Alert archive / Oklahoma / Tornado Watches in 2007

Tornado Watch 241

May 5, 200718 counties in Oklahoma; 6 counties in Texas

The Storm Prediction Center issued this tornado watch at May 5, 2007, 9:58 PM CDT for 18 counties in Oklahoma; 6 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
May 5, 2007, 9:58 PM CDT (02:58 UTC)
Expired
May 6, 2007, 5:00 AM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 24 counties

Alfalfa County, OK, Beaver County, OK, Beckham County, OK, Blaine County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Garfield County, OK, Grant County, OK, Greer County, OK, Harmon County, OK, Harper County, OK, Kiowa County, OK, Major County, OK, Roger Mills County, OK, Washita County, OK, Woods County, OK, Woodward County, OK, Collingsworth County, TX, Donley County, TX, Gray County, TX, Hemphill County, TX, Lipscomb County, TX, Wheeler County, TX

The radar

The Vance AFB radar (KVNX), 135 km from the middle of the area, began a volume at 02:58 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
30%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
20%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 5, 10:11 PM CDTTornado WarningOUNEllis34 min
May 5, 10:30 PM CDTTornado WarningOUNDewey45 min
May 5, 10:55 PM CDTTornado WarningOUNWoodward50 min
May 5, 11:11 PM CDTSevere Thunderstorm WarningAMABeaver64 min
May 5, 11:39 PM CDTTornado WarningOUNWoodward36 min
May 5, 11:45 PM CDTTornado WarningAMAGray31 min
May 6, 12:02 AM CDTSevere Thunderstorm WarningAMADonley58 min
May 6, 12:33 AM CDTSevere Thunderstorm WarningAMAGray57 min
May 6, 12:38 AM CDTSevere Thunderstorm WarningOUNHarper52 min
May 6, 12:51 AM CDTSevere Thunderstorm WarningAMAHemphill54 min
May 6, 1:28 AM CDTSevere Thunderstorm WarningAMAGray62 min
May 6, 1:52 AM CDTSevere Thunderstorm WarningOUNHarper38 min
May 6, 2:14 AM CDTSevere Thunderstorm WarningOUNEllis46 min
May 6, 2:18 AM CDTSevere Thunderstorm WarningAMAWheeler57 min
May 6, 2:28 AM CDTSevere Thunderstorm WarningOUNHarper, Woods47 min
May 6, 5:00 AM CDTSevere Thunderstorm WarningOUNRoger Mills45 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

Lamont, OK (KLMN), launched 00:00Z, 3.0 hours before the alert went out and 182 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, Lamont, OK at 00:00Z on 2007-05-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3637 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, Lamont, OK at 00:00Z on 2007-05-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 125 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
3637 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
577 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
125 m²/s²
0-3 km storm-relative helicity
180 m²/s²
Significant tornado parameter
3.3
Supercell composite
14.4

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 060256
SEL1  
SPC WW 060256
OKZ000-TXZ000-061000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 241
NWS STORM PREDICTION CENTER NORMAN OK
955 PM CDT SAT MAY 5 2007

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

       WESTERN OKLAHOMA
       THE EASTERN TEXAS PANHANDLE

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 955 PM
UNTIL 500 AM CDT.

TORNADOES...HAIL TO 1.5 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 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 15 MILES NORTH OF ALVA
OKLAHOMA TO 60 MILES SOUTHWEST OF CLINTON 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.

OTHER WATCH INFORMATION...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 234. WATCH NUMBER 234 WILL NOT BE IN EFFECT AFTER
955 PM CDT. CONTINUE...WW 236...WW 237...WW 238...WW 239...WW
240...

DISCUSSION...ISOLATED TO WIDELY SCATTERED SUPERCELLS POSING A THREAT
FOR TORNADOES MAY PERSIST/DEVELOP THROUGH EARLY SUNDAY AS WEAK COLD
SURGE MOVING E ACROSS THE OK/TX PANHANDLE ENCOUNTERS RICH MOIST
ENVIRONMENT OVER THE ERN PANHANDLE/WRN OK.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 22030.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 5, 7:34 PM CDTMesoscale DiscussionSPCTillman56 min
May 5, 7:48 PM CDTTornado WatchSPCComanche, Jackson, Tillman7 hr
May 5, 11:24 PM CDTMesoscale DiscussionSPCBeaver, Ellis, Harper, Roger Mills, Woods, Woodward66 min
May 6, 3:37 AM CDTMesoscale DiscussionSPCAlfalfa, Beckham, Blaine, Custer, Dewey, Ellis and 9 more53 min
May 6, 7:50 AM CDTMesoscale DiscussionSPCAlfalfa, Beckham, Custer, Dewey, Greer, Harmon and 4 more85 min
May 6, 9:19 AM CDTTornado WatchSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Cleveland and 37 more5 hr
May 6, 11:41 AM CDTMesoscale DiscussionSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Cherokee and 43 more94 min
May 6, 1:47 PM CDTMesoscale DiscussionSPCBeckham, Ellis, Greer, Harmon, Harper, Jackson and 3 more58 min
May 6, 1:59 PM CDTTornado WatchSPCAlfalfa, Beaver, Beckham, Blaine, Caddo, Canadian and 36 more8 hr
May 6, 2:36 PM CDTTornado WatchSPCBrown, Callahan, Coke, Coleman, Concho, Crockett and 23 more7 hr

Nearby

Tornado Watches in Oklahoma, 2007Tornado Watches in Texas, 2007Every tornado watch in 2007

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.