Area Forecast Discussion
Issued by NWS Blacksburg, VA
FXUS61 KRNK 240746
Area Forecast Discussion
National Weather Service Blacksburg VA
346 AM EDT Fri Mar 24 2017
High pressure off the coast will establish a warmer and more moist
southerly flow across the Appalachians and central mid Atlantic region
into the weekend. A slow moving cold front will enter from the west on
Sunday with a chance for showers and possibly a thunderstorm. Our
weather then looks to remain unsettled through next week as a series of
disturbances move across the central and southern part of the country,
keeping a chance for showers and thunderstorms in our forecast through
.NEAR TERM /THROUGH TONIGHT/...
As of 345 AM EDT Friday...
It`s looking like a quiet end to the workweek as an upper level ridge
is the dominant weather feature over the Appalachians, though there
will be a fair amount of cloud cover around. At the surface, high
pressure along the middle Atlantic coast will continue to push offshore
today. Satellite imagery shows some lower clouds extending back from
the NC mountains toward the Gulf coast, guidance supports return flow
around the high drawing these clouds up into the region this afternoon
along and east of the Blue Ridge into Southside. Additionally, a short
wave will swing through the Ohio valley along a warm front on the rim
of the upper ridge. This is generating some shower/storms well off to
our northwest, but expect some showers to brush by to our north today
with lower clouds extending southward into the region. Quiet weather
then continues tonight as the ridge axis crosses the region and high
pressure at the surface remains parked off the mid Atlantic coast.
With a deepening southerly flow, temperatures will moderate
considerably from readings yesterday with highs about 10 degrees warmer
which will be above normal for late March.
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
As of 345 PM EDT Thursday...
A pattern transition will be underway this weekend as
predominate northwest flow aloft comes to an end, replaced by
unsettled split flow with series of southern stream storm
systems of Pacific origin to parade across the CONUS. First in
this series of storm systems will arrive Sunday. Until its
arrival, the first half of the weekend will be dry, Saturday
certainly a great day to be outdoors with temperatures in the
Late Saturday, moisture will be on the increase west of the
Appalachians per the approach of an upper low to lifting out of
the Southern Plains. Showers/thunderstorms associated with this
system will be advancing east across the Tennessee Valley into
far southwest VA or southern WV Saturday night. The upper low
will then take a more northward track into the Ohio Valley and
weaken as it encounters the upper ridge along the eastern
seaboard. This will result in a weakening of the thunderstorm
activity as it crosses the mountains, but still sufficient
forcing, instability, to promote high probability of showers
areawide for Sunday. Temperatures Sunday will be just a tad
lower thanks to cloud cover and precipitation, but with
increasing dewpoints, overnight lows will be warmer.
With regard to QPF, models are in fairly good agreement,
advertising 1/2 to 3/4 inch of rain along and west of the Blue
Ridge Sunday, and 1/4 to 1/2 inch east of the Blue Ridge.
Severe weather is not expected for our CWA for this first
.LONG TERM /TUESDAY THROUGH THURSDAY/...
As of 400 PM EDT Thursday...
Next in a series of upper-level low pressure areas will move
from the Southern Plains into the Tennessee Valley/Central
Appalachians late Monday into Tuesday. While this system will
again be weakening as it moves toward the western Atlantic upper
ridge, it will have somewhat better dynamics and instability to
work with than the Sunday system. Therefore, a chance of
thunderstorms anticipated areawide for Tuesday afternoon. This
still does not look like a widespread severe weather maker for
our CWA, but slightly better potential for at least some
stronger storms with small hail per warmer temperatures, higher
surface dewpoints and slightly better instability compared to
the Sunday system. Rainfall amounts again appear to be in the
1/4 to 3/4 inch range over all with this event.
A quieter midweek period appears in order as another upper-
level system deepens but slows as it moves into Texas and an
upper ridge amplifies across the eastern U.S. A weak area of
high pressure from the Great Lakes filters into the area for
midweek. By Friday, this aforementioned system will move into
the Mid-Atlantic region as yet another upper-level low pressure
area moves from the southwest U.S. into Texas.
Temperatures will remain mild through the upcoming week with no
significant intrusions of Canadian air. A slight cooling will
be noted midweek, but temperatures will favor the warm side of
normal with highs in the 60s/70s and lows mainly in the 40s to
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
As of 240 AM EDT Friday...
High pressure along the middle Atlantic coast will continue to
push offshore today and keep our winds from a southerly
direction. Satellite imagery shows some lower clouds extending
back from the NC mountains toward the Gulf coast, and guidance
indicates that our southerly flow will help draw this moisture
up into the region this afternoon mainly east of the Blue Ridge
into Southside VA. While conditions will remain VFR, expect
cigs to develop this afternoon with a downward trend down and
approach MVFR at KDAN. Additionally, a short wave will swing
through the Ohio valley along a warm front on the rim of the
upper ridge. This is generating some shower/storms well off to
our northwest, but expect some showers to brush by to the north
with some lower VFR clouds extending down into KLWB. Expect VFR
conditions to persist into Friday night. Winds will become a
bit gust this afternoon with gusts around 20kts expected mainly
east of the Ridge.
Extended Aviation Discussion...
Moisture starts to increase over the weekend ahead of an upper-
level low pressure area moving northeast from the Southern
Plains. Precipitation is not expected until Sunday when sub- VFR
conditions become more of a possibility. Otherwise looking at
overall VFR to start the weekend with most lower cigs remaining
west of the area until later Sunday at this point. Periods of
unsettled weather will continue into the first half of next week
as a series of upper-level lows track from west to east across