Alert archive / Oklahoma / Tornado Watches in 2012

Tornado Watch 151

April 9, 2012Barber County, Clark County, Comanche County, Kansas; 8 counties in Oklahoma

The Storm Prediction Center issued this tornado watch at Apr 9, 2012, 2:28 PM CDT for Barber County, Clark County, Comanche County, Kansas; 8 counties in Oklahoma. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 9, 2012, 2:28 PM CDT (19:28 UTC)
Expired
Apr 9, 2012, 7:50 PM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt

Counties Barber County, KS, Clark County, KS, Comanche County, KS, Alfalfa County, OK, Blaine County, OK, Dewey County, OK, Ellis County, OK, Harper County, OK, Major County, OK, Woods County, OK, Woodward County, OK

The radar

The Vance AFB radar (KVNX), 101 km from the middle of the area, began a volume at 19:29 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
70%
One or more hailstones of 2 inches or more
50%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 9, 3:39 PM CDTSevere Thunderstorm WarningOUNHarper, Woods51 min
Apr 9, 4:10 PM CDTSevere Thunderstorm WarningOUNHarper, Woods, Woodward65 min
Apr 9, 4:30 PM CDTSevere Thunderstorm WarningOUNWoodward60 min
Apr 9, 5:15 PM CDTSevere Thunderstorm WarningOUNMajor, Woods, Woodward60 min
Apr 9, 5:25 PM CDTTornado WarningOUNWoodward35 min
Apr 9, 5:50 PM CDTTornado WarningOUNDewey, Woodward40 min
Apr 9, 6:00 PM CDTSevere Thunderstorm WarningOUNWoodward45 min
Apr 9, 6:26 PM CDTSevere Thunderstorm WarningOUNDewey, Ellis, Major, Roger Mills, Woodward64 min
Apr 9, 6:29 PM CDTTornado WarningOUNDewey, Woodward31 min
Apr 9, 7:27 PM CDTSevere Thunderstorm WarningOUNCuster, Dewey, Roger Mills63 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

Dodge City, (KDDC), launched 12:00Z, 7.5 hours before the alert went out and 125 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, Dodge City, at 12:00Z on 2012-04-09Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Dodge City, at 12:00Z on 2012-04-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 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
1086 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
64 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.

701 
WWUS20 KWNS 091929
SEL1
SPC WW 091929
KSZ000-OKZ000-100200-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 151
NWS STORM PREDICTION CENTER NORMAN OK
230 PM CDT MON APR 9 2012

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

       SOUTH CENTRAL KANSAS
       NORTHWEST OKLAHOMA

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 230 PM UNTIL 900
PM CDT.

TORNADOES...HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 50 STATUTE
MILES EAST AND WEST OF A LINE FROM 30 MILES WEST NORTHWEST OF
MEDICINE LODGE KANSAS TO 55 MILES SOUTHEAST OF GAGE OKLAHOMA.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU1).

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.

DISCUSSION...ISOLATED THUNDERSTORMS ARE EXPECTED TO FORM IN THE NEXT
1-2 HOURS OVER EXTREME SOUTHERN KS AND NORTHWEST OK...NEAR WEAK
SURFACE BOUNDARY.  MODERATE INSTABILITY AND BACKED LOW LEVEL WINDS
IN VICINITY OF BOUNDARY WILL PROMOTE SUPERCELL STRUCTURES CAPABLE OF
VERY LARGE HAIL...DAMAGING WINDS...AND A FEW TORNADOES.  THREAT
SHOULD PERSIST FOR A FEW HOURS BEFORE CONVECTIVE MODE TRANSITIONS
INTO MORE OF A HAIL/WIND THREAT.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 30025.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 9, 1:54 PM CDTMesoscale DiscussionSPCBarber, Clark, Comanche, Edwards, Ford, Gray and 4 more96 min
Apr 9, 3:06 PM CDTMesoscale DiscussionSPCBeckham, Greer, Harmon, Jackson, Kiowa, Roger Mills and 1 more54 min
Apr 9, 3:23 PM CDTSevere Thunderstorm WatchSPCBeckham, Caddo, Comanche, Custer, Greer, Harmon and 5 more8 hr
Apr 9, 5:37 PM CDTMesoscale DiscussionSPCBeckham, Custer, Greer, Harmon, Jackson, Kiowa and 2 more83 min
Apr 9, 6:27 PM CDTTornado WatchSPCBeckham, Blaine, Caddo, Comanche, Cotton, Custer and 11 more8 hr

Nearby

Tornado Watches in Oklahoma, 2012Tornado Watches in Kansas, 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.