-- Discussion containing changed information from previous version are highlighted. --
737
FXUS61 KRNK 090705
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
305 AM EDT Thu May 9 2024

.SYNOPSIS...
Chances of showers and thunderstorms will continue through
Thursday when a cold front crosses the Mid Atlantic. Cooler
conditions will arrive for the weekend with the potential for
mountain showers. Warmer air should return during next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
As of 230 AM EDT Thursday...

Key Messages:

1) Isolated storms are possible this afternoon and evening.

2) Cooler and drier air begins to filter into the region
tonight.

Decaying MCS continues to drift southeast with the bulk of the
thunderstorm activity in the Carolinas. Some light rain
continues this morning, but will continue to diminish as it
pushes east into the Piedmont areas.

Main surface low and front is still off to the west over the
Ohio Valley. It will progress eastward today and isolated
thunderstorms will be possible by the afternoon hours.
Another MCS currently over western Tennessee and Kentucky
associated with the main cold front will move south of the area,
but debris clouds and possibly some residual rain could move
into the area by daybreak. Forecast uncertainty is high once
again today on how much destabilization will occur. Depending on
the degree of cloudiness and how much rain reaches us later this
morning will have a big impact on storm chance later this
afternoon. The 00Z HRRR Neural Network indicates the best
probability for storms will be between 5PM to about 9PM, mainly
across the Piedmont, east of the mountains. Activity will be
very isolated, but any storms that can develop will feature
damaging winds and perhaps some large hail as a secondary
threat. Storms will quickly weaken after sunset from loss of
heating.

Cold front crosses tonight and the mountains will see some
post- frontal upslope showers. Winds will be a bit gusty too
across the higher elevations.

Highs today will be in the mid/upper 70s across the mountains to
low 80s east of the mountains. Cooler air behind the front
tonight will bring lows down into the mid/lower 50s for the
mountains, upper 50s east of the mountains.
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&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 130 PM EDT Wednesday...

Key Messages:

1. Cooler temperatures for the weekend.

2. Showers and thunderstorm possible late Saturday.

A broad mid level trough will swing through the Great Lakes and
Mid Atlantic, its axis to the east of the area by late Friday,
and northwesterly flow aloft over the central Appalachians. A
cold front crosses the region Thursday, and will be to the east
of the forecast area by the start of this forecast period, with
overall shower and storm activity decreasing into Friday,
although some upslope showers in the west may linger through the
day as a shortwave rounds the base of the trough. Chances for
storms are greatest over the NC Piedmont, where there will be
greater instability. A cooler and drier airmass comes in behind
the front, bringing below normal temperatures for the weekend.
Cold air advection and pressure rises behind the front will lead
to gusty winds for Friday, mainly in the west and higher
elevations.

Subsidence in the wake of the departing wave will keep Saturday
dry to start the day. Another trough digs southward towards
the area by late Saturday, its associated surface low tracking
across the Great Lakes into the upper Mid Atlantic by Sunday.
The cold front crosses through the area late Saturday into
Sunday, increasing precipitation chances through that time
frame. However, thinking coverage of showers and storms will be
limited by the drier airmass overhead.

Temperatures will drop to below normal Friday and through the
weekend behind the frontal passage on Thursday. At this time,
probabilities for low temperatures below 40 degrees are highest,
around 50% to 70%, in the typical cold spots, like Burkes
Garden and Mount Rogers and western Greenbrier County WV,
Saturday morning.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 130 PM EDT Wednesday...

Key Messages:

1. Gradual warming trend through the period.

2. Chances for showers and thunderstorms increase towards
midweek.

Mid and upper level ridging builds in to the west of the area
behind the trough, and surface high pressure expands eastward
into the Mid Atlantic for the start of the long term forecast
period. This will bring an end to the precipitation and keep
Sunday and Monday mostly dry. With high pressure overhead, and
increasing 500mb heights from the ridging, expecting clearer
skies and a warming trend in temperatures. An upper trough
develops in the lee of the Rockies during the first half of the
work week, and deepens as it tracks into the south central US,
and then across the Gulf Coast states, tapping into plentiful
moisture from the Gulf. As the surface high shifts east and into
the Atlantic, precipitation chances increase as the southerly
flow from the high brings some of this moisture into the area.
After Tuesday and further into the middle of the week, long term
models diverge on the placement and timing of the heaviest
precipitation from this system, which lowers forecast confidence
this late in the forecast period. That being said, most of
Tuesday and Wednesday have the greatest chances for showers and
possibly storms.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
As of 230 AM EDT Thursday...

Generally VFR across the region with light showers continuing
across Central Virginia and North Carolina. Shower will continue
to decrease, but perhaps another line of showers approaches
around daybreak for the mountains from a complex of rain/storms
over Kentucky and Tennessee. Not expecting much fog development
this morning due to ample cloud cover.

Should see some gradual clearing through the morning in advance
of an approaching cold front. Some showers are possible across
the mountains later today and perhaps some isolated storms
across the Virginia Piedmont region. Not enough confidence to
put VCTS into the TAFs for DAN/LYH for this afternoon. Cold
front cross the area tonight and winds will begin to increase
towards the end of the 24hr TAF period.

Extended Aviation Outlook...

Lingering upslope flow could provide showers and MVFR ceilings
for BLF and LWB on Friday, while the Piedmont remains VFR due to
downslope flow. Cooler weather will arrive for the weekend. Some
upslope mountain showers may occur during late Saturday into
early Sunday. VFR conditions should persist through Monday as
high pressure takes control of the Mid Atlantic.
-- End Changed Discussion --

&&

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

&&

$$

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