textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Another Heat Advisory issued for Monday.

Aviation forecast was updated for the 18Z TAF issuance.

KEY MESSAGES

1. Heat Advisories continue for this afternoon and again on Monday for Upstate SC, northeast Georgia, and the Charlotte Metro area. Hot and humid weather continues for most of the week, with triple digit heat index likely over the low terrain each afternoon. 2. Diurnal convection develops each afternoon this week, with some strong to severe storms as well as isolated nuisance flooding possible each day.

DISCUSSION

Key message 1: Heat Advisories continue for this afternoon and again on Monday for Upstate SC, northeast Georgia, and the Charlotte Metro area. Hot and humid weather continues for most of the week, with triple digit heat index likely over the low terrain each afternoon.

Stout subtropical ridging slowly retrogrades through the period, but not fast enough to significantly lower heights and thicknesses until later in the week or next weekend. With the continued heat and humidity, another Heat Advisory has been issued for Monday. There may be enough of a break in the heat or humidity to limit the extent of the Advisories for Tuesday and Wednesday, but that's uncertain at this time.

The guidance continues to suggest a trof forming over the eastern CONUS for next weekend which would allow temps to drop to near or even below normal.

Key message 2: Diurnal convection develops each afternoon this week, with some strong to severe storms as well as isolated nuisance flooding possible each day.

The moist and unstable air mass will remain in place across the area through at least the middle of the week. With steep low level lapse rates, high DCAPE and PW values, wet microbursts will be possible with any storm that can grow tall enough. Severe storm coverage could be higher of Monday with an increase in bulk shear potentially leading to some organization.

By Thursday or Friday, a trof developing over the eastern CONUS could bring a period of more widespread daily convection as a series of shortwaves and a slow moving cold front impact the area into the weekend.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

At KCLT and elsewhere: Convection more isolated this afternoon. Have PROB30s at the NC sites where chances are higher. May eventually end up needing a mention at the SC sites but will take a wait and see stance there. Mainly cirrus overnight outside of another round of mountain valley fog, and fog at KHKY. Generally light and variable winds this afternoon, stronger NNW wind at KAVL. Light and variable to calm wind overnight becoming W to NW on Monday.

Outlook: Scattered showers and thunderstorms with associated flight restrictions will be possible each afternoon. Low stratus and fog will be possible each morning, especially in the mountain valleys.

GSP WATCHES/WARNINGS/ADVISORIES

GA...Heat Advisory until 8 PM EDT this evening for GAZ018-026-028- 029. Heat Advisory from noon to 8 PM EDT Monday for GAZ018-026-028- 029. NC...Heat Advisory until 8 PM EDT this evening for NCZ070>072-082. Heat Advisory from noon to 8 PM EDT Monday for NCZ070>072-082. SC...Heat Advisory until 8 PM EDT this evening for SCZ008>014-019- 104>109. Heat Advisory from noon to 8 PM EDT Monday for SCZ008>014-019- 104>109.