Alert archive / Texas / Tornado Watches in 2005

Tornado Watch 250

May 11, 20059 counties in Oklahoma; 24 counties in Texas

The Storm Prediction Center issued this tornado watch at May 11, 2005, 3:25 PM CDT for 9 counties in Oklahoma; 24 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: May 11, 2005, 3:25 PM CDT (20:25 UTC)
Expired: May 11, 2005, 10:00 PM CDT
In force: 7 hr
Issued by: the Storm Prediction Center

All 33 counties

Beaver County, OK, Beckham County, OK, Ellis County, OK, Greer County, OK, Harmon County, OK, Harper County, OK, Jackson County, OK, Roger Mills County, OK, Texas County, OK, Armstrong County, TX, Briscoe County, TX, Carson County, TX, Childress County, TX, Collingsworth County, TX, Cottle County, TX, Crosby County, TX, Dickens County, TX, Donley County, TX, Floyd County, TX, Foard County, TX, Gray County, TX, Hall County, TX, Hansford County, TX, Hardeman County, TX, Hemphill County, TX, Hutchinson County, TX, King County, TX, Knox County, TX, Lipscomb County, TX, Motley County, TX, Ochiltree County, TX, Roberts County, TX, Wheeler County, TX

The radar

The Amarillo radar (KAMA), 131 km from the middle of the area, began a volume at 20:30 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.

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Amarillo Airport, TX (KAMA), launched 12:00Z, 8.4 hours before the alert went out and 130 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: 1231 J/kg
Mixed-layer CIN: -227 J/kg
Mixed-layer LCL: 1143 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 156 m²/s²
0-3 km storm-relative helicity: 99 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.0

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 112026
SEL0  
SPC WW 112026
OKZ000-TXZ000-120300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 250
NWS STORM PREDICTION CENTER NORMAN OK
325 PM CDT WED MAY 11 2005

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

       FAR WESTERN OKLAHOMA AND MOST OF THE OKLAHOMA PANHANDLE
       NORTHWEST TEXAS AND MOST OF THE TEXAS PANHANDLE

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 325 PM UNTIL
1000 PM CDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE MILES
EAST AND WEST OF A LINE FROM 75 MILES NORTHWEST OF GAGE OKLAHOMA
TO 75 MILES SOUTH OF CHILDRESS TEXAS.  FOR A COMPLETE DEPICTION OF
THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS
WOU0).

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 245...WW 246...WW 247...WW
248...WW 249...

DISCUSSION...DEEP MIXING HAS ERODED THE CAP AND IS SUPPORTING AN
AXIS OF MODERATE TO STRONG INSTABILITY OVER FAR WESTERN TX AND THE
TX PANHANDLE...EAST OF A DRY LINE CURRENTLY EXTENDING SWD ACROSS THE
REGION.  DEEP LAYER SHEAR REMAINS IN THE 35-40 KT RANGE OVER THE
AREA...SUGGESTING STORMS WILL DEVELOP QUICKLY AND LIKELY BECOME
SUPERCELLS WITHIN THE NEXT 1-2 HOURS.  VERY LARGE HAIL ALONG WITH
ISOLATED TORNADOES WILL BE PRIMARY THREATS AS STORMS MOVE ENEWD
TOWARDS FAR WRN OK/NWRN TX THROUGH THE EVENING.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 24025.


...EVANS

370,0993 332,0991 332,1011 370,1014

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 10, 9:39 PM CDT	Mesoscale Discussion	SPC	Beaver, Ellis, Harper, Roger Mills, Woods, Woodward	36 min
May 11, 2:25 PM CDT	Mesoscale Discussion	SPC	Beaver, Beckham, Ellis, Harmon, Harper, Roger Mills and 1 more	2 hr
May 11, 6:24 PM CDT	Mesoscale Discussion	SPC	Beaver, Beckham, Ellis, Greer, Harmon, Harper and 3 more	96 min

Nearby

Tornado Watches in Texas, 2005 Tornado Watches in Oklahoma, 2005 Every tornado watch in 2005

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.