Roanoke, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

178
FXUS61 KRNK 190911
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
511 AM EDT Sat Jul 19 2025

.SYNOPSIS...
A quasi-stationary front will remain draped across the northern
Mid-Atlantic through the weekend, with opportunity for scattered
to numerous showers and thunderstorms during the afternoon and
evening. Some of the stronger storms may contain damaging winds,
and the potential for flash flooding is possible if the storms
linger over an area for any length of time.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM EDT Saturday...

Key Messages:

1) Scattered to numerous showers and thunderstorms this
afternoon and evening.

2) Slight Risk for severe storms with greatest potential for
damaging wind and poor drainage flooding along and east of the
Blue Ridge.

A similar setup to yesterday, with showers/storms developing
during the peak heating of the day. Can`t rule out some morning
showers where westerly upglide is occurring on the western
slopes of the Appalachians, but primary threat for shower
activity is reserved for the afternoon.

Nothing has really changed with respect to the upper pattern and
surface synoptic front. A retrograding 3 sigma warm core ridge
for mid-July is moving over Florida and into the eastern Gulf. A
quasi-stationary front extends from the northern Mid-Atlantic to
the Mid-West...underneath and parallel to stronger westerlies
aloft.

Ample buoyancy is again expected across the forecast area with
forecast MLCAPE of 2000-3000 J/KG. Around 20-kt 500-mb
westerlies will support loosely organized multicell clusters as
storms develop through the afternoon...the quasi-stationary
front to our north and the spine of the Blue Ridge acting as
lifting mechanisms (points for ignition). Sporadic thunderstorm
downbursts and wet microbursts producing damaging winds are
possible with greatest potential along and east of the Blue
Ridge where more clustering of the storms is expected to occur
as the storms move downstream into the piedmont.

Precipitable water values have not changed, regional soundings
showing 2 inches. This means storms will be rain efficient with
rates of 2-4 inches per hour. With a mean wind supporting 20 mph
storm movement, this should limit actual residence time over any
given location, so the flash flood threat should be limited to
locations where cell mergers take place or where terrain could
induce regenerative cells. All storms may produce some
localized poor drainage flooding, but life threatening flash
flooding should be more limited/isolated in nature. Model
signals today, suggest areas over northern and central VA into
NWS LWX/AKQ to be have the higher probability for cell mergers
and training effects today. Flash flooding within our CWA will
be more isolated but not necessarily out of the woods for a
localized 4 inch report somewhere within the the forecast area.
If I had to pick one or two counties out of our 40 to "Watch" it
would be Carroll Co. VA, and Surry Co. NC., where the geography
of the Blue Ridge supports a localized pooling of CAPE that can
sustain the regeneration of storm cells for a longer period of
time. Within the past week, both Galax and Mt. Airy have
experienced swift water rescues due to Flash Floods...so
persistence and pattern recognition favors this location along
the Blue Ridge to be the most problematic.

As far as the temperature forecast goes, forecast highs/lows
remain near to slightly above average, with highs in the 80s to
around 90, and lows in the 60s to low 70s.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
As of 300 AM EDT Saturday...

Key Messages:

1. Scattered showers and thunderstorms each afternoon and evening
through Monday.

2. Lower probabilities for showers and storms on Tuesday.

A warm front will start to retreat northward by Sunday, as a low
pressure system tracks across the northeastern US and southern
Canada through the weekend. The cold front will dive southward into
the area by Monday, as 500mb troughing deepens over the northeastern
US and northwesterly flow aloft over the area may help to bring this
system south into the region. That being said, both Sunday and
Monday will have chances of scattered showers and thunderstorms
during the afternoon and evening hours, but higher probabilities
come Monday with the additional synoptic scale lift provided by the
cold front. For Sunday, storms look to fire over the mountains in
the west and in the Ohio Valley, then tracking south and eastward.
The timing of the frontal passage Monday could impact the coverage
of storms, but at this time, greatest probabilities are over the
southern Blue Ridge and south along the VA/NC state line. Heavy
rainfall continues to be one of the main hazards associated with any
convection for the next few days, as PWATs stay above the 90th
percentile relative to climatology, in the 1.5" to 2" range, and so
localized flash flooding remains a concern, especially over areas
that have been hit repeatedly by thunderstorm activity the past few
days. Strong gusty winds will also be a hazard, from wet
microbursts, and could down trees and powerlines.

Surface high pressure slides along the northeast following the front
for Tuesday, and easterly flow off the Atlantic into the area will
help to keep Tuesday slightly cooler, and also limit the coverage of
any showers and storms to just the western mountains. Tuesday will
feel like a refreshing day, with highs in the low to mid 80s
areawide. Sunday and Monday will be similar to recent days, hot and
humid.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
As of 300 AM EDT Saturday...

Key Messages:

1. Temperatures trending warmer, reaching above normal temperatures
by the end of the work week.

2. Lower chances of precipitation through the second half of the
work week.

A strong 500mb ridge builds over the Ohio and Mississippi Valleys
during the midweek, which will bring the next major heat wave of the
summer. To start the long term forecast period, the ridge axis will
still be the west of the area, and so the local forecast area will
be mainly under northwesterly flow aloft, preventing Wednesday from
becoming too hot. However, later in the week, the ridge will expand
eastward and encompass the central and mainly southern Mid Atlantic
region, therefore, temperatures will start to increase to back above
normal for the end of the work week, and return to the upper 80s and
90s, five to ten degrees above climatological normals. Friday looks
to be the hottest day, with probabilities of high temperatures
exceeding 90 degrees between 75% and 90% for the Roanoke Valley and
east of the Blue Ridge. As surface winds turn more southerly and
transport more moisture from the Atlantic and the Gulf, expecting
heat indices to climb again by the end of the week, reaching the
triple digits by Friday. At this time, heat indices range from 100
to 103 degrees in the Piedmont, which is below heat advisory
criteria of 105. The NWS HeatRisk Tool is highlighting those
locations with a Major Risk (level 3 on a scale from 0 to 4) of heat
related impacts for Friday.

With the large ridge over the area and surface high pressure over
the eastern US, subsidence will keep shower and thunderstorm chances
limited for much of this forecast period. By the end of the week and
into the weekend, as ample moisture returns, so do chances for
afternoon and evening showers and thunderstorms.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
As of 500 AM EDT Saturday...

Nil TAF at LWB until FAA provides comms to the AWOS
observations.

General weather pattern remains unchanged with areas of
fog/stratus during the early mornings, and scattered to
numerous showers/storms during the afternoon and early
evenings.

For today, any fog/stratus expected to dissipate by
13Z/9AM, followed by cloud buildups mid-day and scattered to
numerous showers/storms during the afternoon. Blue Ridge is
favor initiation ground for deep convection...a westerly mean
wind pushing individual storm cells off to the east. Some
clustering of storms is expected as they move from the foothills
into the piedmont mid-late afternoon, 18Z-22Z, then decrease in
coverage from sunset through midnight.

OUTLOOK SUNDAY THROUGH WEDNESDAY...

Sunday-Monday night: Flight restrictions possible IVOF
SHRA/TSRA (mainly during the afternoon and evening), as well as
late night/early morning BR/FG.

Tuesday: A cold front is expected to move through the region.
Flight restrictions remain possible IVOF any SHRA/TSRA.

Wednesday: No significant restrictions anticipated at this time.

&&

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

&&

$$

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