Alert archive / Texas / Tornado Warnings in 2015

Tornado Warning 9, NWS Norman, OK

April 22, 2015Knox County, Texas

NWS Norman, OK issued this tornado warning at Apr 22, 2015, 9:33 PM CDT for Knox County, Texas. It was in force for 42 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Apr 22, 2015, 9:33 PM CDT (02:33 UTC)
Expired
Apr 22, 2015, 10:15 PM CDT
In force
42 min
Issued by
NWS Norman, OK
Area
Storm-based polygon
Tornado
Radar indicated
Hail
2.5 in

County Knox County, TX

The radar

The Dyess AFB radar (KDYX), 119 km from the middle of the area, began a volume at 02:35 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.

What was reported inside it

TimeReportWhereRemark
Apr 22, 9:50 PM CDTTORNADO6 Nw Knox City, TXA BRIEF ROPE TORNADO REPORTED BY KNOX COUNTY EM
Apr 22, 10:19 PM CDTTORNADO5 N Knox City, TXBRIEF TOUCHDOWN. RELAYED BY NWS EMPLOYEE

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Apr 22, 2:56 PM CDTTornado WatchSPC9 hr

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 2.6 hours before the alert went out and 249 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-pSkew-T log-p diagram, Fort Worth, TX at 00:00Z on 2015-04-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 800 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 00:00Z on 2015-04-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 91 square meters per square second.1939587897117136Sfc1 km3 km6 km9 kmRMLM
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
800 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
1005 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
91 m²/s²
0-3 km storm-relative helicity
238 m²/s²
Significant tornado parameter
1.2
Supercell composite
8.3

Open this sounding in Storm Lab

The text

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

559 
WFUS54 KOUN 230233
TOROUN
TXC275-230315-
/O.NEW.KOUN.TO.W.0009.150423T0233Z-150423T0315Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE NORMAN OK
933 PM CDT WED APR 22 2015

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHWESTERN KNOX COUNTY IN NORTHERN TEXAS...

* UNTIL 1015 PM CDT
    
* AT 933 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
  TORNADO WAS LOCATED 12 MILES NORTHWEST OF KNOX CITY...MOVING EAST
  AT 30 MPH.

  HAZARD...TORNADO AND TENNIS BALL SIZE HAIL. 

  SOURCE...RADAR INDICATED ROTATION. 

  IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT 
           SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED. 
           DAMAGE TO ROOFS...WINDOWS AND VEHICLES WILL OCCUR.  TREE 
           DAMAGE IS LIKELY. 

* LOCATIONS IMPACTED INCLUDE...
  MUNDAY...KNOX CITY...BENJAMIN AND RHINELAND. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! MOVE TO A STORM SHELTER... SAFE ROOM OR AN INTERIOR
ROOM ON THE LOWEST FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF IN A
MOBILE HOME...A VEHICLE OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL
SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS.
TORNADOES ARE EXTREMELY DIFFICULT TO SEE AND CONFIRM AT NIGHT. DO NOT
WAIT TO SEE OR HEAR THE TORNADO. TAKE COVER NOW.

&&

LAT...LON 3340 9999 3362 9999 3362 9965 3340 9963
TIME...MOT...LOC 0233Z 285DEG 24KT 3350 10000 

TORNADO...RADAR INDICATED
HAIL...2.50IN

$$

AUSTIN
2 follow-up statements
158 
WWUS54 KOUN 230300
SVSOUN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
1000 PM CDT WED APR 22 2015

TXC275-230315-
/O.CON.KOUN.TO.W.0009.000000T0000Z-150423T0315Z/
KNOX TX-
1000 PM CDT WED APR 22 2015

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1015 PM CDT FOR
SOUTHWESTERN KNOX COUNTY...
    
AT 958 PM CDT...A STORM WITH A HISTORY OF PRODUCING TORNADOES WAS 
LOCATED NEAR KNOX CITY...MOVING EAST TO EAST TO SOUTHEAST AT 30 MPH.

HAZARD...TORNADO AND TENNIS BALL SIZE HAIL. 

SOURCE...EMERGENCY MANAGEMENT CONFIRMED TORNADO. 

IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT 
         SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED. DAMAGE 
         TO ROOFS...WINDOWS AND VEHICLES WILL OCCUR.  TREE DAMAGE IS 
         LIKELY. 

LOCATIONS IMPACTED INCLUDE...
MUNDAY...KNOX CITY...BENJAMIN AND RHINELAND. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TO REPEAT...A TORNADO IS ON THE GROUND. TAKE COVER NOW! MOVE TO A
STORM SHELTER... SAFE ROOM OR AN INTERIOR ROOM ON THE LOWEST FLOOR OF
A STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

TORNADOES ARE EXTREMELY DIFFICULT TO SEE AND CONFIRM AT NIGHT. DO NOT
WAIT TO SEE OR HEAR THE TORNADO. TAKE COVER NOW.

&&

LAT...LON 3340 9999 3362 9999 3362 9965 3340 9963
TIME...MOT...LOC 0258Z 285DEG 24KT 3346 9980 

TORNADO...OBSERVED
HAIL...2.50IN

$$

AUSTIN
839 
WWUS54 KOUN 230303
SVSOUN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
1003 PM CDT WED APR 22 2015

TXC275-230315-
/O.CON.KOUN.TO.W.0009.000000T0000Z-150423T0315Z/
KNOX TX-
1003 PM CDT WED APR 22 2015

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1015 PM CDT FOR
SOUTHWESTERN KNOX COUNTY...
    
AT 1001 PM CDT...A STORM WITH A HISTORY OF PRODUCING TORNADOES 
WAS LOCATED NEAR KNOX CITY...MOVING EAST AT 30 MPH. ANOTHER 
POTENTIALLY TORNADIC STORM WAS LOCATED ABOUT 12 MILES WEST OF 
BENJAMIN...AND WAS ALSO MOVING EAST AT 30 MPH.

HAZARD...TORNADO AND TENNIS BALL SIZE HAIL. 

SOURCE...EMERGENCY MANAGEMENT CONFIRMED TORNADO. 

IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT 
         SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED. DAMAGE 
         TO ROOFS...WINDOWS AND VEHICLES WILL OCCUR.  TREE DAMAGE IS 
         LIKELY. 

LOCATIONS IMPACTED INCLUDE...
MUNDAY...KNOX CITY...BENJAMIN AND RHINELAND. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TO REPEAT...A TORNADO IS ON THE GROUND. TAKE COVER NOW! MOVE TO A
STORM SHELTER... SAFE ROOM OR AN INTERIOR ROOM ON THE LOWEST FLOOR OF
A STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

TORNADOES ARE EXTREMELY DIFFICULT TO SEE AND CONFIRM AT NIGHT. DO NOT
WAIT TO SEE OR HEAR THE TORNADO. TAKE COVER NOW.

&&

LAT...LON 3340 9999 3362 9999 3362 9965 3340 9963
TIME...MOT...LOC 0301Z 285DEG 24KT 3345 9978 

TORNADO...OBSERVED
HAIL...2.50IN

$$

The office that day

Everything else NWS Norman, OK issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 22, 7:14 PM CDTSpecial Weather StatementOUNClay46 min
Apr 22, 8:55 PM CDTSpecial Weather StatementOUNFoard50 min
Apr 22, 9:11 PM CDTSevere Thunderstorm WarningOUNFoard, Knox79 min
Apr 22, 10:12 PM CDTTornado Warning Tornado observedOUNBaylor, Knox48 min
Apr 22, 10:45 PM CDTAreal Flood AdvisoryOUNKnox3 hr
Apr 22, 11:45 PM CDTSpecial Weather StatementOUNArcher, Baylor, Clay, Wichita60 min
Apr 23, 12:15 AM CDTSpecial Weather StatementOUNArcher, Clay60 min

Nearby

Tornado Warnings in Texas, 2015Every tornado warning in 2015Tornadoes in 2015

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.