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.