Alert archive / Oklahoma / Tornado Watches in 2001

Tornado Watch 128

April 11, 200119 counties in Kansas; 40 counties in Oklahoma

The Storm Prediction Center issued this tornado watch at Apr 11, 2001, 3:15 AM CDT for 19 counties in Kansas; 40 counties in Oklahoma. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Apr 11, 2001, 3:15 AM CDT (08:15 UTC)
Expired: Apr 11, 2001, 8:00 AM CDT
In force: 5 hr
Issued by: the Storm Prediction Center

All 59 counties

Allen County, KS, Anderson County, KS, Butler County, KS, Chase County, KS, Chautauqua County, KS, Coffey County, KS, Cowley County, KS, Elk County, KS, Greenwood County, KS, Harvey County, KS, Labette County, KS, Lyon County, KS, Marion County, KS, Montgomery County, KS, Neosho County, KS, Sedgwick County, KS, Sumner County, KS, Wilson County, KS, Woodson County, KS, Atoka County, OK, Bryan County, OK, Canadian County, OK, Carter County, OK, Cleveland County, OK, Coal County, OK, Creek County, OK, Garfield County, OK, Garvin County, OK, Grady County, OK, Grant County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Kay County, OK, Kingfisher County, OK, Lincoln County, OK, Logan County, OK, Love County, OK, Marshall County, OK, McClain County, OK, McIntosh County, OK, Murray County, OK, Noble County, OK, Nowata County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Osage County, OK, Pawnee County, OK, Payne County, OK, Pittsburg County, OK, Pontotoc County, OK, Pottawatomie County, OK, Rogers County, OK, Seminole County, OK, Stephens County, OK, Tulsa County, OK, Wagoner County, OK, Washington County, OK

The radar

The Norman radar (KTLX), 53 km from the middle of the area, began a volume at 08:18 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
Apr 11, 3:58 AM CDT	Tornado Warning	OUN	Love	32 min
Apr 11, 4:41 AM CDT	Severe Thunderstorm Warning	OUN	Coal, Pontotoc	34 min
Apr 11, 5:05 AM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal, Johnston	25 min
Apr 11, 5:12 AM CDT	Severe Thunderstorm Warning	OUN	Hughes	33 min
Apr 11, 5:22 AM CDT	Severe Thunderstorm Warning	TSA	McIntosh, Pittsburg	53 min
Apr 11, 5:22 AM CDT	Severe Thunderstorm Warning	TSA	Okfuskee, Okmulgee	53 min
Apr 11, 5:30 AM CDT	Severe Thunderstorm Warning	OUN	Atoka, Bryan	45 min
Apr 11, 6:14 AM CDT	Severe Thunderstorm Warning	TSA	Haskell, Latimer, Pittsburg	46 min
Apr 11, 6:14 AM CDT	Severe Thunderstorm Warning	TSA	McIntosh	46 min
Apr 11, 6:53 AM CDT	Severe Thunderstorm Warning	TSA	McIntosh	52 min
Apr 11, 7:20 AM CDT	Severe Thunderstorm Warning	TSA	Mayes, Wagoner	40 min

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 8.3 hours before the alert went out and 69 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: 1767 J/kg
Mixed-layer CIN: -45 J/kg
Mixed-layer LCL: 678 m above ground
0-6 km bulk shear: 63 kt
0-1 km storm-relative helicity: 114 m²/s²
0-3 km storm-relative helicity: 192 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 3.8

Open this sounding in Storm Lab

The text

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

175 
WWUS9 KMKC 110751
SEL8  

SEL8  
MKC WW 110745
KSZ000-OKZ000-111300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 128
STORM PREDICTION CENTER NORMAN OK
245 AM CDT WED APR 11 2001

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

   SOUTHEAST KANSAS                             
   CENTRAL AND EASTERN OKLAHOMA                           

EFFECTIVE THIS WEDNESDAY MORNING FROM 315 AM UNTIL 800 AM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 70 STATUTE MILES EAST AND WEST
OF A LINE FROM 30 MILES SOUTH OF ARDMORE OKLAHOMA TO 15 MILES NORTH
NORTHWEST OF EMPORIA KANSAS.

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 123...WW 124...WW
125...WW 126...WW 127...

DISCUSSION...BAND OF EMBEDDED THUNDERSTORMS ACROSS CENTRAL OKLAHOMA
WILL CONTINUE TO SPREAD NEWD...WHILE ADDITIONAL UPSTREAM STORMS
ALONG THE DRY LINE MOVE INTO CENTRAL PARTS OF OKLAHOMA AND KANSAS
NEXT SEVERAL HOURS.  VAD AND WIND PROFILER DATA SHOW EXTREMELY
STRONG LOW LEVEL SHEAR SUPPORTIVE OF OCCASIONAL SUPERCELLS. 
DAMAGING WIND GUSTS AND ISOLATED TORNADOES WILL BE ASSOCIATED WITH
STRONGER CELLS DURING THE EARLY MORNING HOURS. 


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. 
MEAN STORM MOTION VECTOR 23055.


...WEISS

335,0981 383,0973 383,0945 335,0954

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 10, 8:30 PM CDT	Severe Thunderstorm Watch	SPC	Cheyenne, Decatur, Finney, Gove, Grant, Gray and 18 more	5 hr
Apr 10, 10:15 PM CDT	Severe Thunderstorm Watch	SPC	Ellis, Graham, Hodgeman, Jewell, Mitchell, Ness and 9 more	6 hr
Apr 11, 12:00 AM CDT	Tornado Watch	SPC	Barber, Barton, Clark, Cloud, Comanche, Edwards and 20 more	4 hr
Apr 11, 2:00 AM CDT	Tornado Watch	SPC	Atchison, Brown, Clay, Dickinson, Douglas, Franklin and 12 more	5 hr
Apr 11, 4:00 AM CDT	Severe Thunderstorm Watch	SPC	Doniphan	5 hr
Apr 11, 9:30 AM CDT	Tornado Watch	SPC	Doniphan, Johnson, Leavenworth, Miami, Wyandotte	6 hr
Apr 10, 9:30 PM CDT	Tornado Watch	SPC	Caddo, Comanche, Cotton, Grady, Jefferson, Stephens and 1 more	6 hr
Apr 11, 6:15 AM CDT	Tornado Watch	SPC	Adair, Cherokee, Choctaw, Craig, Delaware, Haskell and 8 more	6 hr

Nearby

Tornado Watches in Oklahoma, 2001 Tornado Watches in Kansas, 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.