textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Convective trends updated based on radar and latest CAM guidance.

The aviation forecast updated for the 00Z TAF issuance.

KEY MESSAGES

1. Daily shower and thunderstorm chances continue through the weekend. Locally heavy rainfall and a few strong storms possible on Friday. 2. Drier and warmer conditions trend for early next week, with hot temperatures and increased humidity by midweek.

DISCUSSION

Key message 1: Daily shower and thunderstorm chances continue through the weekend. Locally heavy rainfall and a few strong storms possible on Friday.

Convective coverage has been more suppressed today than expected, likely due to the earlier clouds limiting strong heating. Still, isolated showers, and possibly a thunderstorm, will cross the area this evening before dissipating.

A series of shortwaves glide down a persistent trough sitting over the eastern CONUS through Friday, increasing shower and thunderstorm activity. Though these shortwaves appear to be rather weak, it should provide a smidge of forcing, allowing for a few more storms to grow in this broad warm sector. Ample moisture is once again plaguing the area, ticking up confidence in coverage of showers and thunderstorms Friday. Model guidance is spotty, but for what it's worth, CAMs do hint at convection firing up over the mountains and moving east, typical for this area during summer. Main hazard to watch out for is damaging winds and locally heavy rainfall. There could be an isolated location or two that sees a brief stint of flash flooding wherever heavy rains setup. The Storm Prediction Center has carved out a Marginal Risk (1 of 5) for the entire area for Friday. By Saturday, the trough gets shoved offshore by the villainous ridge marching across the central US, eyeing the southeast. These height rises start to shunt convective activity, hedging for a favorable drier-ish period through next week.

Key message 2: Drier and warmer conditions trend for early next week, with hot temperatures and increased humidity by midweek.

As the ridge out west continues to propel the trough offshore, heights begin to rise and leads the way for the return of hot temperatures. As if Monday wasn't bad enough, hot and humid temps appear to creep in, turning a typical start of the week into a slightly less spirited one. Long range guidance signals widespread 90s for locations east of the mountains on Monday and ticking upward each day through the end of the forecast period. Along with repulsive temps, humidity remains rooted, elevating heat indices into the 100s by midweek. Too far out to pinpoint the exact details, but the trend is not our friend as models zoom in on these roasting temps. Stay tuned.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

At KCLT and elsewhere: Convection has been more suppressed than expected, likely due to the earlier clouds holding down strong heating. Still, isolated showers, and possibly a thunderstorm, may move near an airfield early this evening before dissipating. Some of the latest guidance has backed off on the potential for low clouds overnight. This is possible due to the lack of widespread rainfall; however, quite a bit of low level moisture remains across the area, so don't want to remove the clouds at this time. Keep the low clouds through the morning then scatter out for the afternoon along with PROB30s for convection. Light and variable winds through most of the period. KCLT may see light S wind during the afternoon with KAVL seeing light N wind during the morning.

Outlook: Less coverage of SHRA/TSRA for the weekend retreating to mainly the mountains Monday and Tuesday. Mountain valley fog and low stratus is possible each morning.

GSP WATCHES/WARNINGS/ADVISORIES

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