Area Forecast Discussion
Issued by NWS Blacksburg, VA

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FXUS61 KRNK 241733
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
133 PM EDT Sun Jul 24 2016

.SYNOPSIS...
Strong high pressure aloft will continue to bring increasing heat
and humidity today through Monday. A series of weak surface cold
fronts approaching from the northwest should gradually bring an
increasing threat for showers and storms by the middle of next
week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 130 PM EDT Sunday...

Fair weather cumulus clouds beginning to develop over the
mountains but none are threatening to produce rain. Delayed the
timing of diurnal thunderstorms and lowered chances by 10%.
Storms that do manage to form will not last long into the
evening.


As of 211 AM EDT Sunday...

Upper level ridge will continue to shift east today with the core of
the highest heights about overhead this afternoon. This should bring
the warmest air aloft into the region with 850 mb temps of around +24C
later on. After a warm start, expect the hottest temps so far to occur
this afternoon with most spots outside of the higher elevations topping
90 degrees, with 95-100 along/east of the Blue Ridge. This may chase
record highs in spots, espcly BCB/BLF per climate section below. In
addition, heat indices will likely reach 101-104, espcly east of
Highway 29, but moreso in parts of Southside Va where could see brief
105 advisory criteria. However since trends have been for dewpoints to
mix out more while guidance has been too hot, wont hoist a headline for
just a couple counties, mainly Charlotte/Halifax at this point.

Otherwise expecting mainly sunny skies with convection quite limited
given little support aloft and warm mid level temps. Still appears some
weak low level convergence across the western ridges could combine with
heating/instability to pop isolated slow moving storms far west by
mid/late afternoon. This mainly along/west of the Interstate 77
corridor where moisture may be slightly deeper and the cap weaker.
Thus keeping a 20/30 pop espcly west of the Blue Ridge as still expecting
the core of the upstream MCS to stay north for the most part.

Guidance suggesting any evening storms to fade by midnight if not
sooner with the ridge hanging on while more organized convection stays
to the north/west. This should again allow for mainly clear skies
outside of debris clouds overnight, with patchy fog valleys and
muggy lows, mid/upper 60s west to 70-75 east.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
As of 330 AM EDT Sunday...

We will remain in quasi zonal flow on the warm side of the jet stream
through the middle of the week. A shallow trof will drive a surface low
through the Great Lakes/southern Canada and help push a weak front into
the region on Monday. However with zonal flow there will be little
forcing to nudge the front clear of the region, which will allow it to
wash out over the area. The old boundary combined with warm and
unstable air will enhance our coverage of showers and thunderstorms
through the first part of next week. The synoptic environment over our
area does not favor organized severe convection, but will have to watch
for pulse storms with some clustering. With a typically vague
summertime pattern will structure POP girds with the usual diurnal bias
for a peak in the later afternoon/evening, then tapering off during the
overnight hours. Will wait for convection to declare its intentions
before getting more specific with the grids.

High temperatures will continue to run a few degrees above normal with
a slight cooling trend through midweek. Expect highs to be in the
low/mid 90s east of the Blue Ridge with readings generally in the
mid/upper 80s to the west. Lows will be 70 to 75 east, 60s west.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
As of 315 PM EDT Saturday...

Little change in the overall pattern will mean a persistent chance
each day of afternoon and evening showers and thunderstorms.
Northern stream upper trof will bring some lift into the region
Friday. Temperatures will be close to normal through the period.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
As of 128 PM EDT Sunday...

LWB observation have returned as of 17Z Sunday.

Outside of a very isolated diurnal thunderstorm, overall VFR
conditions expected to continue for most of the period with high
pressure aloft in place. Will again see some patchy fog in the
valleys early Monday morning under thin high clouds.

Extended aviation discussion...

Strong high pressure aloft looks to remain in place on Monday with
continued VFR outside of developing convection Monday
afternoon/evening. However coverage of storms on Monday again looks
rather isolated until late and mainly confined to mostly the western
mountains at this point. Ridge will finally weaken through mid week
as an initial cold front sinks toward the area from the northwest.
This should bring about an increase in daily convective coverage
Tuesday into Thursday with periodic MVFR/IFR possible.
Late night and early morning fog will likely occur at the usual
valley locations, and those chances increase across the entire
region if any rain occurs during the afternoon or evening at any
site.

&&

.CLIMATE...
Record high temperatures for today (7/24)

Roanoke.....100 in 1933
Lynchburg...100 in 2010
Danville....101 in 2010
Blacksburg...92 in 1991
Bluefield....91 in 1987

Record high temperatures for Monday (7/25)

Roanoke.....100 in 1934
Lynchburg...102 in 1934
Danville....102 in 2010
Blacksburg...92 in 1987
Bluefield....90 in 1987

&&

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

&&

$$
SYNOPSIS...JH/RCS
NEAR TERM...JH
SHORT TERM...MBS
LONG TERM...MBS
AVIATION...RCS
CLIMATE...JH



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