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000
FXUS61 KRNK 202357
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
757 PM EDT Tue Oct 20 2020

.SYNOPSIS...
Upper level ridging will increase across the Southeast and mid-
Atlantic tonight and tomorrow, contributing to a warming trend
that will push temperatures well above normal through the
remainder of the work week. A cold front is expected to arrive
on Saturday, bringing a modest cool down to the region and
a chance of rain.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
As of 130 PM EDT Tuesday...

High pressure still in control today as a weak wedge continues to
remain in place east of the mountains. Stalled cold front over
the Ohio River Valley will retreat back north as ridging along
the southeast United States builds in for Wednesday.

Expecting clear skies and abundant sunshine throughout the remainder
of the day. After sunset, will begin to see increasing mid-
level/high clouds over the southern/southeast sections of the
CWA as a weak disturbance to our south spreads clouds northward
into the area. Also still maintaining a weak east/southeast flow
keeping enough shallow Atlantic moisture in place to see fog
development again tonight. At the moment, mountain river valleys
along with the Piedmont of Virginia and North Carolina have the
best chance for areas of patchy dense fog through sunrise.
Higher elevations and areas to the west should remain mixed well
enough to inhibit any widespread fog.

Temperatures will remain a couple to several degrees above normal
today and tomorrow as a 588dm upper-level ridge remains in place
over the southeast coast. Expecting highs this afternoon to top out
in the mid 70s. Even warmer tomorrow with some locations reaching
the low 80s. Tonight should remain rather mild in the mid to upper
50s east of the Blue Ridge as fog and high clouds could hinder some
cooling. Mostly clear skies further to the west could allow for more
radiational cooling, with some sheltered locations dropping back
into the 40s.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
As of 130 PM EDT Tuesday...

The big story of the short range portion of the forecast will be
above average temperatures as high pressure underneath a broad ridge
allows for ample warming to take place. As of now, Thursday looks to
be the warmest day of the week, with areas out east nearing the 80
degree mark.

Later in the period, Friday, an advancing front from a low tracking
from the central Plains, toward the Great Lakes region, approaches
the Mid-Atlantic. As this nears, high pressure over the region
weakens and shifts eastward. As high pressure shifts, frontal
advancement is expected to slow, holding any real rain chances off
until Saturday. Any earlier rain chances would be dependent on
return flow interacting with the southern Blue Ridge/NC mountains to
spark isolated showers Friday afternoon. Greatest rain chances and
amounts Saturday with the front will be for the west, as the front
dries out in the Piedmont.

Forecast confidence is moderate.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 130 PM EDT Tuesday...

Guidance since yesterday in the long range has come into better
alignment, with GFS coming into better agreement with the ECMWF and
Canadian: the trough over the Great Lakes/Canada shifts northward.
This prevents waves within the flow from really impacting our area.
Instead, a bulk of the precipitation will fall to our west, though
at this time range it is too early to rule out at least some
rainfall for the western slopes. The rest of the area will remain
under a mix of clouds.

Tuesday into Wednesday, the trough is expected to dig slightly
south, pushing a front into the area, increasing rain chances. At the
same time, a LLJ is projected to set up over the Mid-Atlantic,
bringing windy conditions for the area.

Overall, temperatures during this period will be cooler than the
short range`s, but still remain above average. Increased cloud cover
should especially help keep nighttime temperatures mild.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
As of 740 PM EDT Tuesday...

Weak southeast flow will keep a shallow layer of moisture near
the surface overnight. 3km NAM Bufkit forecast soundings showed
stratus and fog formation around 07Z/3AM. For now have in MVFR
fog across much of the foothills and piedmont of Virginia and
North Carolina. LIFR fog is possible again at KLYH and at KBCB.

Much of the low clouds and fog will begin to mix out around
15Z/11AM but it may take longer in central and eastern Virginia.
VFR conditions are expected in the mountains and foothills for
the afternoon.

Above average confidence for wind.
Average confidence for ceilings.
Below average confidence for visibility.

.Extended Aviation Discussion...

Some sub-VFR conditions early Thursday will give way to VFR
conditions throughout the remainder of Thursday, with possibly
more fog Thursday night/Friday morning. Isolated MVFR showers
are possible mainly in the mountains Friday night. These
conditions look to spread east by Saturday as our next front
crosses through the area.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.

&&

$$
SYNOPSIS...NF
NEAR TERM...BMG
SHORT TERM...RR
LONG TERM...RR
AVIATION...AMS/BMG