-- Discussion containing changed information from previous version are highlighted. --
084
FXUS61 KRNK 120734
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
334 AM EDT Sun May 12 2024

.SYNOPSIS...
High pressure builds today with dry weather through Monday. The
next storm system arrives Monday night into Tuesday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 119 AM EDT Sunday...

Key Messages:

- River valley fog this morning, locally dense.

- Dry and seasonal today with a northwest breeze.

Dense pockets of fog showing up on low cloud satellite in the
river valleys of the mountains and small areas across the I-81
corridor north of Roanoke. Anticipate at least some patchy fog
through dawn in this areas. Drier air with increasing winds
behind a front expected to clear fog out by 8am.

Today should see sunshine and a pressure gradient between the
high to our northwest and the low offshore to provide a breeze
into the afternoon, with gusts 15-25 mph possible across the
mountains and foothills, possibly the piedmont.

Highs today with full sunshine should be close to normal for mid
May with mid 60s to around 70 in the mountains to mid to upper
70s east.

Tonight, high pressure works overhead with light/calm winds. May
start to cloud up late as warm advection high clouds work in
from the southwest. This will figure into the lows tonight as
clear skies at the onset of the evening with lighter winds could
drop temps faster and a few areas could see lower 40s, possibly
touching the upper 30s in the valleys of WV into the Alleghanys.

Forecast confidence is moderate on fog and temps and above
average on winds/sky cover.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
-- Changed Discussion --
As of 230 AM EDT Sunday...

Key Messages:

1. Showers and storms possible late Monday into Tuesday and
Wednesday.
2. Warmer temperatures for the beginning of the work
week.

Ridging aloft and high pressure at the surface over the eastern US
will start the work week off with warmer temperatures. An upper
trough will advance from the central US into the Midwest by
Tuesday, pushing a cold front into the Mid Atlantic by the
middle of the work week, while the surface high shifts offshore.
South and southeasterly return flow around the high will
contribute to increasing moisture and warming temperatures ahead
of the trough, thus increasing instability in the area, which
in turn will increase shower and thunderstorm probabilities as
early as late Monday/early Tuesday morning. The greater chances
for showers and storms will be late Tuesday, as the warm front
lifts northward and cold front approaches closer from the west.
This will continue through Wednesday, until the trough has
finally exited to the east by Thursday. Locally heavy rainfall
is possible from this system, as precipitable water values
exceed the 90th percentile relative to climatology Tuesday into
Wednesday.

Temperatures through this forecast period will be warmest on Monday,
cooler on Tuesday and Wednesday, given plenty of cloud cover and
rain.
-- End Changed Discussion --

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
-- Changed Discussion --
As of 245 AM EDT Sunday...

Key Messages:

1. Showers and storms possible again for the end of the work week.
2. Drier weather for Thursday.

The 500mb trough will exit the area and move offshore by Thursday,
and brief ridging will build back into the area, as a surface high
pushes in behind the cold front, resulting in drier weather for
Thursday. Another upper trough develops just east of the Rockies,
and again tracks eastward by the end of the work week. Southwesterly
flow aloft will draw moisture northward from the Gulf, increasing
chances for showers and possibly thunderstorms by Friday and into
Saturday. Uncertainty remains in the timing and evolution of this
system, and therefore in the locations and time frame of heaviest
rain for the forecast area.

Temperatures generally remain near normal through this forecast
period, with highs in the 70s in the west and upper 70s to low
80s in the east, and lows in the 50s and 60s.
-- End Changed Discussion --

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
As of 125 AM EDT Sunday...

Dense fog possible at LWB this morning and could see IFR fog at
BCB/DAN with low clouds at BLF, VFR elsewhere. This fog and low
clouds expected to gone by 13z as drier air arrives and
northwest winds increase to 8-13kts with gusts to 20-25kt
possible in the mountains/Roanoke by late morning.

Wind subsides after sunset with clear skies.

Above average confidence on winds/sky cover and moderate on fog.


Extended Aviation Outlook...

VFR conditions are expected through Monday under dry, high
pressure.

Precipitation and sub-VFR ceilings and visibilities return to
the region as early as Monday night through midweek. Thursday
should return to VFR most areas with some lingering MVFR
possible in the mountains.

&&

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

&&

$$

SYNOPSIS...AMS/WP
NEAR TERM...WP
SHORT TERM...AS
LONG TERM...AS
AVIATION...AMS/WP