Alert archive / Texas / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 82, NWS Norman, OK

April 1, 2013Foard County, Knox County, Texas

NWS Norman, OK issued this severe thunderstorm warning at Apr 1, 2013, 6:49 PM CDT for Foard County, Knox County, Texas. It was in force for 41 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Apr 1, 2013, 6:49 PM CDT (23:49 UTC)
Expired: Apr 1, 2013, 7:30 PM CDT
In force: 41 min
Issued by: NWS Norman, OK
Area: Storm-based polygon

Counties Foard County, TX, Knox County, TX

The radar

The Altus AFB radar (KFDR), 96 km from the middle of the area, began a volume at 23:50 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 watch it was issued in

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

Issued	Product	Office	Lasted
Apr 1, 3:36 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Amarillo Airport, TX (KAMA), launched 12:00Z, 11.8 hours before the alert went out and 239 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: 53 J/kg
Mixed-layer CIN: -411 J/kg
Mixed-layer LCL: 1662 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 297 m²/s²
0-3 km storm-relative helicity: 327 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Norman, OK wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 1, 6:46 PM CDT, 3 minutes earlier.

Area forecast discussion, Apr 1, 6:46 PM CDT, 3 minutes before

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Hazardous weather outlook, Apr 1, 5:29 PM CDT, 1 hour 20 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE NORMAN OK
529 PM CDT MON APR 1 2013

OKZ004>048-050>052-TXZ083>090-021000-
HARPER-WOODS-ALFALFA-GRANT-KAY-ELLIS-WOODWARD-MAJOR-GARFIELD-NOBLE-
ROGER MILLS-DEWEY-CUSTER-BLAINE-KINGFISHER-LOGAN-PAYNE-BECKHAM-
WASHITA-CADDO-CANADIAN-OKLAHOMA-LINCOLN-GRADY-MCCLAIN-CLEVELAND-
POTTAWATOMIE-SEMINOLE-HUGHES-HARMON-GREER-KIOWA-JACKSON-TILLMAN-
COMANCHE-STEPHENS-GARVIN-MURRAY-PONTOTOC-COAL-COTTON-JEFFERSON-
CARTER-JOHNSTON-ATOKA-LOVE-MARSHALL-BRYAN-HARDEMAN-FOARD-WILBARGER-
WICHITA-KNOX-BAYLOR-ARCHER-CLAY-
529 PM CDT MON APR 1 2013

THIS HAZARDOUS WEATHER OUTLOOK COVERS NORTHERN...WESTERN...
CENTRAL...AND SOUTHERN OKLAHOMA...AND WESTERN NORTH TEXAS.

.DAY ONE...THROUGH TONIGHT...

THUNDERSTORM OUTLOOK...
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHWEST
OKLAHOMA AND WESTERN NORTH TEXAS.

LOCATION...
THE SLIGHT RISK AREA IS SOUTHWEST OF A LINE EXTENDING FROM ERICK
AND MANGUM...TO WALTERS AND WAURIKA.  THE RISK AREA INCLUDES ALL OF
WESTERN NORTH TEXAS.

TIMING...
THE MOST LIKELY TIME FOR SEVERE THUNDERSTORMS WILL BE THROUGH
MIDNIGHT CDT TONIGHT.

IMPACTS...
HAIL UP TO THE SIZE OF HEN EGGS...OR TWO INCHES IN DIAMETER...IS
THE MAIN HAZARD.  WIND GUSTS TO 70 MPH ARE POSSIBLE AS WELL.

RECOMMENDED ACTIONS...
STORM SPOTTER GROUPS AND EMERGENCY MANAGEMENT PERSONNEL ACROSS
THE RISK AREA SHOULD BE PREPARED FOR SEVERE WEATHER OPERATIONS
THROUGH MIDNIGHT CDT.

DISCUSSION...
SCATTERED SEVERE THUNDERSTORMS HAVE DEVELOPED ACROSS WEST TEXAS
AND WILL MOVE INTO WESTERN NORTH TEXAS AND SOUTHWESTERN OKLAHOMA
THROUGH MIDNIGHT CDT.  DUE TO STRONG SHEAR AND STEEP LAPSE
RATES...BUT MARGINAL INSTABILITY...A FEW SEVERE STORMS CAN BE
EXPECTED...WHICH WILL GENERALLY MOVE EAST OR SOUTHEAST.  THERE IS
A CHANCE THE STORMS MAY ORGANIZE INTO A CLUSTER OR LINE...AND
MOVE ACROSS MUCH OF WESTERN NORTH TEXAS...WHICH WOULD INCREASE
THE WIND THREAT.

ALL SEVERE STORMS ARE EXPECTED TO END BY MIDNIGHT CDT...THOUGH
THUNDERSTORM CHANCES WILL CONTINUE THROUGHOUT THE NIGHT ACROSS
WESTERN NORTH TEXAS AND SOUTHERN OKLAHOMA.  CHANCES FOR RAIN SHOWERS
WILL OCCUR TONIGHT ACROSS NORTHERN OKLAHOMA...ESPECIALLY AFTER
MIDNIGHT CDT.

PROBABILITY TABLE...
VALID THROUGH 700 AM CDT TUESDAY APR 2.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...100 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR...40 PERCENT.

OTHER HAZARDOUS WEATHER...
NONE.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...

THUNDERSTORM OUTLOOK...
THERE WILL BE A CHANCE OF THUNDERSTORMS ON TUESDAY ACROSS WESTERN
NORTH TEXAS AND SOUTHERN OKLAHOMA.  NO ORGANIZED SEVERE STORMS
ARE EXPECTED.

OTHER HAZARDOUS WEATHER...
NONE.

THE NEXT SCHEDULED HAZARDOUS WEATHER OUTLOOK WILL BE ISSUED AT
5 AM CDT TUESDAY...WITH UPDATES AS NEEDED.

CMS/11/MBS

In the hours before

Special weather statement, Apr 1, 4:32 PM CDT, 2 hours 17 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
432 PM CDT MON APR 1 2013

OKZ033-TXZ083-012200-
HARMON OK-HARDEMAN TX-
432 PM CDT MON APR 1 2013

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN HARMON AND
NORTHWESTERN HARDEMAN COUNTIES UNTIL 500 PM CDT...

AT 430 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED 9 MILES NORTH-
NORTHWEST OF CHILDRESS TEXAS...MOVING EAST AT 20 MPH. GOLFBALL SIZED
HAIL HAS BEEN REPORTED NORTHWEST OF CHILDRESS WITH THIS STORM. IF
THIS STORM MAINTAINS INTENSITY... SEVERE THUNDERSTORM WARNINGS WILL
BE REQUIRED SOON FOR HARDEMAN COUNTY TEXAS AND PERHAPS HARMON COUNTY
OKLAHOMA.

LAT...LON 3466 9989 3440 9991 3441 9997 3441 10000
      3467 10000
TIME...MOT...LOC 2125Z 274DEG 16KT 3455 10032

..SPEG.

Local storm report, Apr 1, 5:46 PM CDT, 1 hour 3 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 1, 4:32 PM CDT	Special Weather Statement	OUN	Childress	28 min
Apr 1, 5:03 PM CDT	Severe Thunderstorm Warning	OUN	Hardeman	42 min
Apr 1, 5:41 PM CDT	Severe Thunderstorm Warning	OUN	Hardeman	49 min

Nearby

Severe Thunderstorm Warnings in Texas, 2013 Every severe thunderstorm warning in 2013

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.