Area Forecast Discussion
Issued by NWS Blacksburg, VA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KRNK 251017
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
617 AM EDT Mon Mar 25 2024

.SYNOPSIS...
High pressure will keep the weather dry through Tuesday morning.
A low pressure system crossing through the Great Lakes will
slowly bring a cold front and showers through the region Tuesday
afternoon through Thursday. Friday and Saturday look to be
warmer and dry under high pressure.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 200 AM EDT Monday...

Key Message:

1. Dry high pressure continues to remain in control. Dry weather
expected.

High pressure centered over Canada continues to wedge south
along the Appalachians this morning. Strong surface lows in the
Plains and the Atlantic will enhance the high pressure wedge
through tonight.

East/southeast winds will continue through the morning,
allowing areas in southwest Virginia and southeast West Virginia
to remain will-mixed due to downsloping winds. This will keep
temperatures elevated this morning. Areas further east will
have a better chance for radiative cooling, especially sheltered
valleys that decouple. Those that do decouple likely to see
lows in the 20s, however areas that remain mixed likely to see
lows in the mid/upper 30s.

Skies remain mostly sunny today, but will see increasing high
clouds as the frontal system to the west progresses east
throughout the day.

Winds increase overnight for the Mountain Empire and southeast
West Virginia as southeast flow ahead of the approaching front
increases. Could see gusts nearing 35 to 40mph by midnight
across the far western slopes.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
As of 345 AM EDT Monday...

Key Messages:

1) Rain returns to the area Tuesday and continues throughout
much of the area through the period.

2) Temperatures near to slightly above normal through this
period.

The synoptic pattern features a high amplitude ridge along the
east coast with a cutoff low in the western Atlantic (remnants
of our weekend system) and a broad deep upper low anchored over
the southwestern U.S. Thanks to the strong upper ridge just to
our east, the upper trough will progress only slowly east and
largely shear out to our northwest over the OH Valley during the
mid week. A dissipating frontal boundary will drift into the
region slowly from the west Tue-Wed. Likewise, the associated
rain will be in a weakening phase as well. The front will drift
to our southeast Wed-Thu and result in a developing baroclinic
zone across the southeast states for the later half of the week.
A southern stream short wave will then induce an area of low
pressure along the baroclinic zone with widespread rain and even
a few thunderstorms developing across the southeast states Wed-
Thu. The main question here, as is often the case with this
pattern, is how far northwest will the associated rain spread.
Current indication are that the bulk of the rain will remain to
our southeast, but certainly a good amount will spread into our
southeast counties before shifting to the east Wed-Thu. The
threat for thunderstorms remains to our southeast for the most
part.

So in summary, while the first part of this period appears to be
fairly straight forward, the later part is more questionable in
terms of pops and qpf. As of now, rainfall amounts are expected
to range from < 1.00 west of the Blue Ridge to 1 to 1.5 inch
east of the Blue Ridge. WPC has removed the eastern parts of the
CWA from a "marginal" risk of excessive rain for Wed with their
latest update.

Precipitation and east to southeast flow will help to develop an
in-situ wedge across the region Tuesday, which will linger into
Wednesday. This will hold temperatures near normal despite
850mb temperatures averaging a bit above normal for this time of
year. Progressing into Thursday, however, northwest flow the
system to our southeast should help to pull cooler air into the
region from the northwest with temperatures slightly below
normal by then.

Finally, gusty southeast winds are possible across southern WV
and southwest VA west of I-77 early Tuesday, but are expected to
remain below wind advisory criteria. Gusty northwest winds will
be possible Thursday, especially west of the Blue Ridge.

/Confidence Levels in Forecast Parameters/
- Moderate Confidence in Temperatures,
- Moderate to High Confidence in Precipitation Probabilities,
- Moderate Confidence in Wind Direction and Speed.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
As of 415 AM EDT Monday...

Key Messages:

1) Rain from the southeastern U.S. system moves out of the area
by Friday.

2) Northwest flow flow aloft potentially brings showers into the
area by the weekend.

The upper flow becomes more progressive during this period as
the southeastern U.S. system finally moves out to sea Friday. By
the weekend, the upper trough has drifted off the coast and the
flow aloft trends toward a more zonal pattern overall across the
U.S, but maintains a slight northwest tilt across the eastern
U.S.

The focus during this period will be on a northwest flow
disturbance and a potential baroclinic zone focused across or
just to the north of the CWA, in essence setting up very close
to the I-64 corridor. Most long range models show a complex of
thunderstorms developing across the Ohio Valley Fri-Sat which
weakens and drifts southeast into the Mid-Atlantic/Central
Appalachians Saturday and lingers into Sunday along a weak
baroclinic zone as noted above. Confidence in this pattern is
low at this time, but have introduced low chance pops across
much of the area for the weekend.

Temperatures are also problematic, but at this point should be a
bit above normal with westerly flow in advance of any frontal
boundary across the region or just to the north of the CWA.
However, clouds and precipitation could play havoc with any
appreciable warm temperatures, so confidence in NBM temperatures
during the extended period in the 70s is low at this point.

/Confidence Levels in Forecast Parameters/
- Low to Moderate Confidence in Temperatures,
- Low Confidence in Precipitation Probabilities,
- Low to Moderate Confidence in Wind Direction and Speed.

&&

.AVIATION /10Z MONDAY THROUGH FRIDAY/...
As of 615 AM EDT Monday...

VFR conditions through the TAF forecast period.

Winds are the main forecast topic throughout this 24hr TAF
period as high pressure wedges south along the Appalachians.
Winds this morning vary from light/variable in valley locations
to as much as 20 to 25kts across the West Virginia and
southwest Virginia mountains. Southeast flow will increase today
and will see an increase and frequency of wind gusts at BLF.
Could see gusts of around 30kts at times between 8pm/Oz and
2am/6z.

Outside of the expected winds at BLF, winds generally 10kts or
less from the east/southeast through the period.

Some high clouds begin to fill in towards the end of the TAF
period as moisture builds ahead of an approaching front.

EXTENDED AVIATION OUTLOOK...

Clouds will increase on Tuesday as a low pressure system
approaches from the west. The next chance of rain and IFR/MVFR
conditions occurs during Tuesday afternoon into Thursday with a
slow moving cold front.

Conditions will gradually improve by Thursday night as the low
pressure system heads offshore.

Friday is expected to be VFR and warmer.

&&

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

&&

$$

SYNOPSIS...BMG
NEAR TERM...BMG
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...BMG


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.