My Weekend Forecast ( March 5-6 )

Reference my 030416 Forecast for details on this past day.

ALERT For Dense Fog & Freezing Fog At Mid-Upper Elevations Along & North Of The High Knob Massif Tonight Into Sunday AM – Mainly Above 2700 Feet

Some freezing fog coated higher elevations around Norton-Wise into Saturday morning, with another round of dense fog expected to develop overnight into Sunday morning with freezing levels at the 2000 to 2500 feet elevation by morning ( new models tonight have lowered the freezing level by a few hundred vertical feet ) as deep northerly flow develops into Sunday morning.  This will also support some snow showers across upper elevations and drizzle and/or freezing drizzle-snow-mix at middle elevations and just drizzle at lower elevations ( mainly north of High Knob Massif ).

*This will develop on northerly upslope flow with downslope sites mainly having dry and mostly cloudy conditions.

*Snow fell hard, with big flakes, between 3:00 to 4:00 PM and covered roads at highest elevations for a time before melting  some, as the temperature hovered between 32 to 33 degrees.

While a rain-snow mixture fell in Norton-Wise during Saturday afternoon, mostly all snow fell at summit levels of the High Knob Massif with around 0.5″ accumulating on Eagle Knob through late afternoon ( new snow accumulation shown above ).  Tonight very dense fog ( freezing fog ) has settled into the high country with dropping cloud bases expected into middle elevations after Midnight into Sunday morning.  Slow down and take it easy.

Saturday Forecast

Mostly cloudy skies overnight will carry into this morning, with some breaks possible.  This has allowed dense fog to develop with temperatures below freezing.  Light northerly winds will shift SW-SSW by morning on middle to upper elevation ridges and will eventually help dissipate the fog.

Any sunshine will be limited today as mid to high altitude clouds begin increasing in advance of the next fast moving system.  Morning temperatures in the 20s to near 30 will have a chance to rise into the 40s across much of the area before afternoon rain showers develop.  The exception will be at higher elevations in the High Knob Massif where 30s prevail, with snow or a rain-snow mix being possible there.

*As it turned out sleet & snow, with a little rain mixed, fell in the 3000-3500 foot elevation zone with nearly all snow above 3500 ft.

Saturday Night Into Sunday Morning

Following late afternoon-early evening melting off roads, it took little time for snow to recover roadways at high elevations in the High Knob Massif during Saturday Night with another burst of heavy snow ( with riming in clouds and temps in the 20s on N winds producing wind chills as cold as the low-mid 10s ).

Winds will shift NW-NNE behind a cold frontal passage on Saturday evening, with rain showers becoming mixed with or changing to snow in middle elevations, and all snow at upper elevations.  Any snow accumulations, with up to 2″, look to be mostly above 2700-3300 feet in elevation.

A lowering of cloud bases will need to be watched for overnight into Sunday morning on northerly upsloping winds of 5-15 mph, with higher gusts, across mid-upper elevation mountain ridges-plateaus ( in typical locations along and north of the High Knob Massif and Tennessee Valley Divide…such as Wise, Sandy Ridge and adjacent communities which typically have dense upslope fog ).

Freezing fog will be possible at elevations above 2700 feet, with drizzle-freezing drizzle and/or some snow-mix at the lower-middle elevations and snow showers above 3000 ft.

Mid-Morning Sunday Through Sunday Afternoon 

Cloud bases are expected to lift and drier air is currently predicted to overspread the area into the afternoon with skies becoming sunny to mostly sunny.

Winds will become light and temperatures should rise into the 40s to low-mid 50s ( upper 30s to lower 40s over a little snow at highest elevations in the High Knob Massif ).

Sunday Night Into Monday Morning

Some mid-high clouds will be possible as winds will be shifting SSE-SW at 5-15 mph, with higher gusts, across middle-upper elevation mountain ridges & plateaus.

This wind shift marks the beginning of a long awaited warming trend, with temperatures rising at highest elevations overnight into Monday morning.

*Due to an increase in wind chills, this initial warming will not really be felt along mountain ridges ( that comes next week ).

Updated at 9:45 PM on Sunday – March 6, 2016

A large vertical temperature spread, as I originally expected, will develop through tonight into Monday morning with readings varying from frosty, cold 20s  within mountain valleys to upper 30s & 40s across exposed mountain ridges & plateaus ( where the off-setting factor will be an increase in wind chills, especially amid upper elevations where SSE-SSW winds are already gusty ). 

Weekend Summary

Seasonably cold conditions will continue to be felt through most of this weekend before a prolonged warming trend develops next week.

Clouds will remain abundant through Sunday AM, with another fast moving disturbance expected to spread rain and snow showers across the area from Saturday afternoon into Saturday night.

Any sticking snow is likely to be restricted to highest elevations, above 3300 feet in elevation ( dusting up to 2″ or so will be possible at these highest elevations ).

A period where cloud bases will drop needs to be respected by the Midnight-Sunrise period Sunday, when northerly upslope flow will develop.

A period of dense fog, with freezing fog above 2700 feet, will become possible at mid-upper elevations along and north of the High Knob Massif during a period between 10 PM Saturday & 10 AM Sunday.

The elevation of cloud bases ( dense fog ) and the freezing level will need to be updated later as this period gets closer in time.

The main idea being that cloud bases will drop again on upslope flow during late Saturday evening into Sunday morning, with riming and dense fog at upper elevations along and north of the High Knob Massif-Tennessee Valley Divide which may drop into middle elevations ( below 3000 feet ) for a period of time.

Cloud bases are expected to lift and finally dissipate  to produce mostly sunny to sunny skies into Sunday afternoon.  This will allow temperatures to rise into lower-middle 50s in milder locations, with 40s most likely across upper elevations ( coolest over snow at highest elevations and northern slopes within the High Knob Massif ).

A large vertical temperature spread will be likely to develop Sunday Night into Monday morning as winds shift southerly to begin a long awaited and prolonged warming trend.  This will be indicated first at highest elevations where temperatures will tend to rise, after any initial evening declines, overnight into Monday.  Mountain valleys, by contrast, will have temp drops and develop much colder conditions than breezy to gusty ridges ( the offsetting factor for high ridges being an increase in wind chills into Monday AM ).

Extended Look At Next Week

An unseasonably warm period of weather, via a major shift in the upper air flow regime across the USA, is on tap for next week.  Eventually, this will include rises in humidity-dewpoint ( moisture ) levels and showers-thunderstorms ( by late next week-next weekend ).

The eastern USA trough is going to be replaced by ridging as the western ridge breaks down and gives way to troughing.

This will bring needed precipitation to California and will set up a pattern featuring an excessive rainfall potential across the Lower Mississippi Valley.  The eastward extent initially being blocked by ridging in the Atlantic; however, over time this will likely give way enough to allow for rains to move into the Ohio-Tennessee valleys and Appalachians.

This will be such a warm period that it should trigger the first woodland wildflowers of the season to emerge, if not already in milder locations outside the mountains, such as Coltsfoot ( Tussilago farfara ) and Trout Lily ( Erythronium americanum ), along with a few other species.  Enjoy.

For those who suffer from pollen, it should also begin to increase some early tree pollens ( such as maples and the willows ) at lower-middle elevations.

Have a great weekend.

My Forecast For Today ( March 4 )

State Route 619, Routes 237 & 238, as well as others, are icy and snow covered in upper elevations of the High Knob Massif.  Use caution if traveling overnight into morning in this area and at other elevated locations in the area which had sticking snow.  Visibility ( with freezing fog ) is also very low above 3000 feet.  

Otherwise, with temperatures at or below freezing, patches of black ice could form on other surfaces and with freezing fog across upper elevations above 3000 feet.

Overnight Into Mid-Morning

A chance of flurries & light snow showers.  Drizzle possible.  Cold & damp.  Winds shifting NW to NNW at 5-15 mph, with higher gusts, overnight into morning.  Temperatures in the 20s to lower 30s.  Wind chills in the 10s and 20s on exposed mid-upper elevation mountain ridges.  Freezing fog with rime formation at elevations above 3000 to 3300 feet.

Mid-Morning Through This Afternoon

Any flurries-drizzle ending.  Chilly.  Decreasing clouds by mid to late afternoon.  NW winds 5-10 mph, with higher gusts, on mid-upper elevation mountain ridges & plateaus.  Temperatures varying from lower 30s to the lower-middle 40s, coldest at highest elevations.  Wind chills in 20s & 30s.

Tonight Into Saturday Morning

Chance of an early evening sprinkle or snow flurry.  Partly to mostly cloudy in the evening with increasing mid to high altitude clouds overnight into morning.  Winds SW-W at less than 10 mph in most places ( a few higher gusts along mid-upper elevation ridges ).  Temps in the 20s to lower 30s.

Weather Discussion ( March 3-4 )

Afternoon Update

Many mountain wave induced breaks have occurred amid an otherwise persistent overcast this afternoon, with temps varying from around 30 degrees on High Knob to the lower 40s in portions of the Clinch & Powell river valleys.

The only change in my forecast being to skies for this evening, with partly-mostly cloudy conditions now expected with just a chance for a passing sprinkle or snow flurry.

Breaks have occasionally illuminated the beautiful rime capping the sprawling High Knob Massif.

Mountain wave breaks began developing by mid-morning and have increased this afternoon.

Snow depths of around 1″ were reported above 3200 feet in the High Knob Massif this morning, from 0.5″ measured in High Chaparral by my friends Joe & Darlene Fields to about 1″ or a bit more at the summit level.

My friends Wayne & Genevie Riner measured 0.3″ of snow at their official NWS station on Long Ridge of Sandy Ridge as PM temperatures struggled to reach the middle 30s.

The PM Max officially reached 39.7 ( 40 ) degrees in Clintwood.

My Overnight Discussion

Although around 1″ of snow looks to have accumulated at highest elevations in the High Knob Massif, there was little sticking in most places as the mountain area got caught in between a snowband to the north and heavy rain-storms across the Deep South.  That was the main reason I did the afternoon downgrade for this area.

Reference my 030316 Forecast for more details on the past day.

When I saw that setup I knew this area would be getting limited snowfall with air sinking adjacent to the snowband toward the north and around the rain-thunderstorms to the south.

Up to 7″ of snow has been measured within the main band of snow that set up over northeastern Kentucky amid the JKL National Weather Service Forecast Office’s coverage area, with public reports as high as 9″ .

Note the U.S. GFS Model forecast on the 1:00 AM Thursday run did not even have any snow forecast over the area that got the most snow.  The following 7 AM run ( below ) was not much better.

The 7 AM Thursday run of the NAM Model group did have a somewhat better handle on placement of the snow, with  the northeastern Kentucky snowband appearing ( although still forecast to be much weaker than it turned out to be ).

It was not until the snowband was already forming that the high-resolution NAM 4 KM Model finally was able to resolve it somewhat better; although, still not precisely.

The European Model did the best of all models as it did pick up on the northern-northeastern Kentucky snowfall enhancement, but had struggled with placement and amounts.  Most importantly, for this area, it over-estimated snowfall along the mountains at the expense of snowfall in the lowlands of the foothills.

I show the above to illustrate the problems that models have trying to resolve some systems ( especially those possessing separated pieces of energy and/or amid a transitional state before intensification.  This weather system had both these factors going, and more ).

Last night I made an excellent forecast based upon the data at hand, including that of the European Model, which I had used along with the high-resolution NAM to develop a elevation zone break-down in amounts.

The problem, of course, precipitation never did develop as it was forecast by models over this area as atmospheric compensation had to occur for all the air converging at low-levels and rising upward through the atmosphere to crank out snow amid the lowlands to the north.

When air converges and rises over one region it typically will sink into adjacent zones in order to conform to the atmospheric-fluid dynamics principle summarized by the basic Law Of Conservation Of Mass.  This occurs all the time locally, with showers or squalls of rain-snow and throughout the convective ( thunderstorm ) season.  It also is forced throughout the orographic season by the mountains, with formation corridors possessing rising and sinking air.  Remembering always, of course, that this is four dimensional in nature ( i.e., it possesses two horizontal wind components, a vertical wind component, and time ).

Looking ahead, one more weak system passes later Saturday before a significant warming trend to spring levels kicks in to dominate next week.  Eventually, this will crank up the spring thunderstorm machine.

( No, I do not think this is the end of winter.  With good chances for more accumulating snow, especially at higher elevations, before the record books close on this Winter Season of 2015-16 ).

Have a great TGIF.

My Forecast For Today ( March 3 )

Updated At 3:00 PM:  My ALERT For Any Significant Snow Accumulations Is Cancelled – Some Snow Is Possible Tonight-Friday Morning But Amounts Are Expected To Be Light ( Generally Less Than 1″ ).

A band of persistent snowfall had developed from northeastern Kentucky into western-southern West Virginia and will now be the focus of heaviest snowfall amounts during this event in our region

ALERT For An Accumulating Wet Snowfall Developing This Afternoon Into Tonight – All Snow Is Likely Above 2500 to 3000 Feet, With A Mixture Possible Below 2000 to 2500 Feet…Before Changing To All Snow.

Rain and snow will develop across the area this afternoon into tonight, with the elevation of the sticking snow level yet to be determined for this afternoon in locations along and north of the High Knob Massif.  A mix or rain will be likely in the Powell Valley to Big Stone Gap corridor on downsloping winds off the High Knob Massif.

Overnight Into This Morning

Partly-mostly clear evening skies giving way to increasing clouds into morning.  Light SSE-SSW winds at generally less than 10 mph on mountain ridges below 2700 feet.  Winds S to W at 5-15 mph on upper elevation ridges.  Temps varying from the upper 10s to the upper 20s, with readings tending to rise into morning, especially at high elevations.

This Afternoon

Cloudy with rain & snow developing.  All snow above 2500 to 3000 feet.  A mixture possible at lower elevations, with a mixture likely within the Powell Valley to Big Stone Gap corridor.  Winds ESE-SSE at 5-10 mph, with higher gusts, along middle elevation mountain ridges & plateaus.  SE-S winds 10 to 15 mph, with higher gusts, in upper elevations.  Temperatures in the 30s to around 40 degrees before a drop into the 20s to low-mid 30s after precipitation onset.  Wind chills in the 10s & 20s exposed mid-upper elevation ridges.

Tonight Into Friday Morning

Snow at mid-upper elevations.  A mix changing to all snow at lower elevations.  Winds becoming NW-NNW at 5-15 mph, with higher gusts, overnight into morning.  Temperatures in the 20s to lower 30s.  Wind chills in the 10s and 20s on exposed mid-upper elevation mountain ridges.

Snowfall Forecast – Thursday PM to Friday AM

1″ or less at elevations below 1500 feet

1″ to 2″ at elevations of 1500-2500 feet

2″ to 4″ at elevations of 2500-3500 feet

4″+ possible at elevations above 3500 feet

Target Snowfall of 2″ in Norton-Wise ( +/- ) 1″ spread potential.  This implies a general 1″ to 3″ of snow possible.  Locally higher amounts will occur if precipitation is all snow, while amounts could be less if more mix occurs.

*If an easterly component to the low-level flow develops, snowfall will be less than 1″ in the Powell Valley to Big Stone Gap corridor and into portions of Lee County.  If a TIM Circulation should form precipitation amounts could be enhanced in the Norton-Big Stone Gap corridor, with more snow on the cold side of the boundary and enhanced rain on the warmer, sinking air side of the circulation.

Weather Discussion ( March 2-3 )

My Afternoon Update

Precipitation echoes have been over top the area since early this morning but little to nothing ( even sprinkles or flakes ) have reached the surface.

Much of the Mountain Empire has been caught in between main precipitation bands, one to the south with rain-storms and another which has set up from NE Kentucky into West Virginia.  So I have cancelled my ALERT for any significant snowfall.  The Winter Weather Advisory officially remains in effect into Friday AM.

The latest high-resolution NAM 4 KM Model seems to have picked up on the trend and placement of snowfall amounts.

“You have to know when to hold them, and when to fold them,” says Kenny Rogers, so in this case I am folding with respect to significant snowfall.  Some snow may still occur but generally accumulations are likely to be less than 1″ in most places.

The forecast in words will remain unchanged, just snowfall amounts will be much less than expected.  This is the update I was somewhat expecting from last night ( to either go up or down in amounts, amid this middle zone ).

My Overnight Discussion

Reference my 030216 Forecast for more details on the past day.

Flurries and snow showers developed overnight as colder air poured into the mountains with just enough sticking to coat roadways across the High Knob Massif and in a few other elevated locations.

Nice rime formed in freezing fog above 3300 feet.

Low clouds held tough through much of the day.

Clouds finally broke up for some late afternoon sunshine following more flurries, rime, and a nasty cold day that found temperatures struggling to reach 20 degrees at the top of the high country and 30 degrees in Norton-Wise.

A gorgeous, albeit cold, sunset graced the mountains.

Forecast models continue to struggle to resolve the track and precipitation amounts associated with a southward tracking clipper-like system which begins to spread moisture across the mountains by Thursday PM.

The forecast on this system is more difficult than usual since it remains disorganized and will not be in position to really intensify until it reaches the Atlantic Coast, with SE Virginia and the Tidewater around Richmond looking to be amid the main snowfall target zone by late Thursday Night into Friday morning.

The amount of snowfall observed locally this afternoon into Friday morning will be dependent upon moisture and wind direction, which will influence the temperature profile amid lower levels of the atmosphere ( air will be cold enough for all snow across upper elevations with only the amount there being unknown ).  The forecast may need to be updated later today as development of this system is followed over time.

Longer Term Peek

Conditions will remain chilly into this weekend with another weak system passing during Saturday.  This will keep relatively chilly temperatures in place with the real surge of warmth not coming until Monday into Tuesday as Atlantic ridging and western-central USA troughing develops.

A pattern opposite to that recently observed will develop next week with troughing to the west and ridging along-just off the East Coast of the USA.  This is a spring thunderstorm pattern, which will need to be closely followed over time.

Eventually, next week, a large upper trough will set up a return flow from the Gulf of Mexico and increase the potential for showers & thunderstorms.

A major outbreak of severe thunderstorms may develop west of the mountains, along with an excessive rainfall potential.

Have a great Thursday.

My Forecast For Today ( March 2 )

ALERT For A Sharp Overnight Temperature Drop With Developing Flurries & Snow Showers – Be Cautious Of Cold Wind Chills & Patches of Black Ice-Slickness

A significant overnight temperature drop will occur amid gusty NW winds behind the passage of an evening cold front.  Flurries and mostly light snow showers will develop along the upslope side of the mountains, with a dusting up to 1″ being possible ( greatest amounts at highest elevations ).  Use caution for the possibility of black ice or locally slick conditions into this morning.

Overnight Into Mid-Morning

Turning much colder.  Flurries & snow showers developing along the upslope side of the mountains with respect to NW winds.  Temperatures plunging into the 20s ( low-mid 20s in Norton-Wise ), with low-mid 10s at highest elevations in the High Knob Massif ( milder southward toward the Tri-Cities ).  Wind chills plunging into single digits & 10s ( locally lower in gusts atop the High Knob Massif ) overnight into the AM.  Rime formation in upper elevations above 3400 feet.

Mid-Morning Through This Afternoon

Flurries ending.  Skies becoming partly cloudy late.  Cold & blustery.  Winds WNW to NW at 5-15 mph with higher gusts.  Temperatures varying in the 30s at low-middle elevations to around 20 degrees at highest elevations in the High Knob Massif ( upper 20s-low 30s in Norton-Wise ).  Wind chills in the 10s & 20s on exposed mid-upper elevation ridges, except single digits in gusts at high elevations.

Tonight Into Thursday Morning

Partly-mostly clear evening skies giving way to increasing clouds into morning.  Light SSE-SSW winds at generally less than 10 mph on mountain ridges below 2700 feet.  Winds SSW-WSW at 5-15 mph on upper elevation ridges.  Temps varying from the upper 10s to the upper 20s, with readings tending to rise into morning, especially at high elevations.

An Alert For Accumulating Snow will likely be needed for the Thursday Night-Friday Morning period at mid-upper elevations, especially at elevations above 2500-3000 feet.

Weather Discussion ( March 1-2 )

My Early Afternoon Update

My update this afternoon is to cut temperatures even more than I had already ( I was already the coldest forecast out ), with low clouds being slow to clear.

It will become partly cloudy, but MAX temperatures are going to struggle to reach late PM maximums before the sun sets.  Temps at highest elevations will tend to rise overnight into Thursday AM as I already had in the forecast.

Observe extensive rime across the High Knob Massif where enough snow fell to cover roads at the highest elevations.  A dusting was also observed in Clintwood, in the valley, with around 0.2″ .

Temperatures at 1:30 to 2:00 PM varied from 29 degrees in Clintwood to 18 degrees atop the High Knob Massif, with 24 to 25 degrees in Norton-Wise ( the 27 at LNP is wrong ).

My friends Wayne & Genevie Riner submit this interesting photograph showing how the light morning snow created an amazing pattern on a very old Millstone.

Wayne Riner Thoughts On Photograph
Millstone With Snow: In my collection of rocks is an old millstone that was cut by hand many years ago. A light dusting of snow highlights the pattern of twelve grooves.

As of 1:30 PM, below, skies can be seen clearing northwest of the mountains across the Bluegrass and western foothills of Kentucky.

The 2:00 PM image, below, for comparison.  A slow but sure erosion of the low cloud deck from northwest to southeast.

Cloud bases have just lifted to reveal the summit level of the High Knob Massif, a blaze of rime and beauty on trees.

My Overnight Discussion

The month of March 2016 came ROARING into the mountains today and tonight, literally, with strong winds ahead-along a squall line and a cold front.  A wind advisory was needed but not issued officially.

This caused local wind damage as winds became severe in gusts along both the squall line and evening cold front.

While the Flatwoods Mountain Mesonet site adjacent to Pine Mountain takes honors for the highest recorded wind gusts, along the squall line ( above ) and cold front ( below ), it was only one place of many that had these ROARING winds.

We are fortunate to have these mountain ridge observation sites, and I wish there were more on the Virginia side of the border like at the windiest places ( e.g., High Knob Lookout – Pine Mountain ) and in mountain wave zones like Powell Valley.

The Black Mountain Mesonet site recorded a 49 MPH gust with the cold frontal passage at 8:10 PM.

The strongest wind here in Clintwood, which sounded like it might lift off the roof, occurred with the cold frontal squall that passed during the evening ( although the squall line at around 5:00 PM was no slacker ).

A peak gust to 39 mph was reported at Lonesome Pine Airport in Wise, but I do wonder if ( like the temperature ) this might not be reading accurately.  Perhaps we can get a station set up at UVA-Wise to have a check on these reports before next winter rolls around.

Focus now shifts to a blast of cold air, with 12:30 AM temps from the Kentucky Mesonet showing it certainly is coming.  The lower temperatures on the VA-KY border, with 28.9 on Black Mountain and 31.5 on Flatwoods Mountain, are due to elevation ( it is 28 degrees on Eagle Knob of High Knob ).

The coldest air will not arrive until the sunrise to mid-morning period today, with the 850 MB thermal min, and enough Great Lake moisture to kick off flurries and snow showers along the upslope side of the mountains on NW winds.

ROARING SW winds shifted W and now NW in direction as this system passed across the region.  The Flow across Lake Michigan picking up a little moisture as it bends into the mountains.

A Lake Michigan moisture plume will just brush the area with enough moisture for a dusting up to 1″ of snow into this morning ( most places likely having 0.5″ or less ).

Moisture advection being best northeast of this area into central-northern highlands of eastern West Virginia.

Any wetness on decks-porches-walks and other surfaces could cause slick and icy conditions, so please use caution if going outside overnight into this morning as temperatures drop below freezing.  Any snow burst or persistent snow showers could, of course, also cause some slickness.

It appears likely that an ALERT for accumulating snow will be needed by late Thursday into Friday morning.  This will be another elevation biased snow event, with indications for several inches or more at upper elevations above 3000 feet ( the lower limit of the accumulating snow will need figuring out as time gets closer, with places above 2000 to 2500 feet being initially targeted for 2″ or more.

Stay tuned for updates.

Stay Warm On This COLD Wednesday!