021017 Forecast

Mountain Area Forecast ( Feb 10-12 )

ALERT For Strong SW Winds From Late Friday Afternoon Into Saturday For The Cumberland Mountains ( Wind Gusts 30-50+ MPH )

Strong SW winds will develop Friday PM into Friday Night, with ROARING speeds at middle-upper elevations as strong warm air transport occurs.  Strong winds, with mountain waves, are also likely in lower elevations of the Pound to Clintwood corridor.  
Although 30 to 50 mph gusts are expected, local wind gusts could top 60 mph at highest elevations in the High Knob Massif.  Windy conditions will continue through this weekend at high elevations.

Overnight Into Friday Morning

Partly cloudy ( high altitude ice crystal clouds ).  Light and variable winds generally less than 10 mph along mid-upper elevation mountain ridges.  Temperatures widespread in the 10s, with single digits in colder mountain valleys of middle-upper elevations.

Friday Afternoon

Becoming partly-mostly sunny & windy.  SSW-SW winds increasing to 10-20 mph, with higher gusts, on mountain ridges & plateaus below 2700 feet.  SW winds 15-25 mph, with higher gusts, on mountain ridges above 2700 feet.  Temperatures in the 30s to low-mid 40s.  Wind chill factors in the 20s and 30s, except 10s in gusts at highest elevations.

Friday Night Into Mid-Morning Saturday

Partly to mostly clear.  Increasing clouds toward morning with a chance of rain showers.  Windy.  SSW-SW winds 25-35 mph, with higher gusts of 40 to 50+ mph.  Temperatures mostly in the 30s and 40s ( steady or slowly rising at high elevations and locally colder in valleys with calm winds ).  Wind chills in the 20s & 30s ( coldest high elevations ).

Saturday Afternoon

Cloudy.  A chance of rain showers.  Gusty.  SW winds 5-15 mph, with higher gusts, along mountain ridges-plateaus below 2700 feet.  SW-WSW winds 15-25 mph, with higher gusts, on mountain ridges above 2700 feet.  Temps in the 40s to around 50 degrees.  Dense fog developing within upper elevations.

Saturday Night Into Sunday Morning

Low clouds and showers.  Areas of dense fog, widespread amid upper elevations.  SW winds 10-20 mph, with higher gusts, along mountain ridges-plateaus below 2700 feet.  Winds WSW-SW at 15-25 mph, with higher gusts, along mountain ridges above 2700 feet.  Temperatures steady or rising into the 50s in most locations ( upper 40s to around 50 degrees within cooler places ).

The potential for a winter storm with a Great Lake connection into the southern Appalachians is being monitored for the February 15-16 period.  Stay tuned for later updates.


Weather Discussion ( Windy )

My late evening update is to increase sustained wind speeds which are topping 30 mph in Wise and on mountain ridges, with occasional strong gusts into lower elevations around Pound and Clintwood.

Lonesome Pine Airport In Wise – Very Strong SW Winds

It takes a stout tripod to shoot tonight!

Full Moon Rises Over Windy Cumberlands – Late Evening of February 10, 2017


Previous Discussion

The up and down pattern rolls forward with the latest plunge featuring a general 1″ to 3″ of snow across upper elevations in the High Knob Massif.  It was literally a transition from thunderstorms to snow in short order.

Snow occurred without any direct and sustained connection to the Great Lakes, as surface to 850 MB flow trajectories missed the area toward the northeast.  Next week, if the European Model group is accurate, another storm will produce a Great Lake connection that finally reaches the southern Appalachians.  IF that actually occurs then snow amounts will be more significant even though current models do not yet recognize it ( very limited Great Lake moisture has so far been observed in this 2016-17 snow drought season ).
At this time of year a set up like next week might feature a huge winter storm, if northern and southern jet stream waves were to phase; however, at this time, models are keeping those separated until energy reaches the Atlantic Coast where formation of another important Nor’easter occurs.
Snow Depth Of 2″ In High Chaparral of High Knob Massif At 9:46 AM February 9, 2017

Most of the surrounding area reported 1″ or less of snow.

Preliminary Snowfall Reports

UVA-Wise: 0.3″

Clintwood 1 W: 0.4″

Nora 4 SSE: 0.9″

City of Norton Water Plant: 1.3″
( 1″ ground )

High Chapparal of High Knob Massif: 2.0″
( 2″ ground )

Eagle Knob of High Knob Massif: 2.7″
( 1″ to 4″+ ground )

Orographic Wave Clouds Over High Knob Massif – Late PM of February 8, 2017
While it is common for orographic clouds to cap upper elevations amid the High Knob Massif, they also develop & dissipate at times as the crests and troughs of their wave form “flow” or translate across the massif.  I experienced this during the afternoon hours of February 8, well ahead of showers-thunderstorms, with a gush of strong wind carrying dense fog ( clouds ) across the sprawling crest to reduce visibility to mere feet for a while before the wave trough, with subsiding air, would arrive to dissipate the low-level orographic cloud.  Then, after a period of time, the next wave of clouds would build and overspread the high country.
It is possible that this was connected to a higher level wave train; although, without profiler data it was not possible to be certain.  I did observe many waves above the low-level orographic clouds, to include stacked lenticular forms at times.
In Between Orographic Cloud Wave Crests – Late Afternoon of February 8, 2017

Watching the clouds blowing into and across the crest zone in swirling sheets, it was easy to envision how the snow would soon do the same into February 9.  And it did!

European Model 850 MB Temperature Anomalies At 7 PM Wednesday ( Feb 8 )

Snow was minor compared to the HUGE temperature change that occurred as part of this ongoing pattern dominated by UP and DOWN swings.

If considering wind chills, of course, the actual feels-like conditions were even more impressive than these charts   indicated between February 8 and February 9.
European Model 850 MB Temperature Anomalies At 7 PM Thursday ( Feb 9 )
This has been an atypical winter season.  Temperatures tonight have dropped into single digits in high valleys of the High Knob Massif, as they did during February 4, yet conditions are still not prime for ultimate MINS with high clouds developing during a very progressive ( restless ) weather pattern.

Now the focus turns to WIND and plenty of it from Friday through this weekend, with strong winds dominating this period across the mountains.  Initially this wind will keep conditions feeling cold, but eventually milder air wins out yet again as rain showers, low clouds, and areas of dense fog develop this weekend.