Alert archive / Virginia / Special Weather Statements in 2016

Special Weather Statement, NWS Blacksburg, VA

July 25, 2016Roanoke County, City of Roanoke, City of Salem, Virginia

NWS Blacksburg, VA issued this special weather statement at Jul 25, 2016, 5:11 PM EDT for Roanoke County, City of Roanoke, City of Salem, Virginia. It was in force for 34 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 25, 2016, 5:11 PM EDT (21:11 UTC)
Expired
Jul 25, 2016, 5:45 PM EDT
In force
34 min
Issued by
NWS Blacksburg, VA

Counties City of Roanoke, VA, City of Salem, VA, Roanoke County, VA

The radar

The Roanoke radar (KFCX), 41 km from the middle of the area, began a volume at 21:11 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Roanoke, VA (KRNK), launched 12:00Z, 9.2 hours before the alert went out and 41 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Roanoke, VA at 12:00Z on 2016-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 192 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Roanoke, VA at 12:00Z on 2016-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
192 J/kg
Mixed-layer CIN
-107 J/kg
Mixed-layer LCL
1250 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
39 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Blacksburg, VA wrote its last area forecast discussion before this special weather statement went out at Jul 25, 3:52 PM EDT, 1 hour 19 minutes earlier.

Area forecast discussion, Jul 25, 3:52 PM EDT, 1 hour 19 minutes before
Area Forecast Discussion
National Weather Service Blacksburg VA
352 PM EDT Mon Jul 25 2016

.SYNOPSIS...
Strong high pressure aloft will continue to result in hot and
humid weather early this week. A weak cold front approaching from
the north should bring increasing chances of showers and
thunderstorms over the mountains into tonight, and across the region
on Tuesday. This boundary looks to linger over the area through the
rest of the week with added showers and storms possible each day.

&&

.NEAR TERM /THROUGH TUESDAY/...
AS of 352 PM Monday...

Heat advisory remains in effect until 8 pm this evening for
South Central Piedmont of Virginia.

Heat Advisory in effect from noon to 8 pm EDT Tuesday for South
Central Piedmont of Virginia.

Isolated storms are developing over the mountains this afternoon
in the unstable air. These storms have been weakening as they
move east into the Piedmont. An isolated pulse severe
thunderstorm may be possible across the north closer to frontal
boundary this afternoon into this evening.

Upper ridge will slowly weaken or flatten tonight into Tuesday as
shortwave troughing passes to the north. Surface boundary sinks
southward to just north of the area late tonight into Tuesday with
the axis of higher pwats and weak lift strung out from the western
slopes to across the north. This may result in convection linger
especially across the north tonight. Otherwise, partly to mostly
cloudy and very muggy expected tonight. Low temperatures tonight
will range from the mid 60s in the mountains to the mid 70s in the
Piedmont.

The frontal boundary will drop south across our region on Tuesday.
The combination of frontal ascent, orographic lift, and heating will
result in scattered showers and thunderstorms especially during the
afternoon. SPC in day two convection has portions of forecast area
in marginal risk for damaging winds with convective clusters. High
temperatures on Tuesday will range from the lower 80s in the
mountains to the mid 90s in the Piedmont. Heat indices will climb
as high as 105 degrees in the far east.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 300 PM EDT Monday...

The upper level ridge will continue to sink south across the
southeastern US through Thursday. Lowering heights means
temperatures will be a little bit cooler each day. However,
temperatures will remain above normal until we can get a cold front
to pass over the region. Unfortunately, there is no frontal passages
expected this week. Afternoon temperatures will run around 5F warmer
than normal with 80s across the mountains and low to mid 90s east.
Dew points will also remain elevated ranging from the mid 60s to
lower 70s. Heat indices values will run 5F-8F warmer than the actual
temperature.

Some heat relief will come in the form of showers and thunderstorms
each afternoon. Even though these storms may knock temperatures
down, they will increase dew points keeping conditions very
uncomfortable. The coverage of storms will increase each day and
start earlier and end later. With zonal flow aloft, storms will
start across the mountains by noon, then drift east over the
piedmont during the evening hours. Forcing both Wednesday and
Thursday is not ideal for widespread strong storms, however with
zonal flow aloft, any waves rounding the ridge could change that.
For now, we will continue to see a typical summer pattern with
scattered afternoon and evening pulse storms.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 215 PM EDT Monday...

The ridge of high pressure will drift off the southeast coast
Friday, allowing an upper level trough to move over the Ohio and
Tennessee Valleys Friday. Models develop a surface reflection along
a lee trough that will bring an increase chance for strong to
severe storms into the region. Models currently are placing the
stronger dynamics Friday north of DC, but with all the
instabilities, heat and moisture in the region, the chance for
widespread severe weather will increase for the area Friday and/or
Saturday. If we do not see widespread significant weather Friday,
then Saturday will be the day. The upper level trough over the Ohio
Valley strengthens Saturday and will push bulk of the energy east to
the coast on Sunday. The upper level trough remains to our west
Sunday and Monday, which keeps the chance for showers and
thunderstorms in the area.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
As of 148 PM EDT Monday...

SCT to BKN MVFR clouds this afternoon with isolated to widely
scattered IFR conditions near thunderstorms. Ridging aloft will
remain in place this afternoon into tonight, with a bit better
low level convergence developing over the mountains ahead of a
weak cold front to the northwest. Given strong instability would
expect somewhat better tsra coverage mainly west of the Blue Ridge
this afternoon, with perhaps some of this shifting slowly east by
late in the day. Still overall coverage appears scattered to
widely scattered but more clustering potential mountains given
slow movement.

Will keep VCTS at most western sites including KBLF/KBCB and
KLWB this afternoon into tonight. Added the mention vcsh for KROA
with nearby convection.

Despite loss of heating the approach of an upstream cold front and
leftover instability/outflow may keep at least isolated convection
going this evening into tonight. The best chance for any storms
will occur across the north and west. Otherwise should return to
VFR outside of any leftover tsra this evening prior to patchy fog
formation again late.

Ridge is slowly breaking down Tuesday with scattered MVFR/IFR showers
and thunderstorms possible mainly during the afternoon and
evening hours.

Medium to high confidence in ceilings, visibilities and winds
during the taf period.

Extended aviation discussion...

The ridge will weaken through mid week as an initial cold front
sinks toward the area from the northwest. This should bring about
an increase in daily convective coverage Tuesday late afternoon
and evening into Friday with periodic MVFR/IFR possible depending
on exactly how far south the front makes it. Late night and early
morning fog will likely occur at the usual valley locations, and
those chances increase across the entire region if any rain occurs
during the afternoon or evening at any site.

&&

.CLIMATE...
Record high temperatures for Monday (7/25)

Roanoke.....100 in 1934
Lynchburg...102 in 1934
Danville....102 in 2010
Blacksburg...92 in 1987
Bluefield....90 in 1987

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...Heat Advisory until 8 PM EDT this evening for VAZ046-047-058-
     059.
     Heat Advisory from noon to 8 PM EDT Tuesday for VAZ046-047-058-
     059.
NC...None.
WV...None.

&&

SYNOPSIS...RCS
NEAR TERM...KK
SHORT TERM...RCS
LONG TERM...RCS
AVIATION...JH/KK
CLIMATE...JH
Hazardous weather outlook, Jul 25, 3:56 PM EDT, 1 hour 15 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BLACKSBURG VA
356 PM EDT MON JUL 25 2016

VAZ018>020-023-024-035-WVZ043-044-507-508-262000-
CRAIG-ALLEGHANY VA-BATH-BOTETOURT-ROCKBRIDGE-AMHERST-SUMMERS-MONROE-
EASTERN GREENBRIER-WESTERN GREENBRIER-
356 PM EDT MON JUL 25 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL VIRGINIA...SOUTHWEST
VIRGINIA...WEST CENTRAL VIRGINIA AND SOUTHEAST WEST VIRGINIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

STRONG TO ISOLATED SEVERE THUNDERSTORMS PRODUCING DAMAGING WIND
GUSTS COULD OCCUR AHEAD OF A COLD FRONT INTO THIS EVENING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

THERE IS A LOW PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NCZ004>006-020-VAZ043>045-262000-
STOKES-ROCKINGHAM-CASWELL-YADKIN-HENRY-PITTSYLVANIA-CAMPBELL-
356 PM EDT MON JUL 25 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL NORTH
CAROLINA...NORTHWEST NORTH CAROLINA...CENTRAL VIRGINIA AND SOUTH
CENTRAL VIRGINIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

HOT AND HUMID CONDITIONS WILL PERSIST TODAY WITH HEAT INDEX VALUES
BETWEEN 100 AND 104 DEGREES THIS AFTERNOON.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

THERE IS A LOW PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

VAZ046-047-058-059-262000-
APPOMATTOX-BUCKINGHAM-HALIFAX-CHARLOTTE-
356 PM EDT MON JUL 25 2016

...HEAT ADVISORY IN EFFECT UNTIL 8 PM EDT THIS EVENING...
...HEAT ADVISORY IN EFFECT FROM NOON TO 8 PM EDT TUESDAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL VIRGINIA AND SOUTH
CENTRAL VIRGINIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   HEAT ADVISORY.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

 HEAT ADVISORY FOR NOON UNTIL 8 PM TUESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NCZ001>003-018-019-VAZ007-009>017-022-032>034-WVZ042-262000-
ASHE-ALLEGHANY NC-SURRY-WATAUGA-WILKES-TAZEWELL-SMYTH-BLAND-GILES-
WYTHE-PULASKI-MONTGOMERY-GRAYSON-CARROLL-FLOYD-ROANOKE-PATRICK-
FRANKLIN-BEDFORD-MERCER-
356 PM EDT MON JUL 25 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL NORTH
CAROLINA...NORTHWEST NORTH CAROLINA...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...TUESDAY THROUGH SUNDAY.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

In the hours before

Special weather statement, Jul 25, 1:44 PM EDT, 3 hours 27 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BLACKSBURG VA
144 PM EDT MON JUL 25 2016

VAZ033-034-044-251845-
BEDFORD-PITTSYLVANIA-FRANKLIN-
144 PM EDT MON JUL 25 2016

...A STRONG THUNDERSTORM WILL AFFECT
NORTHWESTERN PITTSYLVANIA...EAST CENTRAL FRANKLIN AND SOUTH CENTRAL
BEDFORD COUNTIES...

AT 144 PM EDT...A STRONG THUNDERSTORM WAS NEAR ROCKY MOUNT...MOVING
EAST AT 10 MPH.

WINDS IN EXCESS OF 40 MPH AND PEA SIZE HAIL ARE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
ROCKY MOUNT...
PENHOOK...
NORTH SHORE...
UNION HALL...
AND AJAX.

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

LAT...LON 3697 7987 3706 7988 3716 7947 3693 7955
TIME...MOT...LOC 1744Z 261DEG 10KT 3702 7981

RS
Special weather statement, Jul 25, 3:11 PM EDT, 2 hours before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BLACKSBURG VA
311 PM EDT MON JUL 25 2016

VAZ017-032-252015-
FLOYD-PATRICK-
311 PM EDT MON JUL 25 2016

...A STRONG THUNDERSTORM WILL AFFECT
NORTHEASTERN PATRICK AND SOUTHEASTERN FLOYD COUNTIES...

AT 311 PM EDT...A STRONG THUNDERSTORM WAS OVER ROCKY KNOB RECREATION
AREA...MOVING NORTHEAST ALONG THE BLUE RIDGE AT 10 MPH.

WINDS IN EXCESS OF 40 MPH AND PEA SIZE HAIL ARE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
WOOLWINE...
ROCKY KNOB RECREATION AREA...
ROCKY KNOB SUMMIT...
BUFFALO RIDGE...
AND CHARITY.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

LAT...LON 3682 8043 3694 8024 3690 8020 3687 8023
      3686 8017 3680 8012 3671 8036
TIME...MOT...LOC 1911Z 241DEG 10KT 3681 8034

RS
Special weather statement, Jul 25, 3:15 PM EDT, 1 hour 56 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BLACKSBURG VA
315 PM EDT MON JUL 25 2016

NCZ002-VAZ015-016-252015-
ALLEGHANY-CARROLL-GRAYSON-
315 PM EDT MON JUL 25 2016

...A STRONG THUNDERSTORM WILL AFFECT
NORTHEASTERN ALLEGHANY COUNTY IN NORTHWESTERN NORTH CAROLINA...
SOUTHEASTERN GRAYSON AND SOUTHWESTERN CARROLL COUNTIES IN
SOUTHWESTERN VIRGINIA AND THE CITY OF GALAX...

AT 314 PM EDT...A STRONG THUNDERSTORM WAS NEAR INDEPENDENCE...MOVING
NORTHEAST AT 10 MPH.

WINDS IN EXCESS OF 40 MPH AND PEA SIZE HAIL ARE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
GALAX...
SPARTA...
INDEPENDENCE...
FRIES...
AND ENNICE.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

LAT...LON 3658 8121 3675 8092 3657 8077 3656 8083
      3656 8090 3654 8092 3649 8114
TIME...MOT...LOC 1914Z 241DEG 9KT 3658 8109

RS
Special weather statement, Jul 25, 3:44 PM EDT, 1 hour 27 minutes before
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Special weather statement, Jul 25, 5:11 PM EDT, 0 minutes before
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The office that day

Everything else NWS Blacksburg, VA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 24, 9:15 PM EDTSpecial Weather StatementRNKBland30 min
Jul 25, 1:44 PM EDTSpecial Weather StatementRNKFranklin61 min
Jul 25, 3:11 PM EDTSpecial Weather StatementRNKFloyd64 min
Jul 25, 3:15 PM EDTSpecial Weather StatementRNKCity of Galax60 min
Jul 25, 3:28 PM EDTHeat AdvisoryRNKAppomattox, Buckingham, Charlotte, Halifax29 hr
Jul 25, 5:25 PM EDTSpecial Weather StatementRNKBedford20 min
Jul 25, 5:39 PM EDTSpecial Weather StatementRNKCity of Salem21 min
Jul 25, 6:01 PM EDTSpecial Weather StatementRNKBedford29 min
Jul 25, 3:44 PM EDTSpecial Weather StatementRNKAshe61 min

Nearby

Special Weather Statements in Virginia, 2016Every special weather statement in 2016

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.