Special Weather Statement, NWS Blacksburg, VA

Area Forecast Discussion...CORRECTED
National Weather Service Blacksburg VA
348 PM EDT Sun Aug 29 2021

.SYNOPSIS...
Hot and humid weather, along with daily scattered showers and
thunderstorms, will persist through Tuesday. Rain chances
increase significantly by Wednesday into Wednesday night as the
remnants of Ida approach the central Appalachians. In the wake
of Ida, high pressure will build in from the northwest for next
weekend.

&&

.NEAR TERM /THROUGH MONDAY/...
As of 200 PM EDT Sunday...

Split window satellite imagery shows a differential heating
interface along a frontal boundary stretching from WV/north and
eastern VA and into the Carolinas. Separately, an outflow
boundary which originated from last night's convection in the
region was located from about Roanoke VA to Raleigh-Durham NC.
These two boundaries along with a lee trough over the Blue Ridge
will continue to help focus convection in the region this
afternoon and evening. In addition, weak short wave energy will
round the top of ridging overhead and should help prolong
convection after sunset.

Scattered thunderstorms have already begun near the front/
differential heating boundary this afternoon. Storm motion will
be slow and easterly, but expect some erratic motions eventually
depending on outflow interactions. There is potential for strong
storms along the northern boundary where dew points in the low
to mid 70s and temperatures in the upper 80s have produced a
corridor of higher CAPE values. Any remaining cap/CIN has likely
eroded. Storms will be most numerous over southeastern WV and
generally northeast of I-64, but isolated to scattered cells are
possible along and north of I-81 and along the outflow boundary.

These storms will again have the potential for producing
localized heavy rain and damaging winds through tonight, given
the amount of dry air aloft. With the potential for deep
instability to linger late this evening, the storms may survive
into early Monday morning before finally fading away. Otherwise
overnight, it will remain moist in the low levels with patchy
fog developing where we can get some clearing.

Ridging begins to be suppressed by Ida's circulation Monday as
it moves into MS. Winds turn more southwesterly Monday afternoon
over our area and PWATs begin to tick up a bit. To our north,
the frontal boundary pushes south. These factors will provide
plenty of fuel for widespread showers and thunderstorms to
develop during the afternoon and evening. Localized heavy
rainfall possibly leading to flooding will be exacerbated by an
increasing low level jet and deep warm cloud layers. Severe
weather such as damaging winds look less likely with increasing
mid clouds well ahead of Ida keeping CAPEs lower. Increasing WAA
will keep it quite hot and humid with readings generally in the
mid 80s to mid 90s.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As of 310 PM EDT Sunday...

...The remnants of Ida bring heavy rain and the potential for
localized flooding...

Before Ida even gets here it's much of the same when it comes to our
current weather pattern. Scattered showers and storms with hot and
humid conditions are expected Tuesday thanks to a cold frontal
boundary dropping in from the Ohio River Valley/Great Lakes region.
Unfortunately the front does not make it here as Ida begins the push
north and east into the Mid-South/Cumberland Valley region late
Tuesday morning into Tuesday afternoon. The current 12z runs of
the NAM, Euro, and GFS all continue to show the deeper moisture
with the storm remaining west of the central Appalachians into the
Ohio River Valley. This would make for scattered to spotty
coverage of convection Tuesday afternoon before a more widespread
shield precipitation moves in late Tuesday night into the day
Wednesday.

By late Tuesday night into Wednesday, precipitation intensity will
increase as Ida surges north. The GFS and Euro show subtle
difference in where low pressure will go with general consensus
pointing toward eastern Kentucky and central/southern West Virginia
before surging north and east toward northern Virginia/central
Maryland Thursday morning. Even with the brunt of the rainfall still
expected to pass across the central Appalachains and lower Mid-
Atlantic Wednesday localized flooding concerns cannot be ruled out
especially as precipitable water values surge as high as 2.25
inches Wednesday morning into Wednesday afternoon. With a very moist
atmospheric profile confidence increases a bit more for heavy
rainfall and localized flooding concerns by Wednesday afternoon and
Wednesday night. For that reason, the Weather Prediction Center
keeps area along and west of the Blue Ridge highlighted in a
marginal risk of excessive rainfall through Wednesday morning
possibly into Wednesday afternoon.

As for rainfall, it's really still too early to call. The best guess
this early on would be a general 1 to 3 inches west of the Blue
Ridge with amounts of 1 to 2 inches out east. These amounts could
trend up or down depending on the overall track of the storm. The
further west the track goes the lesser the amounts compared to a
shift east which would mean more.

The 12z model suite remains in good agreement that Ida is in and out
of here by Wednesday night into Thursday. Despite a few leftover
showers drier air will be funneling in and things will quiet on down
as high pressure takes the wheel.

With increasing cloud cover through the period expect temperatures
to suffer. Tuesday will be the warmest in the east with highs in
the upper 70s/low 80s in the west and near 90 in the east. Wednesday
will be out coolest with highs in the low to mid 70s in the west to
near 80 out east.

Confidence is moderate in the short term period pending the track of
Ida.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 310 PM EDT Sunday...

...A calm and comfy stretch of weather heading into the
weekend...

Ida quickly scoots out of here Thursday morning into midday. Both
the GFS and Euro tend to agree with this as drier air quickly rushes
in as a large area of Canadian high pressure builds over the Great
Lakes region. As Ida, departs a few residual showers cannot be ruled
out especially over the mountains of the Greenbrier Valley/Alleghany
Highlands thanks to north to northwesterly flow. Shower activity
will shutdown by late Thursday afternoon and evening as direr air
continues to filter in. Breezy conditions will also be in play with
Ida departing north and east and high pressure coming in from the
north and west tightening the gradient.

Lingering showers will dissipate and skies will clear as we head
into Thursday night as high pressure builds closer to the region.
Winds will shutdown by Friday with lowering humidity and mostly
sunny skies to finish out the workweek. Highs will top out in the
mid to upper 70s over the mountains with low to mid 80s out east by
Friday afternoon. Much of the same can be expected Saturday and
Sunday with highs increasing by a degree or two  each afternoon.
Overnight lows will be nice and crisp especially Friday and Saturday
night as temperatures dip into the 50s. Some locations in the
mountains could even bottom out in the mid to upper 40s on both of
those nights.

Our next chance at a shower or thunderstorm arrives by Monday as a
new front dives into the area. Models right now don't seem to keen
on any widespread rain at this point with a continued warming trend
as high pressure sticks around into early next week.

Confidence remains moderate to high in the long term period.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
As of 200 PM EDT Sunday...

An upper level disturbance passing across the central
Appalachians during tonight along with several boundaries in the
area will continue to support showers and thunderstorms through
tonight. Locally strong winds and brief reductions in visibility
inside the downpours are expected. Believe convection will
linger into the early morning hours of Monday north of Highway
460. Patchy fog is expected again early Monday, though believe
the extent of which will depend on the amount of residual cloud
cover.

Extended Aviation Discussion...

No changes in the extended aviation forecast as periods of
diurnal thunderstorms and morning fog are expected on Monday and
Tuesday. Tropical moisture and more widespread rainfall chances
arrive by mid week, especially when what's left of Ida arrives
Wednesday/Wednesday night. Morning fog will continue to favor
the mountain valleys and areas that receive rainfall each day,
and will be slow to mix out.

&&

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

&&

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

Hazardous Weather Outlook
National Weather Service Blacksburg VA
252 PM EDT Sun Aug 29 2021

NCZ001>006-018>020-VAZ007-009-010-015-043-044-058-059-WVZ042-043-
301900-
Ashe-Alleghany NC-Surry-Stokes-Rockingham-Caswell-Watauga-Wilkes-
Yadkin-Tazewell-Smyth-Bland-Grayson-Henry-Pittsylvania-Halifax-
Charlotte-Mercer-Summers-
252 PM EDT Sun Aug 29 2021

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

.DAY ONE...This afternoon and tonight.

There is a low probability for widespread hazardous weather.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Confidence is increasing that the remnants of Hurricane Ida will
bring the potential for heavy rain and localized flooding to the
region Wednesday and Wednesday night. Continue to monitor the latest
forecasts for any changes in Ida's track and timing.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

VAZ011>014-016>020-022>024-032>035-045>047-WVZ044-507-508-301900-
Giles-Wythe-Pulaski-Montgomery-Carroll-Floyd-Craig-Alleghany VA-Bath-
Roanoke-Botetourt-Rockbridge-Patrick-Franklin-Bedford-Amherst-
Campbell-Appomattox-Buckingham-Monroe-Eastern Greenbrier-
Western Greenbrier-
252 PM EDT Sun Aug 29 2021

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

.DAY ONE...This afternoon and tonight.

Widely scattered showers and thunderstorms continue this evening
mainly across the mountains and foothills. A few of these storms
will have the potential to produce damaging winds and locally heavy
rainfall that may result in flash flooding.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Confidence is increasing that the remnants of Hurricane Ida will
bring the potential for heavy rain and localized flooding to the
region Wednesday and Wednesday night. Continue to monitor the latest
forecasts for any changes in Ida's track and timing.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BLACKSBURG VA
608 PM EDT SUN AUG 29 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0550 PM     HAIL             1 ENE MC COY            37.24N 80.61W
08/29/2021  M0.75 INCH       MONTGOMERY         VA   FIRE DEPT/RESCUE

            MINOR DAMAGE TO EXPOSED VEHICLE. CRACKED
            SINGLE PANE GLASS ON OUTBUILDING.

&&

WP

Special Weather Statement
National Weather Service BLACKSBURG VA
611 PM EDT Sun Aug 29 2021

VAZ011-013-292230-
Giles VA-Pulaski VA-
611 PM EDT Sun Aug 29 2021

...A strong thunderstorm will impact portions of
north central Pulaski and southwestern Giles Counties through 630 PM
EDT...

At 610 PM EDT, Doppler radar was tracking a strong thunderstorm over
White Gate, or near Poplar Hill, moving east at 5 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...
Poplar Hill...
Bane...
White Gate...
and Thessalia.

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 3726 8090 3733 8066 3712 8065 3718 8086
      3719 8087 3718 8089 3719 8091
TIME...MOT...LOC 2210Z 273DEG 6KT 3722 8084

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

VFJ

Special Weather Statement
National Weather Service BLACKSBURG VA
617 PM EDT Sun Aug 29 2021

VAZ011-WVZ044-292245-
Giles VA-Monroe WV-
617 PM EDT Sun Aug 29 2021

...A strong thunderstorm will impact portions of
northeastern Giles and southwestern Monroe Counties through 645 PM
EDT...

At 617 PM EDT, Doppler radar was tracking a strong thunderstorm over
Kimballton, or over Pearisburg, moving east at 5 mph.

HAZARD...Winds in excess of 30 mph and half inch 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...
Pearisburg...
Pembroke...
Mountain Lake...
Kire...
Kimballton...
Cascades...
and Lindside.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3728 8080 3737 8079 3747 8075 3750 8052
      3732 8051
TIME...MOT...LOC 2217Z 273DEG 6KT 3736 8073

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...30 MPH

VFJ

Special Weather Statement
National Weather Service BLACKSBURG VA
620 PM EDT Sun Aug 29 2021

WVZ043-044-292245-
Summers WV-Monroe WV-
620 PM EDT Sun Aug 29 2021

...A strong thunderstorm will impact portions of
central Summers and northwestern Monroe Counties through 645 PM
EDT...

At 620 PM EDT, Doppler radar was tracking a strong thunderstorm over
Hinton, moving southeast at 5 mph.

HAZARD...Winds in excess of 30 mph and half inch 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...
Hinton...
Buck...
Bluestone State Park...
Hix...
Talcott...
Ballengee...
and Bluestone Dam.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3770 8065 3750 8076 3763 8097 3770 8093
      3770 8090 3767 8090 3768 8088 3769 8088
      3770 8089 3773 8090
TIME...MOT...LOC 2220Z 293DEG 5KT 3766 8088

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...30 MPH

VFJ

Special Weather Statement
National Weather Service BLACKSBURG VA
641 PM EDT Sun Aug 29 2021

VAZ013-014-017-292315-
Pulaski VA-Floyd VA-Montgomery VA-
641 PM EDT Sun Aug 29 2021

...A strong thunderstorm will impact portions of
northeastern Pulaski, northeastern Floyd and Montgomery Counties and
the City of Radford through 715 PM EDT...

At 640 PM EDT, Doppler radar was tracking a strong thunderstorm over
Christiansburg, moving east at 5 mph.

HAZARD...Winds in excess of 30 mph and penny 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...
Blacksburg...
Christiansburg...
Radford...
Pilot...
Shawsville...
Terrys Fork...
and Claytor Dam.

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 3730 8026 3727 8022 3701 8020 3704 8064
      3723 8064 3733 8026
TIME...MOT...LOC 2240Z 255DEG 5KT 3712 8040

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...30 MPH

VFJ

Special Weather Statement
National Weather Service BLACKSBURG VA
642 PM EDT Sun Aug 29 2021

VAZ022-292315-
Roanoke VA-
642 PM EDT Sun Aug 29 2021

...A strong thunderstorm will impact portions of
east central Roanoke , the City of Salem and the City of Roanoke
through 715 PM EDT...

At 642 PM EDT, Doppler radar was tracking a strong thunderstorm near
Roanoke, moving east at 10 mph.

HAZARD...Winds in excess of 40 mph and half inch 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...
Roanoke...
Salem...
Vinton...
Cave Spring...
Roanoke Mountain...
and Hollins.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3733 7987 3730 7984 3729 7985 3728 7985
      3727 7986 3723 7984 3722 7985 3722 7987
      3721 7988 3719 7989 3721 8008 3729 8013
      3735 7992
TIME...MOT...LOC 2242Z 269DEG 9KT 3731 8000

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

WP