Severe Thunderstorm Warning 2, NWS Norman, OK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
333 PM CST WED MAR 12 2003

FORECAST CONCERNS IN THE SHORT TERM WILL BE CHANCES OF SEVERE
CONVECTION AS FRONTAL BOUNDARY TO THE NORTH PUSHES ACROSS
THE FA TONIGHT INTO EARLY THURSDAY MORNING.  20Z SOUNDING
SHOWS CAPPING LAYER AROUND 85H WHICH IS EXPECTED TO INHIBIT
CONVECTION UNTIL LATER THIS EVENING.  AS THE FRONT PUSHES SOUTH
THIS EVENING AND UPPER WAVE APPROACHES...ENOUGH LIFT AND CONVERGENCE
MAY ALLOW FOR STORMS TO FORM ALONG OR JUST BEHIND SURFACE FRONT.
ENOUGH INSTABILITY AND LOW WET BULB ZERO HEIGHTS MAY RESULT IN LARGE
HAIL FROM THE STRONGER STORMS.  MOST IF NOT ALL THE CONVECTION THAT
FORMS...SHOULD BE SOUTH AND EAST OF FA BY EARLY THURSDAY MORNING.

RATHER COLD AIR STILL TO OUR NORTH... AND SOME OF THIS MODIFIED AIR
WILL WORK INTO FA...ESPECIALLY NORTH CENTRAL SECTIONS.  UPPER RIDGE
TO BUILD OVER SOUTHERN PLAINS THURSDAY NIGHT INTO FRIDAY SO EXPECT
DRY CONDITIONS WITH SURFACE MOISTURE INCREASING WITH RETURN FLOW ON
FRIDAY.

EXTENDED FORECAST...(SAT-WED)

MEDIUM RANGE MODELS FORECAST SHORTWAVE TO MOVE ACROSS SOUTHERN/
CENTRAL PLAINS DURING THE DAY SATURDAY WITH THE CANADIAN
MODEL THE STRONGEST WITH THIS FEATURE.  RETURN FLOW OF SURFACE
MOISTURE SHOULD START BY FRIDAY INTO FRIDAY NIGHT AS LEE
TROUGH DEVELOPS.  LOOKS LIKE BEST TIMING FOR TSRA WILL BE DURING THE
DAY SATURDAY.

POWERFUL SPRING-TIME SYSTEM SHOULD START TO AFFECT THE AREA LATE
SUNDAY INTO THE EARLY PART OF NEXT WEEK.  MANY QUESTIONS STILL
NEED TO BE ANSWERED WITH THIS SYSTEM...BUT MODELS HAVE BEEN FAIRLY
CONSISTENT THAT MONDAY WILL BRING THE BEST CHANCE OF SEVERE WEATHER.

AS UPPER LOW MOVES SLOWLY NORTHEAST INTO UPPER MISSISSIPPI VALLEY
TUESDAY...COULD SEE MORE STORMS DEVELOP WITH BETTER CHANCE ACROSS
EASTERN PARTS OF FA.

FCSTID = SIX

OKC  52 68 45 72 /  30 10 00 00
HBR  53 69 45 73 /  10 00 00 10
SPS  54 72 46 73 /  10 10 10 00
GAG  43 69 44 77 /  10 00 00 10
PNC  47 66 43 76 /  30 10 00 00
DUA  59 71 49 73 /  30 10 10 00

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

OKZ004>048-050>052-TXZ083>090-131300-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
1210 PM CST WED MAR 12 2003

THIS HAZARDOUS WEATHER OUTLOOK PERTAINS TO CENTRAL AND WESTERN
OKLAHOMA AND WESTERN NORTH TEXAS.

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

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

LOCATION...
THE SLIGHT RISK AREA IS ROUGHLY ALONG AND EAST OF U.S. HIGHWAY 81.

TIMING...
THERE WILL BE A LOW RISK OF THUNDERSTORMS VERY LATE THIS AFTERNOON
AND EARLY THIS EVENING... WITH BETTER CHANCES FOR STORMS FROM LATE
THIS EVENING AND OVERNIGHT. THE SEVERE WEATHER THREAT OVER NORTH
TEXAS SHOULD BE CONFINED TO LOCALES NEAR AND EAST OF A WICHITA FALLS
TO ARCHER CITY LINE... AND SHOULD OCCUR OVERNIGHT.

EXPECTED WEATHER AND IMPACTS...
THE STRONGEST STORMS WILL BE CAPABLE OF PRODUCING HAIL UP TO THE
SIZE OF GOLF BALLS AND WIND GUSTS FROM 60 TO 70 MPH... WHICH MAY
RESULT IN SOME DAMAGE TO ROOFS... WINDOWS AND VEGETATION.

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

DISCUSSION...
A DRYLINE WILL MOVE INTO WESTERN OKLAHOMA THIS AFTERNOON AND A COLD
FRONT OVER NORTHERN OKLAHOMA WILL BEGIN TO MOVE SLOWLY SOUTHWARD BY
EARLY EVENING.  A WARM... HUMID AND INCREASINGLY UNSTABLE AIRMASS WILL
EXIST EAST OF THE DRYLINE AND SOUTH OF THE COLD FRONT.  WARM
TEMPERATURES ALOFT ARE EXPECTED TO PERSIST INTO THIS EVENING... AND
MAY PREVENT THUNDERSTORM DEVELOPMENT ALTOGETHER UNTIL AFTER DARK.
HOWEVER... AN ISOLATED STORM OR TWO CANNOT BE COMPLETELY RULED OUT
LATE THIS AFTERNOON AND EARLY THIS EVENING... WITH THE MOST LIKELY
AREA FOR STORMS DURING THE LATE AFTERNOON AND EVENING OVER NORTH
CENTRAL OKLAHOMA.  THE COLD FRONT WILL MOVE SOUTHWARD TONIGHT AND
SHOULD PROVIDE SUFFICIENT UPWARD MOTION TO ALLOW STORMS TO DEVELOP
AFTER DARK OVER CENTRAL OKLAHOMA... AND SOME STORMS MAY PERSIST FOR
MUCH OF THE NIGHT ALONG AND SOUTHEAST OF THE INTERSTATE 44 CORRIDOR.

ALTHOUGH DEEP LAYER SHEAR IS NOT OPTIMAL FOR THE DEVELOPMENT OF
SUPERCELLS... MODERATE TO STRONG INSTABILITY AND SUFFICIENT SHEAR IS
EXPECTED TO RESULT IN THE STRONGEST STORMS BEING CAPABLE OF GOLF
BALL SIZE HAIL AND DAMAGING WIND GUSTS.

PROBABILITY TABLE...
VALID THROUGH 700 AM CST THURSDAY MAR 13.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...70 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR...60 PERCENT.

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

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY...

THUNDERSTORM OUTLOOK...
THERE WILL BE A CHANCE OF THUNDERSTORMS BEGINNING FRIDAY NIGHT...
THROUGH TUESDAY.  THE BEST CHANCE OF THUNDERSTORMS... AND SEVERE
WEATHER... APPEARS TO BE ON MONDAY.

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

 MILLER