Alert archive / Oklahoma / Tornado Watches in 2002

Tornado Watch 235

May 5, 200220 counties in Oklahoma

The Storm Prediction Center issued this tornado watch at May 5, 2002, 11:00 PM CDT for 20 counties in Oklahoma. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: May 5, 2002, 11:00 PM CDT (04:00 UTC)
Expired: May 6, 2002, 3:00 AM CDT
In force: 4 hr
Issued by: the Storm Prediction Center

Counties Alfalfa County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Comanche County, OK, Custer County, OK, Garfield County, OK, Grady County, OK, Grant County, OK, Greer County, OK, Jackson County, OK, Kay County, OK, Kingfisher County, OK, Kiowa County, OK, Logan County, OK, Major County, OK, Noble County, OK, Oklahoma County, OK, Payne County, OK, Washita County, OK

The radar

The Norman radar (KTLX), 112 km from the middle of the area, began a volume at 04:02 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.

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
May 5, 11:17 PM CDT	Severe Thunderstorm Warning	OUN	Greer, Kiowa	43 min
May 5, 11:44 PM CDT	Severe Thunderstorm Warning	OUN	Beckham, Washita	46 min
May 6, 12:28 AM CDT	Severe Thunderstorm Warning	OUN	Washita	32 min
May 6, 12:35 AM CDT	Severe Thunderstorm Warning	OUN	Caddo	40 min
May 6, 1:09 AM CDT	Severe Thunderstorm Warning	OUN	Canadian, Grady, Oklahoma	51 min

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 4.0 hours before the alert went out and 104 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1804 J/kg
Mixed-layer CIN: -78 J/kg
Mixed-layer LCL: 897 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 152 m²/s²
0-3 km storm-relative helicity: 216 m²/s²
Significant tornado parameter: 1.2
Supercell composite: 6.8

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 060333
SEL5  
SPC WW 060327
OKZ000-060800-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 235
STORM PREDICTION CENTER NORMAN OK
1027 PM CDT SUN MAY 5 2002

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

   SOUTHWESTERN AND CENTRAL OKLAHOMA                           

EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 1100 PM UNTIL
300 AM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 55 STATUTE MILES EAST AND WEST
OF A LINE FROM 20 MILES SOUTHEAST OF ALTUS OKLAHOMA TO 20 MILES
NORTH NORTHWEST OF PONCA CITY OKLAHOMA.

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 231...WW 233...WW 234...

DISCUSSION...TORNADIC SUPERCELLS CONTINUE TO DEVELOP OVER WRN OK
...WITHIN STRONGLY SHEARED ENVIRONMENT.  GIVEN THE STRENGTH OF LOW
AND DEEP LAYER SHEAR ALONG WITH PERSISTENT UPDRAFTS INGESTING
MODERATE SURFACE BASED INSTABILITY...THE THREAT OF TORNADOES WILL
SPREAD SLOWLY EWD INTO CENTRAL OK OVER THE NEXT FEW HOURS.


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. 
MEAN STORM MOTION VECTOR 23025.


...EVANS

342,0995 365,0981 365,0961 342,0980

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 5, 7:30 PM CDT	Tornado Watch	SPC	Alfalfa, Beckham, Blaine, Custer, Dewey, Grant and 9 more	4 hr
May 6, 1:30 AM CDT	Severe Thunderstorm Watch	SPC	Adair, Cherokee, Cleveland, Creek, Delaware, Garvin and 17 more	6 hr

Nearby

Tornado Watches in Oklahoma, 2002 Every tornado watch in 2002

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.