-- Discussion containing changed information from previous version are highlighted. --
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FXUS61 KRNK 271237
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
837 AM EDT Mon May 27 2024

.SYNOPSIS...
An upper level system in advance of a strong cold front will
bring morning thunderstorms with strong winds today, with
storms re-developing across the Virginia and North Carolina
Piedmont regions this afternoon. Once the cold front passes
Monday evening, drier and and slightly cooler temperatures are
expected for much of the coming week.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
As of 745 PM EDT Sunday...

Key Messages:

1. A few severe storms possible this morning in the mountains.

2. Storms redevelop this afternoon east of the Blue Ridge
bringing the potential for damaging winds and large hail.

The immediate threat of severe weather has fizzled this morning.
Some more stratiform type showers continue to fall across the
mountains and just east of the Blue Ridge. These will push east,
and we will watch for re-formation of strong convection later
this morning into the afternoon. Forecasted temperatures were
nudged down as most of the CWA was cooler than expected, and
with ongoing showers and widespread cloud cover, it will be
tough for temperatures to warm stronger than models suggest.

From the previous discussion...

IR satellite imagery shows only a gradual warming of cloud tops
associated with the complex of storms across eastern KY into
northern TN early this morning. Expect the strongest storms
associated with this line to push southeast where the highest
instability is currently located, but there has been a recovery
in MLCAPES across southwest VA and northwest NC and DCAPE values
still remain robust. As a result, expect strong to perhaps
locally severe wind gusts possible as this line enters the
western portion of our CWA, especially in NW NC and far SW VA.

As this line pushes farther east into more stable air, the
severe weather threat diminishes until mid-afternoon. There
still is some uncertainty about where convective initiation
occurs this afternoon, but best combination of shear/instability
per the SPC HREF will likely be just east of our CWA. Still,
enough instability and low level convergence will be in place to
allow storms to develop across the VA and NC piedmont areas
with locally damaging winds and large hail possible.

As the front slips east tonight, the convection will end with
areas of mountain valley fog expected.

Did not stray from NBM temperatures today/tonight.
-- End Changed Discussion --

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
As of 200 AM EDT Monday...

Key Messages:

1. A few upslope showers and isolated storms possible Tuesday
and Wednesday afternoons.

The medium range models are in good agreement keeping the
eastern U.S. under the influence of an upper level trof that is
reinforced on Wednesday by an upper level system pushing south
of the western Great Lakes.

The 00Z SREF does show modest probabilities of SBCAPES exceeding
500 j/kg in central WV, as an upper level cool pool moves over
the area, so an isolated storm cannot be ruled out on Tuesday
in southeast WV. Widely scattered showers and perhaps an
isolated storm is also possible Wednesday afternoon mainly in
southeast WV, but most areas will remain dry with temperatures
close to normal on Tuesday and Wednesday with temperatures
expected to be a few degrees cooler on Wednesday.

Generally followed the NBM guidance for temperatures during this
period.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 145 AM EDT Monday...

Key Messages:

1). Generally benign weather for the later half of the week into the
weekend.

2). Unseasonably cool through much of the period.

3). Little to no rainfall for the Piedmont through the period.
Light showers possible across the western mountains.

The last week of May right into the first week of June will be
dominated by cyclonic northwest flow around a deep upper low
anchored over the eastern Great Lakes. This low pressure area will
only very slowly drift east toward NY/New England through the week
into the weekend, still influencing the weather across the eastern
U.S. over the weekend.

Cold air aloft combined with strong insolation from the late
May/early June sun will result in steep lapse rates during the
daytime. This combined with upslope flow may result in some isolated
to scattered rain showers Thursday across mainly southeast WV during
the daytime. Otherwise, the Thu-Sat time period will be dry.
Deterministic models show little to no precipitation during this
time frame, although the NBM continually wants to blanket the region
with slight chance pops.With ridging building over the area
from the west, both at the surface and aloft, see little if any
support for precipitation during this time frame.

Going into the weekend, the upper ridge begins to shift to the east
and the long standing upper low over the northeast shifts further
east/northeast as well. This will allow a short wave to traverse the
Midwest/OH/TN valley reaching our area by the weekend. However,
there is considerable disagreement among the various models as to
when and how this system will impact the region. Therefore, decided
against the NBM aggressive late week/weekend pops and held off on
any pops above 15% until Sat- Sun.

850mb temperatures will drop from the early double-digit readings in
the low to mid teens deg. C to around +5C to +8C through much of the
later half of the week. Temperatures will be on the cool side for
late May/early June, only reaching the 60s across the higher terrain
west of the Blue Ridge until the weekend, when lower to mid 70s will
return. These readings are 5-10 degrees below normal. Nights will be
chilly with lows in the 40s west and 50s east. A few spots such as
Burkes Garden and Quinwood could see the upper 30s Friday morning
behind a secondary surge of cold air rotating around the upper low.

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

&&

.AVIATION /13Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
As of 700 AM EDT Monday...

IFR to LIFR conditions were noted at all TAF sites except
KBLF and KBCB early this morning due to low clouds and vsbys.
While cigs and vsbys will gradually improve this morning,
showers and thunderstorms across the area will also diminish
before re-developing during the afternoon hours, especially at
KDAN, with lower probabilities of storms at KLYH.

Storms that develop this afternoon will have the potential to
produce wind gusts over 50 MPH and hail, but confidence wasn`t
high enough to put these conditions at any one TAF site. Outside
of the storms, southwest winds will be gusty with gusts 10-20
MPH.

Flying conditions improve after sunset once a cold front moves
through the area, but patchy areas of mountain valley fog
are expected early Tuesday morning.

EXTENDED AVIATION OUTLOOK...

Drier weather arrives Tuesday behind the front with VFR
conditions after morning fog erodes. There is a low chance for
showers and thunderstorms will be possible across WV Tuesday and
Wednesday, otherwise VFR. VFR everywhere Thursday.

Patchy fog with periods of MVFR/LIFR will be possible in the
mornings near mountain and river valleys.
-- End Changed Discussion --

&&

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

&&

$$

SYNOPSIS...PH
NEAR TERM...PH/VFJ
SHORT TERM...PH
LONG TERM...RAB
AVIATION...PH