Severe Thunderstorm Warning 191, NWS Norman, OK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
930 PM CDT APR 29 2003

WILL DROP THE POPS BACK FROM THE HIGHER POPS THAT WERE INTRO EARLIER
THIS EVENING. LINE OF STRONGER STORMS WILL CONT TO SKIRT THE RED
RIVER WITH ANOTHER AREA OF WEAKER STORMS ACROSS NW OK. WITH LOW
LEVEL JET KICKING IN THIS EVENING BOTH AREAS COULD LINGER FOR A
WHILE...BUT THINK ANY SEVERE POTENTIAL WILL REMAIN ALONG AND SOUTH
OF RED RIVER. OTHER THAN CHANGES TO POPS GOING FORECAST IN GOOD
SHAPE. UPDATES OUT SHORTLY.

30

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

136 PM CDT TUE APR 29 2003

ACTIVE WX PATTERN WILL AFFECT THE SRN PLAINS DURING THE NEXT WEEK
WITH SEVERAL OPPORTUNITIES FOR SVR STORMS.  WEAK WARM FRONTAL
BOUNDARY OVER NCENT OK RAPIDLY MIXED NWD EARLIER THIS MORNING..
LEAVING THE ENTIRE CWA IN THE WARM SECTOR. AIRMASS CONTINUES TO
DESTABILIZE WITH DRYLINE NOW SHARPENING UP NICELY OVER THE ERN TX/OK
PANHANDLES.  HIGH-BASED CU EVIDENT IN VIS SAT IMAGERY AT 1745Z SW OF
KLBB GIVES HIGHER CONFIDENCE OF INITIATION ALONG THE DRYLINE THIS
AFTERNOON/EVE. /NOTE TO RADAR USERS - ECHOES EVIDENT ON KLBB/KAMA
WEST OF CLOVIS NM ARE NOT METEOROLOGICAL./ ALTHOUGH DEEP LAYER SHEAR
IS NOT PARTICULARLY STRONG..GIVEN CAPE AOA 2K J/KG EAST OF
DRYLINE..0-6KM SHEAR FROM 30-35 KTS SHUD BE SUFFICIENT TO SUPPORT
SUPERCELLS FROM WTEX NWD INTO WRN KS AND POSSIBLY FAR WRN OK. ANY
SUPERCELLS ARE LIKELY TO BE RATHER SLOW MOVING AND OF THE HP
VARIETY..WITH A POTENTIAL TO PRODUCE VERY LARGE HAIL GIVEN 500 TEMPS
NEAR -15C.

STRONG EWD PUSH ON THE DRYLINE EXPECTED WED AS UPPER SYSTEM EJECTS
INTO THE MISSOURI VALLEY.  ATTM..IT APPEARS THAT THE BEST CHANCES
FOR WIDESPREAD SVR STORMS WILL BE TO THE NORTHEAST OF THE OUN CWA.
ALTHOUGH WE CERTAINLY CANNOT RULE OUT LATE AFTERNOON DRYLINE
STORMS..CAPPING SHUD BE QUITE STRONG THIS FAR SOUTH.  VEERING LOW
LEVEL FLOW MAY ALSO ACT TO LIMIT MASS CONVERGENCE NEAR THE DRYLINE
UNTIL EARLY EVENING WHEN LOW LEVEL WINDS WILL BACK AND CONVERGENCE
INCREASES AS TRIPLE POINT ZIPPERS SWD ALONG COLD FRONT DRYLINE
INTERSECTION.  BEST CHANCES FOR SVR MAY BE OVERNITE WED NITE IN THE
ERN HALF OF THE CWA AS LLJ INCREASES.  NEW MODELS ARE A BIT SLOWER
TO CLEAR FRONT FROM SE ZONES THUR MORNING..SO WILL HOLD ONTO SOME
LOW POPS THERE AS WELL AS WARMER TEMPS.

ACTIVITY WILL BRIEFLY BE PUSHED SWD INTO TEXAS ON FRIDAY WHEN LOW
LEVEL RIDGING WILL BUILD INTO OK/NTEX..BUT DEEP MOISTURE WILL NOT BE
PUSHED TOO FAR AWAY.  SO FAR..FOCUS FOR THE WEEKEND HAS BEEN ON
SUNDAY WHEN MEDIUM RANGE MODELS BRING SIG S/W TROF ONTO PLAINS.
HOWEVER..IF THE 12Z AVN IS REASONABLY CLOSE WITH MASS FIELDS..
THE MORE SIGNIFICANT EVENT FOR THE SRN PLAINS MAY OCCUR SAT AFT/EVE
IN CORRIDOR ALONG THE RED RIVER VALLEY.  MORE TRANQUIL WX EXPECTED
TO PREVAIL FOR MON/TUE AS LOW LEVEL RIDGING BUILD SWD TOWARD OK.
 MILLER

OKC   63  84  59  77 /  10  30  40  20
HBR   63  88  57  78 /  20  20  20  10
SPS   65  89  58  85 /  20  20  30  20
GAG   60  90  48  75 /  20  10  10  10
PNC   65  84  57  75 /  10  40  40  10
DUA   65  83  66  83 /  10  20  40  30

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

OKZ004>048-050>052-TXZ083>090-301200-

HAZARDOUS WEATHER OUTLOOK...CORRECTED TYPO
NATIONAL WEATHER SERVICE NORMAN OK
1200 PM CDT TUE APR 29 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 SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING OVER WESTERN OKLAHOMA AND WESTERN NORTH TEXAS.

LOCATION...
THE SLIGHT RISK AREA IS WEST OF A LINE FROM CHEROKEE... TO LAWTON...
TO ARCHER CITY.

TIMING...
SCATTERED THUNDERSTORMS ARE EXPECTED TO MOVE INTO THE SLIGHT RISK
AREA LATE THIS AFTERNOON AND EVENING. THE MOST LIKELY TIME FOR
SEVERE WEATHER IS BETWEEN 5 PM AND MIDNIGHT.

IMPACTS...
LARGE HAIL WILL BE THE PRIMARY SEVERE WEATHER THREAT. DAMAGING WINDS
ALSO WILL BE POSSIBLE.

RECOMMENDED ACTIONS...
STORM SPOTTER GROUPS AND EMERGENCY MANAGEMENT PERSONNEL IN THE
SLIGHT RISK AREA SHOULD LISTEN FOR REGIONAL WEATHER DISCUSSIONS AND
OTHER UPDATES THIS AFTERNOON...AND BE READY FOR POSSIBLE ACTIVATION
LATE THIS AFTERNOON AND EVENING.

DISCUSSION...
A DRYLINE WILL MOVE INTO THE EASTERN TEXAS PANHANDLE THIS AFTERNOON.
SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG AND AHEAD OF
THE DRYLINE BY LATE AFTERNOON IN RESPONSE TO AFTERNOON HEATING AND
DESTABILIZATION...AND CONVERGING WINDS ALONG THE DRY LINE. THE
STORMS WILL TRACK INTO WESTERN OKLAHOMA AND NORTH TEXAS LATE THIS
AFTERNOON AND THIS EVENING. WINDS ALOFT ARE RELATIVELY WEAK AT ALL
LEVELS AS OF MIDDAY...BUT ARE EXPECTED TO INCREASE SLIGHTLY BY THIS
EVENING. FORECAST VERTICAL WIND PROFILES THIS EVENING INDICATE THAT
VERTICAL WIND SHEAR WILL BE SUFFICIENT FOR SEVERE THUNDERSTORMS...
INCLUDING THE POSSIBILITY OF A FEW HIGH PRECIPITATION SUPERCELLS...
IN THE SLIGHT RISK AREA. DUE TO THE RELATIVELY WEAK WINDS
ALOFT...ANY THUNDERSTORMS THAT FORM WILL LIKELY BE SLOW MOVING.
LARGE HAIL AND LOCALLY HEAVY RAIN WILL BE THE PRIMARY CONCERNS...
BUT SOME STORMS ALSO COULD PRODUCE DAMAGING STRAIGHT LINE WINDS.

PROBABILITY TABLE...
VALID THROUGH 700 AM CDT WEDNESDAY APR 30.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...50 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR...70 PERCENT.

OTHER HAZARDOUS WEATHER...
NO OTHER HAZARDOUS WEATHER IS EXPECTED THROUGH TONIGHT.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY...

THUNDERSTORM OUTLOOK...
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS WEDNESDAY AFTERNOON
AND NIGHT OVER MAINLY CENTRAL AND EASTERN OKLAHOMA. SCATTERED
THUNDERSTORMS WILL BE POSSIBLE BY WEDNESDAY AFTERNOON OVER CENTRAL
OKLAHOMA AS A DRYLINE MOVES INTO THE AREA. HIGHER INSTABILITIES AND
STRONGER WINDS ALOFT WILL BE FAVORABLE FOR SEVERE THUNDERSTORMS.
HOWEVER... WARMING TEMPERATURES AT MID LEVELS COULD ACT TO SUPPRESS
THUNDERSTORM DEVELOPMENT. IF LATER FORECAST INFORMATION SUGGESTS
THAT THE CAP ON WEDNESDAY WILL NOT BE AS STRONG AS CURRENTLY
EXPECTED...THEN PARTS OF THE FORECAST AREA COULD BE UPGRADED TO A
MODERATE RISK ON WEDNESDAY.

THUNDERSTORM CHANCES WILL INCREASE OVER THE AREA AGAIN ON SATURDAY
AND SUNDAY. CURRENT FORECAST DATA INDICATE THE POTENTIAL FOR A
SIGNIFICANT SEVERE WEATHER EVENT IN THE CENTRAL AND SOUTHERN PLAINS
AREA ON OR ABOUT NEXT SUNDAY.

OTHER HAZARDOUS WEATHER...
NO OTHER HAZARDOUS WEATHER IS EXPECTED.

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

REGIONAL WEATHER DISCUSSIONS WILL BE ISSUED AS NEEDED UNDER PRODUCT
IDENTIFIER OKCNOWOKC.

24

TXZ086-089-300115-

SIGNIFICANT WEATHER ADVISORY
NATIONAL WEATHER SERVICE NORMAN OK
802 PM CDT TUE APR 29 2003

THIS SIGNIFICANT WEATHER ADVISORY IS FOR ARCHER AND WICHITA COUNTIES.

A LINE OF STRONG TO POSSIBLY SEVERE THUNDERSTORMS WAS LOCATED FROM
16 MILES NORTHWEST OF ELECTRA TO 25 MILES WEST OF DUNDEE AT 802 PM
CDT...MOVING EAST AT 20 MPH.

THESE STORMS WILL MOVE INTO WESTERN PORTIONS OF ARCHER AND WICHITA
COUNTIES AFTER 830 PM...AND COULD PRODUCE STRONG WINDS AND HAIL.

PEOPLE IN ARCHER AND WICHITA COUNTIES...INCLUDING THE CITIES OF
BURKBURNETT...ELECTRA...IOWA PARK AND WICHITA FALLS...SHOULD MONITOR
THESE STORMS CLOSELY. LISTEN FOR WARNINGS AND WATCH FOR THREATENING
WEATHER CONDITIONS AS THE STORMS APPROACH.

SMITH

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
806 PM CDT TUE APR 29 2003

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

0805 PM    4 S TIPTON                OK   1.75 INCH HAIL
04/29/03   TILLMAN                        REPORTED BY AMATEUR RADIO
                                          OPERATOR

TY/MBB

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
826 PM CDT TUE APR 29 2003

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

0755 PM    14 S ARNETT               OK   .75 INCH HAIL
04/29/03   ELLIS                          REPORTED BY PUBLIC

JLP

TXZ086-089-300200-

SIGNIFICANT WEATHER ADVISORY
NATIONAL WEATHER SERVICE NORMAN OK
845 PM CDT TUE APR 29 2003

THIS SIGNIFICANT WEATHER ADVISORY IS FOR ARCHER AND WICHITA COUNTIES.

A LINE OF STRONG TO POSSIBLY SEVERE THUNDERSTORMS WAS LOCATED FROM 5
MILES WEST OF WICHITA FALLS SOUTH TO DUNDEE AT 843 PM...MOVING EAST
AT 25 MPH.

THESE STORMS WILL MOVE INTO WICHITA FALLS AND HOLLIDAY AREAS BETWEEN
845 PM AND 915 PM...AND COULD PRODUCE STRONG WINDS AND HAIL.

PEOPLE IN ARCHER AND WICHITA COUNTIES...INCLUDING THE CITIES OF
BURKBURNETT...ELECTRA...IOWA PARK AND WICHITA FALLS...SHOULD MONITOR
THESE STORMS CLOSELY. LISTEN FOR WARNINGS AND WATCH FOR THREATENING
WEATHER CONDITIONS AS THE STORMS APPROACH.

30

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
849 PM CDT TUE APR 29 2003

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

0847 PM    SEYMOUR                   TX   .88 INCH HAIL
04/29/03   BAYLOR                         REPORTED BY AMATEUR RADIO
                                          OPERATOR

MBB

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
854 PM CDT TUE APR 29 2003

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

0855 PM    5 S MABELLE               TX   .75 INCH HAIL
04/29/03   BAYLOR                         REPORTED BY AMATEUR RADIO
                                          OPERATOR

JLP