Category Archives: 2016 02 Forecasts

My February 2016 Forecast Archive

020716 Forecast

My Forecast For Today ( February 7 )

ALERT For Accumulating Snow Monday-Wednesday With Bitter Cold Temperatures Tuesday-Wednesday

Abundant moisture will combine with very cold air aloft to produce snow, heavy at times, during a prolonged period beginning Monday and continuing through Wednesday.

Overnight Into Sunday Morning

Cloudy skies giving way to clearing into the predawn to morning hours.  Light SW winds shifting N at 5-10 mph on middle elevation ridges-plateaus below 2700 feet.  N winds 5-15 mph, with higher gusts, along upper elevation ridges.  Temps dropping mostly into the 20s ( variations from 10s in colder valleys, if skies clear during the predawn, to upper 20s-lower 30s along exposed mid-upper elevation ridges ).  Wind chills in the 10s & 20s ( coldest at highest elevations ).

Super Bowl Sunday Afternoon

Sunny with a chance for high clouds late.  N-WNW winds at generally less than 10 mph.  Temperatures varying from the lower-mid 30s in highest elevations of the High Knob Massif to the mid-upper 40s.

Tonight Into Monday Morning

Partly to mostly clear during the evening.  Increasing clouds overnight into morning with a chance for flurries and light snow developing.  SSW-SW winds 5-15 mph, with higher gusts, along mid elevation ridges & plateaus below 2700 feet.  SW-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 ).

The most significant snowfall accumulations Monday, during the period from 8:00 AM to 4:00 PM, are favored along and southwest of the High Knob Massif & Tennessee Valley Divide on SW Upslope Flow ( e.g., Norton-Wise & Sandy Ridge southwest to Big Stone Gap and Lee County verses lighter amounts from Pound-Clintwood to Haysi-Grundy where some mix may occur ).  Updates To Come.
Widespread snow, with embedded bursts of heavy ( whiteout ) snow will be possible from late Monday into Tuesday across the entire area, with heaviest amounts in general favoring W-NW facing slopes along the Cumberland Mountains and Blue Ridge.

 

Weather Discussion ( February 6-7 )

How would you like to photograph in a place where a bear uses an electrical pole as his scratching post?  To see more photographs reference The High Knob Landform website.

Scratching Post For Mr. Hoss
Scratching Post For Mr. Hoss – High Knob Massif

A seasonally cold Saturday was felt across the mountain area with morning MINS in the 10s, amid colder mountain valleys, and 20s along exposed ridges.  The afternoon was dominated by sunshine that gave way to high clouds with temperatures varying from near 30 degrees at summit levels of the High Knob Massif to upper 30s-mid 40s.

Sunset View From Stone Mountain
Sunset View From Stone Mountain In Lee County – February 6, 2016

While snow may not yet be on the mountains, my friend Rodney Parsons submitted a great sunset view from the top of Stone Mountain in northern Lee County ( with some visible wave clouds to boot ).

Nora 4 SSE - Site of Official NWS Station - Elevation 2650 feet
Nora 4 SSE – Site of Official NWS Station – Elevation 2650 feet

Temperatures on this Super-Bowl Sunday will become a little milder than Saturday, but remain chilly, in advance  of a cold front that ushers in weather changes Monday.

NAM 12 KM Model Surface Streamlines and Mean Sea Level Pressure
NAM 12 KM Model Surface Streamlines & Mean Sea Level Pressure – 10 AM Monday
Flow will be SSW-WSW in advance of a cold front from Monday morning through early-mid afternoon, which will tend to favor locations along and southwest of the High Knob Massif and TN Valley Divide for the most snow ( verses downslope locations in river basins of the Russell Fork and Levisa Fork ).
GFS Model 500 MB Temperature Forecast
GFS Model 500 MB Temperature Forecast – 7 PM Monday ( February 8 )

A key to this forecast, regardless of what model one looks at, is very cold air aloft and abundant moisture vertically by later Monday into Tuesday.  This supports widespread snow with embedded snow squalls ( bursts of heavy snow ) that could cause whiteout conditions at times.

*Temperatures aloft at around 17,000 feet are forecast to plunge into the -32 to -36 Celsius range ( -26 to -33 F below zero ) by late Monday into Tuesday.  This will generate steep lapse rates in the vertical ( i.e., rapid drops of temperature with increasing height ) and make the lower atmosphere unstable ( absolutely unstable with respect to air parcels ).
GFS Model 500 MB Temperature Forecast
GFS Model 500 MB Temperature Forecast – 7 AM Tuesday ( February 9 )

Past climatology of the High Knob Massif area shows that heavy snow tends to develop and fall when temperatures aloft become this cold with available moisture.  Otherwise, the flow trajectories are not shown to be from the Lakes on most models until beyond this period for the southern Appalachians ( the lake connected flow remaining from West Virginia northeastward along the mountain chain ).  This needs to be followed and updated on new forecasts.

If later Great Lake connected flow follows, either by mid-week and/or later by next weekend ( when the coldest air mass of the winter season potentially arrives ), this would add greatly to total snowfall amounts along the upslope side of the mountains with potential for very heavy totals in the High Knob Massif.
In a prolonged snowy period like upcoming, total snowfall amounts are likely to be greater than snow depths at any given point in time ( outside of drifting ) due to some melting-sublimation and settlement of snow.

The Bottom Line…A prolonged period of snowy and increasingly colder weather is upcoming this week from Monday through Wednesday-Thursday.  Bitter temperatures are likely during Tuesday-Thursday, with potential for a reinforcing blast of even colder air by this next weekend ( stay tuned for updates ).

**Reference my latest Extended Outlook for details.

Make it a great Super-Bowl Sunday.

020516 Forecast

My Forecast For Today ( February 5 )

Stream Levels Are Dropping But Will Remain Higher Than Normal On Steep Creeks Draining The High Knob Massif & On Mainstem Rivers Today

Overnight Into Mid-Morning

Flurries & light snow showers, then decreasing clouds into the morning.  NW winds 5 to 10 mph, with higher gusts, below 2700 feet.  NW-N winds 10-15 mph, with higher gusts, along mountain ridges above 2700-3000 feet.  Turning colder.  Temperatures dropping into the 10s to lower 20s, with lower to middle 10s at highest elevations.  Wind chills falling into the teens, except single digits above & below zero at highest elevations overnight into morning.  Any accumulations are expected to be light.

This Afternoon

Mostly sunny & chilly.  Light NNW-N winds.  Temperatures varying from the 20s across upper elevations to the lower to middle 30s ( milder in valleys of the Clinch, Powell, Holston rivers toward the Tri-Cities ).

Tonight Into Saturday Morning

Mostly clear.  Some high clouds possible overnight.  Colder.  N winds shifting SSE-SW at 5-10 mph on middle elevation mountain ridges & plateaus below 2700 feet.  Winds SW-W at 5-15 mph, with higher gusts, on ridges above 2700 feet.  Minimum temperatures ranging in the  20s across exposed mid-upper elevation ridges & plateaus, with 10s in colder mountain valleys ( with calm winds ).  Wind chill factors in the 10s on mountain ridges ( single digits to lower 10s at highest elevations ).

 

Weather Discussion ( February 4-5 )

A notable chill was in the Thursday air on northerly winds and abundant clouds.  It was plain cold in the High Knob Massif where I spent part of the afternoon.

Whitewater On Benges Branch of Powell River
Whitewater On Benges Branch of Powell River – High Knob Massif – Feb 4
Although water levels have come way down, it continues to gush on all creeks draining the High Knob Massif.  Caution is advised.
Colorful Waterfall Outcrop on Tributary of Robinette Branch
Colorful Waterfall Outcrop on Tributary of Robinette Branch – Feb 4

Temperatures remained below freezing all afternoon at the highest elevations, with mid 30s to around 40 degrees at lower to middle elevations north of the massif area.

Nora 4 SSE - Site of Official NWS Cooperative Station
Nora 4 SSE – Site of Official NWS Cooperative Station – Elevation 2650 feet

Some flurries and light snow is falling during this early overnight from Clintwood to High Knob.  Accumulations, if any, are expected to be light ( as the forecast indicates ).

JKL Doppler At 1:01 AM
JKL Doppler At 1:01 AM Friday – February 5, 2016

Although snow will not amount to much of anything, cold air is plentiful and making conditions feel like it is below zero degrees at summit levels of the High Knob Massif and Black Mountain during this early overnight ( in gusts ).

Black Mountain MesoNET
Black Mountain MesoNET

Temperatures are in the 20s in Norton-Wise & Clintwood.

Lonesome Pine Airport at 1:35 AM
Lonesome Pine Airport at 1:35 AM Friday – February 4, 2016

Seasonably cold and mostly dry conditions will rule this weekend before snow and colder air begins to take over during early-middle portions of this coming week.

Stay tuned for details.

Have a great TGIF.

020416 Forecast

My Forecast For Today ( February 4 )

ALERT For High Stream Levels Along Steep Creeks Draining The High Knob Massif And On Mainstem Rivers.  Caution Is Advised Around All Streams.

Overnight Into This Morning

Mostly cloudy & colder.  Cloud bases obscuring highest elevations in freezing fog ( riming ), mainly above 3500 feet into morning.  Small chance of flurries.  SW winds shifting WNW to NNW at 5-15 mph, with higher gusts across mid-upper elevation mountain ridges.  Temperatures varying from lower 20s along upper elevation ridges to the upper 20s to lower 30s by sunrise to mid-morning ( milder amid valleys of the Clinch, Powell, Holston rivers ).  Wind chills in the 10s & 20s into morning ( coldest at highest elevations ).

This Afternoon

Partly to mostly cloudy.  Seasonably cold.  Light NW winds generally less than 10 mph.  Temperatures varying from upper 20s at highest elevations in the High Knob Massif to the upper 30s to lower 40s.  Wind chills in the 20s & 30s, except some upper 10s in gusts at highest elevations.

Tonight Into Friday Morning

Becoming cloudy with a chance for flurries and light snow showers.  NW winds 5 to 10 mph, with higher gusts, below 2700 feet.  NW-NNW winds 10-15 mph, with higher gusts, along mountain ridges above 2700-3000 feet ( low clouds with some riming possible at highest elevations ).  Colder.  Temperatures dropping into the 10s to lower 20s, with lower 10s at highest elevations.  Wind chills falling into teens, except single digits above & below zero at highest elevations overnight into morning.  Any accumulation varying from a dusting up to 1″ .

 

Weather Discussion ( February 3-4 )

Morning Update

My forecast is on track, with only slight changes for the afternoon and tonight.

High Knob Massif Webcam
High Knob Massif Webcam – University Of Virginia’s College At Wise

Cloud bases have just been dragging across highest peaks through the morning with riming ( especially amid high gaps where air is accelerated upslope ).

Nora 4 SSE - Elevation 2650 feet
Nora 4 SSE – Elevation 2650 feet
Morning temperatures have varied from low-mid 20s atop the High Knob Massif and Black Mountain to lower 30s in Norton-Wise and along the adjacent ridge communities of Wise & Dickenson.
NASA Visible Image
NASA Visible Image at 9:30 AM – February 4, 2016
Low clouds are extensive, with a few breaks.  I have changed the afternoon wording slightly to reflect the potential of more clouds and added a dusting up to 1″ potential for tonight ( for upslope locations as a upper air disturbance crosses the mountains ).
Big Stony Creek Stream Levels
Big Stony Creek Stream Levels Up To 8:30 AM This Morning ( Feb 4 )

Water levels remain high on steep creeks and mainstem rivers, so my Caution ALERT remains in effect today.

 

My Overnight Discussion

The main weather focus has been on heavy rain and strong rises on creeks and rivers during the past day.  Steep creeks draining the High Knob Massif continue to roar tonight but levels have peaked according to stream gauges.

Big Stony Creek Stream Gauge
Big Stony Creek Stream Gauge At 11:45 PM on February 3, 2016
The Big Stony Creek gauge is excellent to also judge levels on the South Fork of the Powell River, Little Stony Creek, and adjacent steep creeks in the massif.  The main exception being during the summer season when heavy rain events can be concentrated in local drainage basins ( and not extend across the entire massif ).  Any time water levels are within or above Yellow Alert stage the volume is significant and creeks roar ( a pounding roar develops when the level goes above Red Alert stage ).
Forecast For Clinch River At Speers Ferry
Forecast For Clinch River At Speers Ferry

The Clinch River, downstream of the massif, is forecast to crest during the morning to noon period today ( latest MRX projections being just below minor flood stage ).

High Knob Massif Webcam
High Knob Massif Webcam – University Of Virginia’s College At Wise

Outside of heavy morning rains, Wednesday afternoon was very nice with temperatures becoming even milder than expected as low clouds broke relatively fast into mid-day.  An array of high-altitude clouds created a nice sunset.

High Knob Massif Webcam
High Knob Massif Webcam – University Of Virginia’s College At Wise

Focus is now on a return to seasonably cold conditions with mainly dry weather during the next few days.  An upper air disturbance will be pushing across the mountains Thursday evening with limited moisture.  Some flurries and/or snow showers will be possible as air turns colder than today.  Any accumulations currently look to be light as streamlines will be from mid-continent and lack a good moisture source.

*A chance exists for wave development over the western NC area, with movement to and off the Atlantic Coast.  Any snow along the mountains currently looks limited late tonight into Friday, but this will be something to follow on new forecast model runs.
NAM Model 500 MB Vorticity Forecast
NAM Model 500 MB Vorticity Forecast at 10 PM Thursday ( Feb 4 )

The shift back into cold air is well underway now across the high country, on NW upslope flow and increasing low level moisture, and should bring cloud bases down onto highest crestlines from the High Knob Massif to Black Mountain.

Black Mountain MesoNET
Black Mountain MesoNET at 1:00 AM Thursday – February 4, 2016
Temperatures have now dropped below freezing along highest crest lines, with gust chill factors in the 10s, on NW-NNW winds.
European Model 850 MB TEMP & Surface Analysis
European Model 850 MB TEMP & Surface Analysis – 7 PM Wednesday ( Feb 3 )

Bitter air and prospects for snow increase into next week but forecast models have much work to do in order to figure out a complex pattern featuring several jet streams and a array of embedded disturbances.  Axes of main snowfall currently vary from along the mountains to the Atlantic Coast ( from South Carolina to north of the VA Capes ).  Perhaps it will be both, but time will soon tell more.

For a review of recent winter photographs reference this section of the High Knob Landform website ( more to come in days ahead ).

Have a great Thursday.

020316 Forecast

My Forecast For Today ( February 3 )

ALERT For High Stream Levels Along Steep Creeks Draining The High Knob Massif And For Strong Rises On Mainstem Rivers.  Caution Is Advised.

ALERT For Strong SSE-SSW Winds Overnight Into Wednesday Morning In Advance And Right Along A Squall Line Of Potentially Strong-Severe Storms

Strong winds are expected across the entire area but with enhancements along high mountain ridges and in typical mountain wave breaking zones ( e.g., Powell Valley of Wise  County & Clinch River Valley of Russell-Tazewell counties in southwest Virginia & along Pine-Black Mountain in SE KY ).

ALERT For Heavy Rain Potential & Strong Rises On Creeks In The Midnight-Noon Period of Wednesday

The threat for strong rises on creeks will be greatest in those draining the High Knob Massif where snow melt has steep creeks running swift, and in any locations that might have downpours in thunderstorms during the Midnight to Noon period of today.

Overnight Into Mid-Morning

Increasing clouds with showers & thunderstorms becoming likely during the midnight-sunrise period.  Strong to locally severe storms possible.  Windy.  SSE winds 15-35 mph, with higher gusts, below 2700 feet.  SSE-S winds 25-40 mph, with gusts of 50-60+ mph, along upper elevation ridges ( locally severe winds to 60+ mph also possible in mountain wave zones ).  Unseasonably warm & humid.  Temperatures varying from upper 40s to the upper 50s.

The main threat from showers & thunderstorms, other than heavy rainfall, will be the potential for downward transfer of powerful winds aloft to the surface.  The main squall line is expected around sunrise along the Virginia-Kentucky border, reaching western Lee County first ( probably before sunrise ).  Some development will be likely in advance of this main squall line during the overnight.

This Afternoon

Rain & showers ending.  Partly sunny.  Winds SSW-WSW at 10-20 mph, with higher gusts.  Temps widespread in the 40s to upper 50s-lower 60s ( tending to drop late ).

Tonight Into Mid-Morning Wednesday

Becoming cloudy and colder.  Cloud bases obscuring upper elevations with freezing fog ( riming ) above 3000 to 3500 feet overnight into morning.  Chance of flurries or snow showers overnight into the morning.  SW winds shifting WNW to NW at 5-10 mph, with higher gusts across upper elevation mountain ridges.  Temperatures varying from upper 10s to lower 20s along upper elevation ridges to the upper 20s to lower 30s by sunrise to mid-morning ( milder leeward of mountains toward the Tri-Cities ).  Wind chill factors in the 10s & 20s into morning ( single digits at the highest elevations of the High Knob Massif ).

 

Weather Discussion ( February 2-3 )

Afternoon Update

My afternoon update is to add an ALERT for high water on steep creeks draining the High Knob Massif which are near flood stage.  Be very careful along these roaring creeks.

Big Stony Creek Stream Gage At 4:15 PM
Big Stony Creek Stream Gage At 4:15 PM

Big Stony Creek was only 0.6 feet below flood stage as of 12:15 PM.  A new stream level update at 4:15 PM showed a slight drop in the level to 5.5 feet ( 12″ below flood stage ).

Superintendent Andrew Greear, of the City of Norton Water Plant, reported at 4:00 PM that the ROAR of water there had also began to decrease a little.  It was, indeed, a very close shave and a Flood Watch should have officially been issued before this event given recent snow melt + it’s intensity.

Little Stony Creek, as well as many other steep creeks, are ROARING and at very high levels along both sides of the Wise-Scott border into northern Lee County.  Flooding of some low-lying and poor drainage places has occurred.

Clinch River Stream Gage At 4:15 PM
Clinch River Stream Gage At 4:15 PM
The Clinch River at Speers Ferry was a little less than 5 feet below flood stage at 4:15 PM, and is forecast to rise into Thursday.
Clinch River Forecast To Rise
Clinch River Forecast To Rise Into Thursday At The Speers Ferry Point
Rainfall totals topped 2.00″ in the High Knob Massif into today, with 2.24″ reported by the Automated Gauge on Big Stony Creek.  More than 2.00″ also looks to have fallen at Big Cherry Lake Dam.
High Knob Massif Webcam
High Knob Massif Webcam – University Of Virginia’s College At Wise

With relatively rapid afternoon clearing of low clouds temps have risen and I have updated the MAXS, with beginning of cold air transport delayed until tonight.

Nora 4 SSE on Long Ridge of Sandy Ridge
Nora 4 SSE on Long Ridge of Sandy Ridge – Elevation 2650 feet

 

My Overnight Discussion

A beautiful but increasingly windy Tuesday was observed across the mountain area, with additional wind speed rises tonight along mid-upper elevation mountain ridges and in local mountain wave zones.

High Knob Massif Webcam
High Knob Massif Webcam – University Of Virginia’s College At Wise
Observe that a portion of a Circumhorizontal Arc is visible above as sunlight is refracted by ice crystals in high altitude cirrostratus clouds.  Lower clouds are taking on wave forms amid strong winds.
High Knob Massif Webcam
High Knob Massif Webcam – University Of Virginia’s College At Wise

A nice sunset followed amid unseasonably warm air.  PM MAXS varied from low-mid 50s in the High Knob Massif to upper 60s in downslope locations from Pound to Clintwood and Haysi-Grundy ( 67 degrees officially at Clintwood 1 W ).

Black Mountain MesoNET
Black Mountain MesoNET – Elevation 4031 feet

The focus tonight is on ROARING winds, with 30-50+ mph speeds being common across mountain ridges above 2700 feet in elevation.

Flatwoods Mountain MesoNET
Flatwoods Mountain MesoNET – Elevation 2774 Feet

Local mountain wave gusts have also topped 50 mph in portions of the Clinch River Valley, and no doubt also amid portions of Powell Valley in Wise County.

Southwest Virginia Community College
Southwest Virginia Community College
Wind speeds in Wise have been running just below 30 mph at Lonesome Pine Airport ( perhaps higher in other spots there ).
Lonesome Pine Airport
Lonesome Pine Airport

A large shield of rain, with embedded thunderstorms, will be overspreading the mountain area during the overnight.

Eastern USA Regional Doppler Composite
Eastern USA Regional Doppler Composite At 12:18 AM – February 3

The Jackson Dual-Pol Doppler can be viewed for current images.  Note by clicking on “Toggle Map Size” that this image can be viewed at full screen size ( a zoom tool is on the right side and menu options can be removed ).

JKL Dual-Pol Doppler
JKL Dual-Pol Doppler At 12:32 AM – February 3, 2016
This Doppler automatically refreshes itself to the current image if left running in a separate window-tab, with various zoom options.
Quasi-Linear Convective System With Rear Inflow Jet
Quasi-Linear Convective System With Rear Inflow Jet Notches

The main severe threat for the Kentucky foothills into the mountains can be seen on Doppler imagery, with numerous notable echo notches along a wavy squall line which is indicative of rear inflow jets of strong winds aloft.  Transfer of these to the surface is the biggest concern for potential wind damage.

The AMS definition of a Rear Inflow Jet can be read, with transfer of strong winds to the surface in downdrafts which are enhanced by entrainment of drier, mid-level air into the system being the main idea ( this drier mid-level air aids evaporative cooling and enhances negative buoyancy or sinking of air in water loaded downdrafts in this setting ).

HRRR Model Future Doppler Forecast
HRRR Model Future Doppler Forecast At 7 AM Today

It is this enhanced, wavy squall line that models time to reach the Virginia-Kentucky border by around 7:00 AM, earlier for extreme western Lee County.

European Model 850 MB Wind Field Analysis At 7 PM
European Model 850 MB Wind Field Analysis At 7 PM Tuesday
Wind speeds analyzed up to around 80 mph at the 850 MB level is reason for concern as this squall line moves east into morning.

Heavy rainfall and strong rises on creeks, as well as ponding of water, will be the other main concern for the predawn to mid-day period.

Stay tuned to NOAA Weather Radio for possible warnings.

Have a safe Wednesday.

020216 Forecast

My Forecast For Today ( February 2 )

ALERT Remains In Effect For Dense Fog Into The Overnight Along Mid-Upper Elevation Ridges And Plateaus ( Cloud Bases Lifting Off Mid-Elevations Toward Morning – Patchy Dense Fog Other Sites )

ALERT For Strong SSE-SSW Winds From This Afternoon Into Wednesday Morning – In Advance & Along A Line Of Potentially Strong-Severe Storms

Strong winds are expected across the entire area but with enhancements along high mountain ridges and in typical mountain wave breaking zones ( e.g., Powell Valley of Wise  County & Clinch River Valley of Russell-Tazewell counties in southwest Virginia & along Pine-Black Mountain in SE KY ).

ALERT For Heavy Rain Potential & Strong Rises On Creeks In The Midnight-Noon Period of Wednesday

The threat for strong rises on creeks will be greatest in those draining the High Knob Massif where snow melt has steep creeks gushing with water tonight, and in any locations that might have downpours in thunderstorms during the Midnight to Noon period on Wednesday ( February 3 ).

Overnight Into This Morning

Dense fog along middle-upper elevation ridges-plateaus giving way to patchy fog at lower-middle elevations as winds shift from northerly to SE to SSW at 5 to 15 mph.  Temperatures nearly steady in the 40s ( or slowly rising into morning on mid elevation ridges & plateaus ).

This Afternoon

Partly to mostly sunny.  Warm & windy.  SSE winds 10-20 mph, with higher gusts, below 2700 feet.  SSE to S winds at 20-30 mph, with gusts to 40+, on upper elevation ridges.  Local mountain wave gusts becoming possible.  Temps varying from 50 to 55 degrees in upper elevations of the High Knob Massif to the upper 50s to middle 60s ( some upper 60s possible amid downslope communities of the Russell Fork & Levisa Fork basins from Pound to Grundy ).

Tonight Into Wednesday Morning

Increasing clouds with showers & thunderstorms becoming likely during the midnight-sunrise period.  Strong to locally severe storms possible.  Windy.  SSE winds 20-35 mph, with higher gusts, below 2700 feet.  SSE-S winds 30-40 mph, with gusts of 50-60+ mph, along upper elevation ridges ( locally severe winds to 60+ mph also possible in mountain wave zones ).  Unseasonably warm & humid.  Temperatures varying from upper 40s to the upper 50s.

 

Weather Discussion ( February 1-2 )

The new month of February is wasting little time in getting active, with the first weather system spreading rain across the mountain area during Monday.

High Knob Massif Webcam
High Knob Massif Webcam – University Of Virginia’s College At Wise

Cloud bases dropped as low-level winds shifted northerly.  This was well predicted in advance by my forecast last night ( reference my 020116 Forecast for details ).

High Knob Massif Webcam
High Knob Massif Webcam – University Of Virginia’s College At Wise
During the evening some especially dense sections along U.S. 23 included Little Stone Mountain Gap, near Powell Valley Overlook, and the Wise Mountain section at the head of Indian Creek.
Lonesome Pine Airport
Lonesome Pine Airport In Wise

These clouds will remain on the ground in mid-elevations as long as low-level winds possess a northerly component, and will linger after that if the shift to SSE-SSW winds remains light enough overnight to minimize downsloping ( valleys will tend to have dense fog in places ).

Black Mountain MesoNET
Black Mountain MesoNET – Ending At 12:45 AM on February 2, 2016
This shift to southerly winds has now occurred along high crest lines which also remain obscured in orographic pilatus clouds.
Big Stony Creek Stream Gauge
Big Stony Creek Stream Gauge Up To 8:30 PM – February 1, 2016

Snow melt has produced a steady increase in water levels on steep creeks draining the High Knob Massif since beginning on January 26, with a recent peak to above “Red Alert” level indicating a gush ( ROAR ) of tumbling whitewater.

This prolonged period of snow melt run-off is not surprising given the snow cores that I took in the High Knob Massif.  Reference the updated My High Country Focus section for more details.

 Focus now shifts to a major storm system that will begin impacting the Mountain Empire later today as the pressure gradient begins to CRANK winds.  Severe non-storm related gusts will become possible from late today into Wednesday.

Storm Prediction Center DAY 1
Storm Prediction Center DAY 1 – Severe Thunderstorm Risks

Meanwhile, the highest risk for severe thunderstorms will remain west and southwest of the Appalachians; however, this will need to be closely followed as a strong to locally severe thunderstorm can not be ruled out ( main threat being enhanced transfer of severe winds aloft down to surface layers ) as the main squall line reaches the area between Midnight and Sunrise on Wednesday.

NAM 12 KM Model Total Precipitation Forecast
NAM 12 KM Model Total Precipitation Forecast
Outside of the strong wind threat, with possible tree damage and downed power lines, the focus will be on where do main bands of heavy rainfall set up.  The models differ on this and often have trouble with convective rains ( like with orographic precip ).
Given recent snow melt, and ongoing melt, we must hope to keep downpours at a minimum as this system rolls across the area.
GFS Model Total Precipitation Forecast
GFS Model Total Precipitation Forecast

Stay tuned for updates.

High Knob Massif Webcam
High Knob Massif Webcam – University Of Virginia’s College At Wise

Meanwhile, please slow down in this DENSE Fog.

Have A Safe Tuesday.

020116 Forecast

My Forecast For Today ( February 1 )

ALERT For A Period Of Dense Fog Formation During Monday Afternoon-Evening For Mid-Upper Elevations Along & North Of The High Knob Massif & Tennessee Valley Divide On Upsloping Northerly Winds 

Overnight Into Monday Morning

Increasing low-mid clouds.  A chance of light rain-showers by morning.  Winds SSW-SW 10-20 mph, with higher gusts, along middle elevation ridges & plateaus below 2700 feet.  SSW-SW winds 15-25 mph, with higher gusts, along upper elevation mountain ridges.  Temperatures widespread in the 40s to low-mid 50s ( mildest temps on exposed middle elevation ridges-plateaus of the thermal belt ).  Wind chill in the 30s & 40s ( coldest at the highest elevations ).

This Afternoon

Rain & showers.  A chance of thunder.  SW winds shifting NNW-NNE and decreasing to 5-10 mph, with higher gusts along ridges.  Turning cooler.  Cloud bases dropping with potential for dense fog formation from elevations of Wise upward ( along and north of High Knob Massif ).  Patchy fog possible at lower elevations.  Temps dropping to the lower-middle 40s ( a little milder south, lee of mountains, into Clinch, Powell, Holston river valleys toward the Tri-Cities ).

Tonight Into Tuesday Morning

Chance of light rain or drizzle.  Chance of dense evening fog along middle-upper elevation ridges-plateaus giving way to patchy fog at lower-middle elevations as winds shift from northerly to SE-SSW at 5-15 mph.  Temperatures nearly steady in the 40s ( or slowly rising into morning on mid elevation ridges & plateaus ).

*Strong winds and showers-thunderstorms will be likely from late Tuesday into Wednesday.  A line of strong-severe thunderstorms and heavy rainfall will need to be closely watched as it approaches the mountains from the west.  Strong rises on creeks will also be possible.  Stay tuned for updates on this major storm system.

 

Weather Discussion ( Jan 31-Feb 1 )

Sunday was a LONG day for me.  After doing my nightly forecast it was up early to meet my buddy Roddy Addington at the City of Norton Water Plant for a run at the summit.

City of Norton Water Plant
City of Norton Water Plant – 10:25 AM on January 31, 2016
Reference My High Country Focus for more details.

Run-off from snow melt has been steady, but creeks are showing some rise with the Big Stony Creek gauge reaching the “Yellow Alert” stage of 3.0 feet as of 1:45 AM tonight.

Big Stony Creek Stream Gauge
Big Stony Creek Stream Gauge
This will factor into any heavy rainfall upcoming this week.
Lonesome Pine Airport In Wise
Lonesome Pine Airport In Wise

Meanwhile, Saturday Night through Sunday was all about strong SW winds which were simply ROARING like a big 747 had landed on top of High Knob.  Strong winds mixed down into Pound, Clintwood, and across nearly all of Wise and Dickenson counties during this period.

Black Mountain MesoNET
Black Mountain MesoNET Wind Graph

There is absolutely no doubt winds at High Knob Lookout topped 50 mph during this past day, with snow across all of the northern woods being wind blasted and covered by fine particles blown off trees.

European Model 850 MB Wind Field Analysis
European Model 850 MB Wind Field Analysis – 7 AM Sunday ( Jan 31 )

Winds will finally diminish, at least temporarily, today as a cold front passes and the flow turns northerly.  Rain with a possible rumble of thunder will give way to a little cooler conditions and cloud bases will drop later today into this evening to generate a period where dense fog formation will become possible for mid-upper elevations along and north of the High Knob Massif ( patchy fog being possible amid all locations with rain ).

I will try to update this later if possible.

Have a great Monday.