Severe Thunderstorm Warning 397, NWS Norman, OK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
104 PM CDT FRI AUG 23 2002

OUTFLOW BOUNDARY FROM OVERNITE CONVECTION TO OUR NORTH PUSHED AS FAR
SOUTH AS HBR-PNC..BUT BOUNDARY IS NOW RAPIDLY LOSING DEFINITION AS
INSOLATION WORKS OVER SHALLOW COLD POOL AND STRONG PRESSURE FALLS
COMMENCE ON THE HIGH PLAINS IN RESPONSE TO UNSEASONABLY STRONG UPPER
LEVEL SPEED MAX MIGRATING INTO WRN CO ATTM. THERE MAY BE A SMALL
WINDOW OF OPPORTUNITY FOR DEEP CONVECTION WITHIN THE DIFFUSE
RETREATING BOUNDARY ZONE OVER NRN OK THIS AFTERNOON AND EVENING..BUT
CHANCES APPEAR SMALL ATTM DUE TO WARMING MID LEVEL TEMPS AND
MARGINAL BOUNDARY LAYER MASS CONVERGENCE.  THERE MAY ALSO BE SOME
ISOLATED EVENING ACTIVITY IN THE SW ZONES WHERE VERY DEEP MIXING
WILL OCCUR.

MCS EXPECTED TO ORGANIZE TO OUR N/NW TONITE AND SLIDE SEWD ALONG/N
OF BAROCLINIC RIBBON.  BOUNDARY OVER NRN OK SHUD BE PRIMARY FOCUS
FOR CONVECTION SAT/SUN..WITH APPARENT RISK OF AT LEAST SOME SVR DUE
TO QUITE HEALTHY MID LEVEL FLOW BY AUGUST STANDARDS FOR THIS PART OF
THE WORLD AND STRONGLY VEERING LOW LEVEL WIND PROFILES INVOF
BOUNDARY. HOWEVER..IT MAY BE A LATE SHOW WITH INITIATION AGAIN
OCCURING ON THE HI PLAINS WITH AN MCS MOVING SEWD INTO OK LATE
EVENING OR OVERNITE SAT NITE.

CHANCES FOR PRECIP SHUD TREND DOWNWARD FOR THE BEGINNING OF THE
WEEK..WITH SMALL CHANCES FOR STORMS AGAIN MID WEEK WITH NEXT FRONT
IN NW FLOW ALOFT. THUS..THE REST OF THE FORECAST IS LEFT ESSENTIALLY
UNCHANGED WITH A DRY FORECAST INTRODUCED FOR DAY 7.

OKC   72  94  71  90 /  20  30  40  30
HBR   75  98  72  94 /  10  20  30  30
SPS   76 102  75  98 /  10  10  20  30
GAG   71  95  65  89 /  20  30  30  20
PNC   74  92  67  89 /  30  40  50  20
DUA   75  95  73  93 /  10  20  30  30

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

OKZ004>048-050>052-TXZ083>090-231900-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
1152 AM CDT FRI AUG 23 2002

THUNDERSTORM OUTLOOK...
NO SEVERE THUNDERSTORMS ARE EXPECTED THROUGH TONIGHT.

DISCUSSION...
THERE IS A SMALL CHANCE OF THUNDERSTORM DEVELOPMENT THIS AFTERNOON
AND EVENING NEAR A WEAKENING OUTFLOW BOUNDARY THAT MOVED INTO
PORTIONS OF WESTERN AND NORTHERN OKLAHOMA THIS MORNING. WARM MID
LEVEL TEMEPRATURES AND WEAK WIND SHEAR PROFILES ARE EXPECTED TO
PRECLUDE ORGANIZED SEVERE THUNDERSTORM DEVELOPMENT.

THE NEXT CHANCE FOR SEVERE THUNDERSTORMS WILL BE SATURDAY AFTERNOON
THROUGH SATURDAY NIGHT... WITH THE STRONGEST STORMS AND MOST
WIDESPREAD COVERAGE EXPECTED OVER ROUGHLY THE NORTHERN HALF OF
OKLAHOMA. A COLD FRONT IS EXPECTED TO STRENGTHEN OVER SOUTHERN
KANSAS OR EXTREME NORTHERN OKLAHOMA SATURDAY AFTERNOON. LIFT ALONG
AND NORTH OF THE FRONT SHOULD ALLOW THUNDERSTORMS TO DEVELOP BY LATE
AFTERNOON OR EVENING. MODERATE TO STRONG INSTABILITY AND SUFFICIENT
VERTICAL WIND SHEAR PROFILES ARE EXPECTED TO SUPPORT A FEW STORMS
REACHING SEVERE LEVELS.

PROBABILITY TABLE...
VALID THROUGH 7 AM CDT SAT AUG 24.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...40 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR...10 PERCENT.

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

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

JAMES