892
FXUS61 KRNK 230614
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
214 AM EDT Sat Aug 23 2025

.SYNOPSIS...
A cool wedge of high pressure weakens today as a cold front
approaches from the northwest. Scattered showers and
thunderstorms are possible through the weekend. After the cold
front exits late Sunday night, high pressure will return to
bring cooler and drier weather for the rest of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 200 AM EDT Saturday...

Key Messages:

1) Cloudy today with below normal temperatures for highs.

2) Rain chances increase by this afternoon for the mountains
and continue through Monday morning.

3) No severe weather or flooding expected through early Monday
outside of lightning and usual ponding of water.

A high pressure wedge remains over the area this morning, but
will gradually get squashed to the SE through tonight as a cold
front nears from the NW. Weak WNW flow aloft this morning will
gradually shift to troughing as short wave energy over the Deep
South is ingested in the overall flow and moves towards the
coastal Carolinas.

Patchy fog this morning will linger through daybreak. Stratus
will lift some today, but still hangs around through tonight as
overall forcing for ascent increases. Southerly flow will bring
even moister air up from the south ahead of the front to the NW,
and PWATs increase by about a quarter inch by this afternoon to
around 1.2 to 1.4 inches. The juicier air will reside over SE
WV and parts of NC (generally outside of the influence of the
drier wedge area). As a result scattered convection is likely,
although latest CAMs keep most of the activity to our NW before
2 to 4 pm. After that, scattered showers and thunderstorms
develop mainly from the Blue Ridge westward. Through early
Sunday morning, most locations will see QPF amounts of less than
a tenth of an inch, with some ridges seeing around a quarter
inch. Thus not concerned with flooding through Sunday morning,
but urban and small stream flooding is still possible if a
location sees multiple rounds. Cloud cover will limit
instability and severe weather potential, although lightning
is likely at times.

High temperatures will be below normal by 2 to 6 degrees today,
and in the mid 70s to low 80s for most. Tonight, lows will be
near or above normal in insulating cloud cover, with patchy
fog, stratus, showers overnight.

Confidence is high in the near term forecast.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
As of 1230 AM EDT Saturday...

Key Points:

1. Showers and storms expected Sunday, locally heavy rain
possible.

2. Dry Monday and Tuesday.

3. Temperatures trending cooler to values around five below
normal by Tuesday.

A look at the 22 Aug 00Z NCEP Ensemble Mean 500mb Geopotential
Heights shows for Sunday/Sunday night a longwave trough
extending from roughly James Bay south into the mid-Mississippi
Valley and also into the SE US. Ridging is expected across
western CONUS. A closed low will be south of the Gulf of Alaska.
For Monday/Monday night, the axis of the upper trough shifts
east, such that it is almost centered over our region Monday
evening. For Tuesday/Tuesday night, the northern extent of the
trough axis shifts a bit east, but the southern extent over our
region is expected to experience little or no motion. Ridging
continues across western CONUS.

At the surface, for Sunday/Sunday night, a cold front is
expected to move into and through the area, while low pressure
heads northeast along the coast of the Carolinas. High pressure
will be centered along the US/Canadian border near the ND. Its
associated ridge axis is expected to curve southeast into the
mid-West and farther east into the Tennessee Valley. For
Monday/Monday night, the center of the high is expected to move
southeast to near IA/IL with its ridge axis now over our region.
For Tuesday/Tuesday night, little change is expected in the
position of the center of the high. However, the high is
expected to expand in scope and cover a greater portions of
central and eastern CONUS.

A look at the 22 Aug 12Z NAEFS Ensemble Situational Awareness
data shows 850mb temperatures for the area on Sunday around
+16C to +17C, nw-se, across the area. Temperatures quickly head
lower in the wake of a cold front. By Monday afternoon, values
of +11C to +13C, nw-se, are expected over the area. The low end
of this range will fall within the 2.5 to 10 percentile of the
30-year CFSR climatology. On Tuesday afternoon, values will have
continued their fall across the area. Values of +10C to +12C,
n-s, are expected. For western sections of the region, these
values correspond to the 1 to 2.5 percentile of the 30-year CFSR
climatology with the 2.5 to 10 percentile across eastern
sections.

The above weather patterns offers the following forecast. A cold
front will cross the area on Sunday bringing showers and storms.
The back edge of the precipitation is expected to exit eastern
parts of the area by the the evening hours. Some lingering weak
upslope shower activity is possible over the mountains through
midnight. We will need to monitor the potential for locally
heavy rain associated with showers/storms along and immediately
in advance of the cold front. If enough training cells takes
place, we may see scenarios where locally heavy rain/minor
flooding could be possible.

For Monday into Tuesday, dry high pressure will work its way
into the region from the west. Expected temperatures through
the period to trend from slightly above normal to around five
below normal.

Confidence in the above weather scenario is high.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
As of 1230 AM EDT Saturday...

Key Points:

1. Temperatures averaging at least five degrees below normal
through the period.

2. Dry conditions.

A look a the 22 Aug 00Z NCEP Ensemble Mean 500mb Geopotential
Heights shows for Wednesday/Wednesday night, the trough axis
that is expected to be stalled over the region Monday/Tuesday
shifts to over the coast by Wednesday evening. Ridging amplifies
across western CONUS into parts of western Canada. For
Thursday/Thursday night, the trough over the east coast is
expected to remain nearly stalled, and perhaps broaden. Ridging
continues over western CONUS. For Friday, little change is
expected in the synoptic pattern across CONUS as compared to
Thursday`s pattern.

At the surface, for Wednesday/Wednesday night, the center of a
broad region of high pressure moves east and will be
positioned over the Lower Ohio Valley by Wednesday evening. For
Thursday/Thursday night, the center of the high moves east,
crosses our region, and will be centered near the Delmarva
Peninsula by Thursday evening. On Friday, the center of the high
shifts northeast into western Atlantic with a trailing ridge
axis over our region.

A look at the 22 Aug 12Z NAEFS Ensemble Situational Awareness
data shows 850mb temperatures around +10C to +11C, n-s, across
the area on Wednesday. These values will correspond to the 2.5
to 10 percentile of the 30-year CFSR climatology. For Thursday,
values inch up slightly to the +12C to +13C range, e-w, across
the area, but still fall with the 2.5 to 10 percentile. For
Friday, values will be close to +14C across the area with our NC
counties still experiencing values within the 2.5 to 10
percentile.

The above weather patterns offers the following forecast. High
pressure settles over the region by Thursday. With it will be
dry conditions and progressive cooler temperatures. Values
around, or slightly lower than, five degrees below normal will
be commonplace across the region. On Friday, with the center of
the high shifting east, and perhaps the start of some weak
southerly flow, temperatures may inch upward slightly. Enough
moisture may return to parts of the NC mountains to allow for
the development of isolated showers/storms Friday afternoon.

Confidence in the above weather scenario is high.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
As of 200 AM EDT Saturday...

Fog clears out by 14z today areawide, with some MVFR ceilings
hanging on the in the mountains, and VFR ceilings remaining
elsewhere. Possibly a few breaks but overall looks like a cloudy
day. TSRA possible today for BCB/BLF/LWB as a cold front nears
from the NW, mainly after 23/18-20Z through 24/01Z. Afterward,
lingering showers possible through Sunday morning for the
mountains.

Confidence in the above forecast is high.

.EXTENDED AVIATION OUTLOOK...

Additional SHRA/TSRA and sub-VFR conditions after 12Z Sunday
through Sunday night for all terminals before the front pushes
SE early Monday morning. Some patchy fog but mostly stratus
lingers Monday morning. NW winds behind the front will gust to
15-20 knots at times late Sunday night through Tuesday. High
pressure settles in on Monday, with VFR conditions through late
next week. Winds remain NW to N through Wednesday night.

&&

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

&&

$$

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