textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

No significant changes were made to the public forecast.

The aviation discussion was updated to reflect the recent 00Z TAF issuance.

KEY MESSAGES

1. Above normal temperatures with increasing shower and thunderstorm chances through the weekend. A cold front on Tuesday brings a better chance of widespread precipitation and near normal temperatures.

DISCUSSION

Key message 1: Above normal temperatures with increasing shower and thunderstorm chances through the weekend. A cold front on Tuesday brings a better chance of widespread precipitation and near normal temperatures.

A quiet evening is in progress across the western Carolinas, with most of the area finally clearing up after an extended period of thick stratocu. A z500 upper anticyclone currently centered over the eastern Tennessee Valley and southern Appalachians continues to suppress the atmosphere, and should aid in keeping mostly dry and clear conditions across the area for at least the next 24 to 48 hours.

The upper anticyclone remains in place through Friday with a ridge extending from it east over our area. At the surface, a damming high lookalike over the area Wednesday weakens as a back door cold front approaches from the north. A dry forecast is expected Wednesday with diurnal convective chances slowly increasing, mainly across the mountains, Thursday and Friday. Unfortunately, highs rise back into the low to mid 90s outside of the mountains, around 90 in the warmer mountain valleys, by Friday.

The anticyclone weakens and retrogrades over the weekend as a series of shortwaves cross the Mid-Atlantic and an upper low moves west across Florida. The shortwaves help push the back door cold front into the area Saturday which dissipates on Sunday. This keeps shower and thunderstorm chances across the area with highs dropping back into the upper 80s to around 90.

Another cold front moves in from the northwest Monday and east of the area Tuesday. This has the potential for more widespread shower and thunderstorm chances with highs dropping to near normal for Tuesday.

AVIATION /00Z WEDNESDAY THROUGH SUNDAY/

At KCLT and elsewhere: We're VFR virtually everywhere this evening, with clear radar and gradually-diminishing cloud cover after a day spent trying to scatter out the morning stratocu. Low-level moisture remains in place at several observed sounding sites across the area, so although conditions should remain mostly clear outside the mountain valleys much of tonight, still think there's potential for another round of MVFR stratocu again Wednesday morning. AWC and statistical ceiling guidance would suggest the strongest signal along and south of I-85, so went with TEMPOs for the Upstate sites...while confidence was too low for CLT. Also expect the typical mountain valley fog/stratus at KAVL and other mountain valley terminals.

A suppressed day is expected once again on Wednesday. Isolated ridgetop showers may develop in the afternoon, but with too little coverage to warrant inclusion at KAVL. Elsewhere, no rain is expected. Winds will stay out of the NE most of the day, but begin trending ESE by evening.

Outlook: Convective chances and associated restrictions increase going into the weekend. Mountain valley fog and low stratus will be possible each morning.

GSP WATCHES/WARNINGS/ADVISORIES

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