textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Went slightly below NBM for highs on Wednesday as cloud cover is trending higher which should lead to slightly cooler afternoon temperatures.

NBM trending cooler for highs Sunday through Tuesday.

KEY MESSAGES

1. Dry through Saturday before rain chances return late this weekend into early next week. Temperatures remain mostly above normal, with the exception of Sunday.

DISCUSSION

Key message 1: Dry through Saturday before rain chances return late this weekend into early next week. Temperatures remain mostly above normal, with the exception of Sunday.

Ridging dominates the upper pattern while surface high pressure remains in control at the surface over the eastern United States through Saturday. This will act to keep well above normal temperatures and dry conditions around through Saturday. Classic cold air damming looks to ahead of the main precipitation shield on Saturday, allowing cooler (but still above normal) highs to return.

Rain finally returns sometime late Saturday night into Sunday. Confidence on exact arrival time remains low but confidence is fairly high (for now) that rain should hold off until late Saturday night for most locations, which is good news for trick-or-treaters. Classic cold air damming will transition to hybrid cold air damming sometime late Saturday night into Sunday as the main precipitation shield arrives. Temperatures appear to be warm enough for all liquid precipitation at this time. Cold air damming combined with widespread cloud cover and rain may allow highs to briefly drop below normal on Sunday. Rain chances may linger through early next week with the potential for cold air damming to transition to in- situ as the center of the parent high pushes offshore. NBM chance PoPs look good for now on both Monday and Tuesday. Would not be surprised if the NBM continues to trend cooler for highs Sunday through Tuesday, especially if the wedge lingers.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

At KCLT and elsewhere: Dry and VFR through the 18Z TAF period. Cirrus will gradually increase in coverage this evening into Wednesday morning, becoming at least BKN. This should help limit, if not prohibit, mountain valley fog development overnight into daybreak Wednesday. Any breaks in cloud cover may allow brief fog/vsby restrictions to develop but confidence is low. Winds east of the mountains will remain mostly NE through the TAF period. Winds at KAVL will be ESE/SE this afternoon and again Wednesday afternoon, with winds going calm this evening into late Wednesday morning.

Outlook: Dry through Saturday. Cig and vsby restrictions are possible Wednesday night into Thursday morning. VFR should return by Thursday afternoon, lingering into Saturday. However, mountain valley fog/low stratus may develop Thursday night. Rain returns late Saturday night into Sunday, bringing restrictions back to the terminals.

GSP WATCHES/WARNINGS/ADVISORIES

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