textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Updated the aviation discussion for the 12z TAFs.

KEY MESSAGES

1. Slightly cooler and drier conditions are expected today. 2. Diurnal shower and thunderstorm chances return by the end of the week and continue thru the weekend. High temperatures outside the mountains are expected to climb into the mid to upper 90s this weekend.

DISCUSSION

Key message 1: Slightly cooler and drier conditions are expected today.

The departing cold front has moved off the Atlantic Coast early this morning and the breezy NWLY winds behind the front have dissipated over our area. Notably drier and somewhat cooler air has spread across the fcst area in the front's wake as sfc high pressure remains centered just to our NW. The sfc high will drift eastward and weaken as the day progresses. Winds will remain light today and tonight with few to sct high clouds streaming over the area. High temperatures should remain about 3 to 6 degrees below normal today and warm back to near-normal, if not slightly above, on Thursday.

Key message 2: Diurnal shower and thunderstorm chances return by the end of the week and continue thru the weekend. High temperatures outside the mountains are expected to climb into the mid to upper 90s this weekend.

A weak upper trof pattern will remain in place just to our north thru the end of the work week and into the weekend. Increasingly moist, SLY low-level flow will return to the Southeast by late week as the Bermuda High back builds over the region. Each day, thru the weekend, is expected to see a steady increase in afternoon high temperatures. The latest long-range guidance continues to suggest that temperatures will moderate somewhat on Monday, and then warm again by the middle of next week. Piedmont temperatures over the three-day period Friday thru Sunday are expected to reach the mid to upper 90s, while the Upstate remains in the low to mid 90s. Dewpts are expected to be high enough on Saturday and Sunday to produce heat indices near or just above 100 degrees for most of our I-85 Corridor and zones south of it. I cannot rule out Heat Advisory conditions across some of this area. It will depend on how much dewpts mix out each afternoon and whether high tempera- tures trend warmer or cooler. The increasing moisture will bring back the diurnal convective trend with the best chances for showers and thunderstorms over the NC mtns, especially along the NC/TN border region.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/

At KCLT and elsewhere: Expect dry, VFR conditions to prevail thru the 12z taf period with high pressure over the area. Other than few to sct cirrus, skies should remain mostly clear thru the period. Some VFR stratocu is currently making its way over the Upstate, but should dissipate over the next hour or two. Winds will favor a N to NE direction thru the morning at KCLT and the Upstate terminals, then go light and VRB to calm for the remainder of the period. At KHKY and KAVL, winds should remain light and VRB to calm thru the taf period. Outlook: Mostly dry, VFR conditions expected through Thursday. Diurnal shower and thunderstorm chances and their associated restrictions increase again on Friday, especially over the NC mtns, and continue through the weekend.

GSP WATCHES/WARNINGS/ADVISORIES

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