Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 7, NWS Norman, OK

February 9, 2001Grady County, Stephens County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Feb 9, 2001, 12:03 AM CST for Grady County, Stephens County, Oklahoma. It was in force for 42 min. 2 reports came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued: Feb 9, 2001, 12:03 AM CST (06:03 UTC)
Expired: Feb 9, 2001, 12:45 AM CST
In force: 42 min
Issued by: NWS Norman, OK
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Grady County, OK, Stephens County, OK

What was reported inside it

Time	Report	Where	Remark
Feb 9, 12:15 AM CST	Thunderstorm Wind	Marlow, OK	A barn and trees were blown down.
Feb 9, 12:40 AM CST	Thunderstorm Wind 56 M	Duncan, OK	Wind gust was measured by Oklahoma mesonet.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

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

Issued	Product	Office	Lasted
Feb 8, 11:00 PM CST	Tornado Watch	SPC	6 hr

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 6.1 hours before the alert went out and 121 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: 886 J/kg
Mixed-layer CIN: -20 J/kg
Mixed-layer LCL: 590 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 232 m²/s²
0-3 km storm-relative helicity: 226 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 4.6

Open this sounding in Storm Lab

The text

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

375 
WUUS54 KOUN 090606
SVROKC
OKC051-067-137-TXC077-090645-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NORMAN OK
1203 AM CST FRI FEB 9 2001

THE NATIONAL WEATHER SERVICE IN NORMAN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  GRADY COUNTY IN CENTRAL OKLAHOMA
  CLAY COUNTY IN NORTHERN TEXAS
  JEFFERSON COUNTY IN SOUTHERN OKLAHOMA
  STEPHENS COUNTY IN SOUTHERN OKLAHOMA

* UNTIL 1245 AM CST

* AT 1201 AM CST...DOPPLER RADAR DETECTED A LINE OF SEVERE           
  THUNDERSTORMS FROM ARCHER CITY TO 10 MILES SOUTHWEST OF CHICKAHSA  
  MOVING NORTHEAST AT 50 MPH.

* LOCATIONS IN THE WARNING INCLUDE ADDINGTON...ALEX...BRADLEY...
  BRAY...BYERS...CHARLIE...COMANCHE...CORUM...DUNCAN...EMPIRE CITY...
  HASTINGS...HENRIETTA...JOLLY...MARLOW...NINNEKAH...PETROLIA...RUSH
  SPRINGS...RYAN...SUGDEN...TERRAL AND WAURIKA

THESE THUNDERSTORMS ARE CAPABLE OF PRODUCING PARTICULARLY DAMAGING 
WINDS. WIND GUSTS IN EXCESS OF 70 MPH HAVE BEEN REPORTED. MOBILE 
HOMES AND HIGH PROFILE VEHICLES ARE ESPECIALLY SUSCEPTIBLE TO HIGH 
WINDS AND MAY BE OVERTURNED. MOVE TO A STURDY BUILDING AND STAY AWAY 
FROM WINDOWS.

HAIL TO THE SIZE OF NICKELS IS ALSO POSSIBLE. 


LAT...LON 3408 9839 3373 9841 3373 9793 3450 9769
          3491 9768 3497 9806 3413 9814

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 Feb 8, 10:05 PM CST, 1 hour 58 minutes earlier.

Area forecast discussion, Feb 8, 10:05 PM CST, 1 hour 58 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
1005 PM CST THU FEB 8 2001

MAIN CONCERN THIS EVENING HAS BEEN STEADY MOVEMENT OF SHALLOW ARCTIC
AIR INTO NORTHWEST OKLAHOMA AND ASSOCIATED VARIETY OF PRECIP TYPES
NORTH OF THE BOUNDARY. AS OF MID EVENING...COLD FRONT WAS LOCATED
FROM NEAR STILLWATER SOUTHWESTWARD TO NEAR QUANAH TEXAS WITH
TEMPERATURES ACROSS FAR NORTHWEST OKLAHOMA ALREADY INTO THE MID AND
UPPER 20S. RECENT SURFACE OBS AND CALLS TO THAT AREA INDICATE A
MIXTURE OF FREEZING RAIN...SLEET..AND SNOW...WITH OCCASIONAL RUMBLES
OF THUNDER. GROUND TEMPERATURES ARE STILL WARM HOWEVER RELATIVE TO
THE SURFACE AIR WHICH HAS GREATLY LIMITED SIGNIFICANT ACCCUMS OF
ICE/SNOW FROM DEVELOPING. BACK EDGE OF DEEPEST MOISTURE AND
STRONGEST SYNOPTIC SCALE LIFT IS JUST BEGINNING TO ENTER EXTREME
WESTERN OKLAHOMA AT THIS TIME.

COLD FRONT SHOULD ACCELERATE SOUTHEASTWARD AFTER MIDNIGHT AS UPPER
LOW LIFTS OUT ALLOWING ARCTIC AIR TO MOVE FASTER AND FARTHER THAN
EXPECTED INTO THE FORECAST AREA WITH SEVERAL HOURS OF SIGNIFICANT
PRECIP TO FALL INTO SUB FREEZING AIR PARTICULARLY ACROSS NORTH
CENTRAL OKLAHOMA. FOR THIS REASON RECENTLY UPDATED THE WINTER
WEATHER ADVISORY TO INCLUDE NORTH CENTRAL OKLAHOMA AND A FEW MORE
COUNTIES TO THE SOUTH. WOULD NOT BE SURPRISED TO SEE ICE PROBLEMS
DEVELOP EVEN FARTHER SOUTH INTO THE AREA LATE TONIGHT/EARLY FRIDAY
BUT WILL LEAVE THAT UP TO THE MIDNIGHT SHIFT TO DECIDE.

SQUALL LINE ACROSS THE EASTERN TEXAS PANHANDLE SHOULD PICK UP
EASTWARD SPEED AND PERHAPS INTENSITY AS IT ENCOUNTERS DEEPER
MOISTURE OVER CENTRAL TEXAS. SEVERE THUNDERSTORM WATCH ALREADY IN
EFFECT FOR PARTS OF SOUTHWEST OKLAHOMA AND WESTERN NORTH TEXAS FOR
PRIMARILY LARGE HAIL AND SEVERE WIND GUSTS.

UPDATES TO THE ZONES AND WINTER WEATHER ADVISORY HAVE ALREADY BEEN
ISSUED.

.OUN...
OK...WINTER WEATHER ADVISORY TONIGHT OKZ004>018
TX...NONE.
JAMESL

In the hours before

Local storm report, Feb 8, 10:52 PM CST, 1 hour 11 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
1052 PM CST THU FEB 08 2001

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

1025 PM    KNOX CITY                 TX   WIND DAMAGE
02/08/01   KNOX                           POWER LINES DOWN

1040 PM    KNOX CITY                 TX   WIND DAMAGE
02/08/01   KNOX                           POWER LINES DOWN

KT

Local storm report, Feb 8, 11:21 PM CST, 42 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
1121 PM CST THU FEB 08 2001

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

1120 PM    MEERS                     OK   1.00 INCH HAIL
02/08/01   COMANCHE                       AMATEUR RADIO REPORT

KT

Local storm report, Feb 8, 11:33 PM CST, 30 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
1133 PM CST THU FEB 08 2001

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

1120 PM    FREDERICK                 OK   65 MPH WIND GUST
02/08/01   TILLMAN                        REPORTED BY COUNTY
                                          EMERGENCY MANAGER

1120 PM    FREDERICK                 OK   WIND DAMAGE
02/08/01   TILLMAN                        POWER POLES BLOWN
                                          OVER...REPORTED BY
                                          COUNTY EMERGENCY
                                          MANAGER

KT

Local storm report, Feb 8, 11:46 PM CST, 17 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
1146 PM CST THU FEB 08 2001

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

1125 PM    MAYBELLE                  TX   70 MPH WIND GUST
02/08/01   BAYLOR                         AMATEUR RADIO REPORT

1125 PM    MAYBELLE                  TX   WIND DAMAGE
02/08/01   BAYLOR                         SHINGLES BLOWN OFF
                                          ROOF...AMATEUR RADIO
                                          REPORT

1139 PM    GRANDFIELD                OK   60 TO 65 MPH WIND GUST
02/08/01   TILLMAN                        AMATEUR RADIO REPORT

1142 PM    LAWTON                    OK   60 MPH WIND GUST
02/08/01   COMANCHE                       AMATEUR RADIO REPORT

KT

Local storm report, Feb 8, 11:54 PM CST, 9 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
1154 PM CST THU FEB 08 2001

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

1130 PM    3 W MEDICINE PARK         OK   68 MPH WIND GUST
02/08/01   COMANCHE                       RECORDED BY OKLAHOMA
                                          MESONET

1130 PM    3 W GRANDFIELD            OK   67 MPH WIND GUST
02/08/01   TILLMAN                        RECORDED BY OKLAHOMA
                                          MESONET

1153 PM    WICHITA FALLS             TX   58 MPH WIND GUST
02/08/01f   WICHITA                        RECORDED BY ASOS

KT

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 8, 11:35 PM CST	Severe Thunderstorm Warning	OUN	Comanche, Cotton, Tillman	40 min
Feb 9, 12:03 AM CST	Severe Thunderstorm Warning	OUN	Jefferson	42 min
Feb 9, 12:46 AM CST	Severe Thunderstorm Warning	OUN	Carter, Garvin, McClain, Stephens	59 min
Feb 9, 12:46 AM CST	Severe Thunderstorm Warning	OUN	Jefferson	59 min
Feb 9, 1:41 AM CST	Severe Thunderstorm Warning	OUN	Carter, Murray	49 min
Feb 9, 2:03 AM CST	Severe Thunderstorm Warning	OUN	Johnston, Pontotoc	42 min
Feb 9, 2:45 AM CST	Severe Thunderstorm Warning	OUN	Bryan	30 min
Feb 9, 2:58 AM CST	Severe Thunderstorm Warning	OUN	Atoka	32 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2001 Every severe thunderstorm warning in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.