Alert archive / Oklahoma / Tornado Watches in 2010

Tornado Watch 151

May 11, 201018 counties in Oklahoma; 5 counties in Texas

The Storm Prediction Center issued this tornado watch at May 11, 2010, 3:47 PM CDT for 18 counties in Oklahoma; 5 counties in Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
May 11, 2010, 3:47 PM CDT (20:47 UTC)
Expired
May 11, 2010, 9:37 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
3 in
Strongest gust expected
60 kt
All 23 counties

Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Comanche County, OK, Cotton County, OK, Custer County, OK, Dewey County, OK, Grady County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Jefferson County, OK, Kiowa County, OK, Roger Mills County, OK, Stephens County, OK, Tillman County, OK, Washita County, OK, Clay County, TX, Foard County, TX, Hardeman County, TX, Wichita County, TX, Wilbarger County, TX

The radar

The Altus AFB radar (KFDR), 94 km from the middle of the area, began a volume at 20:54 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
50%
One or more EF2 to EF5 tornadoes
30%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
80%
One or more hailstones of 2 inches or more
40%
Six or more combined severe hail and wind reports
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 11, 5:52 PM CDTSevere Thunderstorm WarningOUNBeckham, Custer, Washita24 min
May 11, 7:47 PM CDTSevere Thunderstorm WarningOUNDewey, Ellis, Woodward58 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

Norman, OK (KOUN), launched 12:00Z, 8.8 hours before the alert went out and 119 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, Norman, OK at 12:00Z on 2010-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 748 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, Norman, OK at 12:00Z on 2010-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 179 square meters per square second.19395878Sfc1 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
748 J/kg
Mixed-layer CIN
-314 J/kg
Mixed-layer LCL
744 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
179 m²/s²
0-3 km storm-relative helicity
189 m²/s²
Significant tornado parameter
0.0
Supercell composite
10.9

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 10, 9:21 PM CDTMesoscale DiscussionSPCAtoka, Carter, Cherokee, Coal, Craig, Creek and 26 more54 min
May 10, 9:51 PM CDTMesoscale DiscussionSPCBryan, Choctaw, LeFlore, McCurtain, Pushmataha54 min
May 11, 3:23 PM CDTMesoscale DiscussionSPCBlaine, Caddo, Canadian, Cleveland, Comanche, Cotton and 12 more67 min
May 11, 6:10 PM CDTMesoscale DiscussionSPCBeckham, Blaine, Caddo, Canadian, Comanche, Cotton and 12 more95 min
May 10, 7:34 PM CDTMesoscale DiscussionSPCArcher, Callahan, Eastland, Jack, Jones, Palo Pinto and 5 more56 min

Nearby

Tornado Watches in Oklahoma, 2010Tornado Watches in Texas, 2010Every tornado watch in 2010

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.