Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 03/30/19

Area Forecast Discussion

National Weather Service Blacksburg VA

 1132 PM EDT Fri Mar 29 2019

.SYNOPSIS...
High pressure across the Mid-Atlantic region will provide warm
and mainly dry conditions through early Saturday. A cold front
will then spread showers into the Appalachians and central mid
Atlantic as it moves across the area Saturday night into Sunday,
followed by colder temperatures for the start of next week.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 1113 PM EDT Friday...

Weather fairly quiet tonight with mid and high clouds in place.
A few light showers/sprinkles on radar in the TN valley appear
to falling apart with main 8h moisture transport situated more
over KY and western sections of WV. Still could see an isolate
shower overnight in SE WV.

Previous discussion from early this evening...

Noticing more opaque mid/high clouds per sat/webcams across the
area and upstream. Went with more sky cover as mid/high clouds
should thicken ahead of shortwave moving across the northern
Gulf Coast states tonight. This in turn will keep temps a bit
milder, so adjusted lows a few degrees. Appears any shower or
sprinkle would be confined to the mountains of WV to SW VA, and
of no consequence.


Previous discussion from early this afternoon...

Mid and high clouds combined with some convective debris continue to
push in from the west, though they are having a tough time holding
together. With renewal of diurnal convection upstream expect fresh
supply of clouds will have more success moving over the region as the
day wears on. With the approaching frontal boundary remaining well off
to our west there isn`t much forcing to generate any precipitation in
our neck of the woods and low level moisture is also lacking. However
it looks like convective remnants may brush by close enough to bring a
slight chance of showers to locations from portions of Tazwell up
through western Greenbrier this evening through tonight.

Saturday will start off with a good amount of cloud cover but by the
afternoon the clouds will dissipate a good bit especially east of the
Blue Ridge. This will allow for one last warm day ahead of the slowly
approaching cold front. It will also become rather breezy especially in
the east as low level winds amplify during the afternoon. There looks
to be enough mid level capping to inhibit convective development
through Saturday afternoon, but by late in the day some isolated
showers may start to develop form the mountains of NC up through the
Mountain Empire of VA into southeast WV.

Lows tonight will remain a bit above normal with upper 40s east to
low/mid 40s west. Highs Saturday will be well above normal with low/mid
70s east to upper 60s/lower 70s west.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
As of 130 PM EDT Friday...

A broad upper trough with its accompanying cold front will travel
through the East Saturday night into Sunday. The timing of the
frontal boundary has been fairly consistent on progressive model
run. Fropa will be during the early to mid-morning hours Sunday
which will minimize QPF and limits any thunderstorms. The heaviest
precipitation along and west of the Alleghanys. QPF with this
frontal system is expected to average around 0.25 inch. Low
temperatures Saturday night will range from the mid 30s in northwest
Greenbrier to the mid 50s in the piedmont.

The timing of the front will be important to the redevelopment of
showers and possible thunderstorms Sunday afternoon. At this time,
the redevelopment will be east and south of our forecast area. SPC
convective outlook supports this idea of an absence or jumping
over of our CWA with the general thunder delineation.

Windy conditions are anticipated behind the cold front on Sunday.
However, winds speed are expected to remain below wind advisory
levels. Utilizing an non-diurnal temperatures curve for Sunday,
highs will range from around 40 degrees in west mountains to
the lower 60s in the piedmont.

High pressure will build east into our area on Sunday night. The
850mb temperatures drop to around -2C to -7C by Monday morning. It
will be cold Sunday night into Monday morning with readings from
around 20 degrees in the mountains to the lower 30s in the piedmont.

High pressure will control our weather Monday for the first day of
April. High temperatures will be below normal with values from
the mid 40s in the west to the mid 50s in the east.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 130 PM EDT Friday...

The forecast challenge in the long range is what happens with the
coastal low that develops and lifts north along the East coast.

A strong shortwave dives through the base of the mean upper trough
into the western Gulf Monday. As a result, surface low pressure
rapidly develops across the central Gulf, then tracks northeast
across the Southeast States Tuesday into Wednesday. The exact track
of this system will be important with respect to amounts and type of
precipitation across our area.

The northwestern side of the coastal low could bring a widespread
area of precipitation to our area late Tuesday into Wednesday
morning, before quickly shifting east-northeast of the area. A light
snow event may be possible for the southwest mountains. The 00z
ECMWF supports 1-3 inch across the southwest mountains with light
totals elsewhere. A warm ground will minimize the effects of any
snow.

High pressure will build in quickly behind the low center Wednesday
afternoon. Then the high center will slide east Wednesday night into
Thursday.

&&

.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
As of 713 PM EDT Friday...

We are looking at mid and high level ceilings tonight into most
of Saturday. Not of the question to see some sct/bkn stratocu or
cu during the afternoon Saturday as moisture continues to
increase ahead of a cold front in the mountains, but overall
cloud bases should stay in the VFR range.

Winds will generally be light through the first half of the
period with no impact to aircraft operations. However, low level
winds will be increasing Saturday afternoon and gusts will
increase especially east of the Blue Ridge at KLYH and KDAN.

EXTENDED AVIATION DISCUSSION...

VFR expected until the arrival of a cold front and showers Saturday
night. A period of MVFR CIGs is anticipated Sat night into early
Sunday along with sub- VFR visibilities associated with the
frontal and post-frontal showers. A transition back to VFR is
expected late Sunday into Monday with a primary flight category
of VFR expected Monday.

Model consensus is for a coastal storm to impact the Mid-
Atlantic region Tuesday with high uncertainty as to the
westward extent of the Sub-VFR sensible weather. High pressure
will build toward Wednesday with VFR returning but could see
some lingering MVFR in the mountains.

&&

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

&&

$$
SYNOPSIS...MBS
NEAR TERM...MBS/WP
SHORT TERM...KK
LONG TERM...KK
AVIATION...MBS/WP