497
FXUS61 KRNK 081750
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
150 PM EDT Tue Jul 8 2025

.SYNOPSIS...
Our area will remain in a humid airmass with daily chances for
thunderstorms through this weekend.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
As of 110 PM EDT Tuesday...

Key Messages:

1) Hot, with a Heat Advisory in effect for part of Southside VA
and the NC Piedmont.

2) Scattered storms this afternoon, some strong/severe with
heavy rain.

Overall, not much change in the pattern. A piece of vorticity
aloft will traverse the area this afternoon, with better
shear/lift to the north of Bluefield-Roanoke-Danville, but
moreso north of I-64. Already seeing storms firing up across the
Alleghanys into WV with a few showers popping along/near the
Blue Ridge south of Hillsville, VA.

Expect coverage of storms to increase to the Blue Ridge through
2-3pm per convective allowing models and radar/sat trends.
Temperatures in the mid 80s to lower 90s and a very humid
airmass will promote destablization with SBCAPE exceeding
2000-3000 J/kg this afternoon. The environment will be that of
wet microbursts due to water loading. Additionally, storm motion
being under 15 mph at times, and potential for training of
storms will lead to water issues, but given the scattered
coverage not enough to warrant a watch. Will have to watch
southside VA into the NC piedmont later as this area received
quite a bit of rain 2 days ago.

As we head into tonight, storms will slowly fade but the
piedmont could see isolated convection through midnight.

Some clearing plus high low level moisture and calm winds will
promote fog. Expect best coverage over the mountains and in the
river valley. Will have to monitor for potential dense fog
advisory but should overall be the typical morning fog, that
warrants travel caution.

Wednesday could be more active as models show a stronger wave
moving across the central Appalachians into the mid-Atlantic in
the afternoon. Excessive rainfall and strong/severe storms
possible. Ensembles and models painting more coverage especially
along the Blue Ridge and west, then have potential for 2 areas
of concentrated storms, one forming along the Blue Ridge and
pushing east in the afternoon, and another forming in WV pushing
east to the Blue Ridge.

With potential for more organized storms Wed afternoon and
higher pwats, plus lower flash flood guidance, will hoist a
flood watch for Wed afternoon/evening for portions of the VA/NC
piedmont, mainly along/east of a line from Lynchburg to Danville
to Rockingham County NC.

With convective development potential and more clouds Wednesday
heat indices may be tempered so no heat advisory for Wednesday
at this point, with highs close to 90 east to 80s west.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
As of 1200 PM EDT Tuesday...

Key Points:

1. Daily chances of showers/storms.
2. Localized heavy rain/flooding possible, especially over eastern
and southeastern sections.
3. Slightly above normal temperatures.

A look at the 8 Jul 00Z NCEP Ensemble Mean 500mb Geopotential
Heights shows for Wednesday night a shortwave trough centered over
the Lower Ohio Valley, moving east. A broad area of high pressure
will be centered from southern CA into the Four Corners region, and
extend eastward into the SE US. A shortwave trough will be over the
Pacific Northwest. For Thursday/Thursday night, the shortwave trough
to our west will still be approaching the region, but the ensemble
averaging depicts a broader feature, extending from central Quebec
into the Tennessee Valley. The ridge across the SW US becomes
shunted slightly south as the Pacific Northwest shortwave trough
makes progress eastward towards the Northern High Plains. For
Friday/Friday night, the axis of the shortwave trough approaching
our region is expected to cross the region, and by the evening hours
be centered from ME to Long Island. The shortwave trough over the NW
US moves to over/near the Upper Mississippi River Valley. A general
region of a ridge axis remains positioned over the far SW US to the
SE US.

At the surface, for Wednesday night, a general region of troughiness
is expected to be over the Ohio Valley. By Thursday/Thursday night,
this feature becomes a bit more defined, with a closed surface low
over far southern Quebec, with a cold front trailing into the mid-
Mississippi Valley, and a warm front southeast into New England. By
Friday/Friday night, the surface low loses is definition thanks to
ensemble averaging, leaving a another general region of troughiness
across much of the eastern US.

A look at the 8 Jul 00Z NAEFS Ensemble Situational Awareness data
shows 850mb temperatures around +18C for both Thursday and Friday.

The above weather patterns offers the following forecast. With the
region remaining within a warm/hot and humid airmass, and the
presences of a front/trough near or over the region, daily chances
of showers/storms looks promising each day. Additionally, with the
potential for repeated rounds of precipitation, all the higher the
potential for localized flooding will be. During this time period,
the NAEFS offers the eastern and southeastern portion of the
forecast area with the highest values of Mean Integrated Water
Vapor Transport. This factor may suggest greater weight given to
this region for the potential for flooding, especially given recent
rains across parts of this area as a result of the remnants of
Chantal. Temperatures are expected to average a few degree above
normal for this time of year.

Confidence in the above weather scenario is moderate to high.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 1200 PM EDT Tuesday...

Key Points:

1. Daily chances of showers/storms continues.
2. Temperatures around five to eight degrees above normal.

A look a the 8 Jul 00Z NCEP Ensemble Mean 500mb Geopotential Heights
shows for Saturday/Saturday night that the ridge over the SE US is
expected to expand northward to over our region. A shortwave trough
is expected to be over the Upper Mississippi River Valley,
approaching the western Great Lakes region. For Sunday/Sunday night,
little change is expected in the overall synoptic pattern. The
shortwave trough is expected to make a bit more headway east into
the Great Lakes. For Monday/Monday night, ensemble averaging washes
out the particulars of a shortwave trough over the Great Lakes and
offers a solution of a broader longer wave trough over much of
central Canada extending into most of the northern quarter of CONUS.
Ridging is depicted as broadening northward across roughly the
remaining three-quarters of CONUS. For Tuesday, little to no change
is depicted in the synoptic pattern over CONUS as compared to Monday.

At the surface, for Saturday/Saturday night, a general area of weak
troughiness will exist across the mid-Atlatnic into the SE US, all
the while a more well defined trough exists from the Upper
Mississippi Valley into the Great Lake region. For Sunday/Sunday
night, not a lot changes are expected as compared to Saturday. Weak
troughiness continues from the mid-Atlantic into the SE US, while a
more robust trough will be over the Great Lakes. For Monday/Monday
night, weak low pressure is still depicted over portions of the mid-
Atlantic into the SE US. The trough over the Great Lakes region is
not depicted as pronounced. A ridge of high pressure is noted from FL
to the Lower Mississippi River Valley. For Tuesday, a weak trough is
still depicted from the mid-Atlantic to the SE US with a ridge of
high pressure from FL to the Lower Mississippi Valley and north into
the Lower Ohio Valley.

A look at the 8 Jul 12Z NAEFS Ensemble Situational Awareness data
shows 850mb temperatures increase on Saturday to around +20C.
Similar values are expected Sunday. For Monday, only a small
decrease to +19C to +20C is forecast. On Tuesday, similar values are
expected as compared to Monday. The top end of the range of
temperatures on Monday and Tuesday touch the 90 to 97.5 percentile
of the 30-year CFSR climatology.

The above weather patterns offers the following forecast. Our
weather pattern will remain stagnant through the weekend and into
the early part of next week. With a general area of troughiness over
or near the region, our forecast of daily chances of showers/storms
will continue. With those daily chances will also come daily chances
of localized heavier rains, which in turn could mean locally higher
potential for flooding. Temperatures will trend hotter over the
weekend as compared to late this work week, and remain at those
elevated levels into the start of the next work week.

Confidence in the above weather scenario is moderate to high.

&&

.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
As of 125 PM EDT Tuesday...

Mainly VFR conditions with light WSW winds are expected through
the afternoon. Thunderstorms will be prevalent in a scattered to
numerous fashion this afternoon into evening across the area,
earlier in the mountains and later in the piedmont. Will have
VCTS and a couple hours of thunder at all sites, with potential
IFR.

Any storms will be decaying after 00z, but would not be
surprised if some linger near LYH/DAN til 03z.

Fog will be an issue later tonight and will likely get dense
at LWB and possibly BCB. Depending on clearing and where it
rains will determine fog at terminals.

Any fog/low stratus will erode by 12-14z Wed. Any storms to hold
off til after 18z Wed for the most part with VFR.


.EXTENDED AVIATION OUTLOOK...

The forecast continues in a typical summertime weather pattern
with daily chance of showers/storms during the peak heating
hours each day through Saturday. Morning fog will also be
possible each day, especially at LWB and BCB.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...Heat Advisory until 8 PM EDT this evening for VAZ058-059.
NC...Heat Advisory until 8 PM EDT this evening for NCZ006.
WV...None.

&&

$$

SYNOPSIS...WP
NEAR TERM...WP
SHORT TERM...DS
LONG TERM...DS
AVIATION...WP