Alert archive / Oklahoma / Tornado Watches in 2001

Tornado Watch 193

May 4, 200112 counties in Oklahoma

The Storm Prediction Center issued this tornado watch at May 4, 2001, 5:45 PM CDT for 12 counties in Oklahoma. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: May 4, 2001, 5:45 PM CDT (22:45 UTC)
Expired: May 4, 2001, 11:00 PM CDT
In force: 5 hr
Issued by: the Storm Prediction Center

Counties Blaine County, OK, Caddo County, OK, Canadian County, OK, Cleveland County, OK, Grady County, OK, Kingfisher County, OK, Lincoln County, OK, Logan County, OK, McClain County, OK, Oklahoma County, OK, Payne County, OK, Pottawatomie County, OK

The radar

The Norman radar (KTLX), 37 km from the middle of the area, began a volume at 22:44 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

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

Issued	Product	Office	Counties	Lasted
May 4, 6:07 PM CDT	Severe Thunderstorm Warning	OUN	Grady	38 min
May 4, 6:43 PM CDT	Severe Thunderstorm Warning	OUN	Grady	47 min
May 4, 7:24 PM CDT	Tornado Warning	OUN	Grady	36 min
May 4, 7:28 PM CDT	Tornado Warning	OUN	McClain	32 min
May 4, 7:49 PM CDT	Tornado Warning	OUN	Cleveland, Oklahoma	26 min
May 4, 8:10 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Oklahoma	35 min
May 4, 8:29 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Pottawatomie	46 min

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 10.8 hours before the alert went out and 48 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: 225 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 928 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 8 m²/s²
0-3 km storm-relative helicity: -10 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

000 
WWUS9 KMKC 042243
SEL3  

SEL3  
MKC WW 042233
OKZ000-050400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 193
STORM PREDICTION CENTER NORMAN OK
533 PM CDT FRI MAY 4 2001

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

   CENTRAL OKLAHOMA                           

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 545 PM UNTIL 1100
PM CDT.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO
60 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 55 MILES NORTH OF OKLAHOMA CITY OKLAHOMA TO 40 MILES
SOUTH OF OKLAHOMA 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 191...WW 192...

DISCUSSION...NARROW WEDGE OF RECOVERING BOUNDARY LAYER AIR IS
MOVING N THROUGH CENTRAL OK ATTM...DESTABILIZING REGION AHEAD OF
EXISTING SQUALL LINE OVER SWRN AND W CNTRL OK.  BACKING LOW LEVEL
FLOW...APPARENTLY IN RESPONSE TO SUB SYNOPTIC LOW CENTER NEAR
LAW...HAS INCREASED LOW LEVEL SHEAR TO ABOVE 30 KTS...AND SRH TO
AROUND 250 M2/S2 /ASSUMING STORM MOTION OF 190/35/.   COUPLED WITH
LOW LCLS...POTENTIAL WILL EXIST FOR A FEW BRIEF TORNADOES.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH...EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 50 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. 
MEAN STORM MOTION VtECTOR 20035.

...CORFIDI

;361,0963 344,0963 344,0983 361,0983;

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 4, 2:00 PM CDT	Tornado Watch	SPC	Carter, Comanche, Cotton, Garvin, Jefferson, Johnston and 4 more	6 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.