textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

No significant changes.

The aviation discussion has been updated for the 12z TAFs.

KEY MESSAGES

1. Relatively warm late summer weather will persist through the week, with low risk for significant weather.

DISCUSSION

Key message 1: Relatively warm late summer weather will persist through the week, with low risk for significant weather.

The weather looks fairly quiet over the upcoming week with a low chance for anything significant happening. Even though we have a back-door front moving down from the north later today, the mid/upper anticyclone over the Ozarks builds eastward to the TN valley over the next 24 hours and helps to keep the convective environment generally unfavorable and suppressed. By peak heating the sfc-based CAPE might peak around 500 J/kg. High pressure moving across the Great Lakes should push the front into the region late in the day and that boundary could make the most of what is available, with a focus of easterly flow up against the Blue Ridge Escarpment. That is where isolated showers would form, if at all. The forecast will remain dry in most places. Because of the late frontal passage, we get one more hot day with high temps 5-10 degrees above normal.

The most interesting part of the forecast remains the potential for some weak, dry cold air damming as the sfc high pressure center moves from New England on Tuesday to a position off the coast of New England and the Maritime Provinces on Wednesday. There could be some shallow moisture on an easterly flow on Tuesday that will help keep temps around normal with some increase in low cloudiness, but there won't be any forcing for precip and the moisture doesn't stay for long. The result would be temps rising back above normal on Wednesday with a warmup right back into the lower 90s east of the mountains by the end of the week. Typical weather for having an upper anticyclone/ridge in our midst. As the air mass modifies and warms, we expect a return of high elevation scattered diurnal showers and storms from Thursday onward. The climo precip probs will persist through next weekend.

Meanwhile...as all this is happening late week and next weekend, some of the guidance shows a mid/upper low moving westward across the FL peninsula and the northern Gulf. If this comes to pass, late in the period we would get back into a wetter pattern with deep moisture moving back from the south, but confidence is low.

AVIATION /12Z MONDAY THROUGH FRIDAY/

At KCLT and elsewhere: VFR conditions will prevail at most terminals through the forecast period outside of mountain valley fog and low stratus. Any fog and low stratus that forms will quickly mix out shortly after sunrise. Can't rule out a rogue shower during the afternoon as a backdoor cold front moves into the area, but confidence is too low for a TAF mention at this time as coverage will be isolated at best. Light north to northwest winds overnight, while toggling to a north to northeast position during the daytime hours. Flow is expected to turn east to northeasterly by the evening into tonight behind the aforementioned front and allow winds to pickup to 5-10 kts, while KAVL maintains a northwest component through most of the forecast period with a few low end gusts during the afternoon. Guidance is picking up on cloud development overnight tonight and daybreak Tuesday, which could lead to some cig restrictions.

Outlook: Mostly dry conditions are expected to persist through the middle of the week. Shower chances and associated restrictions increase later in the week. Mountain valley fog and low stratus is possible each morning through the week.

GSP WATCHES/WARNINGS/ADVISORIES

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