Weather Headlines

ALERT For Strong S-SW Winds Developing Overnight Through Saturday Afternoon

Strong SW winds blowing now at upper elevations in the High Knob Massif will increase overnight into Saturday and mix downward across middle into the lower elevations. Wind gusts of 30-50 mph will become widespread, with higher gusts to hurricane force at highest elevations in the High Knob Massif. Local tree damage and power outages will be possible.

*Seasonally cold conditions will be felt tonight through Friday night

*An alert for High Winds will be likely for Saturday (January 18)

*A colder pattern next week features arctic air from Sunday through early week

*The Snow Drought (from 2019) looks to continue with light amounts expected at this time. A few ensemble members are predicting significant snow, but the majority are not. Stay tuned.

Short-Term Forecast

Thursday Night Into Friday Morning

High clouds. NW-NE winds 5-15 mph, with some higher gusts, on mid-upper elevation mountain ridges-plateaus. Temps falling into the 20s, except 10s within the colder mountain valleys and on coldest mountain ridges. Wind chills falling into the 20s, except single digits and 10s on mid-upper elevation mountain ridges (locally sub-zero on highest peaks, such as at the High Knob Lookout).

Cold air transport will continue near the surface into early hours of Friday (the coldest transport centered around 925 MB) as warm air advection begins aloft (high clouds), and on highest mountain ridges into sunrise. Turbulent mixing will oppose decoupling, but frictional terrain drag below an increasing inversion within the 875-775 MB layer should allow many valleys to decouple with developing drainage flows into the overnight.

Increasing high clouds aloft will hinder OLR into the predawn-sunrise period, such that cooling conditions will not be ideal despite the advected presence of very dry (very low dewpoint) air within cold air drainage source locations of the higher mountain terrain during Thursday night into Friday morning.

Friday Afternoon

High & mid-level clouds. Seasonally cold. Easterly winds becoming SE to S at 5-10 mph, with higher gusts. Temps varying from the 30s to low-mid 40s. Wind chills in the 20s and 30s on higher mountain ridges.

Friday Night Into Saturday Morning

Cloudy. A chance of freezing rain or sleet by morning. Becoming windy (beginning on highest ridges and mixing downward into middle-lower elevations into morning). Large vertical temperature spread developing initially between decoupled mountain valleys (light to calm winds) and increasingly windy mountain ridges.

Strong evaporative cooling in a dry low-level air mass will have the potential of causing enough cooling for freezing rain and/or sleet-snow at the onset of precipitation. This will be especially true if precip onset is early Saturday. A more widespread array of frozen precipitation is expected initially along the eastern slopes of the Blue Ridge (reference any SPS or advisories).

SSE-S winds increasing to 10-25 mph, with higher gusts, on mountain ridges & exposed plateaus below 2700 feet. S-SW winds 20-35 mph, with higher gusts, on mountain ridges above 2700 feet. Temps mainly in the 30s, locally colder in sheltered valleys and highest windward facing mountain ridges. Wind chills in the 20s and 30s, except 10s at highest elevations.

Saturday Morning Through The Afternoon

Windy. Rain showers developing. Local downpours, especially in upslope locations. S-SW winds 15-35 mph, with higher gusts (gusts over 50 mph will be possible). Temperatures varying from the upper 30s to upper 40s. Wind chills in the 20s and 30s (coldest high elevations). Areas of fog developing, becoming widespread at high elevations during afternoon-early evening).

Rain will be wind driven in strong upslope flow at mid-upper elevations. This will enhance rain amounts within orographic forcing zones of the High Knob Massif-Black Mountain corridor.

Saturday Night Into Sunday Morning

Windy and turning colder. Evening showers, then a chance of flurries and light snow showers overnight into morning. SW winds shifting WNW at 10-25 mph, with higher gusts. Temps dropping into the middle 10s to mid-upper 20s (coldest at highest elevations). Wind chills single digits and 10s (sub-zero in gusts along highest peaks).

Wind chills will become dangerous to those unprepared at mid-upper elevations during Sunday into Monday. Caution is advised. Riming is expected at highest elevations during much of this period.

Extended Forecast Period

A push of bitter arctic air will arrive this weekend into early next week, with cold air advection beginning Saturday Night into Sunday (January 18-19).

Although some snow showers and flurries will be possible, a Great Lake connection may be too short-lived for significant snow in upslope locations of the southern Appalachians. This will be a trend to follow, given that the Great Lakes are essentially ice free and could be very productive snow squall-plume producers with the right, prolonged flow pattern (which has been limited for the southern Appalachians from last winter up to now).

The coldest air mass will be in place Monday into early Tuesday (January 20-21), with single digits on upper elevation mountain ridges (not including wind chills). Snow cover would make this much more potent, while the lack of snow will help moderate the air mass.

The European Model predicts a rebound to above average temperatures by the middle to end of next week. This is due to a progressive air flow pattern across the Northern Hemisphere, with no high latitude blocking in the right location to lock the colder pattern in place.

The GFS Ensemble Mean maintains colder air along the Appalachians to the Atlantic Coast (above) with more upper troughing versus more ridging (below) on the European Model Ensemble Mean.

The GFS Ensemble Mean says the 10-15+ day period will also trend colder again. Stay tuned for later updates.