363
FXUS61 KRNK 142314
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
714 PM EDT Wed Aug 14 2024

.SYNOPSIS...
High pressure will keep our weather mainly dry through
Thursday. The next widespread chance for rain arrives toward the
end of the week and the weekend, as a low pressure system
approaches from the Ohio River Valley.

&&

.NEAR TERM /THROUGH THURSDAY/...
As of 700 PM EDT Wednesday...

Key Message: Quiet night cooling off into the mid 50s to low
60s.

No significant changes to the forecast for this update. We have
had even less shower activity over the southern Blue Ridge than
we have the past 2 nights, and isolated convective updrafts in
Alleghany and Wilkes will completely diminish shortly.
Temperatures in the 70s and 80s at 7 PM will drop quickly off
into the 50s and low 60s by morning. A PWAT of 0.95" on this
morning`s RNK sounding showed moisture mainly around 700mb. This
PWAT is about 30% of normal for today per SPC sounding
climatology, and one indication it is not very humid. Fog is
possible overnight in mountain and river valleys as dew point
depressions shrink. We will also see occasional cirrus in NW
flow aloft.




As of 200 PM EDT Wednesday...

Key Message: Mainly dry.

Afternoon Cu field may spawn an isolated shower otherwise
expecting dry conditions to close out hump day. Trend after
today will be for increasing moisture, but should sneak out one
more fair weather day Thursday before showers/storms make a
more pronounced impact to the forecast. In the interim, high
pressure is centered to our north with a weak but dry northerly
wind. Winds will become southerly Thursday afternoon as the high
moves to our east...clockwise flow around the high providing
transition to a warmer and moister wind direction. Temperatures
through the near term will be close to normal. Patchy fog
possible again late tonight and early Thursday favoring the
rivers valleys.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
As of 200 PM EDT Wednesday...

Key Messages:

1. Showers and storms possible Friday and Saturday, highest
chances in the afternoons and evening.
2. Near normal temperatures through the period.

By Thursday night, a 500mb trough will be east of the area,
while another trough approaches from the upper Midwest, and a
ridge expanding over the southeastern US. The ridge aloft and
high pressure at the surface will keep conditions dry through
early Friday morning. A frontal system will track across the
Great Lakes region through the end of the week, and the warm
front will lift into the northern Mid Atlantic. Showers and
storms are expected to be ongoing from the overnight period over
the Ohio Valley associated with this system, so could see some
early to mid morning activity as the front progresses eastward,
though that activity will likely weaken upon reaching the
mountains. By the afternoon, diurnal heating will help to
destabilize the atmosphere, and coverage of showers and storms
will increase for the afternoon and evening hours. There is a
marginal risk of any storms reaching severe criteria, mostly
west of the Blue Ridge, as 0-6km shear increases with the
approach of the cold front.

Showers and storms could continue overnight into Saturday
morning, but will more likely wane with the loss of daytime
heating. The slow moving cold will spark additional shower and
thunderstorm development Saturday afternoon and evening. The
front is expected to finally exit to the east by Saturday night,
and activity will diminish Saturday night. Heavy rain is
possible with any showers and storms both Friday and Saturday,
as forecast PWATs near the 90th percentile relative to
climatology, in the 1.5 to 2.0 inch range.

Temperatures will rise a few degrees by Saturday as
south/southwesterly flow advects moisture northward, and
dewpoints will be on the rise, so expect more warmer humid
conditions by the end of the work week. Highs may approach 90 in
the VA Southside and Piedmont, and Roanoke Valley by Saturday.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 200 PM EDT Wednesday...

Key Messages:

1. Chances of showers and thunderstorms continue through the
beginning of the work week.
2. Temperatures right around normal.

Troughing aloft persists over the eastern US through the second
half of the weekend and into the work week. This will keep
chances of showers and thunderstorms in the forecast through
Monday. However, with no appreciable forcing mechanism, like a
front, most of the activity will be diurnal and isolated to
scattered in nature, and not likely to be severe. That being
said, still too far out in the forecast for mesoscale details to
be resolved, so any severe potential is uncertain at this time.

By midweek, the trough will finally push to the east, as a
large ridge over the southern US starts to expand farther east,
and surface high pressure builds over the area. This will bring
about a return of dry weather to the area for the mid to late
week.

Temperatures will be around seasonal normals, with mid 80s in
the east, and mid to upper 70s in the west. Lows will be in
the mid to upper 60s, but could dip into the mid 50s for the
typical cool spots on the clearer nights after the start of the
week.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
As 700 PM EDT Wednesday...

VFR conditions are expected at all terminals through most of
the TAF period.

SCT-BKN CU continues to diminish this afternoon in mainly dry
conditions. Some passing cirrus is expected overnight, along
with fog in mountain and river valleys. Fog most likely at
LWB/BCB/DAN, dissipating by 14Z/10AM Thursday. Winds will
remain light from the east to northeast.


.EXTENDED AVIATION OUTLOOK...

Thursday afternoon should remain dry with VFR conditions across
the Mid Atlantic as high pressure maintains control. However, as
high pressure moves offshore on Thursday night, clouds will
increase from the west due to an approaching cold front. This
front should bring a good chance of showers and thunderstorms
along with potential MVFR/IFR ceilings during Friday and
Saturday. Thunder chances may lower by Sunday as more stable air
arrives behind the cold front.

&&

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

&&

$$

SYNOPSIS...PM
NEAR TERM...PM/SH
SHORT TERM...AS
LONG TERM...AS
AVIATION...PM/SH