Special Weather Statement, NWS Blacksburg, VA

Area Forecast Discussion
National Weather Service Blacksburg VA
205 PM EDT Fri Aug 27 2021

.SYNOPSIS...
Hot and humid weather will prevail through the weekend.
Isolated to scattered shower and thunderstorms persist each
afternoon. Rain chances increase as we go into the next work
week with a tropical air mass and Ida moving into the region.

&&

.NEAR TERM /THROUGH SATURDAY/...
As of 140 PM EDT Friday...

Scattered storms continue through this evening, then more fog is
likely in the morning.

Bermuda high pressure along the coast of SC/NC is gradually pushing
inland over the next 24 hours, with heights increasing over the
southeastern states. This has enhanced our hot and humid air mass,
and kept a lid on widespread showers and thunderstorms. However, a
weak lee surface trough in the area is helping to trigger isolated
afternoon showers and storms along the ridgetops, where orographic
lift is helping to overcome subsidence. PWATs of around 1.60" along
the ridgetops should support heavy rainfall in the more robust cells.
These are typical late summer pulse-type storms, and do not expect
any severe weather.

Apparent temperatures are pushing 100 degrees over southside VA
where temperatures in the 90s are collocated with dew points in the
70s. Temperatures should drop into the upper 50s to mid 60s along
and west of the Blue Ridge into western VA and southeastern WV, and
into the upper 60s to lower 70s over piedmonts of VA and NC.

Another inversion should set up overnight producing similar
conditions to this morning and fostering fog development. Some of it
will be dense and will be slow to mix out Saturday morning under the
late August sun angle.

Ridging remains in place tomorrow, with a backdoor front/wind shift
drifting south through the region. Moisture will be deepest
southeast of this boundary, and so the bulk of the shower/
thunderstorm activity Saturday should be over the VA and NC
piedmonts, with a few cells developing over the mountains. Weak
storms with no upper level support should pose little severe threat,
but localized heavy rainfall remains a concern under these slow
moving cells, especially if they train. Heat index values will again
be high, and in the mid 90s to around 100 degrees over the piedmonts
of VA and NC. Northwest of the Blue Ridge, including western VA and
southeastern WV, it will mostly feel like it's in the mid to upper
80s.

Forecast confidence is high.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
As of 130 PM EDT Friday...

Confidence is high for hot and humid weather to continue with a
chance of afternoon showers and thunderstorms.

Showers and thunderstorms should fade during late Saturday evening
to give way to a quiet but muggy night. By Sunday, a broad upper
level ridge centered over South Carolina should continue the hot and
humid conditions across the Mid Atlantic. Because of high pressure
moving off the New England coast, it will push a backdoor cold front
toward northern Virginia. This boundary should spark more scattered
afternoon showers and thunderstorms. Locations near the Interstate
64 corridor will receive the best chances of rain, but some activity
may spread farther to the southwest along the Blue Ridge.

This backdoor cold front should retreat and head off the New Jersey
shoreline by Sunday night. Conditions should turn temporarily drier
into early Monday, but a cold front from the Great Lakes will
advance over the Ohio River Valley during the afternoon to spark
more scattered showers and thunderstorms. The highest chances of
rain on Monday afternoon will be west of the Blue Ridge, especially
in southeast West Virginia. Heat indices could approach 100 degrees
across the Piedmont. Meanwhile, Hurricane Ida should make landfall
near Louisiana and head northward toward the cold front stretching
over the central Mississippi River Valley by Monday night. This
feature will set the stage for influencing our weather in the long
term section.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 130 PM EDT Friday...

The remnants of Hurricane Ida could bring a wet and unsettled period
for Wednesday and Thursday.

Tuesday appears to remain a typical summer day with hot and humid
conditions and scattered afternoon showers and thunderstorms. The
situation changes notably for Wednesday and Thursday. Timing
uncertainties still exist within the models regarding when the
remnants of Hurricane Ida will move eastward along a cold front from
the central Mississippi River Valley toward the Appalachian
Mountains. At this moment, the GFS is considerably faster than the
ECMWF with bringing tropical moisture overhead on Wednesday and
exiting on Thursday. The ECMWF, however, provides a slower solution
with the remnants of Ida getting stuck more along the cold front and
reaching the Mid Atlantic during Wednesday night into Thursday.

Rainfall chances are thus elevated for Wednesday, Wednesday night,
and Thursday as a compromise between the aforementioned model
solutions. The hydro threat will have to be examined more closely
with future model runs once better agreement can be obtained. Friday
does look drier with the cold front finally shoving the remnants of
Ida offshore and allowing high pressure to build from the northwest.
Temperatures will trend a little cooler toward the latter half of
this week due to the increased cloudiness and widespread rainfall.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
As of 200 PM EDT Friday...

Good flight conditions prevail although isolated TSRA have
developed. These are mostly confined to the mountains, but may
drift off the Blue Ridge a ways. BLF, LWB, BCB, and ROA have
the a chance to see VCTS before storms dissipate tonight.
Overnight tonight, expect more dense fog similar to today with
no change in air mass. LWB will be the last to mix out again
Saturday with another inversion in the morning. Winds will be
light and variable, with a weak wind shift moving south through
the area Saturday.

Extended Aviation Discussion...

Periods of diurnal thunderstorms and morning fog are expected
to persist through the start of next week. Tropical moisture
and more widespread rainfall chances arrive by mid week.
Morning fog will continue to favor the mountain valleys and
areas that receive rainfall, and be slow to mix out.

&&

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

&&

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

Hazardous Weather Outlook
National Weather Service Blacksburg VA
207 PM EDT Fri Aug 27 2021

NCZ001>006-018>020-VAZ007-009>020-022>024-032>035-043>047-058-059-
WVZ042>044-507-508-281815-
Ashe-Alleghany NC-Surry-Stokes-Rockingham-Caswell-Watauga-Wilkes-
Yadkin-Tazewell-Smyth-Bland-Giles-Wythe-Pulaski-Montgomery-Grayson-
Carroll-Floyd-Craig-Alleghany VA-Bath-Roanoke-Botetourt-Rockbridge-
Patrick-Franklin-Bedford-Amherst-Henry-Pittsylvania-Campbell-
Appomattox-Buckingham-Halifax-Charlotte-Mercer-Summers-Monroe-
Eastern Greenbrier-Western Greenbrier-
207 PM EDT Fri Aug 27 2021

This Hazardous Weather Outlook is for north central North Carolina,
northwest North Carolina, central Virginia, south central Virginia,
southwest Virginia, west central Virginia and southeast West
Virginia.

.DAY ONE...This afternoon and tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Scattered thunderstorms are expected across the region Saturday
afternoon. Locally heavy rainfall and isolated damaging wind gusts
are possible with the stronger storms.

By the mid part of next week, the remnants of Hurricane Ida are
expected to impact the region. There remains much uncertainty as to
the exact track and timing of this system, but confidence is
increasing that our region will be impacted by Ida to some degree.
Locally heavy rainfall appears to be the main concern for the area at
this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Special Weather Statement
National Weather Service BLACKSBURG VA
116 PM EDT Fri Aug 27 2021

VAZ013-271745-
Pulaski VA-
116 PM EDT Fri Aug 27 2021

...A strong thunderstorm will impact portions of
west central Pulaski County through 145 PM EDT...

At 116 PM EDT, Doppler radar was tracking a strong thunderstorm near
Gunton Park, or near Pulaski, moving east at 15 mph.

HAZARD...Winds in excess of 30 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Pulaski.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3714 8076 3701 8072 3700 8086 3703 8089
      3706 8091 3707 8091
TIME...MOT...LOC 1716Z 252DEG 14KT 3705 8087

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...30 MPH

SH

Special Weather Statement
National Weather Service BLACKSBURG VA
202 PM EDT Fri Aug 27 2021

VAZ007-010-271830-
Tazewell VA-Bland VA-
202 PM EDT Fri Aug 27 2021

...A strong thunderstorm will impact portions of east central
Tazewell and southwestern Bland Counties through 230 PM EDT...

At 201 PM EDT, Doppler radar was tracking a strong thunderstorm over
Burkes Garden. This storm was nearly stationary.

HAZARD...Winds in excess of 30 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Burkes Garden...
and Gratton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Locally heavy rain will quickly reduce visibility and result in
ponding of water on roadways, standing water in low lying areas, and
minor flooding of creeks, streams, and areas of poor drainage.
Drivers are urged to slow down and use extra caution to avoid
hydroplaning.

&&

LAT...LON 3718 8126 3705 8123 3701 8142 3713 8145
TIME...MOT...LOC 1801Z 073DEG 4KT 3709 8136

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...30 MPH

PW

Special Weather Statement
National Weather Service BLACKSBURG VA
455 PM EDT Fri Aug 27 2021

VAZ012-016-272115-
Wythe VA-Carroll VA-
455 PM EDT Fri Aug 27 2021

...A strong thunderstorm will impact portions of
east central Wythe and northwestern Carroll Counties through 515 PM
EDT...

At 454 PM EDT, Doppler radar was tracking a strong thunderstorm near
Ivanhoe, or near Patterson. This storm was nearly stationary.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Patterson.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Locally heavy rain will quickly reduce visibility and result in
ponding of water on roadways, standing water in low lying areas, and
minor flooding of creeks, streams, and areas of poor drainage.
Drivers are urged to slow down and use extra caution to avoid
hydroplaning.

&&

LAT...LON 3686 8092 3689 8079 3683 8077 3679 8092
TIME...MOT...LOC 2054Z 350DEG 0KT 3684 8087

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

RS

Special Weather Statement
National Weather Service BLACKSBURG VA
503 PM EDT Fri Aug 27 2021

VAZ033-034-272200-
Franklin VA-Bedford VA-
503 PM EDT Fri Aug 27 2021

...A strong thunderstorm will impact portions of south central
Bedford and northeastern Franklin Counties through 600 PM EDT...

At 502 PM EDT, Doppler radar was tracking a strong thunderstorm over
Westlake Corner, or near Moneta, moving southeast at 10 mph.

HAZARD...Wind gusts up to 50 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Penhook...
Smith Mountain Lake State Park...
North Shore...
and Union Hall.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Locally heavy rain will quickly reduce visibility and result in
ponding of water on roadways, standing water in low lying areas, and
minor flooding of creeks, streams, and areas of poor drainage.
Drivers are urged to slow down and use extra caution to avoid
hydroplaning.

If on or near Smith Mountain Lake, get out of the water and move
indoors or inside a vehicle. Remember, lightning can strike out to
10 miles from the parent thunderstorm. If you can hear thunder, you
are close enough to be struck by lightning. Move to safe shelter
now! Do not be caught on the water in a thunderstorm.

&&

LAT...LON 3707 7946 3706 7947 3706 7949 3705 7948
      3702 7950 3703 7953 3705 7955 3704 7955
      3704 7956 3703 7956 3704 7959 3700 7961
      3706 7970 3715 7962
TIME...MOT...LOC 2102Z 299DEG 9KT 3710 7968

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

RS