Severe Thunderstorm Warning 256, NWS Norman, OK

AREA FORECAST DISCUSSION...UPDATED...
NATIONAL WEATHER SERVICE NORMAN OK
800 PM CDT THU MAY 8 2003

OVERALL AFTN FORECAST IN GOOD SHAPE. WILL SEND A QUICK UPDATE
TO MAKE SOME MINOR CHANGES TO POPS AND WINDS. DRY LINE REMAINS TO
THE WEST OF THE OKC METRO AND THERE HAVE BEEN PERIODIC ATTEMPTS TO
GET SOME TOWERING CU TO GO ON THE DRY LINE. TO OUR SOUTH THERE ARE
SOME STORMS GOING ON THE DRY LINE IN NORTH TEXAS SO WILL KEEP POPS
GOING FOR AREAS TO THE EAST OF DRY LINE FOR REMAINDER OF EVENING
WITH SEVERE WORDING IN ZONES. UPDATES OUT SHORTLY.

30

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334 PM CDT THU MAY 8 2003

UPDATED TO ISSUE WIND ADVISORY FOR NW OK FROM 4 UNTIL 7 PM THIS
EVENING. REMAINDER OF FORECAST REASONING REMAINS UNCHANGED.
 MILLER

.OUN...
OK...WIND ADVISORY UNTIL 7 PM THIS EVENING OKZ004-005-009-010.
TX...NONE.
****************************
219 PM CDT THUS MAY 8 2003

...POTENTIAL FOR A SIGNIFICANT SEVERE WEATHER OUTBREAK INCLUDING
SUPERCELLS AND TORNADOES ACROSS THE CENTRAL THIRD OF OKLAHOMA DURING
THE NEXT 3-9 HOURS...

MID/UPPER LEVEL TROF AND SFC LOW CONT TO RAPIDLY DEEPEN OVER WRN
KS/ERN CO EARLY THIS AFTERNOON.. AND THERE IS SUBTLE EVIDENCE OF A
SECONDARY IMPULSE PUSHING EWD ACROSS NEW MEXICO. 18Z OUN SOUNDING
INDICATES THAT CAPPING IS MUCH WEAKER THAN PREVIOUSLY EXPECTED ALONG
DRYLINE ACROSS MOST OF OKLAHOMA.  POTENT THERMODYNAMIC PROFILE IS
EVIDENT WITH VERY HIGH BOUNDARY LAYER MOISTURE CONTENT.. LOW LCL
HGHTS AND STEEP MID LEVEL LAPSE RATES. IN ADDITION..THE HODOGRAPH
SHOWS SIGNIFICANT LOW LEVEL AND DEEP LAYER SHEAR IN PLACE.. HILITED
BY A DISTINCT KINK IN THE HODOGRAPH AT ABOUT 1.5 KM AGL. THIS TYPE
OF LOW LEVEL SHEAR PROFILE IN COMBINATION WITH ABOVE MENTIONED
THERMODYNAMICS HAS OFTEN BEEN ASSOCIATED WITH ENVIRONMENTS
SUPPORTIVE OF LONG LIVED STRONG/VIOLENT TORNADOES.  EXPECT
INITIATION INVOF THE DRYLINE WITHIN THE NEXT COUPLE HOURS WITH
SUPERCELL DEVELOPMENT LIKELY.  SVR THREAT WILL LIKELY CONTINUE WELL
INTO THE NITE AS STRONG UVVS CONT ALONG DRYLINE UNTIL AT LEAST 06Z
ACROSS MUCH OF OKLAHOMA.  LIKELY TO SEE DEVELOPMENT SWD INTO TEXAS
LATER THIS AFT/EVE.

INSTABILITY AXIS WILL RELOAD FRIDAY OVER THE SE ZONES.. AND THEN
EXPAND NWWD INTO REDEVELOPING WARM FRONTAL ZONE FRIDAY NITE.  HAVE
READJUSTED POPS TO ACCOUNT FOR THIS THINKING.  NEXT WAVE WILL EJECT
ONTO THE PLAINS SATURDAY.. BUT MAIN FOCUS FOR ACTIVITY WITH THIS
WAVE LOOKS TO BE NORTHEAST OF THE OUN CWA ATTM. HOWEVER..STILL
LIKELY TO SEE AT LEAST A FEW STORMS ALONG/SE OF I44 CORRIDOR AHEAD
OF DRYLINE/FRONT.  IT APPEARS THAT LOW LEVEL RIDGING WILL FINALLY
BUILD SWD FAR ENUF SUNDAY INTO MONDAY TO ALLOW FOR A BRIEF RESPITE
FROM STORMS..BUT TROPICAL BOUNDARY LAYER AIR WILL BE LURKING CLOSE
BY AND SHUD MOVE BACK NWD MONDAY/TUES AS LONG WAVE TROF RELOADS OVER
THE WRN CONUS.  WE WILL BRING SLGT CHC POPS BACK INTO THE SW ZONES
MONDAY AFTERNOON WITH ONSET OF MOISTURE RETURN.. AND THEN
EXPAND/INCREASE POPS ACROSS THE REST OF THE AREA THRU MID WEEK.
MORE BOUTS OF SVR STORMS SEEM LIKELY AS SIGNIFICANT INSTABILITY AXIS
REMAINS SUPERIMPOSED UNDERNEATH STRONG MID LEVEL FLOW.
 MILLER

OKC   64  89  67  84 /  60  20  20  30
HBR   59  91  64  88 /  10  20  20  20
SPS   66  94  68  92 /  50  30  20  30
GAG   51  89  57  82 /  10  30  30  10
PNC   64  85  67  82 /  60  20  40  20
DUA   71  88  72  88 /  60  20  20  40

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

OKZ004>048-050>052-TXZ083>090-091200-

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE NORMAN OK
920 PM CDT THU MAY 8 2003

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

...MORE SEVERE THUNDERSTORMS STILL POSSIBLE THIS EVENING AND
OVERNIGHT...

THUNDERSTORM OUTLOOK...
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THROUGH TONIGHT
ACROSS PORTIONS OF NORTHERN...CENTRAL...AND SOUTHERN OKLAHOMA...AND
WESTERN NORTH TEXAS.

LOCATION...
THE SLIGHT RISK AREA IS MAINLY ALONG AND EAST OF A LINE FROM
WAKITA...TO HINTON...TO FREDERICK...TO SEYMOUR TEXAS.

TIMING...
SEVERE THUNDERSTORMS COULD DEVELOP AT ANY TIME THIS EVENING AND
OVERNIGHT.

IMPACTS...
SOME OF THE THUNDERSTORMS WILL BE CAPABLE OF PRODUCING HAIL TO THE
SIZE OF BASEBALLS. WIND GUSTS TO 75 MPH AND TORNADOES WILL ALSO BE
POSSIBLE.

RECOMMENDED ACTIONS...
STORM SPOTTER GROUPS AND EMERGENCY MANAGEMENT PERSONNEL ACROSS THE
RISK AREA SHOULD BE PREPARED FOR POSSIBLE SEVERE WEATHER OPERATIONS
FOR THE REMAINDER OF THIS EVENING...AND OVERNIGHT.

DISCUSSION...
A DRY LINE WAS POSITIONED ALONG THE WESTERN EDGE OF THE SLIGHT RISK
AREA...AND IS EXPECTED TO MOVE LITTLE THROUGH THE NIGHT. WITH A VERY
MOIST AND UNSTABLE AIRMASS EAST OF THE DRY LINE...ALONG WITH
FAVORABLE WIND SHEAR PARAMETERS...ISOLATED TO SCATTERED SEVERE
THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE THROUGH TONIGHT.
SUPERCELLS...CAPABLE OF PRODUCING LARGE DESTRUCTIVE HAIL...AND
TORNADOES ARE POSSIBLE.

PROBABILITY TABLE...
VALID THROUGH 700 AM CDT FRIDAY MAY 9.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...40 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR...80 PERCENT.

OTHER HAZARDOUS WEATHER...
NONE.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY...

THUNDERSTORM OUTLOOK...
THUNDERSTORMS ARE POSSIBLE EACH DAY THROUGH WEDNESDAY.  THE DAYS
WITH THE GREATEST RISK OF SEVERE STORMS WILL BE FRIDAY AND
SATURDAY...PRIMARILY EAST OF I-35...AND NEXT TUESDAY AND WEDNESDAY
ACROSS THE ENTIRE AREA.

OTHER HAZARDOUS WEATHER...
NONE.

THE NEXT SCHEDULED HAZARDOUS WEATHER OUTLOOK WILL BE ISSUED AT 7 AM
FRIDAY.

GRAPHICAL OUTLOOKS ARE AVAILABLE ON THE WEB AT
HTTP://WWW.SRH.NOAA.GOV/OUN

11

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
737 PM CDT THU MAY 08 2003

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

0517 PM    OKLAHOMA CITY             OK   TORNADO
05/08/03   OKLAHOMA                       TORNADO ON GROUND AT HWY 77
                                          & 240, REPORTED BY HAM
                                          RADIO SPOTTER

0550 PM    4 S HARRAH                OK   TORNADO
05/08/03   OKLAHOMA                       TORNADO ON GROUND.
                                          REPORTED BY HAM RADIO
                                          SPOTTER

0600 PM    1 N JACKTOWN              OK   TORNADO
05/08/03   LINCOLN                        TORNADO ON GROUND.
                                          REPORTED BY HAM RADIO
                                          SPOTTER

0545 PM    MCCLOUD                   OK   TORNADO
05/08/03   POTTAWATOMIE                   MULTIPLE VORTEX TORNADO ON
                                          GROUND.  REPORTED BY HAM
                                          RADIO SPOTTER

0530 PM    MIDWEST CITY              OK   TORNADO ON GROUND
05/08/03   OKLAHOMA                       MULTIPLE HOUSES HEAVILY DAMAGED,
                                          POWER LINES DOWNED.  DAMAGE
                                          REPORTED BY NWS EL TECH.

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
801 PM CDT THU MAY 08 2003

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

0522 PM    3 S DEL CITY              OK   TORNADO
05/08/03   OKLAHOMA                       DAMAGE REPORTED AT GENERAL
                                          MOTORS PLANT.  REPORTED BY
                                          SPOTTER

0539 PM    CHOCTAW                   OK   TORNADO
05/08/03   OKLAHOMA                       REPORTED BY SPOTTER

OKZ030-090345-

SIGNIFICANT WEATHER ADVISORY
NATIONAL WEATHER SERVICE NORMAN OK
1025 PM CDT THU MAY 8 2003

THIS SIGNIFICANT WEATHER ADVISORY IS FOR POTTAWATOMIE COUNTY.

A LINE OF SEVERE THUNDERSTORMS WAS LOCATED FROM 7 MILES SOUTHWEST OF
WANETTE...TO 19 MILES SOUTHWEST OF WANETTE AT 1025 PM CDT...MOVING
NORTHEAST AT 35 MPH.

PEOPLE IN POTTAWATOMIE COUNTY SHOULD MONITOR THIS STORM CLOSELY.
LISTEN FOR WARNINGS AND WATCH FOR THREATENING WEATHER CONDITIONS AS
THIS STORM APPROACHES.

11

TXZ089-090-090430-

SIGNIFICANT WEATHER ADVISORY
NATIONAL WEATHER SERVICE NORMAN OK
1103 PM CDT THU MAY 8 2003

THIS SIGNIFICANT WEATHER ADVISORY IS FOR ARCHER AND CLAY COUNTIES.

A SEVERE THUNDERSTORM WAS LOCATED NEAR BRYSON AND JACKSBORO AT
11 PM...MOVING NORTHEAST AT 35 MPH. ADDITONAL THUNDERSTORMS MAY
DEVELOP OVER...OR MOVE INTO...ARCHER AND CLAY COUNTIES OVER THE NEXT
2 HOURS.

PEOPLE IN ARCHER AND CLAY COUNTIES SHOULD MONITOR THIS ACTIVITY
CLOSELY. LISTEN FOR WARNINGS AND WATCH FOR THREATENING WEATHER
CONDITIONS AS STORMS APPROACH.

11

OKZ031-090415-

SIGNIFICANT WEATHER ADVISORY
NATIONAL WEATHER SERVICE NORMAN OK
1107 PM CDT THU MAY 8 2003

THIS SIGNIFICANT WEATHER ADVISORY IS FOR SEMINOLE COUNTY.

A SEVERE THUNDERSTORM WAS LOCATED IN SOUTHEAST POTTAWATOMIE
COUNTY... MOVING NORTHEAST AT 30 MPH. IF THIS STORM CONTINUES ITS
CURRENT MOVEMENT AND STRENGTH... A SEVERE THUNDERSTORM WARNING MAY
BE REQUIRED FOR SEMINOLE COUNTY BY 1120 PM.

PEOPLE IN SEMINOLE COUNTY SHOULD MONITOR THIS STORM CLOSELY. LISTEN
FOR WARNINGS AND WATCH FOR THREATENING WEATHER CONDITIONS AS THIS
STORM APPROACHES.

CJS

OKZ032-090445-

SIGNIFICANT WEATHER ADVISORY
NATIONAL WEATHER SERVICE NORMAN OK
1124 PM CDT THU MAY 8 2003

THIS SIGNIFICANT WEATHER ADVISORY IS FOR HUGHES COUNTY.

A SEVERE THUNDERSTORM WAS LOCATED 16 MILES SOUTHWEST OF HOLDENVILLE
AT 1124 PM CDT...MOVING EAST-NORTHEAST AT 40 MPH. THIS STORM IS
CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS. WARNINGS FOR
HUGHES COUNTY ARE LIKELY DURING THE HOUR OR SO.

PEOPLE IN HUGHES COUNTY SHOULD MONITOR THIS STORM CLOSELY. LISTEN FOR
WARNINGS AND WATCH FOR THREATENING WEATHER CONDITIONS AS THIS STORM
APPROACHES.

11