Alert archive / Oklahoma / Tornado Warnings in 2014

Tornado Warning 4, NWS Norman, OK

April 20, 2014Harmon County, Oklahoma; Hardeman County, Texas

NWS Norman, OK issued this tornado warning at Apr 20, 2014, 5:55 PM CDT for Harmon County, Oklahoma; Hardeman County, Texas. It was in force for 35 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Apr 20, 2014, 5:55 PM CDT (22:55 UTC)
Expired: Apr 20, 2014, 6:30 PM CDT
In force: 35 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.75 in

Counties Harmon County, OK, Hardeman County, TX

The radar

The Altus AFB radar (KFDR), 86 km from the middle of the area, began a volume at 22:57 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.

The nearest sounding before it

Amarillo Airport, TX (KAMA), launched 12:00Z, 10.9 hours before the alert went out and 183 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 974 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: -16 m²/s²
0-3 km storm-relative helicity: 12 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.

666 
WFUS54 KOUN 202255
TOROUN
OKC057-TXC197-202330-
/O.NEW.KOUN.TO.W.0004.140420T2255Z-140420T2330Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE NORMAN OK
555 PM CDT SUN APR 20 2014

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHWESTERN HARMON COUNTY IN SOUTHWEST OKLAHOMA...
  NORTHWESTERN HARDEMAN COUNTY IN NORTHERN TEXAS...

* UNTIL 630 PM CDT
    
* AT 555 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
  TORNADO WAS LOCATED 10 MILES NORTHEAST OF KIRKLAND...MOVING EAST AT
  15 MPH.

  HAZARD...TORNADO AND GOLF 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. 

* THIS TORNADIC THUNDERSTORM WILL REMAIN OVER MAINLY RURAL AREAS OF
  SOUTHWESTERN HARMON AND NORTHWESTERN HARDEMAN COUNTIES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! MOVE TO A BASEMENT 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.

&&

LAT...LON 3457 9981 3438 9987 3442 10000 3457 10000
TIME...MOT...LOC 2255Z 287DEG 14KT 3451 9995 

TORNADO...RADAR INDICATED
HAIL...1.75IN

$$

17

1 follow-up statement

035 
WWUS54 KOUN 202305
SVSOUN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
605 PM CDT SUN APR 20 2014

OKC057-TXC197-202314-
/O.CAN.KOUN.TO.W.0004.000000T0000Z-140420T2330Z/
HARMON OK-HARDEMAN TX-
605 PM CDT SUN APR 20 2014

...THE TORNADO WARNING FOR SOUTHWESTERN HARMON AND NORTHWESTERN
HARDEMAN COUNTIES IS CANCELLED...
    
THE TORNADO THREAT HAS DIMINISHED...THEREFORE THE TORNADO WARNING 
HAS BEEN CANCELLED. HOWEVER...LARGE HAIL UP TO GOLF BALLS CAN BE 
EXPECTED AND A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR THE 
AREA. 

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
NORMAN.

REMEMBER...A SEVERE THUNDERSTORM WARNING STILL REMAINS IN EFFECT 
UNTIL 630 PM.

LAT...LON 3457 9981 3438 9987 3442 10000 3457 10000
TIME...MOT...LOC 2301Z 287DEG 14KT 3450 9991 

$$

17

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 20, 4:26 PM CDT	Special Weather Statement	OUN	Beckham	64 min
Apr 20, 4:39 PM CDT	Severe Thunderstorm Warning	OUN	Beckham, Roger Mills	51 min
Apr 20, 5:17 PM CDT	Severe Thunderstorm Warning	OUN	Harmon	43 min
Apr 20, 5:48 PM CDT	Severe Thunderstorm Warning	OUN	Harmon, Jackson	42 min
Apr 20, 5:53 PM CDT	Special Weather Statement	OUN	Ellis, Harper	52 min
Apr 20, 6:13 PM CDT	Special Weather Statement	OUN	Harper	47 min
Apr 20, 6:26 PM CDT	Severe Thunderstorm Warning	OUN	Harmon, Jackson	49 min
Apr 20, 3:30 PM CDT	Areal Flood Advisory	OUN	Archer, Baylor, Clay, Wichita	2 hr

Nearby

Tornado Warnings in Oklahoma, 2014 Tornado Warnings in Texas, 2014 Every tornado warning in 2014 Tornadoes in 2014

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.