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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 131857
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
257 PM EDT Thu May 13 2021

.SYNOPSIS...
Cool high pressure will maintain control on the region through
Saturday. A couple of disturbances may spark a few showers and
isolated storms mainly in the mountains, especially Friday
afternoon.

&&

.NEAR TERM /THROUGH FRIDAY/...
-- Changed Discussion --
As of 230 PM EDT Thursday...

An upper level trough will slowly move over the central Appalachians
tonight, then off the Virginia coast. With dry high pressure
underneath this trough, only shallow scattered cumulus clouds are
expected this afternoon. These clouds will fade away this evening.
Overnight lows will range from the mid 30s to low 40s across the
mountains and low to mid 40s east of the Blue Ridge. Some non-
sheltered mountains valley may see patchy frost again Friday
morning, but areal coverage not enough for another advisory.

As the weak upper level low tracks over the region Friday, more
clouds and a slightly better chance for an isolated afternoon shower
or thunderstorm. There exist some lift and energy associated with
the low overhead, but the main driving force for convection will be
orographical and diurnal heating. The area with the best chance to
see rain will be the Mountains Empire, Grayson highlands and the NW
NC High Country. Highs Friday will be in the 60s across the
mountains and lower 70s east of the Blue Ridge.
-- End Changed Discussion --

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
-- Changed Discussion --
As of 230 PM EDT Thursday...

Dry Saturday. Increasing rain chances Sunday.

High pressure is expected to maintain control through Saturday
promoting mainly dry but cooler than normal weather.

After Saturday, expecting a return flow of moisture associated
with a warm front that will approach from the southwest. This
will introduce first bonafide widespread rain chance with
opportunity for showers continuing early next week as warm front
stalls over the forecast area.

Attm, rainfall amounts do not look all that impressive with
models suggesting a tenth to a quarter of an inch through
Sunday evening...but with warm front hanging up across the area
Sunday night into early next week, expect opportunity for
additional wetting.
-- End Changed Discussion --

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
-- Changed Discussion --
As of 230 PM EDT Thursday...

Unsettled weather expected for the first half of the week.

The overall weather pattern looks to remain fairly active
through midweek as front bisects the region.  Synoptic and
ensemble guidance continue to show fairly good agreement on
this...suggesting potential for waves energy to ripple east
along the front creating opportunities for showers and
thunderstorms. Organization and intensity of this activity will
be highly dependent on the instability which will be highest
upstream of the forecast area across the OH/TN valleys. It
appears that we may remain on the cool side of the front, at
least for Monday, and this will favor temperatures on the
cooler side of guidance per upstream cloud debris and the
tendency for areas east of the mountains to get wedged in when
we remain on the north side of a front. If there is no
significant push to the warm front, which some of the model
guidance suggest, this scenario may play out again Tuesday and
Wednesday with much of the forecast area remaining stuck in a
wedge configuration.

Confidence is low to moderate for exact timing of rain chances
and temperature forecast. Bust potential for temperatures is
high given the pattern. QPF is highly questionable per need to
resolve shower/thunderstorm coverage and whether there is a
chance we could partake in wetting from an upstream MCS. If
there is any certainty, our NW CWA (WV) will maintain the
highest probabilities through the forecast period since this
part of the CWA will be closer to the higher instability region.
-- End Changed Discussion --

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --
As of 200 PM EDT Thursday...

VFR conditions for all sites through the forecast period with some
scattered to broken high based cumulus this afternoon. These clouds
will fade this evening. Winds remain out of the north to northeast
and light.

Extended Aviation Discussion...

Expect mainly VFR through the extended though some spotty showers
could induce sub-VFR especially in the mountains Friday afternoon
into early Saturday and possibly Sunday, but confidence is lower on
that.
-- End Changed Discussion --

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
VA...None.
NC...None.
WV...None.
-- End Changed Discussion --

&&

$$
SYNOPSIS...WP
NEAR TERM...RCS
SHORT TERM...PM
LONG TERM...PM
AVIATION...RCS