Alert archive / Virginia / Tornado Watches in 2012
Tornado Watch 52
The Storm Prediction Center issued this tornado watch at Feb 29, 2012, 3:43 PM EST for 28 counties in Virginia; 4 counties in West Virginia. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 29, 2012, 3:43 PM EST (20:43 UTC)
- Expired
- Feb 29, 2012, 8:39 PM EST
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 32 counties
Alleghany County, VA, Bath County, VA, Bedford County, VA, Bland County, VA, Botetourt County, VA, Carroll County, VA, City of Buena Vista, VA, City of Covington, VA, City of Galax, VA, City of Lexington, VA, City of Martinsville, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, Craig County, VA, Floyd County, VA, Franklin County, VA, Giles County, VA, Grayson County, VA, Henry County, VA, Montgomery County, VA, Patrick County, VA, Pulaski County, VA, Roanoke County, VA, Rockbridge County, VA, Smyth County, VA, Tazewell County, VA, Wythe County, VA, Greenbrier County, WV, Mercer County, WV, Monroe County, WV, Summers County, WV
The radar
The Roanoke radar (KFCX), 75 km from the middle of the area, began a volume at 20:43 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 SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
8 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 29, 4:07 PM EST | Severe Thunderstorm Warning | RNK | Alleghany, Bath | 53 min |
| Feb 29, 4:23 PM EST | Severe Thunderstorm Warning | RNK | Alleghany | 38 min |
| Feb 29, 5:12 PM EST | Severe Thunderstorm Warning | RNK | Giles | 48 min |
| Feb 29, 5:17 PM EST | Severe Thunderstorm Warning | RNK | Alleghany, Bath, Rockbridge, City of Lexington | 28 min |
| Feb 29, 6:15 PM EST | Severe Thunderstorm Warning | RNK | Giles | 26 min |
| Feb 29, 7:01 PM EST | Flash Flood Warning | RNK | Bland, Smyth, Tazewell | 6 hr |
| Feb 29, 7:18 PM EST | Severe Thunderstorm Warning | RNK | Bland, Tazewell | 27 min |
| Feb 29, 7:23 PM EST | Tornado Warning | RNK | Grayson, Smyth, Wythe | 37 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Roanoke, VA (KRNK), launched 12:00Z, 8.7 hours before the alert went out and 122 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 651 m above ground
- 0-6 km bulk shear
- 58 kt
- 0-1 km storm-relative helicity
- 313 m²/s²
- 0-3 km storm-relative helicity
- 338 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
120
WWUS20 KWNS 292044
SEL2
SPC WW 292044
VAZ000-WVZ000-010300-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 52
NWS STORM PREDICTION CENTER NORMAN OK
345 PM EST WED FEB 29 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
WESTERN VIRGINIA
SOUTHEAST WEST VIRGINIA
EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 345 PM UNTIL
1000 PM EST.
TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH OF WHITE
SULPHUR SPRINGS WEST VIRGINIA TO 45 MILES SOUTH SOUTHWEST OF
DUBLIN VIRGINIA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).
REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.
OTHER WATCH INFORMATION...CONTINUE...WW 48...WW 49...WW 50...WW
51...
DISCUSSION...A COMPLEX BOWING STRUCTURE HAS RECENTLY EVOLVED OVER
SRN WV WITHIN A MARGINALLY UNSTABLE BUT STRONGLY SHEARED
ENVIRONMENT. DOWNSTREAM AIR MASS ACROSS THE WATCH AREA WILL
CONTINUE TO DESTABILIZE LATE THIS AFTERNOON INTO EVENING...OWING TO
THE PRESENCE OF A 50+KT WSWLY LLJ WHICH IS ENHANCING HEAT AND
MOISTURE FLUXES. AS SUCH...EXPECT ABOVE-MENTIONED MCS TO ADVANCE
EWD WITH ATTENDANT THREATS FOR DAMAGING WINDS AND PERHAPS A COUPLE
OF TORNADOES.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 350.
MEAN STORM MOTION VECTOR 26050.
...MEADSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 29, 12:11 PM EST | Mesoscale Discussion | SPC | Lee | 2 hr |
| Feb 29, 12:31 PM EST | Tornado Watch | SPC | Lee, Russell, Scott, Washington, Wise, City of Bristol and 1 more | 8 hr |
| Feb 29, 1:37 PM EST | Tornado Watch | SPC | Buchanan, Dickenson | 7 hr |
| Feb 29, 3:23 PM EST | Mesoscale Discussion | SPC | Alleghany, Bath, Bedford, Bland, Botetourt, Carroll and 23 more | 67 min |
| Feb 29, 4:34 PM EST | Mesoscale Discussion | SPC | Lee | 116 min |
| Feb 29, 1:24 PM EST | Mesoscale Discussion | SPC | Boone, Cabell, Calhoun, Jackson, Kanawha, Lincoln and 10 more | 36 min |
| Feb 29, 4:18 PM EST | Mesoscale Discussion | SPC | Barbour, Boone, Braxton, Brooke, Cabell, Calhoun and 31 more | 87 min |
Nearby
Tornado Watches in Virginia, 2012Tornado Watches in West Virginia, 2012Every tornado watch in 2012
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.