Severe Thunderstorm Warning 627, NWS Norman, OK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OKLAHOMA
325 PM CDT SAT JUN 28 2003

MORNING CONVECTION ACROSS WOODS COUNTY IN NORTHERN OKLAHOMA...
EXTENDING INTO SOUTH CENTRAL KANSAS... HAS DISSIPATED DURING THE
AFTERNOON AS THE LOW LEVEL JET DIMINISHED. HOWEVER... ADDITIONAL
DEVELOPMENT ALONG THE RESIDUAL WEAK OUTFLOW BOUNDARY IN NORTHERN
OKLAHOMA IS NOT OUT OF THE QUESTION. SATELLITE INDICATES CU FIELD
PILING UP NEAR THE BOUNDARY EXTENDING FROM HARPER COUNTY SOUTHEAST
INTO BLAINE COUNTY. MODERATE TO STRONG INSTABILITY AND RELATIVELY
WEAK CAP EXISTS ACROSS THE REGION THIS AFTERNOON. ANY STORMS THAT
DEVELOP WILL TEND TO MOVE TO THE SOUTH OR SOUTHEAST DURING THE LATE
AFTERNOON/EVENING HOURS. MEANWHILE... SCATTERED TSTMS WERE BEGINNING
TO DEVELOP IN UPSLOPE FLOW OVER OVER EASTERN COLORADO. THIS ACTIVITY
WILL MOVE SOUTHEAST... WITH SOME OF THE REMNANTS POSSIBLY REACHING
NORTHERN OKLAHOMA LATE TONIGHT. A SURFACE TROUGH IN KANSAS IS
EXPECTED TO DRIFT SOUTH INTO NORTHERN OKLAHOMA ON SUNDAY. THIS
FEATURE... ALONG WITH A RESIDUAL OUTFLOW BOUNDARY THAT IS EXPECTED
TO DEVELOP FROM AN OVERNIGHT MCS IN THE CENTRAL PLAINS... COULD ACT
AS A FOCUS FOR TSTM DEVELOPMENT BY SUNDAY AFTERNOON. AVN IS A LITTLE
MORE AGRESSIVE IN PUSHING THE SURFACE TROUGH INTO SOUTHEAST
OKLAHOMA...WHILE ETA IS WEAKER AND SLOWER. ETA KF HOLDS THE MIDDLE
GROUND AND APPEARS TO BE A REASONABLE COMPROMISE. PCPN CHANCES
EXPECTED TO DIMINISH BY LATE MONDAY AS LOW LEVEL BOUNDARIES AND
UPPER LEVEL FLOW WEAKEN. HOWEVER... A FEW SHWRS/TSTMS COULD LINGER
INTO WEDNESDAY OVER SOUTHEAST OKLAHOMA AS A WEAK UPPER TROUGH
DEVELOPS OVER EASTERN TEXAS AND SOUTHEAST OKLAHOMA. CURRENT TEMP
FORECASTS GENERALLY LOOK GOOD AND MADE ONLY MINOR ADJUSTMENTS TO
THEM.

OKC   66   89   67   86  / 10   20   40   20
HBR   68   91   66   87  / 10   20   40   20
SPS   68   92   69   90  / 10   10   20   20
GAG   66   87   62   84  / 50   40   30    5
PNC   67   87   66   85  / 30   50   40   20
DUA   66   89   68   89  / 10    5   10   20

FORECAST ID = 32

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

OKZ004>048-050>052-TXZ083>090-291200-

HAZARDOUS WEATHER OUTLOOK...UPDATED...
NATIONAL WEATHER SERVICE NORMAN OK
350 PM CDT SAT JUN 28 2003

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

.DAY ONE...TODAY AND TONIGHT...

THUNDERSTORM OUTLOOK...
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHWEST
HALF OF OKLAHOMA THROUGH TONIGHT.

LOCATION...
THE SLIGHT RISK AREA IS NORTHWEST OF A LINE FROM PONCA CITY... TO
EL RENO... TO CHICKASHA... TO HOLLIS.

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

DISCUSSION...
THUNDERSTORMS OVER NORTHERN OKLAHOMA EARLIER THIS AFTERNOON HAVE
DISSIPATED.  THE RESIDUAL OUTFLOW BOUNDARY FROM THESE STORMS
EXTENDED FROM NEAR KINGFISHER... NORTHWESTWARD TO FAIRVIEW... TO
NEAR BUFFALO AND INTO SOUTHWEST KANSAS WHERE IT INTERSECTED WITH A
SYNOPTIC SCALE BOUNDARY THAT EXTENDED INTO EASTERN COLORADO. THE
AIRMASS ALONG AND SOUTH OF THESE BOUNDARIES HAS BECOME EXTREMELY
UNSTABLE THIS AFTERNOON... WITH CAPE VALUES IN EXCESS OF 4500 J/KG.
ALTHOUGH DEEP LAYER WIND SHEAR IS SOMEWHAT WEAK... SHEAR WILL BE
STRONG ENOUGH FOR MULTICELL SEVERE STORMS... AND PERHAPS A COUPLE OF
H-P TYPE SUPERCELLS GIVEN THE EXTREME INSTABILITY.

A FEW THUNDERSTORMS HAVE ALREADY DEVELOPED ALONG THE BOUNDARY IN
EASTERN COLORADO... AND ADDITIONAL STORMS ARE LIKELY TO FORM DURING
THE LATE AFTERNOON AND EVENING FROM EASTERN COLORADO INTO NORTHWEST
OKLAHOMA AND MOVE SLOWLY SOUTH OR SOUTHWEST.  ADDITIONAL STORMS THAT
FORM FARTHER NORTH... MAY ALSO MOVE INTO NORTHERN OKLAHOMA LATE
TONIGHT IN NORTHWEST FLOW ALOFT. LARGE HAIL UP TO THE SIZE OF GOLF
BALLS AND WINDS UP TO 70 MPH WILL BE POSSIBLE WITH THE STRONGEST
STORMS.

PROBABILITY TABLE...
VALID THROUGH 700 AM CDT SUNDAY JUN 29.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...100 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR...90 PERCENT.

OTHER HAZARDOUS WEATHER...
SLOW STORM MOTION THIS EVENING AND OVERNIGHT MAY RESULT IN LOCALLY
HEAVY RAINFALL WITH THE STRONGEST STORMS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY...

THUNDERSTORM OUTLOOK...
CHANCES FOR THUNDERSTORMS WILL CONTINUE ACROSS PORTIONS OF OKLAHOMA
THROUGH MONDAY NIGHT.

OTHER HAZARDOUS WEATHER...
NONE

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

 MILLER