Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 10/01/19
Area Forecast Discussion
National Weather Service Blacksburg VA
1133 PM EDT Mon Sep 30 2019
.SYNOPSIS...
A weakening wedge of high pressure will linger over region
before giving way to very warm temperatures again by midweek. A
cold front will then move through late Thursday with much
cooler conditions expected into the weekend, though little in
the way of rainfall will accompany the front.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 1110 PM EDT Monday...
Expect a mainly cloudy and mild night especially along and east
of the I-81 corridor from the New River Valley to the Southern
Shenandoah Valley as satellite showing cloud cover increasing.
Fog will be an issue where it rained and where lack of cloud
cover resides, mainly in the mountains. Some high-res models
showing light rain/drizzle threat, but overall depth of moisture
seems to shallow overnight and lack of forcing will keep pops
under 15 percent most of the night.
Previous early evening discussion...
Coverage of showers and storms along an instability gradient
with the high pressure wedge is dwindling early this evening and
have isolated coverage til around midnight. Due to rainfall in
the west, anticipate coverage of fog to start sooner this
evening and last through the overnight. However, flow across the
east will be moist and should see stratus deck increase
along/east of the mountains overnight. The previous forecast has
this handled well, so not many edits made this update.
Previous discussion from early this afternoon...
Visible satellite imagery shows that the wedge has eroded from
both the east and west with effects lingering mostly just east
of the Blue Ridge. Radar trends show that convection has
initialized in the west with best heating and destabilization,
while some other showers/thunder are exiting to the east
following a departing short wave. Anticipate an isolated cell or
two may try to get a bit rowdy through early this evening west
of the Ridge, but expect convection will dissipate with loss of
heating this evening/early tonight. The lingering wedge will
then allow for development of low clouds and some fog overnight.
Tuesday may play out much the same as today, though coverage of
showers/storms looks to be less with the best chance form the
Grayson Highlands into the mountains of NC.
Lows tonight will be mild with generally be in the mid/upper
60s. Highs tomorrow will generally be in the mid to upper 80s.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 110 PM EDT Monday...
The upper level ridge bringing warm conditions during this
period will continue to transition across Tennesse going into
Wednesday, eventually locating itself over the Carolinas for
Thursday. 850mb temperatures are still running warm with current
guidance, meaning surface temperatures are going to be running
roughly 15 degrees above average. As previously stated, we are
going to be watching Wednesday and Thursday for another round of
record breaking temperatures. Hard to decide on whether or not
to add some very small pops Wednesday afternoon for some of the
mountains where perhaps enough heating could produce an isolated
storm or two, but going to hold off for now on updating grids
to reflect this since the pop would be very minimal.
A much anticipated cool down is on the way for the weekend: the
census is still leading toward a frontal passage later Thursday to
Thursday night. As previously mentioned, the heat will still be on
before this front for Thursday afternoon. The only negative note with
this front will be the lacking convection with it. Rain chances look
best for isolated to scattered showers and storms west of the Blue
Ridge, with minimal to slim chances for areas east.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 110 PM EDT Monday...
After the front Thursday, high pressure returns as we wedge in
for Friday and Saturday. This will certainly bring the "Fall
Feels" as the cool down remains on track to be nearly 20 degrees
cooler from our recent heat. PWAT amounts start to recover and
increase Sunday as rain chances start to increase along the edge
of the then weakening wedge. From there, our next big frontal
system steps into play with increasing pops Monday with a
lifting warm front moving through the area, followed up by a
strong cold front passage MOnday into Monday night. Confidence
in exact details with this part of the forecast will obviously
increase as we get closer in time.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
As of 710 PM EDT Monday...
Should see terminals tank to LIFR to IFR overnight tonight as
east flow and wedge remain in place. Any showers should weaken
this evening and not impact taf sites. Surface moisture
increased some and with rain, expect fog in the mountain valleys
and to some extent terminals east of the mountains. Will see
best fog threat at LWB/BCB, with better coverage of stratus
along/east of a TNB-BCB-ROA-SHD corridor.
Anticipate gradual improvement to VFR all sites by late Tuesday
morning. Isolated showers/thunderstorms possible again mainly
west of the Blue Ridge Tuesday afternoon, but not enough to
warrant mention in the tafs yet.
Winds will generally be light with little impact to aircraft
operations.
Forecast confidence is high for poor flying conditions after 05z
tonight, especially between 09z-13z.
.Extended Aviation Discussion...
High pressure aloft will build across the region through mid
week, with a transition back to mainly dry VFR conditions. There
will be the normal early morning fog/stratus in the mountain
valleys...confined to the 4AM-9AM time frame, otherwise no
significant weather threats until a strong cold front arrives
late in the week. This cold front looks to cross the region from
the northwest by Friday with an ensuing wind shift and possible
periods of MVFR in showers along the boundary. High pressure
follows with another wedge and possible associated sub-VFR
conditions within lower cigs on Saturday.
&&
.CLIMATE...
The heat returns regionwide for Wednesday and Thursday. Here are
the numbers to beat for mid week...
Wednesday 10/02/2019
Site MaxT Year HiMin Year
KBLF 87 1919 64 1986
KDAN 92 1986 68 1971
KLYH 88 1905 68 1898
KROA 88 1919 67 1971
KRNK 85 1953 60 1986
Thursday 10/03/2019
Site MaxT Year HiMin Year
KBLF 84 1919 66 1941
KDAN 93 1919 69 2012
KLYH 94 1919 72 1898
KROA 91 1919 68 1941
KRNK 86 1954 63 1954
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...MBS
NEAR TERM...MBS/WP
SHORT TERM...RCS/RR
LONG TERM...MBS/RR
AVIATION...MBS/PM/WP
CLIMATE...RCS