Severe Thunderstorm Warning 293, NWS Norman, OK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
845 PM CDT FRI MAY 9 2003

WILL MAKE A QUICK UPDATE. WILL NOT MAKE ANY MAJOR CHANGES AT THIS
POINT...BUT WILL REFOCUS SEVERE THREAT ACROSS CENTRAL INTO NORTHERN
OKLAHOMA FOR THIS EVENING AND DROP POPS BACK SLIGHTLY ACROSS THE
SOUTH. OTHERWISE ONLY MINOR CHANGES TO WINDS...SKIES AND TEMPS.
UPDATES OUT SHORTLY.

30

---------------------------------------------------------

147 PM CDT FRI MAY 9 2003

WELL DEFINED S/W TROF EVIDENT IN 12Z UA DATA OVER NEW MEXICO APPEARS
TO BE AMPLIFYING PER BAND 10 WV IMAGERY FROM RAMSDIS OVER FAR WTEX
ATTM. PRESSURE FALLS ARE NOW INCREASING OVER NW OK..AND SFC WINDS
HAVE BACKED 40-60 DEGREES IN THE PAST COUPLE OF HRS OVR SW OK.  AS
OF YET..SIGNIFICANT BOUNDARY LAYER MOISTURE HAS NOT WORKED BACK
NWWD..BUT EXPECT SIGNIFICANT AIRMASS DESTABILIZATION DURING THE NEXT
SEVERAL HOURS OVER MUCH OF SW OK/NW TX AS WINDS CONT TO
BACK/INCREASE.  FIRST ATTEMPT AT SUSTAINED BL BASED CONVECTION
APPEARS TO HAVE FAILED FOR THE MOMENT TO THE WEST OF KABI..BUT
INCREASING LOW LEVEL VERTICAL VELOCITIES IS EXPECTED TO RESULT IN
RAPID SVR STORM DEVELOPMENT LATE THIS AFTERNOON.  OTHER CONCERN FOR
THE OVERNIGHT HOURS IS THE POTENTIAL FOR CONVECTION TO DEVELOP THIS
EVENING ON THE HI PLAINS AND THEN SPREAD EAST/SOUTEAST ALONG AND
NORTH OF WARM FRONTAL ZONE THAT IS EXPECTED TO BECOME BETTER DEFINED
ACROSS NRN OK OR SRN KS.

SFC LOW WILL MOVE TO THE NORTHEAST OF OKLAHOMA RATHER QUICKLY ON
SATURDAY..AND SHUD RESULT IN VEERING LOW LEVEL FLOW.  ALTHOUGH
MOISTURE MAY BE SOMEWHAT SLOW TO MIX OUT IN THE SE ZONES..POTENTIAL
FOR STORM INITIATION APPEARS TO BE LIMITED WITHIN THE BOUNDS OF OUR
CWA.  DEEP MOISTURE SHUD FINALLY GET PUSHED SWD INTO TEXAS IN WAKE
OF THIS SYSTEM..GIVING A 36-48 HR BREAK IN THUNDERSTORM CHANCES.
HOWEVER..MOISTURE MAY BEGIN TO LEAK BACK NWD ENUF LATE MONDAY TO
ALLOW FOR STORM DEVELOPMENT OVR NW/W TEXAS.

LATEST MEDIUM RANGE MODEL GUIDANCE HINTS THAT A PERIOD OF WNW FLOW
ALOFT MAY BECOME ESTABLISHED OVER THE CENT/SRN PLAINS MID WEEK IN
WAKE OF STRONG GREAT LAKES SYSTEM..AND BEFORE WEST COAST TROF
RELOADS BY LATE IN THE WEEK.  CHANCES FOR STORMS WILL INCREASE
TUE/WED AS INSTABILITY AXIS BECOMES RE-ESTABLISHED ONCE AGAIN A BIT
FARTHER NORTH BENEATH AXIS OF STRONGER MID LEVEL FLOW. IF NRLY
COMPONENT TO MID LEVEL FLOW DOES DEVELOP..PATTERN WILL BECOME
FAVORABLE FOR FORWARD PROPAGATING SVR MCS DEVELOPMENT FROM THE HI
PLAINS SEWD INTO THE SRN PLAINS.
 MILLER

OKC   66  83  50  78 /  40  20  10   0
HBR   58  84  46  80 /  40  10  10  10
SPS   67  90  53  82 /  40  20  10  10
GAG   49  75  39  77 /  30  10  10   0
PNC   67  81  48  75 /  40  20  10   0
DUA   70  88  57  83 /  40  30  10  10

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

OKZ004>048-050>052-TXZ083>090-101200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
1200 PM CDT FRI MAY 9 2003

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

.DAY ONE...THIS AFTERNOON AND TONIGHT...

THUNDERSTORM OUTLOOK...
THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THROUGH TONIGHT
ACROSS MOST OF OKLAHOMA. A SLIGHT RISK AREA SURROUNDS THE MODERATE
RISK AND AFFECTS MUCH OF FAR WESTERN AND SOUTHERN OKLAHOMA... AND
WESTERN NORTH TEXAS.

LOCATION...
THE MODERATE RISK AREA IS EAST OF A LINE FROM ALVA TO ALTUS... AND
NORTH OF A LINE FROM ALTUS TO ARDMORE TO COALGATE.  THE SLIGHT RISK
AREA INCLUDES THE REST OF OKLAHOMA... AND WESTERN NORTH TEXAS.

TIMING...
ISOLATED SEVERE STORMS WILL BE POSSIBLE EARLY THIS AFTERNOON IN
EXTREME SOUTHWEST OKLAHOMA AND ADJACENT PARTS OF TEXAS. MORE-
SIGNIFICANT STORMS ARE EXPECTED TO DEVELOP BY LATE AFTERNOON AND
CONTINUE WELL INTO THE NIGHT.

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. SIGNIFICANT STRUCTURAL DAMAGE WILL BE POSSIBLE IN THE
STRONGEST STORMS.

RECOMMENDED ACTIONS...
STORM SPOTTER GROUPS AND EMERGENCY MANAGEMENT PERSONNEL ACROSS THE
RISK AREA SHOULD BE PREPARED FOR SEVERE WEATHER OPERATIONS THIS
AFTERNOON THROUGH LATE TONIGHT.

DISCUSSION...
THE MAIN SURFACE FEATURE IS A DRYLINE THAT EXTENDED FROM NEAR ENID
OKLAHOMA TO NEAR VERNON TEXAS LATE THIS MORNING. THE DRYLINE IS
FORECAST TO DRIFT FARTHER WEST DURING THE AFTERNOON... PROBABLY
EXTENDING FROM NORTHWEST OKLAHOMA TO NEAR CHILDRESS BY LATE
AFTERNOON. A MID-LEVEL WAVE OVER SOUTHWEST TEXAS THIS MORNING WILL
ADVANCE TO THE NORTHEAST THIS AFTERNOON... AND WILL LIKELY PROVIDE
ADDITIONAL LIFT IN THE VICINITY OF THE DRYLINE. STORMS ARE EXPECTED
TO BECOME MORE NUMEROUS AND INCREASE IN INTENSITY DURING THE MID- TO
LATE-AFTERNOON HOURS AS THESE FEATURES COME TOGETHER. A CONTINUING
FEED OF LOW-LEVEL MOISTURE OVER THE RISK AREAS... ALONG WITH
FAVORABLE WIND PROFILES... WILL LIKELY SUSTAIN THE STORMS INTO THE
NIGHT.

PROBABILITY TABLE...
VALID THROUGH 700 AM CDT SATURDAY MAY 10.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...100 PERCENT.
PROBABILITY OF SEVERE STORMS...NEAR 100 PERCENT.

OTHER HAZARDOUS WEATHER...
NONE.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY...

THUNDERSTORM OUTLOOK...
THUNDERSTORMS ARE POSSIBLE SATURDAY AND THEN EACH DAY FROM MONDAY
THROUGH THURSDAY. THE DAYS WITH THE GREATEST RISK OF SEVERE STORMS
WILL BE NEXT TUESDAY AND WEDNESDAY ACROSS THE ENTIRE AREA.

OTHER HAZARDOUS WEATHER...
NONE.

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

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

CMS

OKZ024-025-028-029-100235-

SIGNIFICANT WEATHER ADVISORY
NATIONAL WEATHER SERVICE NORMAN OK
918 PM CDT FRI MAY 9 2003

THIS SIGNIFICANT WEATHER ADVISORY IS FOR
CANADIAN...CLEVELAND...MCCLAIN AND OKLAHOMA COUNTIES.

UPDATE...AT 918 PM...THE LARGE SEVERE SUPERCELL THUNDERSTORM...
CAPABLE OF PRODUCING A TORNADO...WAS 13 MILES WEST OF UNION CITY...
MOVING EAST AT 25 MPH. THIS IS A RECENT JOG TO THE NORTH FROM IT
PREVIOUS POSITION. ON ITS PRESENT COURSE...THE CENTER OF THE
MESOCYCLONE COULD MOVE INTO EASTERN CANADIAN AND WESTERN OKLAHOMA
COUNTIES...INCLUDING YUKON...MUSTANG...WILL ROGERS WORLD
AIRPORT...AND BETHANY...BETWEEN 945 AND 1000 PM. NEWCASTLE AND MOORE
ARE STILL NOT CLEAR OF THIS THREAT HOWEVER...AND NEED TO MONITOR
THIS CLOSELY.

PEOPLE IN THESE AREAS...NEED TO MONITOR THIS STORM CLOSELY. LISTEN
FOR WARNINGS AND WATCH FOR THREATENING WEATHER CONDITIONS AS THIS
STORM APPROACHES.

JAMES

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
923 PM CDT FRI MAY 09 2003

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

0920 PM    1 SW CUSTER CITY          OK   1.00 INCH HAIL
05/09/03   CUSTER                         REPORTED BY THE PUBLIC

0923 PM    3 NE COGAR                OK   TORNADO
05/09/03   CADDO                          REPORTED BY A SPOTTER

SBS

OKZ025-028-029-100250-

SIGNIFICANT WEATHER ADVISORY
NATIONAL WEATHER SERVICE NORMAN OK
933 PM CDT FRI MAY 9 2003

THIS SIGNIFICANT WEATHER ADVISORY IS FOR CLEVELAND...MCCLAIN AND
OKLAHOMA COUNTIES.

UPDATE...AT 933 PM CDT...TERMINAL DOPPLER WEATHER RADAR INDICATES
AND STORM SPOTTERS OBSERVED A TORNADO 7 MILES WEST OF UNION
CITY...MOVING EAST-NORTHEAST AT 25 MPH. ON IT PRESENT COURSE...THE
CENTER OF THE MESOCYCLONE WILL MOVE INTO YUKON BY 950 PM...AND
TO NEAR BETHANY BY 1005 PM.

PEOPLE IN THESE AREAS...SHOULD PREPARE IN ADVANCE FOR THIS
POTENTIALLY LIFE THREATENING SITUATION. LISTEN FOR WARNINGS AND
WATCH FOR THREATENING WEATHER CONDITIONS AS THIS STORM APPROACHES.

JAMES

OKZ019-100300-

SIGNIFICANT WEATHER ADVISORY
NATIONAL WEATHER SERVICE NORMAN OK
944 PM CDT FRI MAY 9 2003

THIS SIGNIFICANT WEATHER ADVISORY IS FOR LOGAN COUNTY.

UPDATE...AT 943 PM CDT...A THUNDERSTORM WITH A HISTORY OF PRODUCING
TORNADOES WAS LOCATED 3 MILES NORTHWEST OF UNION CITY IN SOUTHERN
CANADIAN COUNTY...MOVING NORTHEAST AT 25 MPH. ALTHOUGH THE
MESOCYCLONE ASSOCIATED WITH THE TORNADO IS A CONSIDERABLE DISTANCE
FROM LOGAN COUNTY...LARGE HAIL COULD FALL WELL IN ADVANCE OF THE
APPROACHING THUNDERSTORM.

PEOPLE IN SOUTHERN LOGAN COUNTY...INCLUDING NAVINA...SEWARD...
GUTHRIE...AND MERIDIAN...SHOULD MONITOR THIS STORM CLOSELY. LISTEN
FOR WARNINGS AND WATCH FOR THREATENING WEATHER CONDITIONS AS THIS
STORM APPROACHES.

JAMES

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
1003 PM CDT FRI MAY 09 2003

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

1001 PM    7 W OKLAHOMA CITY         OK   TORNADO
05/09/03   OKLAHOMA                       REPORTED BY A HAM RADIO
                                          SPOTTER

SBS

OKZ026-100330-

SIGNIFICANT WEATHER ADVISORY
NATIONAL WEATHER SERVICE NORMAN OK
1019 PM CDT FRI MAY 9 2003

THIS SIGNIFICANT WEATHER ADVISORY IS FOR LINCOLN COUNTY.

AT 1019 PM...A TORNADIC SUPERCELL THUNDERSTORM WAS LOCATED OVER WARR
ACRES...JUST WEST OF OKLAHOMA CITY...MOVING NORTHEAST AT 30 MPH. ON
ITS CURRENT PATH...THE CENTER OF THE MESOCYCLONE ASSOCIATED WITH THE
TORNADO WILL CLOSELY PARALLEL THE TURNER TURNPIKE...AND ENTER
WESTERN LINCOLN COUNTY...NEAR LUTHER...AT APPROXIMATELY 10 PM.

DAMAGE HAS ALREADY BEEN CAUSED BY A TORNADO.

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

JAMES