Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 09/03/19

Area Forecast Discussion

National Weather Service Blacksburg VA

 827 PM EDT Mon Sep 2 2019

.SYNOPSIS...
High pressure will build into the region behind a cold front
tonight, bringing fair weather to the Appalachians and central
mid Atlantic region for Tuesday. Hurricane Dorian will move
slowly up the southeast Atlantic coast through midweek. However,
Dorian is expected to remain far enough away from the area to
avoid any significant impacts, with just a chance of showers and
a good breeze expected Wednesday and Thursday.

&&

.NEAR TERM /THROUGH TUESDAY/...
AS of 827 PM EDT Monday...

High pressure will build into our region overnight into
Tuesday. Trimmed backed pops for this evening with the loss of
solar heating. Adjusted temperatures for this evening into
tonight, utilizing the latest surface obs, their trends and
shaped towards NBM. In general, adjusted low temperatures down
in the western mountains a few degrees overnight. Mostly clear
skies will lead to the development of areas of stratus and fog
overnight into Tuesday morning.


As of 225 EDT Monday...

Radar shows widely scattered showers/some thunderstorms are
developing ahead of a cold front approaching from the northwest.
Expect coverage will remain on the scattered side as the
activity develops and spreads eastward. While the best dynamic
support for potentially severe convection resides off to our
northeast, there may be a robust storm or two especially up near
the Interstate 64 corridor. Showers may linger a bit into this
 for VA piedmont, but expect most of the overnight will
be dry as high pressure starts building in form the west. With
some boundary layer moisture and radiational cooling, expect
some areas of fog by daybreak. Any lingering low clouds and fog
will burn off Tuesday morning with a good amount of sun expected
for the afternoon.

Lows tonight will generally be in the upper 50s/around 60 west
of the Blue Ridge with low/mid 60s to the east. Highs on Tuesday
will be warm with low/mid 80s west to upper 80s/near 90 east.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 200 PM EDT Monday...

The big question during this portion of the forecast is what if any
impacts Hurricane Dorian will have on our forecast area. The
official forecast track cone of probable path for Dorian from the
National Hurricane Center tracks the storm from off the coast of
South Carolina Thursday morning to around the Outer Banks of North
Carolina Friday morning with all the probabilities of uncertainty
incorporated with the forecast cone.

While the transition with Dorian is occurring to our south and
southeast, a cold front will be approaching our region from the
northwest Tuesday night into Wednesday, washing out over the region
Wednesday night.

Dorian will first impact our weather pattern by generating a
notable amount of subsidence on the north and northwest side of
its center. This influence will help squelch the impact of the
approaching cold front on our area, and also help yield
increasing temperatures across the area on Wednesday. High
temperatures Wednesday are expected to be in the low to mid 80s
across the mountains and upper 80s to near 90 across the
Piedmont. Precipitation in the form of isolated showers and
storms is expected in associated with the cold front, with the
greatest concentration across the northern sections of the
region. Some lingering showers and storms will continue into
Wednesday evening, with some coverage across eastern sections.
Low temperatures Wednesday night will range from the low to mid
60s across the mountains to upper 60s across the Piedmont.

For Thursday into Thursday night, the far northwest portion of the
precipitation shield around Dorian`s center is expected to skirt the
far southeastern sections of the forecast area with around one-
quarter of an inch of rain, primarily for those areas east and south
of Danville, VA.  Winds will also become gusty from the northeast,
and then the north, reaching gusts around 30 to 35 mph, again across
the far southeastern sections of the region, perhaps along and south
of a line from Danbury, NC to Danville, VA to Charlotte Court House,
VA. Gusts will be weaker the farther west and north of this line
with gusts in WV around or less than 10 mph.

There also may be an area of light precipitation across western
sections of the area. The washed out cold front may act as a
weakness where strong advection of moisture may become realized as
isolated showers.

Winds across the entire region will weaken Thursday night as the
center Dorian is expected to track farther away from the region.
Precipitation will also be on the decrease across the far
southeastern sections of the forecast area.

Plenty of cloud cover across the entire region will limit high
temperatures to the mid to upper 70s for most locations on Thursday.
Low temperatures Thursday night will range from the upper 50s across
the mountains to the lower 60s across the Piedmont.

Confidence in the above portion of the forecast is moderate. The
actual track of Dorian will play a big role in just how much or
little rain/wind gusts the area receives, and what geographical
region that will looks like.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 130 PM EDT Monday...

Friday morning, the pressure gradient on the backside of departing
Dorian will continue to slacken. Any gusty winds still remaining
across the far southeastern sections of the forecast will subside
very quickly through the morning. Precipitation associated with the
departing system is expected to be east of the area Friday morning.
Therefore, have removed mention of any lingering rain in the east.
Skies will still be mostly cloudy to cloudy in the east at sunrise,
with less coverage across western sections. As the day progresses,
all locations will trend to mostly sunny to sunny. High temperatures
will range from the mid to upper 70s across the mountains with low
to mid 80s across the Piedmont.

As we head into and through the weekend, the overall synoptic flow
across our region will trend zonal with gradually building heights.
This transition will yield slightly milder temperatures each day. A
weak front will cross into the area on Sunday and stall near the
NC/VA border, potentially helping to trigger some isolated afternoon
showers near the crest of the Blue Ridge. The vast majority of the
region will remain dry through the weekend.  Lows across the
mountains both Saturday and Sunday morning will likely be in the mid
to upper 50s with upper 50s to around 60 across the Piedmont. Highs
both days will range from the upper 70s to around 80 across the
mountains with mid 80s across the Piedmont.

On Monday, low level flow transitions to a more southerly fetch, and
helps advect high temperatures and moisture levels into the region.
With the stalled front still in place across the region, look for
the development of isolated to scattered showers, especially in the
afternoon. Morning lows will be around the upper 50 to around 60
across the mountains with lower 60s across the Piedmont. Thanks to a
greater amount of cloud cover and scattered precipitation across the
area, high temperatures will trend a little cooler as compared to
the weekend. High will range from the mid 70s to near 80 across the
mountains with reading around 80 to the lower 80s across the
Piedmont.

Confidence in the above section of the forecast is moderate to high.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
As of 733 PM EDT Monday...

Isolated MVFR showers and thunderstorms will diminish this
evening with the loss of solar heating. Outside of convection,
VFR conditions will prevail this evening into tonight.
High pressure will build in behind the front overnight and
expect lingering boundary layer moisture to combine with good
radiational cooling to develop a good amount of IFR fog and
stratus at most sites by daybreak.

Any lingering fog/stratus will burn off Tuesday morning with
VFR conditions expected by late morning into the afternoon.

Winds will generally be light with no significant impact to
aircraft operations.

Medium confidence on ceilings, visibilities and winds
during the taf period.

.Extended Aviation Discussion...

VFR conditions should generally remain intact for the remainder
of this week aside from any nighttime fog or clouds due to
continued southeast flow. While the latest model guidance keeps
Dorian well off to our east, the still may be enough wind to
affect aircraft operations by Thursday. Aviation interests
should monitor the progress of Dorian closely for the next
several days. VFR conditions will prevail Saturday and Sunday.

&&

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

&&

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