Alert archive / Texas / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 85, NWS Norman, OK

April 1, 2013Knox County, Texas

NWS Norman, OK issued this severe thunderstorm warning at Apr 1, 2013, 8:14 PM CDT for Knox County, Texas. It was in force for 46 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, 8:14 PM CDT (01:14 UTC)
Expired: Apr 1, 2013, 9:00 PM CDT
In force: 46 min
Issued by: NWS Norman, OK
Area: Storm-based polygon

County Knox County, TX

The radar

The Altus AFB radar (KFDR), 110 km from the middle of the area, began a volume at 01:13 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

Fort Worth, TX (KFWD), launched 00:00Z, 1.2 hours before the alert went out and 244 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: 2618 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: -2 m²/s²
0-3 km storm-relative helicity: 100 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, 1 hour 28 minutes earlier.

Area forecast discussion, Apr 1, 6:46 PM CDT, 1 hour 28 minutes before

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Hazardous weather outlook, Apr 1, 6:50 PM CDT, 1 hour 24 minutes before

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In the hours before

Special weather statement, Apr 1, 4:32 PM CDT, 3 hours 42 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, 2 hours 28 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 2, 1:24 AM CDT	Special Weather Statement	OUN	Washita	36 min
Apr 2, 1:47 PM CDT	Special Weather Statement	OUN	Comanche, Grady	43 min
Apr 2, 2:34 PM CDT	Special Weather Statement	OUN	Cleveland, Cotton, Grady, McClain, Pottawatomie, Stephens	41 min
Apr 1, 7:29 PM CDT	Severe Thunderstorm Warning	OUN	Knox	46 min
Apr 1, 7:46 PM CDT	Severe Thunderstorm Warning	OUN	Knox	29 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.