the potential for localized flash flooding for locations that receive multiple rounds of heavy rainfall. Drier conditions should return later this morning or early this afternoon. NE'ly flow combined with cloud cover sticking around will lead to below normal highs today. Finally some much needed relief from the heat and humidity!

Key message 2: Drier conditions return Monday night, persisting through mid-week. A cold front will bring rain chances back towards the end of the week. Above normal temperatures return for the rest of the week.

Unfortunately, below normal highs will be short-lived as an upper anticyclone builds into the Southeast Monday night into Tuesday night, lingering over the region through Wednesday. This will, however, allow dry conditions to return Monday night through Wednesday night. The anticyclone gradually breaks down Wednesday night as weak upper troughing tracks eastward and attempts to dig as far south as the Carolinas and northern Georgia Thursday into Friday. This will drag a surface cold front across the GSP forecast area late Thursday night into Friday before stalling over the Southeast over the weekend. As a result, shower and thunderstorm chances should return Thursday into Friday ahead of the front and may linger through the weekend behind the front. Above normal highs can be expected the rest of the week, although some locations may end up near normal Tuesday afternoon.

AVIATION /12Z MONDAY THROUGH FRIDAY/

At KCLT and elsewhere: SHRA will mainly impact the SC terminals through mid-morning. SHRA should improve cigs and vsbys slightly so have this accounted for in the TEMPOs. The NC terminals should remain dry through the TAF period. Seeing mostly IFR to MVFR restrictions across the terminals with the exception of KCLT which is currently VFR (as of 10Z). Cigs will be slow to improve, lifting to VFR by late morning or early afternoon. Wind direction will remain NE east of the mountains and E/SE at KAVL through the period. Low-end gusts of ~16-20 kts should develop east of the mountains by late morning or early afternoon before gradually diminishing by late afternoon or early evening. VFR should linger through daybreak Tuesday outside of the potential for mountain valley fog/stratus. Confidence on restrictions reaching KAVL overnight is too low to mention at this time.

Outlook: Dry and VFR through mid-week outside of morning mountain valley fog and low stratus. Rain chances and possible restrictions back Thursday into Saturday in association with a cold front.

GSP WATCHES/WARNINGS/ADVISORIES

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