Alert archive / Texas / Tornado Watches in 2012

Tornado Watch 82

March 18, 201212 counties in Texas

The Storm Prediction Center issued this tornado watch at Mar 18, 2012, 11:23 PM CDT for 12 counties in Texas. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Mar 18, 2012, 11:23 PM CDT (04:23 UTC)
Expired
Mar 19, 2012, 3:27 AM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
65 kt

Counties Briscoe County, TX, Crosby County, TX, Floyd County, TX, Garza County, TX, Hale County, TX, Hall County, TX, Hockley County, TX, Lubbock County, TX, Lynn County, TX, Motley County, TX, Swisher County, TX, Terry County, TX

The radar

The Lubbock radar (KLBB), 12 km from the middle of the area, began a volume at 04:23 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
60%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Mar 18, 11:29 PM CDTSevere Thunderstorm WarningLUBHockley, Lubbock, Lynn, Terry, Yoakum61 min
Mar 18, 11:30 PM CDTSevere Thunderstorm WarningLUBHale, Lamb60 min
Mar 19, 1:37 AM CDTSevere Thunderstorm WarningLUBBriscoe, Childress, Cottle, Floyd, Hall, Motley53 min
Mar 19, 2:08 AM CDTSevere Thunderstorm WarningLUBChildress, Cottle, Hall52 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

Amarillo Airport, TX (KAMA), launched 00:00Z, 4.4 hours before the alert went out and 179 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, Amarillo Airport, TX at 00:00Z on 2012-03-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Amarillo Airport, TX at 00:00Z on 2012-03-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
4154 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
93 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

941 
WWUS20 KWNS 190423
SEL2
SPC WW 190423
TXZ000-191000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 82
NWS STORM PREDICTION CENTER NORMAN OK
1125 PM CDT SUN MAR 18 2012

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

       WEST CENTRAL TEXAS

EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 1125 PM UNTIL
500 AM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 75 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 40 STATUTE
MILES EAST AND WEST OF A LINE FROM 50 MILES SOUTH OF LUBBOCK
TEXAS TO 45 MILES NORTHEAST OF PLAINVIEW TEXAS.  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 81...

DISCUSSION...SEVERAL CIRCULATIONS HAVE RAPIDLY FORMED ALONG THE
DEVELOPING SQUALL LINE OVER WEST TX.  DESPITE THE RATHER STRONG
CAP...IT APPEARS THE RISK OF TORNADOES IS SUFFICIENT TO UPGRADE THE
ONGOING SEVERE TSTM WATCH FOR PORTIONS OF WEST CENTRAL TX.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 65 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 24035.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 18, 7:37 PM CDTMesoscale DiscussionSPCChildress, Collingsworth, Cottle, Dickens, Fisher, Foard and 13 more53 min
Mar 18, 9:10 PM CDTMesoscale DiscussionSPCChildress, Collingsworth, Cottle, Crosby, Dickens, Donley and 7 more35 min
Mar 18, 10:09 PM CDTMesoscale DiscussionSPCAndrews, Borden, Crane, Crosby, Dawson, Ector and 13 more96 min
Mar 18, 10:50 PM CDTSevere Thunderstorm WatchSPCAndrews, Borden, Briscoe, Castro, Childress, Coke and 39 more11 hr
Mar 18, 11:37 PM CDTMesoscale DiscussionSPCCollingsworth, Donley, Gray, Hemphill, Lipscomb, Ochiltree and 2 more53 min
Mar 19, 1:37 AM CDTMesoscale DiscussionSPCBorden, Childress, Coke, Collingsworth, Cottle, Dickens and 25 more83 min
Mar 19, 1:56 AM CDTSevere Thunderstorm WatchSPCArcher, Baylor, Clay, Foard, Hardeman, Knox and 2 more4 hr
Mar 19, 3:34 AM CDTMesoscale DiscussionSPCWilbarger86 min
Mar 19, 4:13 AM CDTMesoscale DiscussionSPCCoke, Fisher, Foard, Glasscock, Haskell, Howard and 16 more92 min
Mar 19, 4:39 AM CDTSevere Thunderstorm WatchSPCCallahan, Coke, Coleman, Concho, Crockett, Fisher and 22 more7 hr
Mar 19, 10:05 AM CDTMesoscale DiscussionSPCClay, Cooke, Grayson, Montague115 min
Mar 19, 10:46 AM CDTMesoscale DiscussionSPCCallahan, Coke, Irion, Jones, Nolan, Runnels and 4 more89 min
Mar 19, 2:15 PM CDTMesoscale DiscussionSPCBosque, Brown, Collin, Comanche, Concho, Cooke and 26 more90 min
Mar 19, 2:39 PM CDTTornado WatchSPCBandera, Blanco, Bosque, Brown, Burnet, Coleman and 42 more7 hr
Mar 19, 6:05 PM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bastrop, Bexar, Blanco, Bosque and 47 more85 min
Mar 19, 6:21 PM CDTTornado WatchSPCAtascosa, Bandera, Bastrop, Bexar, Blanco, Burnet and 26 more7 hr

Nearby

Tornado Watches in Texas, 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.