textproduct: Greenville-Spartanburg

WHAT HAS CHANGED

No significant changes for this forecast.

KEY MESSAGES

1. Precipitation chances increase Wednesday night and linger into early Saturday across the mountains. Temperatures become cold enough for snow, mainly over the higher elevations along the Tennessee border. 2. Gusty winds and colder temperatures linger behind a strong cold front Thursday through the weekend.

DISCUSSION

Key message 1: Precipitation chances increase Wednesday night and linger into early Saturday across the mountains. Temperatures become cold enough for snow, mainly over the higher elevations along the Tennessee border.

Weak sfc high pressure will linger over our area today, allowing high temperatures to remain about 6 to 10 degrees above normal. At the same time, the large-scale pattern begins to change as steep upper ridging builds to our west, while broad/deep upper trofing develops downstream over the eastern CONUS. Meanwhile, a sfc low forms just south of the Great Lakes and tracks east then northeast Thursday into Friday. The associated cold front is expected to move thru our area on Thursday as the low lifts further NE. Overall, little if any precip is expected outside of the NC mtns for Thursday and Friday. The coldest air so far this fall is expected to spread over our area from Canada by late week. Although this airmass will be relatively dry, NW flow winds and lingering low-lvl moisture along the NC/TN border will increase the chances for the season's first snow. The latest model guidance still suggests that most of the NC/TN border region will get an inch of snow or less. Nonetheless, the most favored areas such as northern Swain County, could get isolated amounts up to 4 inches or so. If moisture ends up lingering longer over these areas, they can expect an uptick in snow amounts. If moisture is lacking, they will get less snow. At present, it still appears that a Winter Wx Advisory will not be needed for any of our zones. If fcst snow amounts and/or coverage increases, an Advisory could be needed.

Key message 2: Gusty winds and colder temperatures linger behind a strong cold front Thursday through the weekend.

Broad/deep upper trofing will persist over the eastern CONUS from Thursday thru the first part of the weekend. Broad sfc high pressure centered well to our NW will maintain a tightened pressure gradient across our area, creating gusty winds from early Thursday thru late Saturday. Wind gusts are expected to be notably stronger over the NC mountains (compared to our lower terrain) during this period, however the latest guidance keeps wind gusts below Wind Advisory criteria of 46 mph. Going forward, if the pressure gradient becomes tighter, fcst wind speeds will likely increase and a Wind Advisory may be needed for some areas. Overall, the higher peaks and ridgetops have a better chance of seeing 40 to 50 mph wind gusts, elsewhere it looks pretty unlikely.

In addition, this amplified synoptic pattern will bring the coldest temperatures so far this season to our fcst area. The latest model guidance still has the coldest temperatures Saturday night into Sunday morning with lows at or below freezing (ie, 32 degrees) across most of our area. Highs from Friday thru early next week are also expected to remain below normal for mid-November. As a reminder, the growing season is considered done after November 11th and no freeze products will be issued for any part of our fcst area after this date.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/

At KCLT and elsewhere: VFR through the period at all terminals, once again. The light/variable wind will continue through the better part of the morning before a SW direction is established by early afternoon as the next weather system approaches. The flow actually improves late in the day and into the evening hours to where some of the Upstate terminals could have occasional gusts from the SW. Any threat of low clouds should hold off until after 12Z Thursday.

Outlook: A cold front may bring precipitation and associated restrictions Thursday into Friday, mainly over the mountains.

GSP WATCHES/WARNINGS/ADVISORIES

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