Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 97, NWS Norman, OK

April 17, 2002Major County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Apr 17, 2002, 7:59 PM CDT for Major County, Oklahoma. 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 outline as issued.

The facts

Issued: Apr 17, 2002, 7:59 PM CDT (00:59 UTC)
Expired: Apr 17, 2002, 8:45 PM CDT
In force: 46 min
Issued by: NWS Norman, OK
Area: Counties, with a storm outline in the text

County Major County, OK

The radar

The Altus AFB radar (KFDR), 160 km from the middle of the area, began a volume at 01:00 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

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 17, 5:15 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Amarillo Airport, TX (KAMA), launched 00:00Z, 1.0 hours before the alert went out and 195 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: -53 J/kg
Mixed-layer LCL: 3565 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 33 m²/s²
0-3 km storm-relative helicity: 63 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

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

000 
WUUS54 KOUN 180058
SVROKC
OKC129-180145-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NORMAN OK
757 PM CDT WED APR 17 2002

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  ROGER MILLS COUNTY IN WESTERN OKLAHOMA

* UNTIL 845 PM CDT

* AT 757 PM CDT...DOPPLER RADAR DETECTED A SEVERE THUNDERSTORM OVER  
CHEYENNE...MOVING NORTHEAST AT 30 MPH. ANOTHER STRONG STORM WAS 
LOCATED IN NORTHEAST ROGER MILLS COUNTY. 

* LOCATIONS IN THE WARNING INCLUDE ANGORA...CHEYENNE AND STRONG CITY

HAIL  TO THE SIZE OF AT LEAST GOLFBALLS IS LIKELY WITH THIS SEVERE 
THUNDERSTORM.

SEVERE THUNDERSTORMS CAN PRODUCE TORNADOES WITH NO ADVANCE WARNING.
MOVE IMMEDIATELY TO A STORM SHELTER... BASEMENT OR STURDY BUILDING IF
A TORNADO IS SIGHTED.

LAT...LON 3560 9981 3551 9961 3583 9936 3594 9952

CJS

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 17, 3:13 PM CDT, 4 hours 46 minutes earlier.

Area forecast discussion, Apr 17, 3:13 PM CDT, 4 hours 46 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
313 PM CDT WED APR 17 2002

MAIN QUESTION IN THE SHORT TERM IS CHANCE FOR CONVECTIVE DEVELOPMENT
ON THE DRYLINE.  THERE HAVE BEEN A ECHOES CYCLING IN THE EASTERN
TIER OF COUNTIES OF THE TEXAS PANHANDLE... BUT NONE HAVE TAKEN HOLD
YET.  CONVERGENCE IS NOT VERY STRONG WITH NO BACKED WINDS TO THE
EAST... BUT WILL HAVE TO CONTINUE TO WATCH.  LATEST RUC AND MESOETA
DO SHOW PRECIP BREAKING OUT IN NORTHWEST OKLAHOMA BY 00Z AND ALONG
THE DRYLINE BY 06Z.  MESOETA ACTUALLY BRINGS THE PRECIP INTO CENTRAL
OKLAHOMA OVERNIGHT.  SPECIAL 20Z SOUNDING MAY ALSO SHED SOME LIGHT
ON THE THERMODYNAMIC STRUCTURE... SO MAY MAKE A LAST MINUTE CHANCE.
BUT WILL KEEP PRELIM 20S IN THE EVENING.

CHANCE FOR PRECIP INCREASES THURSDAY NIGHT AND FRIDAY AS SURFACE
FRONT MOVES INTO THE AREA.  WILL MAINTAIN THE HIGH POPS THURSDAY
NIGHT THROUGH FRIDAY NIGHT WITH THE FRONT IN THE VICINITY.  MODELS
SHOW FRONT MAY BE MOVE THROUGH SOUTHEAST SECTIONS LATER THAN
FORECAST... SO WILL BUMP TEMPS UP A TOUCH IN THE SOUTHEAST ON
SATURDAY.

...SPEG.
OKC   66  82  62  72 /  20  20  50  60
HBR   64  83  60  73 /  20  20  30  50
SPS   68  85  63  79 /  20  20  30  50
GAG   60  88  47  66 /  20  20  30  50
PNC   66  83  58  68 /  20  20  50  60
DUA   67  85  66  78 /  20  20  50  60

.OUN...
OK...NONE.
TX...NONE.

In the hours before

Local storm report, Apr 17, 6:32 PM CDT, 1 hour 27 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
632 PM CDT WED APR 17 2002

TIME (CDT) .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0613 PM    15 N MOORELAND            OK   1.00 INCH HAIL
04/17/02   WOODWARD                       QUATER SIZE REPORTED BY
                                          PUBLIC

Local storm report, Apr 17, 6:45 PM CDT, 1 hour 14 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
645 PM CDT WED APR 17 2002

TIME (CDT) .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0640 PM    FREEDOM                   OK   .75 INCH HAIL
04/17/02   WOODS                          REPORTED BY COOP OBSERVER

0635 PM    21 N MOORELAND            OK   .88 INCH HAIL
04/17/02   WOODWARD                       REPORTED BY PUBLIC

Local storm report, Apr 17, 6:53 PM CDT, 1 hour 6 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
653 PM CDT WED APR 17 2002

TIME (CDT) .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0645 PM    3 E CAMP HOUSTON          OK   2.75 INCH HAIL
04/17/02   WOODS                          BASEBALL HAIL REPORTED
                                          BY SPOTTER

Local storm report, Apr 17, 7:09 PM CDT, 50 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
709 PM CDT WED APR 17 2002

TIME (CDT) .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0650 PM    4 E FREEDOM               OK   2.75 INCH HAIL
04/17/02   WOODS                          TENNIS BALL TO BASEBALL
                                          SIZE HAIL REPORTED BY SPOTTER

Local storm report, Apr 17, 7:32 PM CDT, 27 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
732 PM CDT WED APR 17 2002

TIME (CDT) .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0710 PM    7 NNE LEEDEY              OK   1.75 INCH HAIL
04/17/02   DEWEY                          GOLFBALL SIZE HAIL REPORTED
                                          BY PUBLIC

Local storm report, Apr 17, 7:55 PM CDT, 4 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
755 PM CDT WED APR 17 2002

TIME (CDT) .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0751 PM    1 N CESTOS                OK   .75 INCH HAIL
04/17/02   DEWEY                          REPORTED BY SPOTTER

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 17, 7:01 PM CDT	Severe Thunderstorm Warning	OUN	Dewey	44 min
Apr 17, 7:13 PM CDT	Severe Thunderstorm Warning	OUN	Beckham, Roger Mills	47 min
Apr 17, 7:48 PM CDT	Tornado Warning	OUN	Dewey	27 min
Apr 17, 7:50 PM CDT	Tornado Warning	OUN	Beckham	40 min
Apr 17, 7:53 PM CDT	Severe Thunderstorm Warning	OUN	Woodward	37 min
Apr 17, 7:58 PM CDT	Severe Thunderstorm Warning	OUN	Roger Mills	47 min
Apr 17, 8:03 PM CDT	Severe Thunderstorm Warning	OUN	Harmon	27 min
Apr 17, 8:18 PM CDT	Severe Thunderstorm Warning	OUN	Dewey	42 min
Apr 17, 8:29 PM CDT	Severe Thunderstorm Warning	OUN	Woodward	46 min
Apr 17, 8:29 PM CDT	Severe Thunderstorm Warning	OUN	Beckham	61 min
Apr 17, 8:47 PM CDT	Severe Thunderstorm Warning	OUN	Major, Roger Mills, Woods	43 min
Apr 17, 8:55 PM CDT	Severe Thunderstorm Warning	OUN	Harmon	50 min
Apr 17, 9:10 PM CDT	Tornado Warning	OUN	Beckham	35 min
Apr 17, 9:26 PM CDT	Severe Thunderstorm Warning	OUN	Roger Mills	49 min
Apr 17, 9:43 PM CDT	Severe Thunderstorm Warning	OUN	Dewey	47 min
Apr 17, 9:43 PM CDT	Tornado Warning	OUN	Beckham	32 min
Apr 17, 9:53 PM CDT	Tornado Warning	OUN	Washita	37 min
Apr 17, 10:00 PM CDT	Severe Thunderstorm Warning	OUN	Custer	60 min
Apr 17, 10:19 PM CDT	Tornado Warning	OUN	Custer	41 min
Apr 17, 11:17 PM CDT	Severe Thunderstorm Warning	OUN	Dewey	28 min
Apr 17, 11:30 PM CDT	Severe Thunderstorm Warning	OUN	Major, Woods, Woodward	45 min
Apr 17, 11:53 PM CDT	Tornado Warning	OUN	Major	37 min
Apr 18, 12:28 AM CDT	Tornado Warning	OUN	Major, Woods	32 min
Apr 18, 12:51 AM CDT	Tornado Warning	OUN	Alfalfa, Woods	39 min
Apr 18, 1:22 AM CDT	Severe Thunderstorm Warning	OUN	Grant	38 min
Apr 18, 1:26 AM CDT	Tornado Warning	OUN	Alfalfa	34 min
Apr 18, 1:57 AM CDT	Tornado Warning	OUN	Alfalfa, Grant	33 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2002 Every severe thunderstorm warning in 2002

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.