Alert archive / Oklahoma / Tornado Watches in 2001

Tornado Watch 764

October 9, 200119 counties in Oklahoma

The Storm Prediction Center issued this tornado watch at Oct 9, 2001, 5:30 PM CDT for 19 counties in Oklahoma. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Oct 9, 2001, 5:30 PM CDT (22:30 UTC)
Expired: Oct 9, 2001, 9:00 PM CDT
In force: 4 hr
Issued by: the Storm Prediction Center

Counties Alfalfa County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Cleveland County, OK, Comanche County, OK, Cotton County, OK, Garfield County, OK, Garvin County, OK, Grady County, OK, Grant County, OK, Kay County, OK, Kingfisher County, OK, Logan County, OK, McClain County, OK, Noble County, OK, Oklahoma County, OK, Payne County, OK, Stephens County, OK

The radar

The Norman radar (KTLX), 71 km from the middle of the area, began a volume at 22:30 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

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

Issued	Product	Office	Counties	Lasted
Oct 9, 5:55 PM CDT	Tornado Warning	OUN	Blaine, Caddo	50 min
Oct 9, 6:43 PM CDT	Tornado Warning	OUN	Caddo	32 min
Oct 9, 7:13 PM CDT	Tornado Warning	OUN	Caddo	32 min
Oct 9, 7:34 PM CDT	Tornado Warning	OUN	Grady	41 min
Oct 9, 7:45 PM CDT	Severe Thunderstorm Warning	OUN	Caddo	30 min
Oct 9, 7:54 PM CDT	Severe Thunderstorm Warning	OUN	Canadian	51 min
Oct 9, 8:10 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, McClain	50 min
Oct 9, 8:17 PM CDT	Tornado Warning	OUN	Grady, McClain	28 min
Oct 9, 8:46 PM CDT	Tornado Warning	OUN	Cleveland, McClain	29 min
Oct 9, 8:47 PM CDT	Tornado Warning	OUN	Grady	43 min
Oct 9, 8:52 PM CDT	Severe Thunderstorm Warning	OUN	Canadian	38 min

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 10.5 hours before the alert went out and 60 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: 212 J/kg
Mixed-layer CIN: -197 J/kg
Mixed-layer LCL: 603 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 228 m²/s²
0-3 km storm-relative helicity: 292 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.0

Open this sounding in Storm Lab

The text

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

430 
WWUS9 KMKC 092223
SEL4  

SEL4  
MKC WW 092216
OKZ000-100200-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 764
STORM PREDICTION CENTER NORMAN OK
516 PM CDT TUE OCT 9 2001

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

   WESTERN AND CENTRAL OKLAHOMA                           

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 530 PM UNTIL 900
PM 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 45 STATUTE MILES EAST AND WEST
OF A LINE FROM 40 MILES SOUTH SOUTHEAST OF FORT SILL OKLAHOMA TO 35
MILES 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 761...WW 762...WW 763...

DISCUSSION...TORNADIC SUPERCELLS OVER WEST CENTRAL OK ARE EXPECTED
TO CONTINUE MOVING ENEWD 25-30 KT AS MID/UPPER LEVEL SHORT WAVE
TROUGH EVIDENT IN WATER VAPOR IMAGERY PROGRESSES ACROSS WRN TX
TOWARD OK.  STORMS WILL GRADUALLY BE MOVING INTO A COOLER AIR MASS
OVER CENTRAL OK WHERE VISIBLE IMAGERY SHOWS WAVE/BILLOW CLOUD
STRUCTURE...SUGGESTING STORMS WILL BECOME INCREASINGLY ELEVATED AS
THEY MOVE EWD.  NONETHELESS...THREAT FOR LARGE HAIL AND TORNADOES
MAY CONTINUE FOR THE NEXT SEVERAL HOURS GIVEN THE STRONG LOW LEVEL
SHEAR/HELICITY AND INCREASING SURFACE PRESSURE FALLS. 


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 23030.


...WEISS

370,0964 340,0972 340,0985 370,0982

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 9, 2:30 PM CDT	Tornado Watch	SPC	Beckham, Custer, Dewey, Ellis, Greer, Harmon and 9 more	7 hr

Nearby

Tornado Watches in Oklahoma, 2001 Every tornado watch in 2001

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.