010918 Forecast

Mountain Area Forecast ( Jan 9-11 )

ALERT For Areas Of Dense Fog Overnight Into Tuesday Along With Localized Icy Patches On Some Roadways

Lingering low-level moisture trapped beneath an inversion will continue to produce abundant fog overnight into Tuesday, with areas of drizzle.  While most temperatures will remain near to above freezing, a few valleys may remain near to below 32 F.
Radiational cooling by Tuesday Night into Wednesday AM will keep near saturated to saturated conditions at lower to middle elevations while drier air overspreads upper elevations, above 3000 feet.

An Alert For Mountain Wave Wind Gusts, And Strong General Winds At Upper Elevations, May Be Needed By Late Wednesday Into Thursday

Overnight Into Tuesday Morning

Low clouds with areas of dense fog.  SW-W winds 5-15 mph with higher gusts on mid-upper elevation mountain ridges and plateaus.  Temperatures widespread in the 30s.  Wind chills in the 20s to lower 30s ( coolest highest elevations ).

Tuesday Afternoon

Low clouds with areas of dense fog, especially at higher elevations.  Light winds, except W-SSW at 5-10 mph along upper elevation mountain ridges.  Chilly and damp with temperatures mainly in the lower-middle 40s.

Tuesday Night Into Wednesday Morning

Low clouds with areas of dense fog at lower-middle elevations.  Becoming partly-mostly cloudy at upper elevations.  Winds SSE-SSW 5-15 mph, with higher gusts, along mid-upper elevation mountain ridges.  Temps in the 30s, except near steady or rising in the 40s along higher mountain ridges.

Wednesday Morning Through The Afternoon

Becoming partly-mostly sunny.  Milder and gusty.  SSE-S winds increasing to 10-20 mph with higher gusts.  Temps varying from 40s to low 50s in upper elevations to the upper 50s to around 60 degrees.

Wednesday Night Into Thursday Morning

Partly-mostly cloudy.  Windy.  Unseasonably mild.  SE-SSE winds 10-25 mph, with higher gusts, at elevations below 2700 feet.  SE-SSE winds 20-30 mph, with higher gusts, along mountain ridges above 2700 feet.  Temperatures widespread in the 40s to around 50 degrees.

The potential for major storm development, with rain to snow and an influx of bitterly cold air, is being monitored for the late week and weekend period ( January 12-14 ).


Weather Discussion ( Brief Thaw )

Abundant low-level moisture is trapped beneath an inversion layer left over in wake of the Monday system which dropped everything but the kitchen sink on the mountain landscape ( snow, sleet, freezing rain, rain ).

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

If this low-level inversion does not mix out Tuesday, abundant moisture will continue as some terrain models suggest with drier air advecting into upper elevations by Tuesday Night into early Wednesday to set the stage for a very nice but increasingly gusty Wednesday.

Wednesday is looking to be the best day of the week, in general, as strong winds develop by Wednesday night into Thursday on SE-S flow to increase moisture into the Blue Ridge.
NAM 12 KM Model 300 MB Forecast At 7 AM Friday – January 12, 2018

All eyes will then focus upon a upper wave digging into the eastern USA by later this week, with potential for phasing between sub-tropical and polar jet streaks suggesting the potential of major cyclogenesis ( storm development ).

Although details remain to be worked out, a setting like this could generate rain-thunderstorms in its warm sector and a synotpic-scale snowband with wrap-around and/or NW Flow snow developing on its cold side.  Stay tuned.