textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

No major changes.

KEY MESSAGES

1. Dry through mid-week with daily shower and thunderstorm chances returning starting Friday in association with a cold front. Above normal temperatures linger through early next week, with the heat and humidity expected to peak on Friday.

DISCUSSION

Key message 1: Dry through mid-week with daily shower and thunderstorm chances returning starting Friday in association with a cold front. Above normal temperatures linger through early next week, with the heat and humidity expected to peak on Friday.

Flattening upper anticyclone controls the weather pattern through Thursday keeping dry conditions around. A more humid airmass returns starting Thursday, peaking on Friday as the western periphery of an upper ridge remains extended over the Southeast. The upper trough tracking eastward out of the Midwest now appears to remain just north and west of the GSP forecast area Friday into the weekend per the latest 00Z global model guidance. This may prevent the surface cold front from pushing across the entire GSP forecast area on Friday. The front may even reactivate as a warm front and lift back northward late Friday into early Saturday. As a result, the heat and humidity will stick around through the weekend. Regardless of the front being able to push across the entire CWA, shower and thunderstorm chances are still expected to return ahead of and along the frontal boundary starting Friday, lingering into the weekend as SW'ly flow leads to an influx of rich Gulf moisture across the Southeast. PWATs east of the mountains should peak ~1.8" to 2.25" Friday night into Sunday night which is above the 90th percentile for this time of year. Although the rain will be beneficial, there could be a low-end hydro threat for areas that see multiple rounds of heavy rainfall. Should see the heavy rainfall threat lower early next week as PWATs decrease slightly in response to another upper anticylcone building over the Southeast. This should help suppress shower and thunderstorm activity east of the mountains somewhat while keeping daily chances for shower and thunderstorms mostly confined to the mountains. This heat dome will keep hot and humid conditions around through early next week. Although Heat Advisory criteria is not expected through the forecast period, some locations in the Charlotte Metro and in the Upper Savannah River valley may see heat index values reach into the triple digits each afternoon Friday into early next week. Fall cannot come soon enough.

AVIATION /06Z WEDNESDAY THROUGH SUNDAY/

At KCLT and elsewhere: Dry and VFR outside of the potential for another round fog and stratus to develop closer to daybreak at KHKY and KAVL. Thus, maintained TEMPOs for these terminals for possible LIFT to MVFR restrictions from 09Z-12Z. Any fog/stratus that develops should lift around or shortly after daybreak. Calm winds are expected at KAVL and KHKY through daybreak. Winds at KCLT should remain light and SE'ly while winds across the SC terminals remain light and NE'ly through daybreak. Winds could go calm to light and VRB at times at KCLT and the SC terminals. Winds will turn more S'ly by late morning or early afternoon across the terminals.

Outlook: A cold front should bring back daily shower and thunderstorm chances (and possibly restrictions) Friday into the weekend. The probability of morning fog/low stratus will also increase, especially in the mountain valleys.

GSP WATCHES/WARNINGS/ADVISORIES

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