Area Forecast Discussion
Issued by NWS Blacksburg, VA

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FXUS61 KRNK 181144

Area Forecast Discussion
National Weather Service Blacksburg VA
644 AM EST Thu Jan 18 2018

High pressure over the Lower Mississippi Valley will move east
across the Gulf Coast states today through Friday. Low pressure will
develop in the Central Plains on Sunday then track into the Great
Lakes by Tuesday. This system will push a cold front through the
area on Monday and Tuesday.


As of 250 AM EST Thursday...

Closed upper low was over eastern North Carolina this morning. This
low will move offshore and begin to fill today. At the surface high
pressure was over the Lower Mississippi Valley with a lee trof along
the central and southern Appalachians. The trof was tightening the
pressure gradient leading to increased wind speeds this morning. The
850MB jet will pick up to around 50 knots this afternoon which will
prolong the gusty winds at higher elevations, especially in
southeast West Virginia and along the Blue Ridge north of Roanoke.

Satellite pictures showed the clouds had cleared out of the foothills
and piedmont of Virginia and North Carolina. Snow will hold
temperatures below guidance today and tonight despite the warm air
advection at 850MB. Dry air mass does favor a large diurnal
temperature spread but expect solar insolation that goes toward snow
melt to counteract that.

Low clouds along the western slopes of the Appalachians this morning
with a few flurries. Boone, NC was reporting a reduced visibility
and light snow with a clear sky. Based on the wind of 15G25MPH the
observation instruments are likely sensing some blowing snow. Models
have a bulk of this cloud cover dissipating around 10AM.


As of 330 AM EST Thursday...

The upper pattern will be transitioning to more of an eastern
ridge/western trof, which will bring breezy and much warmer conditions
to the region this weekend. By late Saturday developing low pressure
over the Rockies will start to push a warm front in our direction.
However the better moisture and isentropic lift will only brush the
Appalachains and central mid Atlantic region, bringing just a slight
chance for a shower far west Saturday evening through Sunday morning.

Temperatures will warm to well above normal levels with readings by
Sunday rising well into the 50s, though lingering snow cover mainly east
of the Blue Ridge will temper the warm up.


As of 235 PM EST Wednesday...

We stay warmer than normal ahead of a deep trough/closed low
moving across the central U.S. Monday which then sends a front
across us Tuesday with a threat of showers. Colder air behind it
may bring a few snow showers to the mountains of WV, but temps
behind this system are not as cold as the pattern we are in now.


As of 635 AM EST Thursday...

High pressure will move from the Lower Mississippi Valley to the
Gulf Coast region today and tonight. Satellite pictures showed a
narrow strip of IFR clouds on the western slopes of the
Appalachians between KMGW and KJFZ. Conditions were VFR across
the rest of the region. The lower clouds were already beginning
to erode. High confidence this cloud cover will dissipate by

Winds will also be gusty today from the northwest, up to 30
knots in the mountains and 15 to 20 knots elsewhere. Winds will
diminish tonight. LLWS is in the TAFs tonight for KROA,KLYH and

Extended Discussion...

Dry air will and high pressure will cover the region Friday
through Sunday. VFR conditions are expected as well as warming
temperatures. Moisture will return to west Sunday night into
Monday with sub-VFR conditions possible ahead of another cold
front. VFR conditions should return late Tuesday.


As of 245 PM EST Wednesday...

NOAA Weather Radio, WXL60 (Roanoke Transmitter) which broadcasts at
162.475 MHz remains off the air. Telephone company will be working
on this and hope to have it back up by Thursday afternoon.


VA...Wind Chill Advisory until 10 AM EST this morning for VAZ007-
NC...Wind Chill Advisory until 10 AM EST this morning for NCZ001-
     Winter Weather Advisory until 1 PM EST this afternoon for
     Winter Weather Advisory until noon EST today for NCZ004>006.
WV...Wind Chill Advisory until 10 AM EST this morning for


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