Alert archive / Virginia / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 21, NWS Blacksburg, VA

April 15, 20175 counties in Virginia

NWS Blacksburg, VA issued this severe thunderstorm warning at Apr 15, 2017, 1:51 PM EDT for 5 counties in Virginia. It was in force for 39 min. 6 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Apr 15, 2017, 1:51 PM EDT (17:51 UTC)
Expired: Apr 15, 2017, 2:30 PM EDT
In force: 39 min
Issued by: NWS Blacksburg, VA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

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

The radar

The Roanoke radar (KFCX), 46 km from the middle of the area, began a volume at 17:53 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.

What was reported inside it

Time	Report	Where	Remark
Apr 15, 1:54 PM EDT	HAIL 0.25	5 Se Catawba, VA	TIME RADAR ESTIMATED
Apr 15, 1:55 PM EDT	HAIL 0.5	1 Nw Salem City, VA
Apr 15, 2:06 PM EDT	TSTM WND DMG	3 Nw Roanoke, VA	TREE DOWN ON POWER LINES ALONG GARSTLAND DR NW
Apr 15, 2:07 PM EDT	TSTM WND DMG	2 Sw Roanoke, VA	TREE DOWN ON POWER LINE RESULTING IN POWER OUTAGES ALONG WINDSOR AVENUE.
Apr 15, 2:10 PM EDT	HAIL 0.88	1 Nw Salem City, VA
Apr 15, 2:25 PM EDT	HAIL 0.88	2 Ne Roanoke, VA

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Roanoke, VA (KRNK), launched 12:00Z, 5.9 hours before the alert went out and 31 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 15 J/kg
Mixed-layer CIN: -212 J/kg
Mixed-layer LCL: 1097 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 130 m²/s²
0-3 km storm-relative helicity: 108 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

097 
WUUS51 KRNK 151751
SVRRNK
VAC019-023-161-770-775-151830-
/O.NEW.KRNK.SV.W.0021.170415T1751Z-170415T1830Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service BLACKSBURG VA
151 PM EDT SAT APR 15 2017

The National Weather Service in BLACKSBURG has issued a

* Severe Thunderstorm Warning for...
  Northeastern Roanoke County in west central Virginia...
  The City of Salem in west central Virginia...
  The City of Roanoke in west central Virginia...
  Southwestern Botetourt County in west central Virginia...
  West central Bedford County in south central Virginia...

* Until 230 PM EDT

* At 151 PM EDT, a severe thunderstorm was located over Salem, moving
  east at 20 mph.

  HAZARD...60 mph wind gusts and quarter size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees. 

* Locations impacted include...
  Roanoke...
  Salem...
  Vinton...
  Montvale...
  and Catawba.

This includes The following Locations The Salem Fairgrounds and
Roanoke Regional Airport.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. For your
safety, move to an interior room on the lowest floor of a sturdy
building. Stay away from windows.

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

When it is safe to do so, please send your reports of hail of any
size, as well as reports of any wind damage, including downed trees
or large limbs, to the National Weather Service by calling toll free
at 1...8 6 6...2 1 5...4 3 2 4. Reports and pictures can also be
shared on the National Weather Service Blacksburg Facebook page and
on Twitter.

&&

LAT...LON 3741 7973 3719 7973 3720 7978 3723 7978
      3723 7980 3722 7979 3721 7980 3723 7982
      3722 7983 3722 7985 3721 7988 3725 8014
      3739 8013
TIME...MOT...LOC 1751Z 268DEG 19KT 3733 8007 

HAIL...1.00IN
WIND...60MPH
 
$$

PW

2 follow-up statements

969 
WWUS51 KRNK 151813
SVSRNK

Severe Weather Statement
National Weather Service BLACKSBURG VA
213 PM EDT SAT APR 15 2017

VAC019-023-161-770-775-151830-
/O.CON.KRNK.SV.W.0021.000000T0000Z-170415T1830Z/
Roanoke VA-City of Salem VA-City of Roanoke VA-Botetourt VA-
Bedford VA-
213 PM EDT SAT APR 15 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 230 PM EDT
FOR
NORTHEASTERN ROANOKE...SOUTHWESTERN BOTETOURT AND WEST CENTRAL
BEDFORD COUNTIES...THE SOUTHEASTERN CITY OF SALEM AND THE CITY OF
ROANOKE...

At 212 PM EDT, a severe thunderstorm was located near Vinton, moving
east at 25 mph.

HAZARD...60 mph wind gusts and quarter size hail. Hail up to nickel 
         size has been reported by the general public in the city of 
         Salem.

SOURCE...Radar indicated. 

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees. 

Locations impacted include...
Roanoke...
Salem...
Vinton...
Montvale...
and Stewartsville.

This includes The following Location Roanoke Regional Airport.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for LARGE HAIL AND DAMAGING WINDS. For your
safety, move to an interior room on the lowest floor of a sturdy
building. Stay away from windows.

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

When it is safe to do so, please send your reports of hail of any
size, as well as reports of any wind damage, including downed trees
or large limbs, to the National Weather Service by calling toll free
at 1...8 6 6...2 1 5...4 3 2 4. Reports and pictures can also be
shared on the National Weather Service Blacksburg Facebook page and
on Twitter.

&&

LAT...LON 3723 8004 3740 8002 3741 7973 3719 7973
      3720 7978 3723 7978 3723 7980 3722 7979
      3721 7980 3723 7982 3722 7983 3722 7985
      3721 7988
TIME...MOT...LOC 1812Z 273DEG 23KT 3732 7991 

HAIL...1.00IN
WIND...60MPH
 
$$

Loconto

639 
WWUS51 KRNK 151828
SVSRNK

Severe Weather Statement
National Weather Service BLACKSBURG VA
228 PM EDT SAT APR 15 2017

VAC019-023-161-770-775-151837-
/O.EXP.KRNK.SV.W.0021.000000T0000Z-170415T1830Z/
Roanoke VA-City of Salem VA-City of Roanoke VA-Botetourt VA-
Bedford VA-
228 PM EDT SAT APR 15 2017

...THE SEVERE THUNDERSTORM WARNING FOR 
NORTHEASTERN ROANOKE...SOUTHWESTERN BOTETOURT AND WEST CENTRAL
BEDFORD COUNTIES...THE SOUTHEASTERN CITY OF SALEM AND THE CITY OF
ROANOKE WILL EXPIRE AT 230 PM EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore the warning will be allowed to expire.  However small hail
and gusty winds are still possible with this thunderstorm.

When it is safe to do so, please send your reports of hail of any
size, as well as reports of any wind damage, including downed trees
or large limbs, to the National Weather Service by calling toll free
at 1...8 6 6...2 1 5...4 3 2 4. Reports and pictures can also be
shared on the National Weather Service Blacksburg Facebook page and
on Twitter.

LAT...LON 3723 8004 3740 8002 3741 7973 3719 7973
      3720 7978 3723 7978 3723 7980 3722 7979
      3721 7980 3723 7982 3722 7983 3722 7985
      3721 7988
TIME...MOT...LOC 1827Z 268DEG 19KT 3732 7986 

$$

Loconto

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 15, 3:48 AM EDT	Special Weather Statement	RNK	Campbell	57 min
Apr 15, 12:46 PM EDT	Special Weather Statement	RNK	Montgomery, City of Radford	59 min
Apr 15, 1:45 PM EDT	Special Weather Statement	RNK	City of Roanoke, City of Salem	45 min
Apr 15, 1:56 PM EDT	Special Weather Statement	RNK	Carroll	49 min
Apr 15, 2:26 PM EDT	Special Weather Statement	RNK	Bedford, City of Roanoke	49 min
Apr 15, 3:49 PM EDT	Special Weather Statement	RNK	Pittsylvania	41 min

Nearby

Severe Thunderstorm Warnings in Virginia, 2017 Every severe thunderstorm warning in 2017

Sources

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