Hail in Oklahoma, May 13, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
225 PM CDT TUE MAY 13 2008

.DISCUSSION...
COLD FRONT CONTINUES TO WORK SOUTHEAST THROUGH THE AREA ALTHOUGH
THE FORWARD PROGRESS HAS SLOWED. LAPS ANALYSIS SHOWS INCREASING
INSTABILITY AND WEAKENING CAP WHICH WILL LIKELY ALLOW SOME
CONVECTION TO BEGIN HERE IN THE NEXT HOUR OR TWO. EXPECT
CONVECTION TO BECOME MORE WIDESPREAD INTO THE EVENING HOURS NEAR
AND SOUTHEAST OF THE FRONT AS UPPER JET NOSES INTO THE AREA OVER
THE CWA. FRONT STALLS OVER SOUTHERN OKLAHOMA OR NORTH TEXAS
OVERNIGHT IN RESPONSE TO SURFACE CYCLOGENESIS AS MAIN WAVE
APPROACHES THE AREA. EXPECTED WIDESPREAD THUNDERSTORMS NEAR AND
NORTH OF THE FRONTAL BOUNDARY AS THE UPPER TROUGH MOVES OVER THE
PLAINS. AFTER INITIAL TROUGH MOVES BY... MODELS ARE SHOWING THE
MEAN TROUGH REDEVELOPING JUST TO THE WEST AND IT THEN MOVING
ACROSS THE AREA THURSDAY AND THURSDAY NIGHT. THIS KEEPS THE CHANCE
OF RAIN LINGERING INTO THURSDAY... ALTHOUGH BY THIS TIME THE LOW
LEVEL MOISTURE IS BEING PUSHED FARTHER SOUTH SO WILL KEEP POPS
LOW.

AFTER THIS MOVES THROUGH... UPPER TROUGH LINGERS IN THE MIDWEST
THROUGH THE WEEKEND KEEPING THE AREA UNDER A NORTHWEST FLOW AND A
GENERALLY DRY PATTERN. ECMWF SHOWS LARGE-SCALE FLOW PATTERN
EVOLVING INTO A MORE ZONAL PATTERN EARLY IN THE NEXT WEEK WITH
ANOTHER TROUGH DEVELOPING IN THE WEST TOWARD THE END OF THE
FORECAST PERIOD... WHILE THE GFS /BOTH OPERATIONAL AND ENSEMBLE
MEMBERS/ REINFORCE THE MIDWEST TROUGH AND KEEP THE AREA UNDER
NORTHWEST FLOW.

&&

.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK  59  71  52  70 /  40  50  70  20
HOBART OK         57  70  50  69 /  50  60  50  20
WICHITA FALLS TX  63  77  56  72 /  60  50  50  10
GAGE OK           51  62  46  68 /  10  70  60  20
PONCA CITY OK     55  68  49  65 /  20  50  90  20
DURANT OK         67  81  63  72 /  60  50  60  20

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE NORMAN OK
255 PM CDT TUE MAY 13 2008

OKZ004>048-050>052-TXZ083>090-141200-
HARPER-WOODS-ALFALFA-GRANT-KAY-ELLIS-WOODWARD-MAJOR-GARFIELD-NOBLE-
ROGER MILLS-DEWEY-CUSTER-BLAINE-KINGFISHER-LOGAN-PAYNE-BECKHAM-
WASHITA-CADDO-CANADIAN-OKLAHOMA-LINCOLN-GRADY-MCCLAIN-CLEVELAND-
POTTAWATOMIE-SEMINOLE-HUGHES-HARMON-GREER-KIOWA-JACKSON-TILLMAN-
COMANCHE-STEPHENS-GARVIN-MURRAY-PONTOTOC-COAL-COTTON-JEFFERSON-
CARTER-JOHNSTON-ATOKA-LOVE-MARSHALL-BRYAN-HARDEMAN-FOARD-WILBARGER-
WICHITA-KNOX-BAYLOR-ARCHER-CLAY-
255 PM CDT TUE MAY 13 2008

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 THIS AFTERNOON AND
THIS EVENING ACROSS PORTIONS OF OKLAHOMA AND WESTERN NORTH TEXAS.

LOCATION...
THE MODERATE RISK COVERS LOCATIONS EAST OF A LINE EXTENDING FROM
CHANDLER AND SHAWNEE...TO PAULS VALLEY AND DUNCAN...TO HENRIETTA
TEXAS. A SLIGHT RISK AREA SURROUNDS THE MODERATE RISK AND COVERS
LOCATIONS AS FAR WEST AS ENID...WEATHERFORD...AND LAWTON IN
OKLAHOMA...AND VERNON AND BENJAMIN IN TEXAS.

TIMING...
THE MOST LIKELY TIME FOR SEVERE THUNDERSTORMS WILL BE FROM 4 PM
UNTIL MIDNIGHT. THE MAIN HAZARD DURING THIS RANGE OF TIME WILL BE
VERY LARGE HAIL AND DAMAGING WINDS. A FEW TORNADOES WILL ALSO BE
POSSIBLE IN THE MODERATE RISK AREA. TOWARD AND AFTER MIDNIGHT...
THUNDERSTORMS WILL LIKELY EVOLVE INTO ONE OR MORE LINES AND CLUSTERS
WITH THE POTENTIAL FOR LARGE HAIL AND DAMAGING WIND GUSTS CONTINUING.

RECOMMENDED ACTIONS...
STORM SPOTTER GROUPS AND EMERGENCY MANAGEMENT PERSONNEL ACROSS THE
RISK AREA SHOULD BE PREPARED FOR SEVERE WEATHER OPERATIONS FROM 4 PM
THROUGH TONIGHT.

DISCUSSION...
A COLD FRONT WILL BECOME STATIONARY NEAR OR JUST EAST OF THE
INTERSTATE-44 CORRIDOR...OR NEAR THE WESTERN EDGE OF THE MODERATE
RISK AREA. RECENT OBSERVATIONS INDICATE THAT THE CAP HAS WEAKENED
BUT IS NOT COMPLETELY ERODED. HOWEVER...CONVERGENCE ALONG A
PRE-FRONTAL TROUGH IS EXPECTED TO BE SUFFICIENT FOR AT LEAST
ISOLATED STORM DEVELOPMENT LATE THIS AFTERNOON. THE WIND AND THERMAL
PROFILES WILL BE SUFFICIENT FOR SUPERCELL THUNDERSTORMS... SOME OF
WHICH MAY BE LONG-LIVED AND SIGNIFICANT...AND PRODUCE EXTREMELY
LARGE AND DAMAGING HAIL. DAMAGING WINDS WILL BE A SECONDARY
CONCERN...WITH AN ATTENDANT THREAT OF TORNADOES IN THE MODERATE RISK
AREA WITH ANY SUPERCELLS THAT DEVELOP SIGNIFICANT DEVIANT MOTION.

LATER THIS EVENING...THE MENTIONED COLD FRONT IS EXPECTED TO MOVE
SOUTHWARD AND STALL AGAIN NEAR THE RED RIVER. STORM ORGANIZATION IS
EXPECTED TO BECOME MORE LINEAR NEAR THE COLD FRONT AT THIS TIME...
AND EVOLVE INTO A LARGE EAST AND SOUTHEAST MOVING COMPLEX. LARGE
HAIL...DAMAGING WINDS...AND FLASH FLOODING RAINS WILL REMAIN A
THREAT WITH ANY STORM COMPLEX INTO THE OVERNIGHT HOURS.

PROBABILITY TABLE...
VALID THROUGH 700 AM CDT WEDNESDAY MAY 14.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...100 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR... 80 PERCENT.

OTHER HAZARDOUS WEATHER...
NONE.

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

THUNDERSTORM OUTLOOK...
THERE IS A SLIGHT RISK FOR THUNDERSTORMS SOUTH OF A LINE FROM HOBART
TO SEMINOLE ON WEDNESDAY AS A SLOW-MOVING UPPER-LEVEL STORM SYSTEM
MOVES FROM SOUTHERN NEW MEXICO INTO NORTH TEXAS. THIS WILL PROVIDE
INCREASING FAVORABLE WIND AND THERMAL STRUCTURES FOR A FEW SEVERE
THUNDERSTORMS.

OTHER HAZARDOUS WEATHER...
HEAVY RAINFALL THAT MAY FORM ACROSS OKLAHOMA AND WESTERN NORTH TEXAS
WEDNESDAY THROUGH WEDNESDAY NIGHT COULD CAUSE FLOODING. A FLOOD
WATCH MAY BECOME NECESSARY FOR THIS AREA.

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

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