Mountain Area Forecast ( May 16-19 )

ALERT For The Potential Of Dense Fog As Cloud Bases Drop From Upper Elevations Into Middle Elevations By Wednesday Morning For Locations Along & North Of The High Knob Massif-Tennessee Valley Divide.  Caution For Travelers Is Advised.

A redevelopment of showers, with dropping cloud bases, on a northerly wind shift is expected into the predawn-morning hours of Wednesday.  Conditions will continue to be cooler than average for this time of year, especially for locations along and north of the High Knob Massif and Tennessee Valley Divide. 

Overnight Into Tuesday Morning

Showers developing.  Thunder possible.  SSE-SSW winds increasing to 5-15 mph, with higher gusts, along middle elevation mountain ridges-plateaus.  SSW to SW winds increasing to 10-20 mph, with higher gusts, along mountain ridges above 2700 feet.  Temperatures widespread in the 40s to lower 50s.

Tuesday Afternoon

Showers & thunderstorms becoming likely.  Locally heavy rainfall.  SW winds 5-15 mph, with higher gusts, becoming northerly.  Temperatures varying from the 50s to middle 60s ( coolest in upper elevations ).  Dense fog across upper elevations, with patchy fog in other locations.

Tuesday Night Into Wednesday Morning

Chance of evening showers, then showers becoming likely by the predawn-morning.  Dense fog possible along middle-upper elevation ridges-plateaus.  N-NE winds at generally less than 10 mph.  Temperatures widespread in the 40s to lower-middle 50s.

Wednesday Afternoon

Cloudy & chilly.  Chance of rain.  Low clouds.  Winds NNE-ENE at 5-10 mph, with higher gusts along middle to upper elevation mountain ridges-plateaus.  Temperatures in the upper 40s to mid-upper 50s ( coolest in upper elevations ).

Wednesday Night Into Thursday Morning

Low clouds.  Chance of showers & drizzle.  Chilly.  Winds NE to ESE at generally less than 10 mph.  Temperatures in the 40s to around 50 degrees.

Weather Discussion For May 16-18

Late Tuesday PM Update

Another cooler than normal day for this time of year once again featured temperatures struggling to break 60 degrees in locations along and north of the High Knob Massif.

Afternoon MAXS reached 60 degrees at Nora 4 SSE and 63 degrees in Clintwood ( with 0.41″ of total rainfall / 5.53″ in May ).

Tuesday PM ( May 17 ) temperatures remained in the 50s for places above 2700 feet in elevation, despite a continuation of southerly air flow.  A shift to northerly wind direction is delayed on latest model runs until the predawn-morning hours of Wednesday.

Following mid-morning to early afternoon showers, low clouds, and areas of fog some welcomed early evening breaks in the overcast have developed above Wise.

Temperatures are expected to cool some on Wednesday with northerly flow for locations along and north of the High Knob Massif and Tennessee Valley Divide.

Previous Discussion

A cold & frosty morning greeted the new work week into Monday with WIDESPREAD ( not patchy ) frost observed throughout the mountain valleys and hollows of central-northern Wise and Dickenson counties.

Skies became mostly clear into Sunday night ( below ) with dewpoints below freezing at middle-upper elevations.

Freezing temperatures were even reported into portions of the typically milder Clinch River Valley, with 32 degrees and some minor plant damage observed in The Pines section near the community of Dungannon into Monday morning.

Why would this not occur, with dewpoints in the 20s to around 30 degrees from the elevation of Norton-Wise on upward under decreasing winds and mostly clear skies.

MIN temperatures varied from the upper 20s to lower 30s in many valleys, with an official MIN of 33 degrees observed in Clintwood.  The MIN reached 30 degrees in Norton.

*NOTE for those asking, temperatures reported by WCYB are not located in Clintwood but are in the South of the Mountain area in the Ramey Flats community ( north of the Pound River ).  This site tends to be warmer on cold air drainage nights than valleys such as the Holly Creek Valley ( Clintwood ) and Georges Fork area.

The Weatherbug station at Norton Elementary School is not “officially” online and has been reportedly flagged by AWS for a temperature error that seems to be most pronounced ( but likely exists all the time ) during nights with cold air drainage into the Norton valley.

Mid-high cloud did increase rapidly into Monday morning such that day-time MAX temps into the afternoon remained cooler than I had anticipated at lower-middle elevations along and north of the High Knob Massif.

It was a struggle for temperatures to reach into the 50s from Norton-Wise to Clintwood and the adjacent ridge communities ( 57 degrees being obtained in Clintwood ).

While there are some significant differences in model forecast rainfall amounts during the next few days, the general pattern will be damp and cooler than normal for this time of year.

The high resolution NAM Model is looking particularly nasty for locations along and north of the High Knob Massif for Tuesday and Wednesday, with low cloud bases developing on northerly upslope flow.  I have already posted an ALERT for the potential of DENSE FOG at middle-upper elevations for later Tuesday into Wednesday morning.  Stay tuned for updates to see if this may need to be changed or extended.

*The above requires advance warning since travelers along U.S. 23, for example, tend to run from no fog into dense fog upon driving up Indian Creek Mountain onto the Wise Plateau from the north, and from Powell Valley toward Little Stone Mountain Gap and the Overlook area from the south.  Rapid drops in visibility upon going into clouds are very dangerous for motorists unaware.

Mountain Area Forecast ( May 15-17 )

ALERT For Mountain Valley Frost Formation Sunday Night Into Monday Morning – Especially For Locations Along & North to Northeast Of The High Knob Massif

Below freezing temperatures will occur at highest elevations into Sunday Morning, amid unseasonably cold wind chills, with limited frost potential across middle to lower elevations where skies stay cloudy.  If skies clear overnight the threat for frost will increase within mountain valleys into Sunday Morning.

Partly to mostly clear skies, low dewpoints, and light winds will promote more favorable conditions for frost formation in valleys during Sunday Night into Monday Morning.  Min temperatures in the upper 20s to middle 30s are expected, with coldest conditions within mid-upper elevation valleys in the High Knob Massif to Burkes Garden corridor of southwestern Virginia.

Widespread frost will be possible on valley floors and impact communities such as Addington, Big Laurel, Burkes Garden, Coeburn, Dante, Elk Garden, Georges Fork, Nora, Norton, Ramsey, Stephens, Tacoma, Tazewell and Trammel ( to note only a few ).  Shady Valley and other typically cold valleys in NE Tennessee and NW North Carolina will also be at risk.

Little to no frost is currently expected on exposed middle elevation mountain ridges & plateaus, and within major river valleys where fog formation will be likely along rivers such as the Clinch, Powell, Holston, Cumberland, and in lower portions of the Russell Fork and Levisa Fork drainages.

Overnight Into Sunday Morning

Partly to mostly cloudy.  Cold.  Gusty WNW-NW winds 5-15 mph, with higher gusts, along mountain ridges below 2700 feet ( decreasing some into morning ).  NW-N winds 10-20 mph, with higher gusts, along mountain ridges above 2700 feet.  Temperatures dropping the 30s, except 20s to around 30 degrees in colder locations at the highest elevations.  Wind chills in the 20s along upper elevation mountain ridges ( 10s in gusts on the highest peaks ).

Sunday Afternoon

Mostly sunny.  Deep blue skies.  Unseasonably cool.  Winds WNW at 5-15 mph, with higher gusts.  Temps varying from the 40s in upper elevations to the upper 50s to low-mid 60s.

Sunday Night Into Monday Morning

Mostly clear evening skies with some increasing high clouds overnight into morning.  W-NW evening winds shifting N to NE into morning at under 10 mph.  Temperatures varying from 30s to lower 40s on mid-upper elevation mountain ridges-plateaus to the 20s to lower 30s in colder valleys with patcy to widespread frost formation.  Fog possible within major river valleys and around large lakes.

Monday Afternoon

Increasing clouds.  Milder.  ESE-SSE winds at generally less than 10 mph.  Temperatures varying from 50s across upper elevations to the 60s in lower-middle elevations.

Monday Night Into Tuesday Morning

Showers developing.  Thunder possible.  SSE-SSW winds increasing to 5-15 mph, with higher gusts, along middle elevation mountain ridges-plateaus.  SSW to SW winds at 10-20 mph, with higher gusts, along mountain ridges above 2700 feet.  Temperatures in the 40s to lower-middle 50s.

Tuesday Afternoon

Showers & thunderstorms becoming likely.  Locally heavy rainfall.  SSW-SW winds 5-15 mph, with higher gusts, along mountain ridges-plateaus below 2700 feet.  SW-WSW winds 10-20 mph, with higher gusts, along mountain ridges above 2700 feet.  Temperatures in the 50s to lower-middle 60s.

Weather Discussion ( May 14-17 )

A gusty and colder air mass moved into the mountains during Saturday with falling afternoon temperatures felt along and north of the High Knob Massif.

Saturday afternoon ( May 14 ) temperatures fell through the 50s into the 40s amid middle elevations along and north of the High Knob Massif ( locations between 2000 & 3000 feet ).  This included Norton, Wise, and adjacent communities.

Locations above 3000 feet, amid the upper elevations, saw temps drop through the 40s into the 30s.

Temperatures dropped into the 30s between 4:00 to 5:00 PM atop the High Knob Massif and Black Mountain, with much colder wind chills on gusty NW winds.

Breaks in the overcast occurred lee of the Cumberland Mountains and adjacent Cumberland Plateau, with some low-level terrain blocking also slowing down the cold air advection.

The result was large temperature differences between locations along and north-northwest of the High Knob Massif verses places to the south and southeast ( 30s and 40s verses 50s and 60s ).

Focus on Saturday Night into early hours of the overnight were on partly-mostly cloudy skies and temperatures that had already dropped below freezing at highest elevations.

At 2:15 AM a air temperature of 30 degrees combined with N wind gusts to 20 mph to generate a 17 degree wind chill factor at the 4031 foot elevation of the Black Mountain Mesonet site located along the Virginia-Kentucky border ( near Harlan-Wise line ).

Forecast soundings above Wise show that the air dries significantly into Sunday with deep blue skies like autumn  ruling the mountain landscape through the afternoon.

Although an increase in high altitude cloudiness is shown into Monday morning ( below ), the low-level air remains very dry with dewpoints in the 20s amid middle to upper elevations being conducive for strong radiational cooling and development of cold air drainage flows into mountain valleys during Sunday Night.

The threat for widespread frost must be respected, especially in mountain valleys of Wise, Dickenson, Russell and Tazewll counties where air will be driest at 900-800 mb. A freeze being possible in colder locations.

Little to no frost is expected on exposed middle elevation mountain ridges & plateaus, and within major river valleys where fog formation will be possible along rivers such as the Clinch, Powell, Holston, Cumberland, and in lower portions of the Russell Fork & Levisa Fork drainages.

Focus into the new work week shifts back to wetness, with showers and downpours in thunderstorms expected to return by Monday Night into Tuesday.

May 2016 has already produced as much or more rainfall than March+April combined in many places along the mountainous Virginia-Kentucky border.

Mountain Area Forecast ( May 12-15 )

There Is An Increasing Risk For Frost In Mountain Valleys In Coming Days, Especially By Sunday Night Into Monday AM – Please Stay Tuned For Updates

Temperatures will drop to around freezing at highest elevations in the High Knob Massif during Saturday Night Into Sunday Morning.  An abundance of upslope clouds, on WNW flow, will limit the frost potential during this time.  However, drier air and low dewpoints will combine with light winds beneath High Pressure to generate strong radiational cooling and cold air drainage into mountain valleys during Sunday Night into Monday Morning.

There will be potential for high clouds into Monday AM, but they may not be thick enough to prevent temperatures from falling to around or below freezing in colder mountain valleys ( MINS are currently expected to drop into the 20s to low-mid 30s in valleys, with coldest conditions in mid-upper elevation valleys at 2000 to 3000+ feet above sea level within the High Knob Massif to Burkes Garden corridor of southwestern Virginia ).

A heavy frost-freeze potential will be possible in and around such communities as Norton-Ramsey, Tacoma-Coeburn, Tazewell and Burkes Garden ( to note a few places ).

I will issue a new forecast late Saturday to cover this potential.

Previous Alerts & Statements

ALERT For High Stream Levels And Ponding Of Water In Poor Drainage & Low Lying Areas Of Northern Wise and Dickenson Counties Into Thursday Evening

*A rainfall total of 1.85″ has been officially measured in Clintwood since Midnight, with 1.45″ since Noon Thursday.  Poor drainage and street flooding has occurred, with high stream levels in the area.  Caution Is Advised.

The RLX NWSFO has included Dickenson & Buchanan counties in a Flash Flood Watch Until 8:00 AM Friday

The Storm Prediction Center Maintains A Marginal Risk For Severe Thunderstorms Through Thursday Night – Stay Tuned To NOAA Weather Radio And Severe Weather Alert Systems For Any Possible Watches Or Warnings Which May Be Needed

Overnight Into Thursday Morning

Showers & thunderstorms developing.  Downpours likely.  Winds SW-WSW 5-15 mph along mountain ridges-plateaus below 2700 feet.  WSW to WNW winds 5-15 mph, with higher gusts, along mountain ridges above 2700 feet.  Temperatures in the 50s to low-mid 60s.

Thursday Afternoon

A chance of hit-miss showers & thunderstorms.  Warm and humid.  S-SW winds 5-15 mph, with higher gusts, outside of any local storms.  Temperatures varying from upper 60s to lower 70s in upper elevations to the upper 70s to lower 80s   ( warmest at lower elevations in the Russell Fork and Levisa Fork basins ).

Thursday Night Into Friday Morning

Showers & thunderstorms becoming likely.  Some storms could be strong to locally severe.  Heavy rainfall possible.  SW to WNW winds 10-20 mph, with higher gusts, along middle to upper elevation mountain ridges and plateaus.  Temperatures dropping into the 50s to around 60 degrees    ( around 50 degrees at highest elevations ).

Friday Afternoon

Becoming partly to mostly sunny.  Cooler & less humid.  WNW winds 5-15 mph, with higher gusts.  Temperatures varying from 50s in upper elevations to the upper 60s to middle 70s ( warmest in lower elevations ).

Friday Night Into Saturday Morning

Partly to mostly clear in the evening.  Increasing clouds overnight into morning.  Winds becoming SW at 5-10 mph, with higher gusts, along middle elevation mountain ridges and plateaus below 2700 feet.  W-SW winds 10-20 mph, with higher gusts, on mountain ridges above 2700 feet.  Temps in the upper 30s to mid 40s within colder valleys to the middle to upper 40s across exposed ridges and plateaus.

Saturday Afternoon

A chance of showers.  Thunder possible.  Windy.  SW winds shifting WNW at 10-20 mph, with higher gusts ( especially along mountain ridges ).  Turning colder.  Temperatures in the 50s to lower-middle 60s, then dropping through the 40s and 50s ( coldest in upper elevations ) during mid-late afternoon, amid blustery conditions.

Saturday Night Into Sunday Morning

Partly to mostly cloudy.  Cold.  Gusty WNW-NW evening winds decreasing to less than 10 mph overnight along middle elevation ridges-plateaus below 2700 feet.  WNW to NW winds 10-20 mph, with higher gusts, along mountain ridges above 2700 feet ( decreasing some into morning ).  Temperatures dropping into the middle 30s to lower 40s, except around or below freezing in coldest locations at the highest elevations.  Wind chills in the 20s along upper elevation mountain ridges, with 10s in gusts at highest elevations.

Temperatures are expected to drop to around or below freezing along the highest mountain ridges into Sunday Morning.  Stay tuned for updates on low temperatures in other locations, with potential for mountain valley frost formation in colder places.

Weather Discussion ( May 11-14 )

Early Thursday Evening Update

Repeated downpours of heavy rain have impacted northern Wise & Dickenson counties since Noon Thursday with rain totals of 1.00″ to 2.00″ ( around 1.50″ in Clintwood ).

A total of 1.85″ has been officially measured in Clintwood since Midnight, with a strong overnight storm followed by repeated downpours of heavy rain, spiced with lightning-thunder, since Noon Thursday.  Flooding of poor drainage locations and high stream levels has resulted.  A Flash Flood Watch is now in effect until 8:00 AM Friday for Dickenson & Buchanan counties.

As of 7:00 PM Thursday the May rainfall tally of 4.74″ in Clintwood is more than measured during March+April combined ( 3.65″ ).

Other May rainfall totals of 4.00″ to 5.00″+ have occurred in portions of the High Knob Massif, with significant flow on whitewater creeks draining the high country.

Any of these wet locations could be subject to significant run-off and flash flooding if additional heavy rainfall develops later tonight into Friday AM along and in advance of an approaching cold front.  Please remain alert to NOAA Weather Radio for any additional watches and/or warnings.

Previous Discussion

Showers and downpours in thunderstorms produced heavy rainfall amounts across the mountain area during the pre-dawn hours of Wednesday, with widespread 0.50″ to 1.50″+ amounts being common.

Specific Rainfall Totals

Clintwood: 0.45″
John Flannagan Dam: 0.47″
Grundy: 0.54″
City of Norton WP: 0.83″
Big Black Mountain: 1.04″
Dungannon: 1.16″
Little Mountain: 1.36″
Stony Creek near Ka: 1.60″
Upper Norton Reservoir: 2.41″

The heaviest rain amounts fell from the High Knob Massif southwest into western portions of Lee County, with strong rises on whitewater creeks draining the massif and in some locations across western-southern Lee County.

A vertical stream level rise of 2.4 feet generated roaring whitewater on Big Stony Creek ( draining 41.9 square miles of the High Knob Massif into northern Scott County ).  This was the highest stream level observed so far in May.  Strong rises, to gushing levels, were also observed on South Fork of the Powell River ( draining Big Cherry Lake Basin ) and on other steep creeks such as Clear Creek and the Little Stony along either side of the Wise County-Scott County border.

The heaviest rains fell above the great band of calcareous cliffs that ring much of the High Knob Massif, above which early-mid spring conditions currently exist verses late spring in valleys resting far below.

The focus during this early overnight of Thursday is once again on another batch of showers and downpours in thunderstorms moving across Kentucky.

As of 1:50 AM Thursday they are just beginning to develop into the mountains, in hit-miss fashion, along the High Knob Landform & Cumberland Mountains.

Short range models are struggling to capture this activity so uncertainty exists as to how much will make it into the mountains overnight into early Thursday.  Since forecast models generally under-estimated rainfall amounts into early Wednesday, the potential for more downpours must be respected.  Places that had heavy rain into Wednesday will be most likely to have strong rises on streams ( since the ground is already saturated ) if they have downpours.

Stay tuned to NOAA Weather Radio for any possible watches or warnings that might be needed.

My New Forecast ( May 10-12 )

Updated At 2:00 AM Wednesday – May 11

ALERT For Downpours Of Heavy Rain During The Predawn-Early Morning Hours Of Wednesday

The Storm Prediction Center Has A Marginal Risk Of Severe Thunderstorms Across The Entire Region For Wednesday and Thursday

An Upgrade To A Higher Level Of Risk Will Be Possible For Portions Of The Region.  Stay Tuned For Updates.

Overnight Into Tuesday Morning

Mostly cloudy.  Mild.  Chance of a rain shower.  SSE-SSW winds 5-10 mph, with some higher gusts, along mountain ridges & plateaus below 2700 feet.  SSW-SW winds 5-15 mph, with higher gusts, along mountain ridges above 2700 feet.  Temperatures widespread in the 50s to low-mid 60s.

Tuesday Afternoon

Partly-mostly cloudy.  Chance of showers & thunderstorms.  Some storms could be strong to locally severe, especially late.  S to SW winds 5-15 mph, with higher gusts.  Temps varying from 60s in upper elevations to mid-upper 70s.

Overnight Into Wednesday Morning

Showers & thunderstorms.  Some storms could be strong to locally severe.  Downpours of heavy rainfall likely.  SSW-SW winds 5 to 15 mph, with higher gusts, along mountain ridges-plateaus below 2700 feet.  SW winds 10-20 mph, with higher gusts, along mountain ridges above 2700 feet.  Mild with temperatures in the 50s to lower-middle 60s.

At least a marginal risk for strong to locally severe thunderstorms will continue Wednesday and Thursday, amid many dry hours.  Remain alert for the potential of strong-severe thunderstorm development.

Wednesday Afternoon

Warm & humid.  A chance of showers & thunderstorms.  Winds SW-W at 5-15 mph.  Temperatures varying from the 60s to around 70 degrees in upper elevations to the upper 70s to lower 80s.

Wednesday Night Into Thursday Morning

A chance of showers & thunderstorms.  Winds SW-WSW 5-15 mph along mountain ridges-plateaus below 2700 feet.  WSW to WNW winds 5-15 mph, with higher gusts, along mountain ridges above 2700 feet.  Temperatures in the 50s to low-mid 60s.

Thursday Afternoon-Evening

A chance of showers & thunderstorms.  Some storms could be strong to locally severe.  Warm & humid.  S-SW winds mainly under 10 mph ( outside of storms ).  Temperatures varying from upper 60s to lower 70s in upper elevations to the upper 70s to lower 80s ( warmest at lower elevations in the Russell Fork-Levisa Fork basins ).

Weather Discussion ( May 8-12 )

Tuesday Evening Update

A very active afternoon-early evening to the west of the mountains has resulted in Severe Thunderstorm Watch Number 163 being issued up to the Virginia-Kentucky line.

A line of thunderstorms is likely to impact counties along the Virginia-Kentucky border after midnight, except for northern portions of Dickenson-Buchanan counties where severe thunderstorms are possible earlier.

Local development could occur in advance of such storms, as recently seen along and northeast of Pine Mountain ( with local development trying to get started in the High Knob Massif area ).

A total of 1.11″ of rain was recorded at the Upper Norton Reservoir with downpours associated with late evening thunderstorms that moved northeast across Powell Valley into the High Knob Massif during late Tuesday evening.

As of 2:00 AM Wednesday a non-severe line of thunderstorms, with heavy rainfall, was moving east across SE Kentucky and will impact the Cumberland Mountains overnight into Wednesday AM.  Although downpours of heavy rainfall and lightning will remain most prominent, kinks ( bows ) in the approaching line continue to suggest localized strong-gusty winds will remain possible.

Stay tuned to NOAA Weather Radio for possible additional watches and/or warnings which may be needed through Wednesday-Thursday.

Previous Discussion

Partly to mostly cloudy skies, with a little cooler temps, were observed on Mother’s Day which became better as the day progressed.

May 2016 has been wet, relative to March-April, with a stormy pattern expected to continue through much of this week before a break by late week into the early weekend gives way to another stormy period into next week.

*Cooler conditions are expected Friday-Saturday as a boundary stalls to the south, with return flow expected to then renew the threat for showers & thunderstorms by late weekend-early next week ( with a heavy rainfall potential ).  Stay tuned for updates.

The main focus Tuesday-Tuesday night will be on the potential for strong to severe thunderstorm development.

The SPC has expanded a slight risk region up against the  western slopes of the Cumberland Mountains, with a noted potential for an upgrade to part of this slight risk region, to enhanced status, being possible by later Tuesday.

Rounds of showers and thunderstorms, some strong to locally severe, will remain possible Wednesday & Thursday in advance of a upper air trough and surface cold front.

It is likely that the most favorable period for strong-severe thunderstorms during this mid-week time frame will come on Thursday as the surface front and trough approach from the west.  Stay tuned for updates on this potential.

The NAM and GFS models illustrate how problematic it is trying to forecast rainfall at this time of year, with highly varied amounts over only short distances ( as the models guess where these MAXS and MINS will be, note that the key word being GUESS ).

If the late week cold front stalls south of the mountain area, as currently suggested by the European Model group, then the potential for a heavy to excessive rainfall event may arise by next week ( with rainfall this week becoming a factor in the ultimate risk ).

*During May 1-9 more rain has fallen in Clintwood ( 2.43″ ) than fell during all of March ( 1.54″ ) or April ( 2.11″ ).  It seems likely May will soon produce more rain than March-April combined.

Superintendent Gary Hampton, of the Big Stone Gap WP, reported the greatest April rainfall in the area with 4.64″ measured at the Big Cherry Lake Dam in the High Knob Massif ( 6.82″ during March-April and 22.28″ during January 1-April 30 ).

My Weekend Forecast ( May 7-9 )

The Storm Prediction Center Has Issued A Marginal Risk For Severe Thunderstorms Later Today-Tonight For Locations Along & North To Northwest Of The Cumberland Mountains

Overnight Into Saturday Morning

Partly cloudy.  WNW-NW winds 5-10 mph, with higher gusts, along mountain ridges and plateaus below 2700 feet.   Winds WNW-N 10-15 mph, with higher gusts, on mountain ridges above 2700 ft.  Temperatures in the 40s to around 50 degrees, except dropping into the 30s in colder mountain valleys ( especially along and north of High Knob Massif ).

Saturday Afternoon

Partly cloudy & warmer.  Chance of a hit-miss shower or thunderstorm.  Becoming gusty.  WSW-W winds 10-20 mph with higher gusts.  Temperatures varying from 60s in upper elevations to the mid-upper 70s to around 80 degrees.

Saturday Night Into Sunday Morning

A chance for showers & thunderstorms.  Some storms could be strong to locally severe ( prolific lightning & damaging winds being the greatest threats ).  W-NW winds 10-20 mph, with higher gusts, along mid-upper elevation mountain ridges-plateaus.  Temperatures widespread in the 50s.

Sunday Afternoon

Partly to mostly cloudy.  Chance of a hit-miss shower or thunderstorm.  NW winds 5-10 mph, decreasing late and becoming variable to Easterly.  Temperatures varying from the 60s to the lower-middle 70s.

Sunday Night Into Monday Morning

Partly to mostly cloudy.  Winds becoming SSW-SW at 5-15 mph along middle elevation ridges-plateaus.  Winds SW-W 10-20 mph, with higher gusts, along upper elevation ridges.  Temperatures varying from the 40s to lower 50s in valleys to the 50s to lower 60s across exposed mid-upper elevation mountain ridges & plateaus.

A rather active and stormy pattern looks to dominate much of next week, with occasional rounds of showers & thunderstorms.

Weather Discussion ( May 6-9 )

From cold and blustery weather the pattern is now shifting back into late spring mode with warmer air poised to spread across the mountain region this weekend.

*The greatest snowfall reports during recent days featured 3.7″ on Mount LeConte and 3.5″ in Mount Mitchell State Park, both sites being above 6000 feet.  A total of 3.0″ was reported on Beech Mountain.  Only a trace of snow occurred atop the typically snowy locations of the High Knob Massif and Snowshoe Mountain ( at 4850 feet ).  The coldest air aloft passing south across the Great Smokies and southern Blue Ridge.

The focus now shifts back to May flowers & showers, with the Storm Prediction Center recently including much of southwestern Virginia within a marginal risk for severe thunderstorm development from late today into Sunday morning ( with WNW to ESE storm motion ).

This is in basic agreement with the latest European Model forecast, with higher storm chances from central-northern Wise County across Dickenson-Buchanan counties than across Scott & Lee counties.

The NAM Model group is a bit farther southwest, but clearly also shows a bias toward better coverage-chances toward the northeast verses southwest in far southwest Virginia.

Thunderstorms look to develop over western and central Kentucky during Saturday afternoon, and to spread east to southeast Saturday night into Sunday morning.  It will be a very close call for this year’s Kentucky Derby, as to whether storms will impact the race or not.

While mean storm trajectories, via the mean flow field, will favor a E to ESE motion, outflow boundaries that interact with terrain features across central-eastern Kentucky could allow for storm development to build SE-S ( with new development often favored on the inflow side ).

Thus, all of the VA-KY border counties will need to be alert for the possibility of thunderstorms impacting any given location ( as well as parts of northeastern-eastern TN ).

As always, stay tuned to NOAA Weather Radio for any possible watches and/or warnings that may be needed from late Saturday Into Saturday Night-Sunday AM.

My Forecast For May 5-7

Unseasonably cold weather, for May, will continue into Friday.  Any snow accumulations are expected to be above 4000 to 4500 feet and mainly restricted to highest peaks from the Smokies to Mount Rogers.

*Colder mountain valleys could drop into the 30s the next few nights, with frost possible if skies can become partly to mostly clear and winds light ( Friday AM and/or Saturday AM having better chances for partial clearing than Thursday AM ). 

Overnight Into Thursday Morning

Colder.  Chance of drizzle or light rain showers ( mixed at highest elevations ).  Dense fog becoming freezing fog at highest elevations.  WNW-NW winds 5-15 mph, with higher gusts, on mid-upper elevation mountain ridges-plateaus.  Temperatures varying from upper 20s to lower 30s at the highest elevations in the High Knob Massif to the upper 30s to lower 40s.  Wind chills in the 20s and 30s along mountain ridges, with 10s in gusts on the highest peaks ( some rime formation possible along the highest ridges-peaks ).

Thursday Afternoon

Mostly cloudy.  Chance of rain showers, especially by late, mixed with snow at highest elevations.  Local sleet or small hail possible at lower-middle elevations.  Chilly for May.  WNW to NW winds at 5 to 15 mph, with higher gusts.  Temps varying from 30s across upper elevations to the 40s to around 50 degrees ( milder south toward the Tri-Cities ).  Wind chills in the 20s and 30s.

Thursday Night Into Friday Morning

Chance of rain showers in the evening ( possibly mixed with snow on highest peaks ).  Partly to mostly cloudy overnight with chance of a shower.  WNW-NW winds 5-15 mph, with higher gusts, below 2700 feet.  NW to N winds 10-20 mph, with higher gusts, along mountain ridges above 2700 feet.  Temperatures varying from low-mid 30s to the low-middle 40s.  Wind chills in the 20s and 30s, except 10s in gusts along highest ridges.

Friday Afternoon

Mostly cloudy.  Continued chilly.  Chance of rain showers.  Winds NW-NNW at 10-20 mph, with higher gusts, along middle-upper elevation ridges & plateaus.  Temperatures varying from the 40s to mid-upper 50s.  Wind chills in the 30s and 40s ( coldest at the highest elevations ).  Warmer south toward the Tri-Cities.

Friday Night Into Saturday

Mostly cloudy during the evening.  Chance of a showers.  Then becoming partly cloudy overnight.  WNW-NW winds 5-10 mph, with higher gusts, along mountain ridges and plateaus below 2700 feet.   Winds WNW-NW 10-15 mph, with higher gusts, along mountain ridges above 2700 ft.  Temperatures in the 40s to around 50 degrees, except dropping into the 30s in colder mountain valleys if skies become partly cloudy.

Showers & thunderstorms will become possible as warmer air returns this weekend, displacing the cold, Canadian air mass moving into the region Thursday.

Weather Discussion ( May 4-7 )

Rain became mixed with wet snow at highest elevations in the High Knob Massif during Wednesday Night, with big flakes falling but not sticking ( temp in mid 30s ).

Temperatures as of 5:00 AM on Thursday ( May 5 ) have fallen to around freezing atop the High Knob Massif and Black Mountain, with much colder wind chill factors ( in the 10s to lower 20s amid northerly wind gusts in cap clouds…DENSE FOG ).

While it is too early for Blackberries to bloom, Dewberries are in bloom…so maybe this is Dewberry Winter!

Due to very cold air aloft, clouds will be abundant by day into Friday with chances for showers ( mixed with snow within highest elevations above 3500-4000 feet and all snow above 5000-5500 feet ).  Small hail or sleet will continue to be possible with some of the showers.

Note the puffy, vertically stacked clouds, with cold air aloft.  Any sunshine during Thursday and Friday will tend to develop clouds, due to rapid drops in temperature with increasing elevation.  At night; however, there will be a chance for clouds to break.  If clearing should occur it would allow temps to become colder in mountain valleys with readings dropping into the 30s.  Currently, the best chances for this would be Friday AM and/or Saturday AM as the Upper Low moves farther east.  A frost or local freeze risk could arise in colder valleys if skies clear for a prolonged period.

Precipitation beneath upper lows can be tricky, with the latest NAM 12 KM Model run forecasting heaviest amounts to remain east of the Cumberland Mountains and southern Appalachians ( in general ) today into Friday ( above ).

Rainfall increases with warm air advection showers and thunderstorm development into this weekend along and west of the Appalachians ( below ).

Keep Warm Amid This Dewberry Winter!

My Forecast For Today ( May 3-5 )

Very cold air aloft will support the development of numerous showers & thunderstorms, especially from late Tuesday into Thursday.  Many will be capable of producing hail.  As cold air deepens some snow and sleet will become possible by Wednesday Night into Thursday, especially across upper elevations.

*Some accumulation of snow-sleet will be possible above 3500 feet into Thursday Morning as unseasonably cold air, and wind chills, impacts the mountain region.  Some mix of wintry precipitation will be possible at lower-middle elevations.

Overnight Into Tuesday Morning

A chance of rain showers.  Areas of dense fog at highest elevations and in places that had heavy Monday rainfall.  Winds shifting WNW-NW at 5-15 mph along middle-upper elevation mountain ridges into morning.  Temperatures dropping into the 40s to middle-upper 50s ( coolest along highest mountain ridges ).

Tuesday Afternoon

Mostly cloudy.  Cooler.  A chance of showers.  Local thunder possible.  WNW-NW winds at 5-10 mph, with higher gusts.  Temps varying from upper 40s to lower 50s at highest elevations to the middle to upper 60s.

Tuesday Night Into Wednesday Morning

Mostly cloudy.  Chilly.  A chance of showers.  Local thunder & small hail possible.  W-NW winds generally less than 10 mph below 2700 feet.  W-NW winds 5-15 mph, with higher gusts, on mountain ridges above 2700 feet.  Temperatures varying from upper 30s to lower 40s at highest elevations to the mid 40s to around 50 degrees.

Wednesday Afternoon

Partly to mostly cloudy.  A chance of showers and hail producing thunderstorms.  SW-W winds at 5-15 mph, with higher gusts.  Temperatures varying from the 40s to lower 50s at highest elevations to the middle-upper 60s ( warmest at lower elevations and south toward the Tri-Cities ).

Wednesday Night Into Thursday Morning

A chance of showers and hail producing thunderstorms during the evening.  Rain showers becoming mixed with and changing to snow-sleet overnight into morning in the upper elevations ( mixed precipitation possible in middle to lower elevations ).  WNW-NW winds 5-15 mph, with higher gusts, on mid-upper elevation mountain ridges-plateaus.  Temperatures varying from upper 20s to lower 30s at the highest elevations in the High Knob Massif to the upper 30s to lower 40s.  Wind chills in the 20s and 30s along mountain ridges, with 10s in gusts on the highest peaks ( some rime formation possible along the highest ridges-peaks ).

Weather Discussion ( May 2-5 )

The stormy weather pattern that has opened May will be continuing through coming days, with forces driving this storminess shifting toward instability based cold air aloft.

Increasingly cold air aloft will begin to deepen in the vertical during coming days, with a large lapse rate or difference between surface layers and altitudes above 15,000 feet within the atmosphere, where air temps will plunge to -10 to -20 degrees ( Fahrenheit ) below zero.

This pattern is simply straight out of winter, with only modification by the time of year ( e.g., high May sun angles, longer days, warmer ground temperatures and low-level moisture via evaporation and transpiration ) working to ease some of the pain of a late season cold blast.

During May a setting analogous to the heart of winter creates other complicating factors, namely it enhances instability driven by increasingly cold air aloft and lapse rates ( differences in temperature between surface layers and altitudes above 10,000 to 20,000 feet in the free air ).

Numerous showers and thunderstorms will become possible as this instability increases, with many being capable of producing hail as the freezing level aloft drops.  Past settings like this have occasionally generated copious amounts of small to medium size hail.  A spring example being April 15 in 1998 when VDOT snow plows had to be called out for 3-4″ hail depths on routes such as U.S. 23 and State Route 80.

At a time of year when gorgeous spring ephemeral wildflowers are part of the main show, such a late season blast of cold air might seem unheard of; however, it is actually rather common ( and over the long-term locally gave rise to a May 10 spring planting rule…not to plant tender vegetation prior to this time due to cold air ).

At times the cold air blasts can be substantial enough to support snow, with May falls of snow recently being documented during May 1989 ( 2-4″+ ) and May 1992 ( 2″ up to 2-3 feet ).  May snow flakes being most recently observed during May 2005.

 It is too early to know what night or nights will be most favorable for valley frost, but an early estimate would be following the break-down of the northerly-northwest low-level flow into the upslope side of the mountains by late Thursday into Friday morning.  Stay tuned for updates.

My Updated Forecast ( April 30-May 3 )

ALERT For Heavy Rainfall With Strong To Severe Thunderstorms Monday Afternoon Into Monday Night

*The Storm Prediction Center Has Issued A Severe Thunderstorm Watch Effective Until 10:00 PM Monday

In addition, due to heavy weekend rains the threat for rapid rises along streams and flooding of low lying, poor drainage locations needs to be respected.  Please turn around, don’t drown if encountering a water covered roadway.

Saturday Afternoon

Cloudy & cool with light rain & drizzle.  Thunder possible, especially south to southeast of the High Knob Massif and Tennessee Valley Divide.  Northerly winds 5-15 mph, with higher gusts, along mid-upper elevation mountain ridges and plateaus.  Temps in the 50s to mid 60s along and north of the High Knob Massif-Tennessee Valley Divide, with 70s to lower 80s to the south and southeast.

Saturday Night Into Sunday Morning

Showers & thunderstorms becoming likely.  Some storms may be strong.  Downpours possible.  Winds becoming SSE to SSW at 5 to 15 mph, with higher gusts, below 2700 feet.  Winds SSW to SW at 10 to 20 mph, with higher gusts, along mountain ridges above 2700 feet.  Temperatures mainly in the 50s and 60s ( coolest at highest elevations ).

Sunday Afternoon

A chance of hit-miss showers & thunderstorms.  Winds SSW-SW at 5-15 mph, with higher gusts.  Temperatures varying from 60s across upper elevations to the 70s to around 80 degrees ( warmest at lower elevations ).

Sunday Night Into Monday

A chance of showers.  Thunder possible.  Winds SSW to SW at 5-15 mph, with higher gusts, along mountain ridges and plateaus below 2700 feet.  Winds SW-WSW 10-20 mph, with higher gusts, on mountain ridges above 2700 feet.  Temps in the 50s to lower 60s.

Monday Afternoon

Mild & humid with showers & thunderstorms developing.  Some storms may be strong to severe with torrential rain and strong winds-hail.  Winds SSW to SW 5-10 mph, with higher gusts.  Temperatures varying from the 60s across upper elevations to the mid-upper 70s in lower elevations.

Monday Night Into Tuesday Morning

Showers & thunderstorms.  Rainfall may be heavy at times.  Thunderstorms may be strong to severe during the evening.  Winds shifting WNW-NNW at 5-15 mph into the overnight and morning.  Temperatures dropping into the 40s to mid-upper 50s ( coolest along high mountain crestlines ).

Weather Discussion ( April 30-May 3 )

An update on this Monday ( May 2 ) is for the threat of strong-severe thunderstorm development and heavy rainfall, especially for counties along and west of the Virginia-Kentucky stateline & Cumberland Mountains.

Rainfall totals reached 1.00″ to 2.00″ in many places along the Virginia-Kentucky border during the weekend, with training storms having already developed over the foothills of eastern Kentucky on this Monday afternoon.  An eastward propagation during the afternoon will need to be closely followed.

Brief showers already observed Monday in Clintwood have been pounding with large drops and fast fall rates ( often a signal that the atmosphere is primed for torrential rainfall production ).

Severe thunderstorms just brushed the Clintwood area late Sunday, with Summer Salyers reporting dime size hail and moderate rainfall north of town in the Skeetrock community.  Very large hail fell along portions of Pine Mountain into the Hurley area of Buchanan County.

Rainfall Totals Observed May 1 to 9:00 AM on May 2

Clintwood 1 W: 1.35″
( 3.48″ since April 1 )

Upper Norton Reservoir: 1.33″
( 6.69″ since April 1 )

City of Norton Water Plant: 1.15″
( 4.17″ since April 1 )

Coeburn Water Treatment Plant: 1.12″
( 4.69″ since April 1 )

The month of April was atypically dry.  During only 24-36 hours, rainfall at the beginning of May was 63% as much in Clintwood, one of the drier locations, as observed during all of April.

An update on this Saturday is to account for a northerly wind shift into the Cumberland Mountains that has kept temperatures in the 50s ( highest elevations ) and 60s to generate a large north-south difference across the region.

Saturday PM temperatures reached 80 degrees or higher in parts of the Tennessee Valley verses only 50s above 3000 feet across the High Knob Massif, with low-mid 60s in Norton-Wise & Clintwood amid development of light rain and drizzle.

The best chance for any thunder through the remainder of this afternoon will be south & southeast of the Cumberland Mountains, before a wind shift back toward the SSE-SSW will allow more unstable air to come northward tonight into Sunday.

The Storm Prediction Center maintains a marginal risk for severe thunderstorm development through Sunday.

The strongest storms this afternoon remain far to the south over the Dixie States and Gulf Coast.

Forecast model runs today are cranking out heavy rainfall amounts, but timing and placement of heaviest rains does remain in question.

The NAM Model group is forecasting the heaviest rains to develop tonight into Sunday morning.

The Saturday AM run of the European Model is most bullish with a surge of heavy rain and storms by late Monday into Tuesday, with the GFS Model somewhat in the middle but generally closer to the NAM with heaviest amounts being predicted for tonight into Sunday.

The RLX NWSFO ( Charleston, WV ) has issued a Flood Watch for most of their coverage area through Sunday.

Clearly, models are showing the potential for heavy rainfall but timing and placement differences are raising questions as to when and where this will occur.  This continues to be one of the driest spring’s on record, which also remains a factor in any heavy rain forecasts.

Stay tuned to NOAA Weather Radio for any additional watches and/or warnings that may be needed through the next few days.

My New Forecast ( April 26-28 )

Showers & Thunderstorms Will Become Likely By Late Tuesday Into Tuesday Night.  Some Storms Could Be Strong To Locally Severe ( A Marginal Risk Has Been Issued By The Storm Prediction Center )

Overnight Into Tuesday Morning

Partly to mostly clear.  Winds SSW-SW 5-15 mph, with higher gusts, along middle elevation ridges-plateaus at elevations below 2700 feet.  Winds SW-WSW 10-20 mph, with higher gusts, along mountain ridges above 2700 ft.  Mild with temperatures varying from the 50s to lower 60s on exposed mountain ridges-plateaus to the 40s to lower 50s within mountain valleys.

Tuesday Afternoon

Partly to mostly cloudy.  Unseasonably warm.  Increasing humidity and haze.  A chance of showers & thunderstorms by mid-late afternoon.  Winds SSW-WSW at 5-15 mph, with higher gusts.  Temperatures varying from 60s to lower 70s at upper elevations to the lower-middle 80s ( warmest at low elevations of the Russell Fork & Levisa Fork basins ).

Tuesday Night Into Wednesday Morning

Showers & thunderstorms likely.  Some storms may be strong to locally severe.  Downpours are possible.  Winds becoming variable generally less than 10 mph outside of storms.  Winds WSW-W at 5-15 mph, with higher gusts, along mountain ridges above 2500-3000 feet.  Mild with temperatures in the 50s to lower 60s.

Wednesday Afternoon

Warm & humid.  A chance of showers & thunderstorms.  Downpours possible.  Winds SSW-SW at 5-15 mph, with higher gusts.  Temperatures varying from the 60s at the highest elevations to the mid-upper 70s.

Wednesday Night Into Thursday Morning

Partly to mostly cloudy.  Humid with areas of dense fog possible.  Scattered showers & thunderstorms.  Some Storms May Be Strong.  Downpours likely.  Winds SSW to W at 5-10 mph along middle-upper elevation mountain ridges and plateaus.  Temperatures widespread in the 50s.

A marginal risk for severe thunderstorms has been issued by the Storm Prediction Center for the entire region on Thursday.  Stay tuned to NOAA Weather Radio for any possible watches and/or warnings that may be needed.

Weather Discussion ( April 24-28 )

Weather is never dull amid the mountains, or so it seems, with chilly conditions on Saturday giving way to coldness into Sunday morning ( April 24 ).  While the MIN reached a chilly 38 degrees in Clintwood, amid fog, there was frost in higher mountain valleys.

MIN temperatures dropped below freezing in colder valleys of the High Knob Massif to Burkes Garden corridor, with an official MIN of 31 degrees in Burkes Garden being representative of valleys at around the 3000 foot level.

Amid the trend of this spring, temperatures soared from 38 degrees up to 80 degrees in Clintwood by late Sunday before dropping back ( plunging ) to 42 degrees by Monday AM.

Back to work Monday was simply gorgeous, and warm, but with a rather notable difference in temperatures between upslope locations in the High Knob Massif, Norton-Wise and Sandy Ridge communities on breezy-gusty SW winds verses the downslope locales ( much warmer ) from Pound-Grundy.

Max temperatures on Monday afternoon varied from 60s above 3200 feet in the High Knob Massif to 73 degrees at the 2650 foot level of Nora 4 SSE to 80 degrees at the 1560 foot elevation of Clintwood 1 W.

The overnight hours of Tuesday is featuring a typical nocturnal inversion with 40s in cooler mountain valleys verses upper 50s to low 60s along mid-upper elevation mountain ridges and plateaus   ( 47 degrees in Clintwood vs 63 degrees at LNP in Wise at 4:15 AM ).

The focus now shifts to a stormy, much more active weather pattern with a major severe outbreak of thunderstorms and tornadoes across the nation’s heartland today into tonight.  A few strong-severe thunderstorms may also develop on a warm frontal boundary and move southeast into the west side of the Appalachians by late today into tonight.

Other showers & thunderstorms, of a more hit-miss nature, may develop amid the warm sector south of the warm front by late in the afternoon into this evening.  The most organized storms, with a possible MCS type cluster, will track along & south of the warm front and will bear close watching by tonight for locations from the Cumberland Mountains to the northwest & north.

Downpours could produce locally heavy rainfall amounts between Tuesday Night and Thursday Night, with several rounds of showers and thunderstorms being possible.

Stay tuned to NOAA Weather Radio for any possible watches or warnings that may be needed during the next 24-48 hours.