My Forecast For Today ( February 8 )
ALERT For Accumulating Snow Today Into Thursday Morning With Bitterly Cold Temperatures-Wind Chills During Tuesday Into Thursday. This Pattern Is Likely To Continue Through This Weekend Into Next Week To Mark A Harsh Period Of Winter In The Appalachians.
Although No Official Winter Storm Warning Has Been Issued For Wise County by MRX, Let There Be No Doubt That Conditions Tonight Into Tuesday Will Be Just As Bad Or Worse Than In Any Of The Tennessee Mountain Counties, That Currently Are Under A Warning, Amid The Norton-Wise & High Knob Massif Area
New high-resolution model runs are playing down the AM snow, via dry low-levels, despite a healthy looking Doppler to the west. As noted in my weather discussion, models will struggle in this type of pattern on daily details.
A break in activity will be possible behind any morning snow before new development begins Monday afternoon. Due to very cold air aloft, bursts of heavy snow ( amid general snowfall ) will be capable of producing whiteout conditions at times from this afternoon into Tuesday-Wednesday. Increasingly bad conditions are expected as air turns bitterly cold Tuesday & Wednesday, with the worst conditions likely to develop along W-NW facing slopes and interior crests of the High Knob Massif & Black Mountain.
Overnight Into Mid-Morning
Increasing clouds into morning with a chance for a period of snow. SSW to SW winds 5-15 mph, with higher gusts, along middle elevation ridges & plateaus below 2700 feet. SW to WSW winds increasing to 10-20 mph, with higher gusts, along upper elevation mountain ridges above 2700 feet. Temperatures mostly in the 20s to lower 30s. Wind chills in the 10s & 20s ( coldest highest elevations ).
Mid-Morning Through Monday Afternoon
Any AM snow giving way to a break. Then snow showers and snow squalls developing during the afternoon ( possible mixture at lower elevations, especially Russell Fork & Levisa Fork basins ). SW winds shifting W at 5-15 mph, with higher gusts along mid-upper elevation ridges & plateaus. Temps varying from 20s at highest elevations to the mid-upper 30s. Wind chills in the 10s & 20s across upper elevations.
Tonight Into Tuesday Morning
Light snow, snow showers & bursts of heavy snow. Turning bitter into morning. W-WNW winds 10-20 mph, with higher gusts, on mid-upper elevation mountain ridges & plateaus. Temps dropping into low 10s at highest elevations and into upper 10s to low-mid 20s at lower-middle elevations. Wind chills dropping into single digits & 10s, except 0 to -10 below zero at highest elevations in the High Knob Massif & Black Mountain. Extensive rime formation at highest elevations.
Snowfall Forecast – Monday Through Thursday AM
A general 6″ to 12″+ along upslope side of mountains
3″ to 6″ on downslope side of mountains
Target snowfall of 8″ in Norton-Wise ( +/- ) 2″ Error Potential. This implies a potential for 6″ to 10″ of snowfall. Snow depths at any given time, outside of drifting, are expected to be less than total snowfall by 1-3″ due to melting-sublimation-settlement.
Extreme snowfall totals are expected to vary from more than 12″ amid highest elevations in the High Knob Massif to 3″ or less in portions of the Tennessee Valley ( downslope of mountains ).
This snowfall will occur over a prolonged period of time and generally be of low to very low density ( fluffy ). This tends to enhance settlement over time as snow depth increases. Note snowfall totals are between Monday AM and Thursday AM ( i.e., snowfall totals by Thursday Morning are currently projected to reach forecast values ).
A prolonged rime event is expected for upper elevations, above 3300 feet, in the sprawling High Knob Massif where significant accumulations are likely during the next few days.
Stay tuned for updates on this preliminary forecast.
Weather Discussion ( February 8 )
My Afternoon Update
New model runs into the overnight were correct in playing down the morning snow, with no more than flurries as low level air remained dry.
No more than a dusting was on the ground atop the High Knob Massif at early afternoon. That would soon change!
Whiteout conditions developed in the Norton-Wise, Sandy Ridge and High Knob Massif area amid wind driven snow.
The mountain landscape was quickly transformed into a wintry wonderland, but at the price of catching motorists who had not kept up with my forecast of blinding snow squalls off-guard.
This snow covered middle-upper elevations above 2000 feet, with sticking and melting to the northeast in lower elevations of the Russell Fork Basin ( Pound-Clintwood ).
Temperatures which spiked to 40 degrees amid the “break” into mid-day have now quickly dropped below freezing at all elevations above 2000 feet along and north of the High Knob Massif ( low 20s atop High Knob, with NW wind gusts to 30 mph generating WCFs down to around 5 degrees above zero at 4:00 PM amid riming ).
Focus now shifts to new convective bursts developing beneath bitterly cold air aloft to the west, with conditions expected to become extremely bad across the mountain area this evening into the overnight period in advance of a very compact vorticity max and excellent divergence ( diffluence of isobaric contours ) aloft ( the echoes across middle KY & middle TN will tend to intensify along the Cumberlands ).
Low-level temperatures will be dropping to enhance the bad conditions expected tonight into Tuesday morning. Caution is advised for anyone planning to travel during this time.
Orographic pilatus clouds capping the high country of the High Knob Massif is a signal for enhanced snowfall ahead, via riming of snowflakes and increased volume of snow reaching the ground.