textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Still on track for triple digit heat indices by midweek.

KEY MESSAGES

1. Afternoon shower and thunderstorms chances remain through Monday, with increasingly sparse coverage expected each day afterward. 2. Hot and humid conditions return after Monday. Dangerous heat index values arrive in the low terrain by the second half of the week.

DISCUSSION

Key message 1: Afternoon shower and thunderstorms chances remain through Monday, with increasingly sparse coverage expected each day afterward.

The trough begins to shift eastward as height rises occur ahead of the ridge pushing east. Pattern becomes more stagnant as the subtropical ridge expands over the south and starts to stint convective activity. But, before this occurs, got another round of typical summertime showers and thunderstorms each afternoon through at least Monday. Higher chances over the mountains as usual through the evening hours and the same for Sunday. Drier air filters in with the high pressure and decreases rain chances east of the mountains for Sunday, onward. Guidance depicts a drier period with only a slight chance of showers through at least midweek.

Key message 2: Hot and humid conditions return after Monday. Dangerous heat index values arrive in the low terrain by the second half of the week.

By Monday, the ridge continues to push eastward and the subtropical ridge dominates across the south. What this means is a rise in temperatures once again, reminding us all that summer is still in full swing. Long range guidance depicts temps ticking upward starting on Monday and reaching the mid to upper 90s from Tuesday onward. Heat indices also start to creep up, spotty at first, but soon more widespread 100+ by midweek. Closer to Wednesday, areas east of the mountains could be feeling heat index values in the 101 to 106 range, increasing confidence that a Heat Advisory may be needed. Either way, the revenge of summer is upon us and there is still no cold front on the horizon.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

At KCLT and elsewhere: A mix of MVFR and VFR this afternoon across the terminals with BKN/FEW lower clouds. A few TSRA/SHRA possible in the mountains and KCLT, so PROB30 to cover it. Confidence isn't high enough to justify elsewhere. BR possible overnight, MVFR/IFR vsby for KAVL/KHKY, with 6SM at KCLT after 07z through mid morning. This depends on rain too, so less rain, less BR. Light to calm winds overnight with S/SE winds for Sunday.

Outlook: Scattered showers and storms possible through Monday. Mountain valley fog and low stratus likely each morning through the first part of next week.

GSP WATCHES/WARNINGS/ADVISORIES

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