Alert archive / Oklahoma / Tornado Warnings in 2009

Tornado Warning 13, NWS Norman, OK

April 18, 2009Woods County, Oklahoma

NWS Norman, OK issued this tornado warning at Apr 18, 2009, 3:20 PM CDT for Woods County, Oklahoma. It was in force for 40 min. 3 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 18, 2009, 3:20 PM CDT (20:20 UTC)
Expired
Apr 18, 2009, 4:00 PM CDT
In force
40 min
Issued by
NWS Norman, OK
Area
Storm-based polygon

County Woods County, OK

The radar

The Vance AFB radar (KVNX), 72 km from the middle of the area, began a volume at 20:21 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 18, 3:40 PM CDTHAIL 16 E Camp Houston, OK
Apr 18, 3:56 PM CDTHAIL 1.52 E Cora, OKRELAYED VIA SPOTTER NETWORK
Apr 18, 4:00 PM CDTHAIL 1.75Cora, OK

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 18, 1:28 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Lamont, OK (KLMN), launched 12:00Z, 8.3 hours before the alert went out and 131 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, Lamont, OK at 12:00Z on 2009-04-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 452 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lamont, OK at 12:00Z on 2009-04-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 square meters per square second.1939587897Sfc1 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
452 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
456 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
60 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.7

Open this sounding in Storm Lab

The text

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

000 
WFUS54 KOUN 182020
TOROUN
OKC151-182100-
/O.NEW.KOUN.TO.W.0013.090418T2020Z-090418T2100Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE NORMAN OK
320 PM CDT SAT APR 18 2009

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* TORNADO WARNING FOR...
  CENTRAL WOODS COUNTY IN NORTHWEST OKLAHOMA...

* UNTIL 400 PM CDT

* AT 321 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 6 MILES
  SOUTHEAST OF FREEDOM...MOVING NORTH AT 10 MPH.

* THE TORNADO WILL GENERALLY REMAIN IN RURAL AREAS OF WOODS COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. LEAVE MOBILE HOMES AND VEHICLES. IF POSSIBLE...MOVE
TO A BASEMENT OR STORM SHELTER. OTHERWISE MOVE TO AN INTERIOR ROOM OR
HALLWAY ON THE LOWEST FLOOR. STAY AWAY FROM WINDOWS AND OUTSIDE
WALLS.

&&

LAT...LON 3690 9872 3667 9901 3669 9906 3670 9906
      3698 9905
TIME...MOT...LOC 2021Z 200DEG 10KT 3672 9903

$$
1 follow-up statement
000 
WWUS54 KOUN 182042
SVSOUN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
342 PM CDT SAT APR 18 2009

OKC151-182100-
/O.CON.KOUN.TO.W.0013.000000T0000Z-090418T2100Z/
WOODS OK-
342 PM CDT SAT APR 18 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 400 PM CDT FOR CENTRAL
WOODS COUNTY...

AT 342 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR DETECTED A 
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THE MOST 
DANGEROUS PORTION OF THE STORM WAS LOCATED 7 MILES EAST OF 
FREEDOM...MOVING NORTHEAST AT 10 MPH.

* ANY TORNADO WILL GENERALLY REMAIN IN RURAL AREAS OF WOODS COUNTY.

LAT...LON 3670 9898 3671 9905 3672 9906 3698 9905
      3690 9872
TIME...MOT...LOC 2042Z 215DEG 8KT 3675 9898

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 17, 7:39 PM CDTSevere Thunderstorm WarningOUNGreer, Harmon51 min
Apr 17, 8:39 PM CDTSevere Thunderstorm WarningOUNBeckham, Custer, Roger Mills36 min
Apr 18, 8:31 AM CDTDense Fog AdvisoryOUNCarter, Comanche, Cotton, Garvin, Greer, Harmon and 7 more2 hr
Apr 18, 2:28 PM CDTSevere Thunderstorm WarningOUNWoods, Woodward47 min
Apr 18, 3:08 PM CDTSevere Thunderstorm WarningOUNWoods52 min
Apr 18, 3:39 PM CDTSevere Thunderstorm WarningOUNHarper, Woods, Woodward66 min
Apr 18, 3:59 PM CDTSevere Thunderstorm WarningOUNWoods61 min
Apr 18, 4:27 PM CDTSevere Thunderstorm WarningOUNDewey, Major, Woods, Woodward48 min
Apr 18, 4:45 PM CDTTornado WarningOUNAlfalfa, Woods45 min
Apr 18, 4:59 PM CDTSevere Thunderstorm WarningOUNWoods31 min
Apr 18, 5:10 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Blaine, Dewey, Major, Woods65 min
Apr 18, 5:18 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Grant, Woods57 min
Apr 18, 6:11 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Blaine, Garfield, Grant, Kingfisher, Major34 min

Nearby

Tornado Warnings in Oklahoma, 2009Every tornado warning in 2009Tornadoes in 2009

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.