Hail and Damaging Wind in Oklahoma, May 31, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
252 PM CDT SAT MAY 31 2008

.DISCUSSION...
WILL BE A WAITING GAME FOR CONVECTION THROUGH TONIGHT. AT LEAST
THREE AREAS TO WATCH THROUGH EARLY EVENING. MAIN AREA OF CONCERN
WILL BE NORTH-CENTRAL OKLAHOMA WHERE WEST TO EAST STATIONARY FRONT
IS COINCIDENT WITH OUTFLOW BOUNDARY FROM EARLY MORNING CONVECTION.
BOUNDARY LAYER TRIPLE POINT CURRENTLY LOCATED OVER LOCATIONS JUST
WEST OF ENID...AND IS EXPECTED TO DRIFT SLOWLY TO THE NORTH AND
WEST INTO THE EVENING HOURS. IN THE COOLER/MOIST REGIME NORTH OF
THE FRONT AND EAST OF THE OUTFLOW BOUNDARY HAS ALLOWED STCU FIELD
TO FORM...WHICH AT LEAST THROUGH MOST OF THE AFTERNOON...SHOULD
ALLOW WEAK CAP TO HOLD. H7 S/WV TROF...EVIDENT IN U/A AND SATL
TRENDS OVER NM...ALONG WITH INCREASING LOW-LEVEL JET...SHOULD
ALLOW SCATTERED OR NUMEROUS THUNDERSTORMS TO DEVELOP NEAR AND
NORTH OF STATIONARY FRONT. IF WE DO NOT GET ANY STORMS OVER
EXTREME NORTHERN OKLAHOMA NEAR THE FRONT...EVENT MAY BE LATE
EVENING AND OVERNIGHT WITH MCS TYPE ACTIVITY DIVING SOUTHWARD
FROM KANSAS.

ANOTHER AREA TO MONITOR IS WEAK CONVERGENCE AXIS OVER SOUTHEAST
AND SOUTH-CENTRAL OKLAHOMA. LACK OF CAP AND HIGH INSTABILITY OVER
THIS PORTION OF FORECAST...AS DEPICTED BY OBJECTIVE ANALYSIS
PROGRAMS...LIKELY A RESULT OF ERRONEOUS AWOS DEWPOINT READINGS
BEING INGESTED INTO ANALYSIS FIELDS. GIVEN THIS AND WEAKENING
CONVERGENCE TRENDS...FEEL CHANCES ARE QUITE SMALL FOR STORMS.
THIRD AREA OF INTEREST WILL BE OVER WEST-CENTRAL AND SOUTHWEST
OKLAHOMA...IN AREA OF BACKING/ACCELERATING FLOW JUST EAST OF
SOUTHERN TEXAS PANHANDLE SURFACE LOW. THIS REGION IS STRONGLY
CAPPED...BUT WITH TEMPS EXPECTED TO REACH AROUND THE CENTURY
MARK...CANNOT RULE OUT AN ISOLATED STRONG/SEVERE STORM OR TWO
WHICH WILL BE DIURNALLY DRIVEN.

MENTIONED FRONT IS PROGD TO GET SHOVED SOUTHWARD TOWARD THE I-40
CORRIDOR LATE TONIGHT AND TOMORROW MORNING...IF ENOUGH CONVECTION
CAN BE REALIZED. LOCATIONS NEAR AND NORTH OF THIS FRONT WOULD HAVE
THE OPPORTUNITY FOR STRONG SEVERE STORMS AGAIN LATE TOMORROW AND
TOMORROW NIGHT. WILL LEAVE POPS MAINLY CONFINED TO NORTHERN INTO
PORTIONS OF CENTRAL OKLAHOMA FOR SUNDAY/SUNDAY NIGHT.

ANOTHER FRONTAL SURFACE MAY TRY TO ENTER NORTHERN PORTIONS OF
OKLAHOMA LATE TUESDAY INTO WEDNESDAY...AND DESPITE RELATIVELY
STRONG CAP...A FEW STORMS CANNOT BE RULED OUT ACROSS NORTHERN
OKLAHOMA DURING THIS TIME FRAME. OF GREATER IMPACT MAY BE WHAT
EVOLVES OUT OF PROGD UPPER LOW THAT WILL DEEPEN OVER GREAT BASIN
AND HEADS TOWARD CENTRAL AND SOUTHERN PLAINS AROUND THURSDAY.
AGAIN...STRONG CAP WILL HAVE TO BE OVERCOME...BUT GIVEN PROGD
FORCING AND SHARP DRY LINE...A SIGNIFICANT SEVERE WEATHER EVENT
LIKELY OVER THE REGION.

&&

.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK  69  92  71  95 /  30  20  10  10
HOBART OK         71  98  71  98 /  20  10  10  10
WICHITA FALLS TX  73  98  73  99 /  10  10   0   0
GAGE OK           63  88  66  96 /  30  20  10  10
PONCA CITY OK     68  83  69  93 /  60  60  30  20
DURANT OK         70  93  73  94 /  20  10   0   0

&&

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

25/11

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
818 PM CDT SAT MAY 31 2008

OKZ004>048-050>052-TXZ083>090-011200-
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-
818 PM CDT SAT MAY 31 2008

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

.DAY ONE...TONIGHT...

THUNDERSTORM OUTLOOK...
THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS NORTH
CENTRAL OKLAHOMA. A SLIGHT RISK OF SEVERE THUNDERSTORMS EXTENDS
SOUTH AND WESTWARD INTO NORTHWEST... WEST-CENTRAL AND CENTRAL
OKLAHOMA.

LOCATION...
THE MODERATE RISK AREA COVERS LOCATIONS NEAR AND NORTHEAST OF A LINE
EXTENDING FROM CHEROKEE...TO ENID AND STILLWATER. THIS INCLUDES THE
CITIES OF MEDFORD...ENID...PONCA CITY...AND STILLWATER. THE SLIGHT
RISK AREA EXTENDS SOUTH AND WESTWARD TO A LINE EXTENDING FROM ELK
CITY...TO NORMAN AND HOLDENVILLE.

TIMING...
THE MOST LIKELY TIME FOR SEVERE WEATHER WILL BE THROUGH THE
OVERNIGHT HOURS.

IMPACTS...
VERY LARGE HAIL...OVER TWO INCHES IN DIAMETER...WILL BE THE MAIN
CONCERN. DAMAGING WIND GUSTS AND INTENSE LIGHTNING WILL BE A
SECONDARY CONCERN. A TORNADO THREAT WILL ALSO BE SEEN MAINLY ACROSS
THE MODERATE RISK AREA THIS EVENING.

RECOMMENDED ACTIONS...
STORM SPOTTER GROUPS AND EMERGENCY MANAGEMENT PERSONNEL IN THE RISK
AREAS SHOULD PLAN TO MAINTAIN SEVERE WEATHER OPERATIONS THROUGH THE
OVERNIGHT HOURS.

DISCUSSION...
A WEAK AND SLOW-MOVING FRONT EXTENDED FROM WEST CENTRAL INTO NORTH
CENTRAL OKLAHOMA THIS EVENING. DAYTIME HEATING HAS RESULTED IN A
VERY UNSTABLE AIRMASS ACROSS PARTS OF OKLAHOMA AND WESTERN NORTH
TEXAS. STORMS MAY INITIATE NEAR THE FRONT THIS EVENING. STRONG
DEEP-LAYER WIND SHEAR WILL SUPPORT ORGANIZED SEVERE THUNDERSTORMS...
SOME OF WHICH WILL BE SUPERCELLS.

A LOW LEVEL JET IS EXPECTED TO DEVELOP THIS EVENING AND OVERNIGHT...
WITH THUNDERSTORMS EXPECTED TO DEVELOP ACROSS PARTS OF WESTERN AND
CENTRAL KANSAS. THESE STORMS ALONG WITH POSSIBLY ANY STORMS THAT
DEVELOP NEAR THE FRONT THIS EVENING ARE EXPECTED TO FORM ONE OR MORE
LARGER CLUSTERS AND MOVE TO THE EAST AND SOUTHEAST...AFFECTING  MORE
OF THE LOCATIONS IN THE SLIGHT RISK AREA. HAIL AND DAMAGING WINDS
WILL BE THE MAIN CONCERNS WITH THE CLUSTERS OF STORMS LATER TONIGHT.
THE LOW LEVEL JET WILL LIKELY HELP MAINTAIN THUNDERSTORM DEVELOPMENT
THROUGH THE OVERNIGHT HOURS.

PROBABILITY TABLE...
VALID THROUGH 700 AM CDT SUNDAY JUNE 1.
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...SUNDAY THROUGH FRIDAY...

THUNDERSTORM OUTLOOK...
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS AGAIN ON SUNDAY AND
SUNDAY NIGHT... OVER BASICALLY THE SAME AREAS THAT ARE IN THE SLIGHT
RISK TODAY AND TONIGHT. THE SURFACE FRONT MAY DRIFT A LITTLE FARTHER
SOUTH INTO CENTRAL OKLAHOMA ON SUNDAY... DUE TO THE EFFECTS OF
RAIN-COOLED AIR FROM THUNDERSTORMS TODAY AND TONIGHT. LARGE HAIL
AGAIN WILL BE THE PRIMARY CONCERN.

STRONG TO SEVERE STORMS MAY BE POSSIBLE AGAIN TUESDAY NIGHT INTO
WEDNESDAY. HOWEVER... THE BETTER SEVERE WEATHER CHANCES WILL BE
AROUND NEXT THURSDAY... AS A POWERFUL LATE-SPRING STORM SYSTEM FORMS
OVER THE ROCKIES AND MOVES INTO THE PLAINS. THIS SYSTEM HAS THE
POTENTIAL TO PRODUCE A SIGNIFICANT SEVERE WEATHER EPISODE OVER THE
CENTRAL UNITED STATES... INCLUDING PARTS OF OKLAHOMA AND WESTERN
NORTH TEXAS. ALL INTERESTS IN THE SOUTHERN PLAINS REGION ARE
ENCOURAGED TO LISTEN FOR FURTHER UPDATES TO THE FORECAST REGARDING
SEVERE WEATHER POTENTIAL DURING THE LATTER HALF OF NEXT WEEK.

OTHER HAZARDOUS WEATHER...
NONE.

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

MAXWELL

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
842 PM CDT SAT MAY 31 2008

OKZ015-016-010200-
DEWEY OK-CUSTER OK-
842 PM CDT SAT MAY 31 2008

...SIGNIFICANT WEATHER ADVISORY...

THIS SIGNIFICANT WEATHER ADVISORY IS FOR CUSTER AND DEWEY COUNTIES.

A STRONG THUNDERSTORM WAS LOCATED OVER PUTNAM AT 842 PM CDT...MOVING
NORTHEAST AT 23 MPH.

SMALL HAIL AND WINDS AROUND 50 MPH ARE POSSIBLE.

WR