Special Weather Statement, NWS Blacksburg, VA

Area Forecast Discussion
National Weather Service Blacksburg VA
320 PM EDT Tue Jul 18 2017

.SYNOPSIS...
An upper low will continue to support the development of
scattered mainly afternoon showers and thunderstorms into
Wednesday. As the system drifts south of the region on
Thursday, it will herald a stretch of even warmer and more
humid weather for the end of the work week into the upcoming
weekend, along with a slowly increasing threat for additional
showers or thunderstorms.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
As of 315 PM EDT Tuesday...

An upper level low is currently positioned over the Blue Ridge and
Shenandoah Valley region. In conjunction with an airmass that is
moderately unstable, this has promoted scattered showers and
thunderstorms within about 40 miles either side of the Blue Ridge.
More isolated storm coverage exists in the Alleghany Highlands.

Storm motions have been highly erratic with weak winds aloft,
heavily influenced by terrain and/or convective outflow with DCAPEs
of 800-1100 J/kg. However they will move into a more unstable
environment present off the Blue Ridge foothills. Strongest
reflectivity cores will be capable of gusty to at times damaging
winds in this environment, along with periodic instances of hail up
to 1" in diameter.

With no other significant sustaining force, storms should begin
to diminish in number and strength after sunset with many areas
trending dry by mid-evening. In its place will be clearing
skies and light to calm winds, which should help generate areas
of patchy fog overnight tonight. The Greenbrier and New River
Valleys, along with any location that saw rain this afternoon.
Lows tonight mainly in the 60s.

For Wednesday, aforementioned upper low will slowly pivot into the
eastern VA through the day. Daytime heating should afford some
isolated to scattered showers and thunderstorms again, with the best
chance east of the Blue Ridge, and particularly in the
Piedmont. Synoptic-scale subsidence aloft may keep areas west of
the Blue Ridge on the dry side despite warm and somewhat humid
conditions. Even in the Piedmont, coverage may only be isolated
to scattered. Highs on Wednesday should be in the mid 80s to
mid 90s. Apparent temperatures in the central VA Piedmont may
near 100 degrees when the muggy dewpoints are factored in.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
As of 315 PM EDT Tuesday...

Weak upper closed low pressure forecast to drift slowly south
into southern GA during the short term period as an upper ridge
of high pressure builds over the system and east into the mid-
Atlantic region from the central plains.

Increasing temperatures in the lower and mid troposphere will
help to boost daytime high temperatures well into the 80s to
near 90 in the mountains, with mid-upper 90s common in the
Piedmont. Despite the increasing heat and humidity, dew point
values are not expected to be high enough to push heat indexes
to the 105F advisory level.

Gradual warming of temperatures aloft and increasing weak subsidence
on the backside of the upper low should limit extent of
diurnally-driven thunderstorm development. However, despite the
development of a weak capping inversion, an isolated brief
shower/storm still can't entirely be ruled out in the mountains
and foothills, where differential heating and localized
topographical forced ascent will be maximized, but most areas
will remain dry - as has been the case for many weeks in some
locations.

Overall, expect a relatively dry, uneventful, and warm to hot short-
term period, but not hot enough to threaten any day or nighttime
records.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 315 PM EDT Tuesday...

Very warm/hot weather expected to persist through much of the
long-term forecast period. Weak upper closed low expected to
drift west into AL over the weekend, then shear slowly northeast
back toward the southern and central Appalachians by early next
week. Meanwhile, a series of short wave trofs in the northern
stream are forecast to scoot east through the Great Lakes, with
the strongest on Sunday into Monday likely to push cool
front/baroclinic zone south toward or through the Blacksburg
forecast area later Monday or Monday night.

Whether the surface front can progress this far south while
pushing against a strong Bermuda high pressure system still
remains somewhat in question, but the frontal proximity,
combined with at least some moisture streaming back northeast
in advance of southern closed/shearing low should support a
slowly increasing threat for mainly diurnally-driven
showers/thunderstorms into portions of the Blacksburg forecast
area, especially in the mountains (Saturday) and into most
areas Sunday into early next week as the front nears or moves
southeast through the region.

Little overall change in airmass expected until the possible
frontal passage - with a continuation of relatively hot days
with warm nighttime lows, but with only a very limited threat
for any record breaking readings. Cooler air may arrive by
Tuesday, driving temperatures back down 5-7F and closer to
seasonal levels.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
As of 126 PM EDT Tuesday...

Scattered showers and thunderstorms continue to develop within
a 40 mi range either side of the Blue Ridge in VA/NC, slowly
drifting south to southwest. Occasional to frequent lightning,
localized IFR to LIFR visibilities in heavy downpours possible
if thunderstorms affect a specific TAF, with the strongest
thunderstorms through 23z being capable of gusty winds and small
hail as well. Threat will also exist along the southern Blue
Ridge in NC for aviation interests with flight routes into and
around the Blue Ridge. For the TAFs, opted for VFR VCTS
prevailing conditions with frequent amendments likely given the
slow moving nature of the storms. Storms should dissipate in
number and intensity with sunset. Outside of thunderstorm
outflow gusts, prevailing winds will be light and variable.

For tonight, as has been the case the past couple nights, look
for patchy areas of radiation fog to develop in the favored
airports near river valleys (Lewisburg and Blacksburg). This
should be especially the case tonight as boundary layer winds
are even lighter than the past couple days. Will also indicate
4SM BR with a related layer of IFR stratus at Danville and
Lynchburg toward morning as well.

For Wednesday, any fog should burn off readily shortly after
sunrise. Returning VFR cumulus anticipated again tomorrow.
Chances for showers and storms appear after 18z Wednesday, but
mainly in the Piedmont. Winds light.

Aviation Extended Discussion...

The upper level trough will head offshore by Wednesday night.
Lingering showers or thunderstorms with brief MVFR to IFR
visibilities appear restricted to Lynchburg and Danville
Wednesday afternoon. Convective activity should then become
even more sparse as capping takes place aloft Thursday into the
early weekend. Overall, it appears that VFR conditions will
primarily reign through the daytime hours. There could be some
MVFR/IFR fog and ceilings during the early morning hours in the
cooler mountain valleys like LWB. Hot and humid weather will
prevail through the end of the week.

&&

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

&&

SYNOPSIS...AL
NEAR TERM...AL
SHORT TERM...WERT
LONG TERM...WERT
AVIATION...AL

Hazardous Weather Outlook
National Weather Service Blacksburg VA
1039 AM EDT Tue Jul 18 2017

VAZ007-046-047-WVZ042-043-508-191445-
Tazewell-Appomattox-Buckingham-Mercer-Summers-Western Greenbrier-
1039 AM EDT Tue Jul 18 2017

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

.DAY ONE...Today and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

NCZ005-006-VAZ044-045-058-059-191445-
Rockingham-Caswell-Pittsylvania-Campbell-Halifax-Charlotte-
1039 AM EDT Tue Jul 18 2017

This Hazardous Weather Outlook is for north central North Carolina,
central Virginia and south central Virginia.

.DAY ONE...Today and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

NCZ001>004-018>020-VAZ009>020-022>024-032>035-043-WVZ044-507-191445-
Ashe-Alleghany NC-Surry-Stokes-Watauga-Wilkes-Yadkin-Smyth-Bland-
Giles-Wythe-Pulaski-Montgomery-Grayson-Carroll-Floyd-Craig-
Alleghany VA-Bath-Roanoke-Botetourt-Rockbridge-Patrick-Franklin-
Bedford-Amherst-Henry-Monroe-Eastern Greenbrier-
1039 AM EDT Tue Jul 18 2017

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...Today and tonight.

Widely scattered strong thunderstorms are possible this afternoon,
between 1 and 8 pm. The strongest thunderstorms may be capable of
producing gusty winds and hail.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Special Weather Statement
National Weather Service BLACKSBURG VA
312 PM EDT TUE JUL 18 2017

VAZ018-022-023-182015-
Botetourt-Craig-Roanoke-
312 PM EDT TUE JUL 18 2017

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN ROANOKE...SOUTHEASTERN
CRAIG AND SOUTHWESTERN BOTETOURT COUNTIES...THE CITY OF SALEM AND
THE WESTERN CITY OF ROANOKE...

At 311 PM EDT, a strong thunderstorm was located near Daleville,
moving southwest at 10 mph.

Winds in excess of 40 mph and half inch hail are possible with this
storm.

Locations impacted include...
Roanoke...
Salem...
Troutville...
Catawba...
and Abbott.

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

LAT...LON 3744 7987 3719 8002 3729 8024 3731 8026
      3734 8026 3735 8028 3753 8006
TIME...MOT...LOC 1911Z 029DEG 9KT 3743 8002

KK

Special Weather Statement
National Weather Service BLACKSBURG VA
315 PM EDT TUE JUL 18 2017

NCZ006-182015-
Caswell-
315 PM EDT TUE JUL 18 2017

...A STRONG THUNDERSTORM WILL AFFECT SOUTHERN CASWELL COUNTY...

At 314 PM EDT, a strong thunderstorm was located over Prospect Hill,
moving southwest at 20 mph.

Winds in excess of 40 mph and half inch hail are possible with this
storm.

Locations impacted include...
Jericho...
Prospect Hill...
Camp Springs...
Leasburg...
and Topnot.

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

LAT...LON 3625 7952 3629 7953 3641 7915 3640 7914
      3624 7916
TIME...MOT...LOC 1914Z 060DEG 16KT 3629 7921

KK

Special Weather Statement
National Weather Service BLACKSBURG VA
317 PM EDT TUE JUL 18 2017

NCZ003-019-020-182000-
Surry-Yadkin-Wilkes-
317 PM EDT TUE JUL 18 2017

...A STRONG THUNDERSTORM WILL AFFECT SOUTHWESTERN
SURRY...SOUTHEASTERN WILKES AND YADKIN COUNTIES...

At 317 PM EDT, a strong thunderstorm was located over Pleasant Hill,
moving southeast at 35 mph.

Winds in excess of 40 mph and pea size hail are possible with this
storm.

Locations impacted include...
Elkin...
Yadkinville...
Jonesville...
Boonville...
and Ronda.

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

LAT...LON 3606 8098 3626 8109 3641 8090 3607 8051
      3605 8050
TIME...MOT...LOC 1917Z 327DEG 29KT 3627 8090

KK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BLACKSBURG VA
321 PM EDT TUE JUL 18 2017

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

0238 PM     HAIL             4 E ENNICE              36.55N 80.94W
07/18/2017  E1.25 INCH       ALLEGHANY          NC   PUBLIC

&&

JRUCKMAN

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>