The Storm Prediction Center Has Issued A Slight Risk For Severe Thunderstorm Development Wednesday Afternoon-Evening Into The Overnight ( With An Enhanced-Moderate Risk Toward The Southwest )
Storm Prediction Center Risk Regions ( Updated 2:05 AM on April 5, 2017 )Storm Prediction Center Summary Discussion
Stay tuned to NOAA Weather Radio and your favorite media sources for Watches and Warnings that may be needed later Wednesday into Wednesday night.
The Potential For Accumulating Snowfall Is Also Being Monitored For Thursday Into Friday ( Significant Snow Amounts Will Be Possible, Especially At The Middle To Upper Elevations Above 2500 to 3000 Feet ).
Overnight Into Tuesday Morning
Showers likely. A chance of thunder. SSW to WSW winds increasing to 10-20 mph, with higher gusts ( especially on middle to upper elevation mountain ridges. Temperatures widespread in the upper 40s to mid-upper 50s. Dense fog on high mountain ridges ( widespread in High Knob Massif ).
Tuesday Afternoon
Partly to mostly sunny. Warm. SW-W winds 5-15 mph, with higher gusts. Temperatures varying from lower-middle 60s in upper elevations to the lower-middle 70s.
Tuesday Night Into Wednesday Morning
Partly to mostly clear. Light winds. Large vertical temp spread between colder valleys and milder ridges. Temps varying from 30s to lower 40s in colder valleys to the lower-middle 50s along exposed ridges.
Wednesday Afternoon
Partly sunny ( high clouds ). Warm & windy. A chance of hit-miss afternoon showers & thunderstorms ( any storms could become strong to severe ). SSE to S winds 10-20 mph, with higher gusts. Temperatures varying from 50s at highest elevations to the upper 60s to middle 70s.
Wednesday Evening Into Thursday Morning
Showers & thunderstorms. Some storms could be strong to severe. Downpours likely. Widespread dense fog ( capping orographic clouds ) at upper elevations in High Knob Massif. Winds shifting SW & increasing to 10-20 mph, with higher gusts. Turning colder by morning. Evening temperatures widespread in the 50s, then dropping into the 40s and 30s by morning ( coldest at upper elevations ).
Rain showers will change to snow showers at highest elevations in the High Knob Massif during Thursday morning, with snow levels dropping during the day into middle and perhaps lower elevations ( by late ) along the upslope side of the mountains. Accumulations during the day are currently expected to be mainly at the highest elevations, with sticking snow levels then dropping rapidly through middle elevations by mid-late PM into early evening.
Thursday Afternoon
Windy & turning cold. Rain showers changing to snow showers. Sticking snow levels dropping toward 2000 to 2500 feet by late. SW winds shifting WNW at 15-25 mph, with higher gusts. Temperatures falling into the 30s at lower-middle elevations, into the 20s at upper elevations, within locations along and north to northwest of the High Knob Massif-Tennessee Valley Divide ( milder to the south ). Wind chills dropping into the 10s and 20s.
Widespread snow, heavy at times, is expected along the upslope side of the mountains ( WNW-NW of the Cumberland-Allegheny Front ) Thursday evening into Friday morning. Significant snow amounts will be possible, especially at mid-upper elevations above 2000-3000+ feet.
Thursday Night Into Friday Morning
Snow & snow showers. Snow heavy at times. Windy. Cold. Winds WNW-NW at 15-25 mph, with higher gusts. Temps varying from upper 20s to lower 30s to the upper 10s to lower 20s at highest elevations ( milder lee of mountains into the Great Valley ). Wind chill factors varying from 10s to lower 20s to the single digits and 10s ( except near to below zero in stronger gusts at highest elevations in the High Knob Massif and other major mountain ranges ).
Cold night-time temperatures will continue through this upcoming weekend, especially in mountain valleys.
Weather Discussion ( Blast Of Winter )
A clash of spring and winter is the main focus for coming days, with strong-severe thunderstorms ( and a possible outbreak of severe storms ) giving way to upslope snow.
Although spring activity has been increasing in the natural world, the Ole Man Of Winter has different ideas amid this 30th Year Anniversary Week of the great April 2-5, 1987 snowstorm that buried the mountain landscape.
Yellow Tulips ( Tulipa spp. ) of John & Mae Mullins Gardens – April 2, 2017
The April 2-5, 1987 snowstorm produced snow depths of 20″ to 26″ in Clintwood ( total fall was 33.8″ ). Gary Hampton reported 3 feet of snow depth at the City of Norton Water Plant, at the base of the High Knob Massif, with electrical engineer Carl Henderson, of Blue Ridge Public Television, reporting 2-6 feet ( 4 feet average ) depths on Eagle Knob of the High Knob Massif.
Honey Bee ( Apis spp. ) Working A Pussy Willow ( Salix discolor ) – April 2, 2017
Although snowfall amounts are not expected to be anything like April 1987, it is certainly possible that 6″ to 12″ of snow could fall in upper elevations of the High Knob Massif. It remains too early to forecast exact amounts, but the signal and pattern is very strong and has been consistent among ensembles and operational runs of medium range models for a strong orographic upslope event ( where snowfall is enhanced along the windward side of the mountain chain via forced convergence and upward rise of air on WNW-NW flow streaming from a Great Lake’s moisture source ).
As is almost always the case at this time of year, this will be an elevation biased event ( greatest snowfall amounts will be at the highest elevations ) with decreasing sticking & snow amounts as elevation decreases. In addition, at all elevations, more snow will tend to fall than is ever able to remain on the ground at any given time during the event.
Due to strong inverse orographics ( i.e., negative forcing ) lee of the major mountain barriers, snowfall and amounts are expected to be very limited downstream of the High Knob Massif-Tennessee Valley Divide and Blue Ridge.
As already noted above, please stay tuned for updates and possible changes in this scenario.
Storm Prediction Center Risk Regions ( Updated 2:05 AM on April 5, 2017 )
Meanwhile, the front end of this next storm system will again bring showers and thunderstorms with an enhanced to moderate risk from southern Kentucky through southern Tennessee. A slight risk is now outlooked across much of the Mountain Empire. Note that this could change again depending upon how activity develops Wednesday.
Stay tuned to NOAA Weather Radio and your favorite media sources for Watches and Warnings that may be needed later Wednesday into Wednesday night.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Nice orographic clouds during Monday afternoon ( March 3 ), with capping pilatus ( above ) and multiple wave clouds ( below ) on SW air flow trajectories streaming into & across the High Knob Massif.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Chilly Conditions Are Expected To Continue Through Saturday Into Sunday Morning
Overnight Into Friday Morning
Showers & thunderstorms developing. Downpours likely. Windy. SSE to SSW winds 10-25 mph, with higher gusts, shifting SW by morning. Temperatures in the 50s to lower 60s, dropping into the upper 40s to middle 50s by morning. Coolest at highest elevations.
Friday Afternoon
Mostly cloudy and cooler. Chance of hit-miss showers. Low clouds ( fog ) at the highest elevations. Winds WSW-WNW 10-20 mph, with higher gusts. Temperatures in the 50s to around 60 degrees at lower-middle elevations and in the 40s to around 50 degrees at upper elevations ( along and northwest to north of the High Knob Massif-Tennessee Valley Divide ).
Friday Night Into Saturday Morning
Cloudy and chilly. A chance of light showers or drizzle. Low clouds with dense fog at upper elevations. WNW-NW winds 5-15 mph, with higher gusts. Temperatures dropping into the low-mid 30s to low-mid 40s ( coolest within the highest elevations ). Wind chills in the 20s and 30s along mid-upper elevation mountain ridges.
The potential for low-level temperature inversion development is being monitored for Saturday. An inversion would hold low clouds ( dense fog at upper elevations ) over the mountain area through the day Saturday, with unseasonably cold conditions.
If the inversion mixes out ( breaks up ) conditions will turn partly cloudy and temperatures will be somewhat milder with sunshine.
Saturday Afternoon
Low clouds ( dense fog at upper elevations ). Chance of drizzle. Unseasonably cool. NW to NNW winds 5-10 mph, with higher gusts. Temperatures hovering in the 30s and 40s to near 50 degrees. Coldest at highest elevations.
Saturday Night Into Sunday Morning
Becoming partly cloudy to clear. Areas of dense fog at low-middle elevations. Frost and freezing conditions in higher mountain valleys ( above 2500-3000 feet ). Winds N-NE at 5-10 mph, with higher gusts, on middle to upper elevation mountain ridges. Temperatures varying from 20s in colder valleys at higher elevations to readings rising into the 40s along highest mountain ridges ( otherwise, temperatures widespread in the 30s ).
*The potential for an unseasonably cold, wintry pattern is being monitored for the April 6-10 period. Stay tuned for updates.
Weather Discussion ( Changeable )
The dawn of mid-spring, with April marking the middle month of Meteorological Spring, is looking to feature a changeable weather pattern. Everything from spring thunderstorms to snow could occur in the mountains.
Bloodroot ( Sanguinaria canadensis ) Begins Blooming On March 29, 2017
Certainly such radical swings in weather conditions are typical in the mountains at this time of year. Past climatology is full of all weather types, from record warmth to big falls of snow…such as observed during the great snowstorm of April 2-5 in 1987.
The next few days are likely to serve up quite a range in weather conditions, from warm winds and overnight showers and downpours in thunderstorms to chilly air Friday night through Saturday into Sunday morning.
HRRR Model Rainfall Forecast Next 15-Hours ( To 11:00 AM Friday – March 31 )
Beyond the potential for some thunderstorms to be strong or locally severe during the overnight, the most uncertain aspect of this short-term forecast period will be Saturday when some high resolution models are showing a rather classic low-level inversion setting. If this develops it will trap low clouds over the mountains, with reinforcement by low-level N-NE upslope flow into the Cumberland range, to generate unseasonably cool ( cold ) conditions.
NAM Model Forecast Sounding Above Norton At 11:00 AM Saturday
Observe how the RED temperature line meets the GREEN dewpoint line on the left side of this forecast sounding ( above left ), with a SHARP turn to the right by the RED line. This sharp right turn is a rise in temperature to mark the inversion whose bottom is shown just above the 850 MB level ( the top being around 800 MB to make the inversion layer at least 50 MB thick or 1600 feet in this case ).
By 8:00 PM Saturday ( below ) the RED-GREEN temp-dewpoint line meet only within a thin layer, increasing the chance that by this time ( before or after ) the cloud layer will mix out or break up. All the dry air above signals that high mountain valleys will be prone to frosty conditions into Sunday morning, with lower to middle elevation valley frost dependent upon whether fog forms or not.
NAM Model Forecast Sounding Above Norton At 8:00 PM Saturday
Morning lows in the 30s to lower 40s ( 41 degrees in Clintwood ) into morning hours of March 30, within colder mountain valleys, signals that air cold enough for frost and sub-freezing conditions could be felt by Saturday Night into Sunday morning; however, at this time it looks most likely in higher valleys where formation of fog will be less likely ( at elevations above 2500-3000 feet ). This will need to be updated for valleys at lower elevations.
European 51-Member Ensemble MEAN 500 MB Height Anomalies: Days 6-10
A temporary flip in the pattern across North America is looking more likely by the 6-10 day forecast period, with unseasonably cold conditions possible. This is a trend that will need to be monitored through coming days as it would mean widespread sub-freezing conditions and even some late season snowfall ( i.e., should it evolve as currently shown by the Ensemble Mean ).
European 51-Member Ensemble MEAN 850 MB Temp Anomalies: Days 6-10
There is plenty of time for changes to occur in this extended pattern that might move it away from such a cold solution, so be sure to check back for later updates.
Mostly cloudy with a chance of showers. Thunder possible. Winds S to SW at 5-15 mph, with higher gusts, on mountain ridges & plateaus below 2700 feet. Winds S-SW 10-20 mph, with higher gusts, on mountain ridges above 2700 ft. Mild with temperatures varying from the mid-upper 40s to the middle 50s ( except chilly at highest elevations with dense fog and wind chills in the upper 30s to lower 40s ).
Tuesday Afternoon
Mostly cloudy. A chance of showers. Winds shifting WNW-NW at 5-15 mph, with higher gusts. Temperatures varying from 50s in upper elevations to the mid-upper 60s.
Tuesday Night Into Wednesday Morning
Mostly cloudy. Low clouds ( dense fog ) at the highest elevations. A chance of showers. Winds N-NE at 5-10 mph. Temperatures in the 40s to around 50 degrees. Wind chills in the 30s at highest elevations.
Wednesday Afternoon
Partly cloudy. Light NNE-NE winds. Temperatures varying from the 50s to low-mid 60s ( around 50 degrees at highest elevations in the High Knob Massif ).
Wednesday Night Into Thursday Morning
Partly to mostly clear. Winds becoming SE-S at 5-15 mph, with higher gusts, on mid-upper elevation mountain ridges. Large evening temperature spread developing between cool valleys and milder ridges. Temperatures dropping into the 30s in colder valleys versus near steady or rising temps in the 40s to low 50s on exposed mid-upper elevation ridges.
Strong SSE-SSW winds are expected to develop during Thursday afternoon into Thursday night in advance of the next round of showers and thunderstorms.
Weather Discussion ( Stormy Pattern )
A stormy spring pattern will continue at times through this week into next week as the seasonal transition is underway.
Coltsfoot ( Tussilago farfara ) In Bloom On March 27, 2017
Although April 15 to May 15 is typically the most explosive period within the mountains for spring rebirth, numerous species of flora and fauna are beginning to become more visible ( especially at lower-middle elevations ).
MIN temperatures dipped to 0 degrees on March 16, and into the 10s on March 23, in high valleys of the High Knob Massif where spring is typically slow to emerge.
Big Cherry Wetland Valley of High Knob Massif – March 22, 2017
Somewhat cooler air will be felt on northerly winds Tuesday into Wednesday before the next upward surge of wind and temperatures occur Thursday in advance of the next round of showers and thunderstorms to close out the week.
Following a break, another significant system is likely next week with more showers-storms. A shot of colder air will be possible by the middle-end of next week ( typical for April ).
NWS Precipitation Analysis-Estimate Past 21 DAYS
Although the above NWS Precpitation Analysis-Estimate is too low for the High Knob Massif area, where up to 6.00″+ has fallen in March, the gradient is generally correct with portions of Dickenson County being smoky over the past weekend due to wild fires ( March precipitation totals of 3.00″ or less in places ). So a wetter pattern is generally good news for the mountain area as a whole.
Mostly clear. Large vertical temperature spread between colder valleys and milder mountain ridges. SW-W winds generally under 10 mph along mid-upper elevation ridges. Temperatures varying from upper 10s to mid 20s in colder valleys to the 30s on exposed mountain ridges.
Monday Afternoon
Increasing clouds. Milder. SSW-WSW winds 5-15 mph, with higher gusts. Temperatures varying from low-mid 50s in upper elevations to the lower-middle 60s.
Monday Night Into Tuesday Morning
Cloudy & windy. A chance of showers & thunderstorms developing overnight into morning. SSW to WSW winds increasing to 10-20 mph, with higher gusts, at elevations below 2700 feet. SW-W winds 15-25 mph, with higher gusts, on mountain ridges above 2700 feet. Temps widespread in the upper 40s to middle 50s. Fog becoming dense at high elevations with orographic clouds.
Due to a quicker frontal passage, showers and thunderstorms will mainly be south of the Cumberland Mountains, with low clouds and fog not expected to be as much of a factor.
Tuesday Afternoon
Partly cloudy and unseasonably warm. A chance of hit-miss showers and thunderstorms. Winds NW-N at 5-10 mph with some higher gusts. Temps from low-mid 50s at highest elevations to the lower-middle 60s.
Tuesday Night Into Wednesday Morning
Partly to mostly cloudy. Turning chilly. Winds N at 5-15 mph, with higher gusts. Temperatures dropping into low-mid 20s to the low-mid 30s. Wind chill factors in the 10s and 20s ( coldest at highest elevations ).
Wednesday Afternoon
Mostly sunny. Chilly. Winds N-NNE at 5-15 mph, with some higher gusts. Temperatures varying from the 30s in upper elevations to the middle-upper 40s ( only low 30s at highest elevations within the High Knob Massif ). Wind chill factors in the 20s and 30s ( coldest at highest elevations ).
Wednesday Night Into Thursday Morning
Mostly clear. Cold. Some high clouds possible overnight into morning. Large vertical temperature spread forming between colder valleys and milder ridges. Winds shifting SE-SSW at 5-10 mph, with some higher gusts, along mid-upper elevation mountain ridges. Temperatures varying from 10s to lower 20s in colder valleys to the lower 30s on exposed mountain ridges.
Weather Discussion ( Spring Pattern )
A shift from a winter dominated pattern into one featuring early spring conditions ( with UP-DOWN temp fluctuations ) is expected through the next week to ten days as the mean upper air ridge position shifts back toward the western portion of North America.
Eagle Knob of High Knob Massif At 10:19 AM Sunday – March 19, 2017
Some light snow and a nice coating of rime decorated the high country into Sunday morning. Although cloud bases later lifted it was a chilly and mostly cloudy Sunday in the Cumberlands.
Majestic St. Patrick’s Day Sunrise Above Long Ridge of Sandy Ridge – March 17
Wayne Riner Photograph Thoughts… St. Patrick’s Day Sunrise: The sunrise color lasted only a few moments, but for those few seconds, the sun colored the world the colors of gold and yellow. Soon, gray covered the sky.
Mother Nature has blessed the mountain area with some beautiful atmospheric displays in recent days, as captured by my friend Wayne Riner ( above ) and myself below.
Majestic Sunbeams From Flag Rock Recreation Area of High Knob Massif – March 18
Light winds and a temperature of 28 degrees at 11:00 PM in Clintwood signaled, to no surprise, frosty cold conditions would rule mountain valleys into Monday morning.
Upper elevation valleys, above 2700-3000 feet, would be coldest with 10s to lower 20s versus temperatures that will hover in the 30s ( or slowly rise ) overnight into Monday morning on exposed mountain ridges.
Strengthening nocturnal temperature inversions at this time of year often signal a milder day upcoming, and such will be the case Monday to contrast with the chilly air felt Saturday afternoon and Sunday.
SW winds and sunshine before increasing PM clouds will set the stage for a temperature surge in valleys Monday as mixing breaks up the strong overnight inversion. Add in downsloping air and many valleys will experience 35-40+ degree temperature rises.
Focus by tonight into Tuesday will be on increasing winds and the development of showers & thunderstorms.
NAM 12 KM Model Total Precipitation Forecast – Next 84-Hours
As is often the case when convection begins to rule, models are not in agreement regarding where heaviest rainfall amounts will occur.
GFS Model Total Precipitation Forecast – Next 84-Hours
The MEAN of the 51-Member European Ensembles is predicting heaviest amounts across southern Kentucky into southwestern Virginia and northeastern Tennessee, which seems reasonable given the air flow and orographics.
Storm Prediction Center Convective Outlook For Tuesday ( March 21 )
Some thunderstorms could be strong to locally severe and the above graphic is expected to change with new updates.
Colder air returns later Wednesday into Thursday with more frost and below freezing temperatures expected.
ALERT For Strong SW Winds At Higher Elevations Above 2500 To 3000 Feet During Friday Night
A combination of rainfall and snow melt will make strong rises on creeks draining the High Knob Massif & Black Mountain possible by Saturday. Caution Is Advised.
Wednesday Night Into Thursday Morning
Mostly cloudy through the evening then becoming partly to mostly clear. A chance for snow flurries, especially along the upslope side of the High Knob Massif. Bitter cold. NW winds 5-15 mph, with higher gusts, below 2700 feet. NW winds 10-20 mph, with higher gusts, above 2700 feet. Temperatures dropping into single digits and 10s, coldest at upper elevations. Wind chills from 0 to -10 below at highest elevations to single digits and 10s.
Thursday Afternoon
Mostly sunny. Cold. WNW winds 5-10 mph, with some higher gusts. Temperatures varying from low-mid 20s at highest elevations to the mid-upper 30s ( milder at lower elevations with no snow cover ).
Thursday Night Into Friday Morning
Clear early then increasing mid-high clouds. Winds shifting SW-W at 5-15 mph, with higher gusts, along middle-upper elevation mountain ridges. Temperatures varying from the single digits and 10s in valleys to rising readings through the 20s to lower 30s on exposed middle-upper elevation mountain ridges-plateaus ( coldest temps within high valleys of the snow covered High Knob Massif ).
A chance for brief frozen types, in colder valleys as well as at highest elevations, will exist during mid-morning into noon.
Due to interaction with cold, snow-covered ground, fog could become extremely dense at upper elevations in the High Knob Massif later Friday into Friday Night. Caution is advised.
Friday Afternoon
Cloudy & windy. Showers developing with a chance for elevated convection. Downpours becoming possible late. SSW-SW winds 10-20 mph, with higher gusts, at elevations below 2700 feet. Winds SW to WSW 15-25 mph, with higher gusts, along mountain ridges above 2700 feet. Chilly with temps becoming widespread in the 30s to lower 40s. Dense fog forming with orographic clouds capping upper elevations of the High Knob Massif.
Friday Night Into Saturday Morning
Showers with a chance of thunder. Downpours likely. Wind driven rain upper elevations in the High Knob Massif. SW winds 10-20 mph, with higher gusts, on mountain ridges & plateaus below 2700 feet ( decreasing some by morning ). Winds SW to WSW 20-30 mph, with higher gusts, along mountain ridges above 2700 ft. Temps widespread in the mid-upper 30s to middle 40s. Wind chills in the 20s & 30s, coldest at highest elevations. Areas of dense fog, widespread at upper elevations.
Snow showers & flurries will be likely Saturday Night into Sunday Morning. Accumulations of up to 1″ will be possible above 3000 ft. Low clouds with dense, freezing fog ( riming ) will occur at highest elevations. Cloud bases will drop into the early morning hours of Sunday toward 3000 feet ( or locally lower ) before skies break.
Weather Discussion ( Recap Of Storm )
A recap of the winter storm, which was not forecast by the MRX NWSFO to strike Wise County ( pitiful job ) finds that it ranks as either a tie for the heaviest or as the heaviest event of this 2016-17 Winter Season at elevations above 3000 feet within the sprawling High Knob Massif of Wise County and northern Scott County in southwestern Virginia.**
March 13-15 Storm Snowfall-Depths ( Mean Ground Depth AM March 15 )
High Chaparral of High Knob Massif 7.0″ Snowfall ( 6″ ground depth )
Eagle Knob of High Knob Massif 10.0″ Snowfall ( 6-12″+ depths )
**Where hundreds of families live and so many more work, travel and enjoy an array of outdoor recreation.
Accumulating snow was widespread along the upslope side of the mountains, NW of the Cumberland-Allegheny Front, and spotty in nature ( as expected ) lee of the mountains into the Clinch, Powell, and Holston river valleys.
Eagle Knob of High Knob Massif At 10:18 AM March 15 ( 5 degrees with -10 to -20 WCF )
This event produced all snow at highest elevations in the massif with 5″ of accumulation into Tuesday morning ( during the wet snowfall phase ) and at least 5″ more into Wednesday morning during the dry snowfall phase ).
If anything this 10.0″ storm snowfall total is low, as many factors work together at this point in the season to reduce the snow depth which generally was in the 6″-12″+ range ( becoming wind blown into morning hours of March 15 ).
High Chaparral of High Knob Massif At 10:45 AM on March 15, 2017
Dropping downward to 3300 feet a mean snow depth of 6″ was measured in the High Chaparral community by veteran snow observes Joe & Darlene Fields on Wednesday morning. The total snowfall at this elevation was at least 7.0″ and breaks down by time periods as follows:
High Chaparral of High Knob Massif Elevation 3300 feet
*7:00 AM Tuesday: 2″ Snow Depth
5:00 PM Tuesday: 4″ Snow Depth
10:00 AM Wednesday: 6″ Snow Depth
*General 4″ to 5″ snow depths at the summit level
Snowfall into Tuesday morning ( March 14 ) was wet and fell with minimal northerly winds. Some melting and settlement occurred even within these upper elevations. It was essentially all snow at the summit level with a period of rain and rain-snow mix to wet snow in High Chaparral.
Generally no sticking occurred below 1500 to 2000 feet elevation into Tuesday morning. During the day, frequent snow showers and flurries began sticking at all elevations along the upslope side of the mountains; however, I observed sticking-melting several times in Clintwood as some sunshine ( mainly insolation through clouds ) occurred between showers.
The worst widespread driving conditions developed across Wise-Dickenson counties between sunset Tuesday and sunrise Wednesday when very cold air aloft combined with Great Lake moisture and upsloping NW winds to generate widespread snow showers-flurries and snow squalls.
High Chaparral of High Knob Massif At 10:46 AM – March 15, 2017
The January 27-30 winter storm also produced 7.0″ of total snowfall in High Chaparral to tie this event for the heaviest of the 2016-17 Winter Season ( to date ). This has, of course, been an OFF winter season with respect to snow but still this was a significant event for upper elevations.
Mean Ground Depth In High Chaparral of High Knob Massif – Morning March 15, 2017
A combination of wet snow, then dry snow and riming produced winter wonderland conditions.
Beauty In High Chaparral of High Knob Massif At 10:46 AM – March 15, 2017
Roads became so slick that even UVA-Wise closed classes for Wednesday, along with Wise County and Dickenson County where it is more common for classes to be closed.
High Knob Massif Webcam – University Of Virginia’s College At Wise
The other aspect neglected by official forecasts has been simply brutal wind chills for this time of year at higher elevations ( from Norton-Wise upward in elevation ).
High Knob Massif Webcam – University Of Virginia’s College At Wise ( Blowing Snow )
Wind chills have been in the 0 to -20 below zero range, with locally even colder values no doubt at wind prone highest locations in the High Knob Massif.
Black Mountain Mesonet – Sample Hour Ending At 9:20 AM – March 15, 2017Black Mountain Mesonet – Sample Hour Ending At 2:15 PM – March 15, 2017
The main aspect I missed in the forecast into Wednesday was the sky coverage, with mostly cloudy skies holding tough amid continuation of a Great Lake moisture plume that continued to produce PM flurries on High Knob.
A recap of models finds that the GFS did terrible on this event for the local mountains. The European picked up on the wet snowfall phase but underestimated amounts at higher elevations. It missed the dry, Great Lake moisture snowfall phase completely.
All models under-estimated the moisture advection from the Great Lakes which generated the significant snowfall during Tuesday night into Wednesday morning, with the NAM 3-4 KM picking up on the moisture plumes but under-estimating snow amounts at all elevations along the upslope side of the terrain.
Past climatology of similar events ( such as the cited March 2013 Miller B-A to bomb scenario ) once again proved to be a powerful guide to what this winter storm produced along the western front range of the mountains.
ALERT For Accumulating Snowfall For Monday Night Into Tuesday AM At Elevations Above 2000-2500 Feet
Rain & snow will develop across the mountain area Monday night, followed by a change to all snow from the top down into Tuesday morning. Snow levels are expected to drop toward 2000-2500 feet. This will be a high density ( wet ) snow, with rain-snow mix or rain expected across lower elevations.
ALERT For Bitterly Cold Temperatures-Wind Chills And Intense Bursts Of Heavy Snow Late Tuesday Into Wednesday Morning With NW Upslope Flow
Colder air and widespread snow showers and local snow squalls are expected to develop Tuesday afternoon into Wednesday AM. Bursts of heavy ( whiteout type ) snow is likely Tuesday Night into Wednesday AM with NW Upslope Flow and very cold air aloft. This will be a low density ( dry ) snow at all elevations. An additional 1″ to 4″ of snow will be possible ( areas along the upslope side of the mountains which missed the wet snow into Tuesday AM will have accumulations Tuesday night into Wednesday ).
Overnight Into Monday Morning
Partly cloudy ( high clouds ). SSE winds increasing to 5-10 mph, with higher gusts, along mountain ridges-plateaus below 2700 feet. SSE-SSW winds 10-20 mph, with higher gusts, along mountain ridges above 2700 feet. Temps from around 20 degrees in colder locations to around 30 degrees. Wind chills in the 10s & 20s along higher mountain ridges.
Monday Afternoon – Updated
Becoming cloudy. Winds SE to SSE at 5-15 mph, with higher gusts, on mid-upper elevation mountain ridges & plateaus. Temperatures varying from upper 30s to lower 40s at the highest elevations to the lower-middle 50s.
Monday Night Into Mid-Morning Tuesday
Rain changing to heavy, wet snow above 2000-2500 feet. Rain & snow at elevations below 1500-2000 feet. Light and variable winds shifting WNW to NW and increasing to 10-20 mph, with higher gusts, by morning. Temps dropping into the lower 20s to lower 30s ( coldest at highest elevations ). Wind chills from single digits & 10s at upper elevations to the 20s at middle and lower elevations.
Tuesday Afternoon-Early Evening
Mostly cloudy. Colder. A chance of snow showers-flurries. Temperatures steady or slowly falling into the 20s at mid elevations, into the 10s at upper elevations, and to around freezing at low elevations by late afternoon-early evening. Winds NW at 10-20 mph, with higher gusts. Wind chills plunging into the single digits & 10s by late afternoon, except below zero at highest elevations.
Tuesday Night Into Mid-Day Wednesday
Widespread snow showers, flurries and snow squalls. Bursts of intense snow possible. Turning bitterly cold. Winds NW at 10-20 mph, with higher gusts. Temperatures dropping into the single digits at highest elevations and into the 10s at middle-lower elevations ( along and north to northwest of the High Knob Massif-Tennessee Valley Divide, somewhat milder lee of mountains into the Great Valley ). Wind chills from 0 to 15 degrees below 3000 feet and from 0 to -15 degrees below zero above 3000 feet.
Wednesday Afternoon
Becoming sunny. Cold. WNW-NW winds 10-20 mph, with higher gusts. Temperatures varying from the 10s in upper elevations to the 20s to around 30 degrees at middle-lower elevations. Wind chills in the single digits and 10s, except below zero in gusts at upper elevations ( above 3000 feet ).
*Snow Depth Forecast ( March 13-15 )
2″ or less below 2000 feet ( along upslope side of mountains )
2″ to 4″ at 2000 to 3000 feet
4″ to 8″ above 3000 feet
Little to no accumulation is expected lee of mountains into river valleys of the Clinch, Powell & Holston, with possible exception of cold air ( instability ) supported snow bursts.
Target snow depth of 3″ in Norton-Wise ( +/- ) 1″ error potential. This implies that 2″ to 4″ will be possible in the Norton-Wise area above 2000 feet elevation, with lower amounts below this level.
*Total snowfall amounts will be greater than snow depths in most all places due to melting, settlement, compression and other factors.
Weather Discussion ( Winter Storm )
Tuesday Overnight Update
Sticking snow levels dropped, as expected, down into the 2000 to 2500 foot elevation zone into the overnight with mountain ridges in Dickenson County and much of central-southern Wise County having accumulations.
High Knob Massif Webcam – University Of Virginia’s College At Wise
The greatest accumulations occurred at upper elevations in the High Knob Massif where up to 4″ or more of snow stuck at highest elevations ( especially in the woods & on grass ).
Eagle Knob of High Knob Massif – In Between Wet Snow & Upcoming Dry Snow
New snow showers and flurries will develop in coming hours but the main action is looking to develop by late Tuesday into Wednesday morning when very cold air aloft and moderately strong NW Upslope Flow will combine with Great Lake moisture to generate widespread snow showers and snow squalls, with intense bursts of snow likely, as both temperatures and wind chills plunge to bitter levels.
Monday Evening Update
Wet snow has been pouring down on Eagle Knob of the High Knob Massif through the evening with the greatest amounts sticking to the grass and leaves.
Eagle Knob of High Knob Massif At 10:10 PM – March 13, 2017 ( Roads Covered )
As of 10:00 PM roads on Eagle Knob and High Knob are snow covered ( roads were last to have sticking ), with this view above looking across the roadway on Eagle Knob.
*As of Midnight several inches of snow accumulation has been reported atop the High Knob Massif. And it is pouring down!
Monday Afternoon Update
I have updated the forecast to account for latest model trends and conditions which show a slower development of precipitation and warmer afternoon temperatures.
High Knob Massif Webcam – University Of Virginia’s College At Wise
The only other change includes a slight downward adjustment in forecast snowfall amounts & depths.
Previous Discussion
Forecasters in the southern Appalachians have had a rough time trying to pin down this late season winter storm. It is now coming as a hybrid Miller B + Miller A storm that will transition into a 977 mb ( 28.85″ ) bomb by late Tuesday along the New England coastline.
European Model Surface-850 MB Analysis At 8:00 PM Sunday – March 12, 2017
At this time of year a notable factor in most winter storms is elevation, with an elevation bias expected to dominate the first part of this event when wet snow will develop by late Tuesday into Wednesday morning. This is likely to be heavy, wet snow.
NAM 12 KM Model Total Snowfall Forecast To 8:00 AM Thursday – March 16, 2017
There remains a considerable spread in model forecast snow amounts, with little snow being predicted by the GFS Model west of the Eastern Continental Divide. This solution is for now being rejected given close agreement between the NAM and European models as well as past climatology of similar hybrid to bomb events.
*A similar storm with a hybrid A+B to bomb evolution during March 2013 resulted in a general 2″ to 6″ of snow across the area. That system was weaker and the Great Lakes not as free of ice.
GFS Model Total Snowfall Forecast To 8:00 AM Thursday – March 16, 2017
With dry air currently in place there will be a considerable evaporative cooling potential with onset of virga and then precipitation later Tuesday.
There still remains a considerable error potential during this event, more than I have allowed for in forecast snow depths given a couple of factors:
Phase 1 – The Wet Snow Period: While heavy, wet snow is nearly certain at upper elevations, above 3000 to 3500 feet, the bottom limit or level of accumulating snow during this period remains only a best estimate. Right now I am going with the idea of wet snow sticking above 2000 feet.
However, if a northerly component develops in low-levels this could combine with significant +UVV ( upward vertical motion aloft ) to drop snow levels more than I indicate for locations along and north of the High Knob Massif where low-level air will be forced to rise ( if that happens then locations like Pound and Clintwood could get into sticking snow Tuesday Night into Wednesday morning versus only rain-snow and little to no accumulation ).
Phase 2 – The Dry Snow Period: This period is easiest with respect to precipitation type as air will be turning bitterly cold and all elevations will have precipitation which falls in the form of snow.
The wild card or unknown during this time period is the amount of Great Lake moisture reaching the mountains. Are forecast models resolving the fact of the Great Lakes being completely ICE FREE. If not, then snowfall amounts during this period could be more than I have indicated. At the least, it is nearly certain that snow will be widespread along the upslope side of the mountains with respect to NW flow during Tuesday Night into Wednesday morning.
Embedded within widespread snow showers and flurries will be snow squalls and the potential for streaks of snow. Given a combination of steep lapse rates with very cold air aloft + moisture in the prime dendritic snow crystal growth zone + moderate ( at least ) orographic forcing…the result will be bursts of intense snow. Local thundersnow would certainly not be out of the question in this type of setting.
European Ensemble MEAN 850 MB Temp Anomalies To 8:00 AM Friday ( March 17 )
The other big story will be the COLD. This is going to be a very cold week versus average for March, with the core of greatest temp anomalies centered over the Ohio Valley and southern-central Appalachians. “Shiver all me timbers.”
This Week In Weather History
In Wake Of The March 1993 Superstorm
You can see the car in this photograph ONLY because I used it as a snowboard to measure the monster snowfall associated with the great Superstorm of March 12-14 in 1993.
One of the greatest winter storms of my life occurred during this week 24 years ago when low pressure began bombing as it lifted out of the Gulf of Mexico.
Storm Snowfall Totals ( March 12-14, 1993 )
Grundy: 17.3″
Burkes Garden: 25.5″
Wise 1 SE: 28.9″
Clintwood 1 W: 34.5″
High Chaparral of High Knob Massif: 46.0″
*High Knob-Eagle Knob of Massif: 58.0″
*Verified by EMS and VDOT as well as Steve Blankenbecler of Virginia-Kentucky Communications. A group of 15 individuals became stranded in upper elevations of the High Knob Massif. Their rescue was an amazing ordeal which required D-9 dozers and logging equipment combined with much good work by the Scott & Wise County EMS and other volunteer rescue personnel.
The great blessing, someone had a cell phone which in 1993 were not yet common ( a cell tower on Eagle Knob allowed them to be able to communicate with EMS officials during the rescue event ). This was a phenomenal task given snow drifts of 15 to 25 FEET.
Joe & Darlene Fields, and family, began measuring snow in the community of High Chaparral at the beginning of the 1992-93 winter season. During the Superstorm they kept track of snowfall by measuring and sweeping their deck positioned on the windward side of the house.
**Although I already knew it well by this time from previous winter storm events, the great March 1993 Superstorm confirmed that the High Knob Massif is a wicked force to be reckoned with during events that couple strong orographics and dynamics. The only total analogous to this reported was 60″ on Mount LeConte.
Mount LeConte is more than 2,000 vertical feet taller than High Knob, so you must understand that there is more to orographic forcing than just elevation, much more! If you understand that then you will be ahead of forecast models from the start ( hint, hint )!
An ALERT For Accumulating Snowfall Will Likely Be Needed For Late Monday Into Tuesday
Rain and snow will develop across the mountain area Monday afternoon, with mostly all snow above 3000-3500 feet elevation. Preliminary snow amounts of 2″ to 6″ are expected at elevations above 2000 feet into Tuesday. Bitterly cold air with additional upslope snow showers is expected late Tuesday into Wednesday.
Thursday Night Into Friday Morning
Becoming windy & cloudy. Rain developing. Downpours likely. Thunder possible. SW to WSW winds increasing to 10-25 mph, with higher gusts. Temperatures in the 40s to lower 50s, then dropping around and after sunrise.
Friday Morning Through Friday Afternoon
Showers mixing with or changing to snow at mid-upper elevations before ending by mid-morning to mid-day. A light accumulation possible on mountain peaks. Becoming partly to mostly sunny. Windy and turning colder. NW-NNW winds 10-25 mph, with higher gusts. Temperatures falling into the 30s to lower 40s at middle-lower elevations along & north-northwest of the High Knob Massif, and into the 20s to lower 30s at upper elevations ( milder leeward of the mountains into the Great Valley ). Wind chills dropping into the 20s & 30s, with 10s at highest elevations.
Friday Night Into Saturday Morning
Mostly clear early then increasing mid-high altitude clouds. Cold. NW-N winds 5-15 mph, with higher gusts along mid-upper elevation mountain ridges. Temperatures dropping into the low-mid 10s to low 20s ( coldest upper elevations ). Wind chills in the single digits and 10s, except below zero in gusts on highest mountain ridges in upper elevations.
Saturday Afternoon
Mostly cloudy. Unseasonably cold for the season. Winds northerly at generally less than 10 mph. Temperatures from lower-middle 20s at highest elevations to the 30s at middle-lower elevations.
Saturday Night Into Sunday Morning
Partly-mostly cloudy. NNW-NNE winds generally under 10 mph. Cold. Temperatures varying from single digits to mid 10s in upper elevations to the low-mid 20s on exposed mid elevation mountain ridges-plateaus.
A Major Winter Storm will be the main event across the eastern USA through mid week. Locally the trend has been toward development of wet snowfall at middle to upper elevations late Monday into Tuesday, with a rain-snow mixture at lower elevations ( below 2000 feet ). Bitterly cold air & upslope snow showers ( low density snow ) are expected by late Tuesday into Wednesday.
Weather Discussion ( Pay The Piper )
A gorgeous late afternoon-early evening on the campus of UVA-Wise was deceptive, as the Ole Man of Winter plots to make us pay for a mild Winter 2016-17 season!
Beautiful Early Evening – University Of Virginia’s College At Wise – March 9, 2017
A series of 3 waves will be impacting the mountain region into early next week, with the third wave of the triplet now looking to become the most potent ( as often is the case ).
JKL Doppler At 2:10 AM Friday – Bright Banding With Snow Aloft
Wave number 1 will generate overnight-predawn rain that may change to snow before it ends, with any accumulation likely being above 3200-3500 feet in elevation.
Wave number 2 has been trending farther and farther south, with the axis of heaviest snowfall now expected across the state of Tennessee ( 5 to 7 days ago this axis was along the great Ohio River with 12″ of snow shown in HTS ).
*Up until the 00z run on March 10 ( 7 PM March 9 ) the operational European Model had adjusted the snow band southward on every single run. I have been doing this a long time and that type of consistent adjustment is not often observed.
**The southward adjustment in the storm track resumed during March 10 with the latest European Model run forecasting the heaviest snow to be south of Mount LeConte in SW NC.
GFS Model Total Snowfall Forecast To 8:00 AM Monday – March 13, 2017
Wave number 3 will come out of the Gulf of Mexico and become a bomb of a cyclone as it trends toward a Miller A storm track, along and off the East Coast, during the early to middle portions of next week.
GFS Model Total Snowfall Forecast To 8:00 AM Wednesday – March 15, 2017
The exact track of this wave is yet to be set, which will be very important into Monday as a band of heavy, wet snow could impact portions of the Mountain Empire ( or all the area ) as a low pressure moves out of the Gulf to along the Carolina-Virginia coast ( a slight inland track could cause a crippling snowfall for portions of the region, while a track along and just off the coast would cause lesser impacts ).
Once the storm lifts north and bombs it will become about upslope NW-N flow snowfall that is likely to generate some significant amounts along the Cumberland and Allegheny mountains, and the windward side of the Blue Ridge, during early-middle portions of next week as unseasonably cold air engulfs the region.
The Bottom Line…Much colder ( bitter ) air will be felt Friday into Saturday as winter returns. The second of three waves will cause snow to develop late Saturday into Sunday Morning south toward the Great Smokies, with latest models suggesting heaviest snow might even be south of Mount LeConte. No snow is now expected farther north across the Cumberlands.
Wave number 3 now looks to become the strongest, and most potent, as low pressure develops in the Gulf of Mexico late this weekend with movement northeast to off the Atlantic Coast where it will bomb out into an intense low pressure. Heavy to potentially crippling snow could result for portions of the region, and this will need to be closely followed in coming days.
A Colder Pattern With Potential Of Accumulating Snowfall Is Being Monitored For This Weekend ( March 11-12 ). Check Back For Later Updates On A Possible Winter Storm.
Overnight Into Wednesday Morning
Cloudy & windy with a chance of rain showers through early-mid overnight, then clearing skies toward morning. WNW-NW winds 15-25 mph, with higher gusts, decreasing to 5-15 mph ( with higher gusts ) by morning. Temperatures dropping into the lower-middle 30s to low-mid 40s ( coldest in upper elevations ). Wind chills falling into the 20s & 30s along mid-upper elevation mountain ridges ( 10s in gusts at highest elevations ).
Wednesday Afternoon
Partly-mostly sunny. WSW-WNW winds 5-15 mph, with higher gusts. Temperatures varying from mid-upper 40s at highest elevations to the upper 50s to lower 60s.
Wednesday Night Into Thursday Morning
Partly-mostly clear ( some high clouds ). Winds SW-WSW at 5-15 mph, with higher gusts, along higher mountain ridges. Temps varying from the 20s to lower 30s in colder valleys to the 40s along exposed mountain ridges-plateaus.
Thursday Afternoon
Mostly sunny. Mild. SW winds 5-15 mph with some higher gusts. Temperatures varying from low-mid 50s in the upper elevations to the lower to middle 60s.
Thursday Night Into Friday Morning
Becoming windy & cloudy. Rain developing by morning. Downpours possible. SW-WSW winds increasing to 10-25 mph, with higher gusts. Temperatures in the 40s to lower 50s ( dropping early in valleys then rising overnight ).
Friday Afternoon
Showers ending. Becoming partly cloudy. Windy and turning colder. NW-NNW winds 10-25 mph, with higher gusts. Temperatures falling through the 40s at middle to lower elevations, and through the 30s in upper elevations. Wind chills dropping into 20s & 30s ( coldest above 3000 feet in elevation ).
Weather Discussion ( Winter Storm? )
The main focus in coming days will be on a series of upper disturbances in the flow field crossing North America, with one or more having the potential to generate some wintry precipitation. Is a significant snowfall upcoming? Perhaps, but it remains too early in the game to declare a winner.
Big Cherry Wetland Valley of High Knob Massif – March 4, 2017
The setting is not like 27 years ago this week when we were already certain that a major March storm ( a Superstorm or Snow Hurricane ) would hammer the mountain region.
GFS Model Total Snowfall Forecast – Next 5 DAYS
In this case models have been consistently showing snow, but with variations in amounts and the tracks of more than one system. It appears that Saturday afternoon into Sunday will initially offer the best chance for significant snowfall.
GEM ( Canadian ) Model Total Snowfall Forecast – Next 5 DAYS
The system above follows a lead wave that brings rain into Friday, and comes in advance of yet another storm system which could be a bigger deal for the Northeastern USA ( and possibly add snow to the southern-central Appalachians ).
GOES West Water Vapor Image At Midnight – March 8, 2017
With swirls responsible for upcoming weather still over the Pacific Ocean, it is simply too soon to forecast exactly how this will play out over the area ( and certainly too early for snowfall amount predictions ). Models which are and have been forecasting snow amounts are used for guidance, not gospel, at this point in time.
The Bottom Line…A colder pattern is upcoming by this weekend into early to middle parts of next week. The potential for snowfall, possibly significant, is being monitored. Check back for later updates.
ALERT For Strong S-SW Winds For Monday Night Through Tuesday For The Cumberland Mountains
Friday Night Into Saturday Morning
Mostly clear. Cold. Diminishing winds, except NW-N at 5-10 mph, with a few higher gusts, on upper elevation mountain ridges. Temperatures dropping into the 10s and 20s ( near 10 degrees in colder valleys of upper elevations ).
Saturday Afternoon
Becoming partly to mostly cloudy. Milder. Light & variable winds. Temperatures varying from 30s in upper elevations to the middle-upper 40s.
Saturday Night Into Sunday Morning
Mostly clear. Winds W-WNW 5-15 mph, with higher gusts, along upper elevation mountain ridges. Temperatures from the 10s to lower 20s in colder valleys to the 30s on exposed ridges and plateaus.
Sunday Afternoon
Mostly sunny & warmer. Light SSE-SSW winds 5-10 mph. Temperatures varying from 40s to around 50 degrees in upper elevations to the upper 50s to lower 60s.
Sunday Night Into Monday Morning
Increasing clouds. S-SW winds 5-15 mph, with higher gusts, on mountain ridges & plateaus below 2700 feet. Winds SSW to SW at 10-20 mph, with higher gusts, on mountain ridges above 2700 feet. Temperatures from 30s in cooler valleys to the 40s on exposed ridges-plateaus.
Weather Discussion ( Back To Spring )
A weak upper air disturbance and upsloping NW winds worked together to produce a brief fall of moderate snow along the Cumberland Mountains into Friday morning.
High Knob Massif Webcam – University Of Virginia’s College At Wise
A general 1″ to 2″ of snow fell amid upslope locations along and north to northwest of the High Knob Massif and Black Mountain, from Clintwood to Norton-Wise into adjacent Harlan County of southeastern Kentucky.
Ground Depth In High Chaparral of High Knob Massif – Elevation 3300 feet
Snow came down heavily at times in the High Knob Massif, with some pellets of graupel snow showing up in the ground accumulation measured by veteran snow observer Darlene Fields in the High Chaparral community.
Eagle Knob of High Knob Massif at 6:31 AM on Friday – March 3, 2017
*As often is the case, snow fell mostly horizontally on Eagle Knob of the High Knob Massif with ground variations from bare areas to several inches. Roadways were covered and slick.
Caleb Ramsey measured 1.0″ of accumulation at the City of Norton Water Plant at the base of the massif. A low density snow with only around 0.03″ of water content in the rain gauge ( in both Norton & Clintwood ), that likely included a little undercatch given gusty winds.
High Knob Massif Webcam – University Of Virginia’s College At Wise
With clear skies the focus now is on a very cold night with temperatures in mountain valleys being coldest as winds decouple ( go calm ) and are replaced by drainage flows.
*MINS as low as single digits to around 10 degrees could occur in colder valleys of the High Knob Massif where some snow remains on northern slopes. These valleys are proving to be the coldest in southwestern Virginia.
Looking ahead more wild weather swings are showing up, with a range from thunderstorms to more snow certainly possible during the next week to 10 days.
European 51-Member Ensemble MEAN 500 MB Height Anomalies: Days 6-10
A WILD 5-10 day period is currently being predicted by the European Model Ensembles as a huge temperature gradient sets up between anomalous warmth over the Southwestern USA-southern Plainis and anomalous cold over the Upper Lakes and Northeastern USA.
European 51-Member Ensemble MEAN 850 MB Temp Anomalies: Days 6-10
A Period Of Snow & Snow Showers Is Expected During The Predawn To Mid-Morning Hours Of Friday. Snow Amounts Of A Dusting Up To 1″ Is Expected Along The Upslope Side Of The Mountains ( A Little More Possible At Upper Elevations Of The High Knob Massif ).
Caution For Slick Patches On Area Roadways.
*Some school schedule changes will be possible given the timing and cold conditions expected around sunrise into mid-morning. Stay tuned to your favorite media sources for updates on any delays or closings.
Predawn Snowfall Report
As of 6:00 AM Friday Morning between 0.5″ to 1″ of snow has accumulated in Clintwood, with 1″ or more at higher sites in central-southern Dickenson & Wise counties ( 1-2″ on Eagle Knob of the High Knob Massif at 6:00 AM where roads are snow covered & slick ). Locally more than 2″ of snow will accumulate at highest elevations.
Overnight Into Thursday Morning
Partly-mostly cloudy. Gusty & turning colder. W-NW winds 10-20 mph, with higher gusts. Temperatures varying from around 20 degrees at highest elevations to near 30 degrees. Wind chills falling into the 10s and 20s, except single digits along high mountain ridges.
Thursday Afternoon
Partly-mostly sunny. WNW winds 5-15 mph, with higher gusts. Temperatures varying from low-mid 30s in upper elevations to the low-mid 40s.
Thursday Night Into Mid-Morning Friday
Mostly clear during the evening, then increasing clouds with snow showers & flurries developing during the pre-dawn to mid-morning period. A dusting up to 1″ of snow accumulation possible. WSW-W winds shifting NW at 10-20 mph, with higher gusts. Temperatures varying from the upper 10s-low 20s at highest elevations to the upper 20s to lower 30s. Wind chills in the 10s & 20s, except single digits to around 0 degrees in gusts at highest elevations.
*The most snow accumulation into mid-morning Friday will be favored at high elevations from the High Knob Massif and Black Mountain to Whitetop-Mount Rogers and the Brumley to Garden Mountain section of Clinch Mountain and Big A Mountain.
Friday Afternoon
Becoming mostly sunny. Cold. NW winds 10-20 mph, with higher gusts. Temperatures varying from low-mid 20s in upper elevations to the mid-upper 30s. Wind chills in the 10s & 20s, with some single digits in gusts highest peaks.
Friday Night Into Saturday Morning
Partly-mostly clear. Cold. Diminishing winds, except NW-N at 5-10 mph, with a few higher gusts, along upper elevation mountain ridges. Temperatures dropping into the 10s and 20s ( near 10 degrees in colder valleys of upper elevations ).
Saturday Afternoon
Becoming partly-mostly cloudy. Milder. Light & variable winds. Temperatures varying from 30s in upper elevations to the mid-upper 40s.
Weather Discussion ( Spring to Winter )
Thursday Evening Update
Beginning Of Meteorological Spring – Afternoon of March 2, 2017
A chilly air mass will combine with a upper wave to develop snow showers & flurries into the predawn to mid-morning hours of Friday. Just enough snow may fall to create some slick travel on mountain roadways. Caution is advised.
HRRR Model Future Doppler Forecast At 5:00 AM Friday – March 3, 2017
Previous Discussion
A gush of high winds roared across the Virginia-Kentucky stateline to mark a gust front out ahead of a squall line containing strong-severe thunderstorms Wednesday.
Partial List Of Storm Reports On March 1, 2017
More than 1200 preliminary storm reports have been collected by the Storm Prediction Center for the February 28-March 1 period, and that does not include significant damage which occurred in Pound as well as other places across Wise, Dickenson and Buchanan counties where power outages also occurred.
High Knob Massif Webcam – University Of Virginia’s College At Wise
Morning clouds were abundant over the High Knob Massif amid strong low-level lifting on roaring SW winds. At the same time, by contrast, sunshine was much more prevalent in the Pound to Clintwood corridor on downslope SW flow.
NAM 4 KM Model Forecast Sounding Above Pound At 10:00 AM Wednesday
The NAM 4 KM Model forecast 3-hour sounding on Wednesday indicated “marginal tornado” above the Town of Pound in far northern Wise County, Va., which meant that conditions in the vertical were borderline for tornado development.
While a local spin-up certainly could have occurred, most of the area was subjected to strong straight-line winds which reached sustained speeds of 35 mph, with gusts to 47 mph, at Lonesome Pine Airport in Wise. Much higher local gusts occurred in the area with the squall line gust front, as well as inside local storms within the convective system.
Storm rainfall totals topped 2.00″ in the High Knob Massif, with around 1.00″ measured in Clintwood at the other end of the range.
NAM 4 KM Model Total Snowfall Forecast
The NAM 4 KM Model is wanting to put down a light coating in lower elevations ( foothill and bluegrass terrain ) of northern Kentucky. While that may be possible, amounts may be too ambitious outside of the higher terrain in the mountains.
Cold air today into Friday will now bring a chance for some flurries and snow showers in the predawn to mid-morning period of Friday. Any accumulations will be light and likely most favored in upper elevations since again no good Great Lake connection can be had ( the moral of Winter 2016-17 ).
NAM 4 KM Model MIN Temperature Forecast For Saturday AM – March 4, 2017
The stage will be set for a very cold Saturday morning as winds diminish. The wild card being if skies can remain clear? If skies remain clear the potential for 10s in many mountain valleys will be realized, with the very coldest at upper elevations ( above 3000 ft in the High Knob Massif ) dropping to around 10 degrees.
