Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 365, NWS Tulsa, OK

September 7, 2001Osage County, Pawnee County, Oklahoma

NWS Tulsa, OK issued this severe thunderstorm warning at Sep 7, 2001, 6:43 PM CDT for Osage County, Pawnee County, Oklahoma. It was in force for 62 min. 9 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
Sep 7, 2001, 6:43 PM CDT (23:43 UTC)
Expired
Sep 7, 2001, 7:45 PM CDT
In force
62 min
Issued by
NWS Tulsa, OK
Area
Whole counties; the outline is the Mesonet’s reconstruction

Counties Osage County, OK, Pawnee County, OK

The radar

The Tulsa radar (KINX), 95 km from the middle of the area, began a volume at 23:44 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
Sep 7, 6:45 PM CDTHail 0.75Shidler, OK
Sep 7, 6:55 PM CDTThunderstorm Wind 61 EPawnee, OKThunderstorm winds estimated at 70 miles an hour blew a tree and a few power poles down.
Sep 7, 7:10 PM CDTThunderstorm Wind 52 MForaker, OK
Sep 7, 7:20 PM CDTHail 0.75Cleveland, OK
Sep 7, 7:20 PM CDTThunderstorm Wind 57 ECleveland, OK
Sep 7, 7:30 PM CDTHail 1.75Hominy, OK
Sep 7, 7:35 PM CDTThunderstorm Wind 61 EHominy, OK
Sep 7, 7:45 PM CDTThunderstorm Wind 63 MWynona, OK
Sep 7, 7:50 PM CDTHail 0.75Maramec, OK

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.

IssuedProductOfficeLasted
Sep 7, 3:15 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 11.7 hours before the alert went out and 175 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, Norman, OK at 12:00Z on 2001-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1886 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, Norman, OK at 12:00Z on 2001-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 345 square meters per square second.19395878Sfc1 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
1886 J/kg
Mixed-layer CIN
-225 J/kg
Mixed-layer LCL
610 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
345 m²/s²
0-3 km storm-relative helicity
307 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

859 
WUUS54 KTSA 072343
SVRTUL
OKC113-117-080045-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TULSA OK
643 PM CDT FRI SEP 7 2001

THE NATIONAL WEATHER SERVICE IN TULSA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  OSAGE COUNTY IN NORTHEAST OKLAHOMA
  PAWNEE COUNTY IN NORTHEAST OKLAHOMA

* UNTIL 745 PM CDT

* AT 641 PM CDT...DOPPLER RADAR INDICATED SEVERE THUNDERSTORMS 
ALONG   A LINE EXTENDING FROM 8 MILES NORTH OF FORAKER TO 17 MILES 
SOUTHWEST OF PAWNEE...MOVING EAST AT 30 MPH.

* SOME LOCATIONS NEAR THE PATH OF THESE STORMS INCLUDE...RALSTON...
  CLEVELAND...SKEDEE...BLACKBURN...MARAMEC...HALLETT...PAWNEE...
  HULAH...FORAKER...BIGHEART...PEARSONIA...OKESA...BURBANK...
  BARNSDALL...FAIRFAX...WYNONA...AVANT...HOMINY...OSAGE...SHIDLER AND
  PAWHUSKA.

STORM SPOTTERS REPORTED QUARTER SIZE HAIL IN WEBB CITY IN OSAGE 
COUNTY.

HAIL TO THE SIZE OF GOLF BALLS AND WIND GUSTS TO 70 MPH CAN BE 
EXPECTED IN THE WARNED AREA.

A TORNADO WATCH IS ALSO IN EFFECT. TORNADOES CAN DEVELOP SUDDENLY
FROM SEVERE THUNDERSTORMS. BE ALERT FOR RAPIDLY CHANGING WEATHER
CONDITIONS.

THIS IS A DANGEROUS STORM. IF YOU ARE NEAR ITS PATH YOU SHOULD
PREPARE FOR VERY LARGE HAIL AND STRONG DAMAGING STRAIGHT LINE WINDS.
SEEK SHELTER IN A STURDY BUILDING AND STAY AWAY FROM WINDOWS

LAT...LON 3702 9656 3671 9679 3636 9696 3617 9701
          3619 9633 3619 9607 3679 9600 3703 9601

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 Tulsa, OK wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 7, 3:30 PM CDT, 3 hours 13 minutes earlier.

Area forecast discussion, Sep 7, 3:30 PM CDT, 3 hours 13 minutes before
EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
330 PM CDT FRI SEP 7 2001

WILL SEE A COUPLE OF SHOTS AT SEVERE WEATHER AND POTENTIALLY SOME
HEAVY RAIN OVER THE AREA THE NEXT FEW DAYS.  FIRST ROUND JUST NOW
BEGINNING TO THE WEST AS STRONG SHORTWAVE MOVING FROM CO/NM INTO KS
AND OK PANHANDLE STARTING TO FIRE SOME STORMS ALONG
COLDFRONT/DRYLINE.  ACTIVITY EXPECTED TO FORM INTO A SQUALL LINE
THAT WILL MOVE ACROSS THE AREA TONIGHT.  POTENTIAL FOR SEVERE
WEATHER WILL BE GREATEST OVER NORTHEAST OK THROUGH THE
EVENING...WITH STORMS EXPECTED TO BE WEAKENING SOME AS THEY MOVE
INTO NORTHWEST AR AND SOUTHEAST OK LATER TONIGHT.  ALSO SOME CONCERN
FOR HEAVY RAIN...BUT WITH DRY CONDITIONS OF THE RECENT PAST AND
STORMS MOVING QUICKLY...SHOULD SEE NO WIDESPREAD PROBLEMS.
SOMETHING TO KEEP IN MIND THOUGH IF ADDITIONAL HEAVY RAINS
MATERIALIZE SATURDAY NIGHT/SUNDAY.

FIRST SHORTWAVE WILL LIFT QUICKLY TO THE NORTHEAST TONIGHT WITH
SECOND SHORTWAVE EVIDENT ON WATER VAPOR DIVING SOUTHWARD FROM ID/MT
THROUGH THE ROCKIES.  WITH FIRST SHORTWAVE QUICKLY MOVING OFF TO THE
NORTHEAST...COLD FRONT IS EXPECTED TO HANG UP SOMEWHERE OVER THE
AREA TILL SECOND SHORTWAVE MOVES ACROSS THE AREA SATURDAY NIGHT AND
SUNDAY.

WILL GO WITH CATEGORICAL OR LIKELY POPS FOR TONIGHT...THEN CHANCE
POPS AREAWIDE DURING THE DAY ON SATURDAY.  AREA WILL BE BETWEEN THE
TWO SYSTEMS FOR MUCH OF THE DAY ON SATURDAY...BUT WITH FRONT
EXPECTED TO STRETCH ACROSS THE AREA AT LEAST SOME LOW POPS
WARRANTED.  LIKELY POPS THEN AGAIN SATURDAY NIGHT AND SUNDAY AS
SECOND SYSTEM SWINGS THROUGH THE AREA WITH POTENTIAL FOR SEVERE
WEATHER OR HEAVY RAIN POSSIBLE AGAIN.

BEYOND SUNDAY...FORECAST LOOKS DRY AS UPPER RIDGE BUILDS BACK IN.

FCSTID = 4
TUL   68  85  68  75 /  80  30  70  60
FSM   68  88  70  78 /  70  40  60  70
MLC   71  88  70  77 /  70  40  60  70
BVO   66  82  65  73 /  80  30  70  60
FYV   68  84  66  74 /  80  40  70  70
BYV   69  84  67  74 /  80  40  70  70
MIO   68  84  66  74 /  80  30  70  60
MKO   68  85  68  75 /  80  30  70  60
F10   68  85  68  75 /  80  30  70  60
HHW   72  88  70  78 /  60  30  60  70

.TSA...
AR...NONE.
OK...NONE.

In the hours before

Special weather statement, Sep 7, 1:05 PM CDT, 5 hours 38 minutes before
ARZ001-002-010-011-019-020-029-OKZ049-053>076-081100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
105 PM CDT FRI SEP 7 2001

...NUMEROUS SEVERE THUNDERSTORMS ARE EXPECTED IN PARTS OF NORTHEAST
OKLAHOMA THIS EVENING...

...A FEW SEVERE THUNDERSTORMS ARE EXPECTED ACROSS THE REST OF
EASTERN OKLAHOMA AND NORTHWEST ARKANSAS TONIGHT...

A STRONG UPPER LEVEL STORM SYSTEM LOCATED OVER SOUTHEAST COLORADO
EARLY THIS AFTERNOON WILL MOVE EAST INTO THE OKLAHOMA PANHANDLE BY
THE LATE AFTERNOON HOURS BEFORE LIFTING RAPIDLY NORTHEAST AND
WEAKENING OVERNIGHT. SURFACE LOW PRESSURE WILL DEEPEN BY LATE
AFTERNOON ALONG THE OKLAHOMA/KANSAS BORDER NORTH OF ENID AND MOVE
NORTHEAST TO SOUTHERN IOWA LATE TONIGHT. A COLD FRONT WILL EXTEND
SOUTHWEST FROM THE LOW AND WILL MOVE SLOWLY EAST INTO NORTHEAST
OKLAHOMA TONIGHT.

SEVERE THUNDERSTORMS ARE EXPECTED TO DEVELOP IN NORTH CENTRAL
OKLAHOMA AND SOUTHERN KANSAS LATE THIS AFTERNOON AND MOVE NORTHEAST
INTO NORTHEAST OKLAHOMA THIS EVENING. LARGE HAIL TO BASEBALL
SIZE...DAMAGING WINDS TO 80 MILES AN HOUR AND ISOLATED TORNADOES MAY
OCCUR TO THE WEST OF A BARTLESVILLE TO BRISTOW LINE BETWEEN 6 PM AND
11 PM THIS EVENING. THE BEST CHANCE FOR TORNADOES IN THE OUTLOOKED
AREA WILL BE BETWEEN 6 AND 9 PM.

THUNDERSTORMS WILL WEAKEN TOWARDS MIDNIGHT AS THE UPPER LEVEL STORM
MOVES NORTHEAST AWAY FROM THE AREA. HOWEVER...A FEW STORMS WILL
STILL LIKELY PRODUCE DAMAGING WIND GUSTS OF 60 TO 70 MILES AN HOUR
LATER TONIGHT AS THEY MOVE EAST INTO NORTHWEST ARKANSAS AND
SOUTHEAST OKLAHOMA.

.SPOTTER ACTIVATION...
EMERGENCY MANAGEMENT AGENCIES AND STORM SPOTTER GROUPS IN NORTHEAST
OKLAHOMA WILL LIKELY NEED TO BE ACTIVATED BY 6 PM THIS EVENING.
SPOTTER ACTIVATION WILL BE LIKELY AFTER 11 PM IN NORTHWEST ARKANSAS
AND SOUTHEAST OKLAHOMA.

THE COLD FRONT IS EXPECTED TO STALL ACROSS NORTHEAST OKLAHOMA
SATURDAY AS ANOTHER UPPER LEVEL STORM APPROACHES FROM THE WEST.
SEVERE THUNDERSTORMS WILL LIKELY REDEVELOP ACROSS EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS LATE SATURDAY AFTERNOON AND CONTINUE INTO
SATURDAY NIGHT.

.DISCUSSION...
CLOUDS WILL CONTINUE TO BREAK UP THIS AFTERNOON ALLOWING STRONG
HEATING WITH TEMPERATURES WARMING INTO THE 90S AHEAD OF THE COLD
FRONT. WARM TEMPERATURES ALOFT WILL PREVENT THUNDERSTORM DEVELOPMENT
IN EASTERN OKLAHOMA AND NORTHWEST ARKANSAS DURING THE AFTERNOON.
COOLING ALOFT ASSOCIATED WITH THE STRONG UPPER LEVEL SYSTEM AND
STRONG CONVERGENCE EAST OF THE SURFACE LOW AND ALONG THE COLD FRONT
WILL RESULT IN EXPLOSIVE THUNDERSTORM DEVELOPMENT LATER THIS
AFTERNOON...ROUGHLY ALONG AN ENID OKLAHOMA TO WICHITA KANSAS LINE.

THESE STORMS WILL QUICKLY BECOME SEVERE WITH THE POTENTIAL FOR
SUPERCELLULAR STORMS WITH VERY LARGE HAIL...DAMAGING WINDS AND
POSSIBLY ISOLATED TORNADOES. THESE STORMS WILL MOVE NORTHEAST INTO
WESTERN SECTIONS OF OSAGE AND PAWNEE COUNTIES BY EARLY EVENING.

AS THE EVENING WEARS ON...STORMS WILL BECOME MORE LINEAR IN NATURE
WITH A GRADUAL WEAKENING TREND. THE LARGE HAIL AND TORNADO THREAT
WILL END BY AROUND MIDNIGHT...BUT DAMAGING WINDS WILL REMAIN LIKELY
WITH A FEW STORMS WELL PAST MIDNIGHT.

THREAT TABLE
VALID THROUGH 7 AM SATURDAY

THREAT AREA 1...WEST OF A LINE FROM BARTLESVILLE TO BRISTOW
THUNDERSTORM PROBABILITY...100
SEVERE PROBABILITY IF STORMS OCCUR...100
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...80

THREAT AREA 2...WEST OF A LINE FROM JAY TO OKMULGEE
THUNDERSTORM PROBABILITY...100
SEVERE PROBABILITY IF STORMS OCCUR...100
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...60

THREAT AREA 3...EAST OF A LINE FROM JAY TO OKMULGEE
THUNDERSTORM PROBABILITY...80
SEVERE PROBABILITY IF STORMS OCCUR...60
SIGNIFICANT SEVERE PROBABILITY IF STORMS OCCUR...30

THREAT AREAS DEFINE THE GREATEST RISK. PROBABILITIES ARE IN PERCENT.
SIGNIFICANT SEVERE IS DEFINED AS F1 OR GREATER WIND/TORNADO DAMAGE
AND/OR GOLFBALL SIZE HAIL OR LARGER.

.OTHER HAZARDS...
A WIND ADVISORY IS IN EFFECT FOR MOST OF NORTHEAST OKLAHOMA THIS
AFTERNOON. REFER TO /OKCNPWTUL/ FOR FURTHER INFORMATION ON THE WIND
ADVISORY.

RELATED GRAPHICAL INFORMATION CAN BE FOUND AT:
WWW.SRH.NOAA.GOV/TULSA
Local storm report, Sep 7, 6:42 PM CDT, 1 minute before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
642 PM CDT FRI SEP 07 2001

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

0635 PM    WEBB CITY                 OK    1 INCH HAIL
09/07/01   OSAGE                           QUARTER SIZE HAIL.
                                           PUBLIC REPORT.

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 7, 5:43 PM CDTSevere Thunderstorm WarningTSAOsage62 min
Sep 7, 6:13 PM CDTSevere Thunderstorm WarningTSAPawnee47 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2001Every 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; radar from the NEXRAD Level II archive.