textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

Lowered dewpoints on Wednesday and Thursday to account for increased mixing potential compared to previous forecasts.

Updated the aviation forecast to reflect the recent 18Z TAF issuance.

KEY MESSAGES

1. Low-end fire danger conditions continue today and are expected again tomorrow. A Fire Danger Statement is in effect for northeast Georgia thru 7 PM this evening. 2. Dry high pressure persists through early next week. Temperatures will fall below normal beginning Friday, then steadily return to normal through next week.

DISCUSSION

Key message 1: Low-end fire danger conditions continue today and are expected again tomorrow. A Fire Danger Statement is in effect for northeast Georgia thru 7 PM this evening.

Dry, seasonably cool conditions continue today, with sprawling high pressure still in place across the Southeast. Sunny conditions are still expected the next few days, with highs in the lower 70s and lows in the 40s east of the NC mountains. Forecast soundings for today and tomorrow continue to depict deep afternoon mixing and increasingly feature little to no inversion atop the mixed layer. As a result, still think there's potential for dewpoints to crash this afternoon, and especially Thursday afternoon, resulting in RHs falling to critical values across much of the area. It is fortunate that low-level winds are expected to slacken enough that little to no overlap between critical RHs and dangerously gusty winds will take place.

Nonetheless, excessively dry conditions will support low-end fire danger, and a Fire Danger Statement is in effect for northeast Georgia until 7 PM this evening.

Key message 2: Dry high pressure persists through early next week. Temperatures will fall below normal beginning Friday, then steadily return to normal through next week.

A broad surface high will remain in place through the remainder of the week, maintaining quiet conditions across the area. A pattern change is in store for Friday, as reinforcing high pressure settles over New England, instigating a brief period of synoptically-driven cold air damming going into the weekend. As a result, temperatures should settle a category or two below normal over the weekend...with lows in the low 40s...cold enough for some frost potential. Sans any good upper forcing, it still appears unlikely that any rain or significant cloud cover will develop with CAD...and the air mass will simply modify going into next week, allowing temperatures to creep back up toward normal.

Meanwhile, the upper pattern will finally show some signs of life beginning Sunday or Monday, as an upper low initially centered over the Four Corners region of the Southwest begins lifting northeastward, and ridging over the central and eastern CONUS starts to break down in response. By the end of the seven-day forecast period, a more progressive and dynamic upper pattern will be setting in, but incipient dry air is still expected to severely limit rain changes through the middle of next week.

AVIATION /18Z WEDNESDAY THROUGH MONDAY/

At KCLT and elsewhere: VFR expected at all six TAF sites through the period. Light NE winds are expected through the period at all terminals, with the exception of AVL, where the French Broad Valley will keep winds more of a N/NW bearing. Some valley fog should develop again tonight, but is not expected to make it to AVL before dawn. NE winds and SKC skies continue on Thursday.

Outlook: Dry, VFR conditions persist through the remainder of the week and into the weekend. Mountain valley fog and low stratus will be possible each morning.

GSP WATCHES/WARNINGS/ADVISORIES

GA...INCREASED FIRE DANGER until 7 PM EDT this evening for GAZ010- 017-018-026-028-029. NC...None. SC...None.