A hard freeze will occur in mountain valleys during Tuesday Night into Wednesday Morning, with frost formation also possible in other places within Wise, Scott, Lee, Dickenson, Russell & Tazewell counties.
Heavy frost will again be likely in colder mountain valleys during Wednesday Night into Thursday Morning ( no frost is expected at exposed middle-upper elevations, especially on ridges-plateaus ).
Overnight Into Tuesday Morning
Showers developing. Windy. SSW-SW winds 10-25 mph, with higher gusts, shifting N into morning and decreasing to 5-15 mph. Turning cooler into morning with readings dropping into the 40s, except 30s at highest elevations.
Tuesday Afternoon
Becoming sunny ( deep blue skies ) and chilly. N-NNE winds 5-15 mph, with higher gusts. Temps varying from 40 to 45 at upper elevations to the mid-upper 50s ( milder at lower elevations in the Clinch, Powell, and Holston river valleys ).
Tuesday Night Into Wednesday Morning
Clear. Heavy frost formation in mountain valleys. Light northerly winds shifting SE-S along upper elevation ridges into morning at 5-10 mph. Temperatures varying from 20 to 25 degrees in colder mountain valleys to the lower-mid 30s ( mildest along middle elevation ridges-plateaus ).
Wednesday Afternoon
Mostly sunny. Light winds becoming ENE-NNE. Milder. Temperatures varying from low-mid 50s at the highest elevations to the middle-upper 60s.
Wednesday Night Into Thursday Morning
Partly to mostly clear. Winds ESE-SE at 5-15 mph along middle-upper elevation mountain ridges. Large vertical temperature spread with 20s in colder mountain valleys verses upper 30s to middle 40s along exposed ridges.
Weather Discussion ( April 11-14 )
Spring 2016 has been lacking in rain, but not in wind. This has been a very windy spring season, with some relief from these strong winds finally expected to develop through mid week as high pressure builds over the Appalachians.
Cluster of Rue-anemone ( Thalictrum thalictroides ) – PM of April 11, 2016
Any nature photographer is especially aware of wind, since out of the TOP 10 problems dealt with in taking high resolution shots the wind will generate ( directly or indirectly ) most of the problems.
Mayapple ( Podophyllum peltatum ) With Flower Bud On Top
The Mayapple above is newly emerged, with a flower bud that is still mostly visible above the leaves. This will change in coming days as these leaves continue to unfurl and rise above the bud.
Eventually a lack of rainfall will become a concern if precip totals do not begin increasing in coming weeks. Right now, with low evaporation rates and still cold nights, it is not a major problem ( outside of grass for hay that needs rain ).
A dry signal in the models is that higher totals have consistently been predicted a few days in advance of systems, to only decrease as the system in question gets closer in time to becoming reality. An exception, being the recent snowfall which was as productive as expected ( especially across upper elevations ).
European Model 850 MB Wind Field Analysis At 8 AM Monday – April 11, 2016
In a typical spring, wind like this would act to enhance the orographic forcing and make rainfall more productive. So when this does not happen within favored locations like the High Knob Landform corridor it is an important signal that should not be overlooked ( since past climatology dictates that this can be a dryness or drought precursor ).
European Model 850 MB Wind Field Analysis At 8 PM Monday – April 11, 2016
While another substantial cold front, with another notable temperature gradient, is pushing into the mountains only a relatively scrawny line of showers has formed.
European Model 850 MB TEMP-Surface Analysis At 8 PM Monday – April 11, 2016
Dryness this spring being directly connected to excessive wetness over the lower Mississippi Valley and Deep South as atmospheric compensation acts to force subsidence aloft over this region as air migrates outward away from deep convection to the southwest and south of the southern Appalachians.
Doppler Radar Base Reflectivity At 2:58 AM Tuesday – April 12, 2016
Deep blue skies will return today following this frontal passage as high pressure begins to take control. This will lead into a mid-late week period featuring development of easterly flow as the High shifts east and a wedge of cooler air ( at least by day ) sets up along and east of the Blue Ridge ( low dewpoint air and less clouds will act to generate cold nights along the western side of the Appalachians ).
While all locations will be cold Tuesday Night into Wednesday AM, mountain valleys will be coldest and will become the focus for the coldest air during nights throughout the remainder of this week.
