112619 Forecast

Weather Headlines

Rime formation continues on this Thanksgiving morning for highest elevations in the High Knob Massif (riming for the past 6-hours as of 10 AM). For visitors to the High Knob Lookout, expect wind chills in the single digits and 10s, in gusts, with temperatures in the 20s under a strong low-level inversion.

ALERT For HIGH Winds Continues Along The Blue Ridge In Cross-Barrier Flow

A strong low-level jet streak moving up along the western side of the Appalachians will cause high winds to develop into the predawn to morning hours of Wednesday (27 November).

850 MB Streamline Flow Field_USA

**NAM 12 KM Model_850 MB Wind Speed-Streamlines_7 AM Wednesday_27 Nov**

Wind gusts of 40 to 50+ mph will be likely, amid what looks to be a nearly classic high wind setting within a developing dry slot of a strong mid-latitude cyclone.

250 MB Streamline Flow Field_USA

It does not take a meteorologist to tell what directions will be favored if you, your family, or friends are flying across the USA during this Thanksgiving holiday.

**Classic Mid-latitude Cyclone High Wind Setting**

Peak reported wind gusts along the Appalachians are likely to reach 60 to 100 mph, with the potential for places like Grandfather Mountain to top 100 mph during this event.

Hurricane force wind gusts will become possible on highest peaks, with hunters in the woods and visitors to places like the High Knob Lookout Tower urged to exercise extreme caution. Dense clouds and wind driven rains will also occur prior to the arrival of dry air within the cyclone’s dry slot.

**Classic High Wind Setting In Developing Dry Slot of Mid-Latitude Cyclone**

Due to a unidirectional flow developing aloft, with 100 knot winds at 500 MB and 130+ knot winds at upper-level jet stream levels, I have extended the alert for high winds through Wednesday into the evening due to turbulent mixing enhanced by abundant afternoon sunshine.

The strongest low-level jet winds, blasting high peaks, will be during the 4 AM to 10 AM period, with strong wind gusts mixing downward into all elevations at times during the daylight and early-mid evening hours. High winds with downward transfer from upper jet stream levels and local channeling (such as through the gaps on Grandfather Mountain, Fancy Gap, and High Knob) and wave breaking will become a concern.

Turbulent mixing will begin to diminish after sunset along the western side of the Appalachians, but will continue along the eastern slopes of the mountain chain as a positive mountain torque is strengthened by a developing cross-barrier pressure gradient Wednesday night into early on Thanksgiving day.

**NAM 3 KM Model_850 MB Wind Speed-Streamline Forecast_3 AM Thanksgiving**

Folks traveling north and east should be alert to strong cross-winds on portions of I-81 and I-77 (Fancy Gap), along with other roadways.

**Updated_Actual High Wind Reports

High Wind Reports_NWS And Research Stations
(27 November to 9:00 AM 28 November)

#Grandfather Mountain, NC: 97 MPH

(# 81.2 MPH sustained winds recorded at 4:39 AM 28 Nov)

1 NNE West Jefferson, NC: 71 MPH

2 NNE Snowshoe, WV: 67 MPH

5 E Canaan Heights, WV: 65 MPH

4 WNW Rugby, VA: 64 MPH

1 NE Bent Mountain, VA: 61 MPH

Jefferson, NC: 61 MPH

4 NW Wintergreen, VA: 60 MPH

Pikeville 13S, KY: 57 MPH
(Adjacent to Pine Mountain)

Burkes Garden, VA: 56 MPH

Boone, NC: 56 MPH

1 SE Marion, VA: 51 MPH

Lonesome Pine Airport: 40 MPH

Updated – The Next Snowfall Potential

A Recap Of Recent Wintry Events_Lingering Autumn Color

The potential for significant snow accumulations in the mountains, with snow squalls and bursts of heavy snow, on Great Lake connected NW upslope flow is increasing for the December 2-3 period.