Alert archive / Oklahoma / Tornado Watches in 2001

Tornado Watch 766

October 9, 200122 counties in Oklahoma

The Storm Prediction Center issued this tornado watch at Oct 9, 2001, 9:00 PM CDT for 22 counties in Oklahoma. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Oct 9, 2001, 9:00 PM CDT (02:00 UTC)
Expired: Oct 10, 2001, 1:00 AM CDT
In force: 4 hr
Issued by: the Storm Prediction Center

All 22 counties

Cherokee County, OK, Cleveland County, OK, Creek County, OK, Garvin County, OK, Haskell County, OK, Hughes County, OK, Latimer County, OK, Lincoln County, OK, Logan County, OK, McClain County, OK, McIntosh County, OK, Muskogee County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Payne County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Tulsa County, OK, Wagoner County, OK

The radar

The Norman radar (KTLX), 54 km from the middle of the area, began a volume at 02:04 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

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

Issued	Product	Office	Counties	Lasted
Oct 9, 9:13 PM CDT	Tornado Warning	OUN	Cleveland, McClain	32 min
Oct 9, 9:41 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Oklahoma	49 min
Oct 9, 10:32 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Oklahoma	43 min

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 2.0 hours before the alert went out and 65 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: 1756 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 567 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 413 m²/s²
0-3 km storm-relative helicity: 448 m²/s²
Significant tornado parameter: 4.3
Supercell composite: 15.8

Open this sounding in Storm Lab

The text

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

452 
WWUS9 KMKC 100127
SEL6  

SEL6  
MKC WW 100123
OKZ000-100600-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 766
STORM PREDICTION CENTER NORMAN OK
823 PM CDT TUE OCT 9 2001

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

   CENTRAL AND EASTERN OKLAHOMA                           

EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 900 PM
UNTIL 100 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 80 STATUTE MILES EAST AND WEST
OF A LINE FROM 45 MILES WEST SOUTHWEST OF MCALESTER OKLAHOMA TO 20
MILES WEST OF TULSA 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...THIS TORNADO WATCH REPLACES TORNADO WATCH
NUMBER 761...TORNADO WATCH NUMBER 764.  WATCH NUMBER 761...764 WILL
NOT BE IN EFFECT AFTER 900 PM CDT.  CONTINUE...WW 763...WW 765...

DISCUSSION...SUPERCELL THUNDERSTORMS CONTINUE TO MOVE EWD ACROSS
CENTRAL OK IN ASSOCIATION WITH MID/UPPER LEVEL TROUGH EVIDENT ON
WATER VAPOR IMAGERY.  VAD WIND PROFILES ACROSS THE REGION EXHIBIT
VERY STRONG LOW LEVEL SHEAR AND HELICITY INDICATING CONTINUING
THREAT FOR SUPERCELLS AND POSSIBLE TORNADOES.


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 25030.


...WEISS

343,0975 361,0974 361,0944 343,0950

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 10, 12:00 PM CDT	Severe Thunderstorm Watch	SPC	Atoka, Bryan, Carter, Coal, Johnston, Latimer and 7 more	5 hr
Oct 10, 4:00 PM CDT	Severe Thunderstorm Watch	SPC	LeFlore, McCurtain	5 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.