Severe Thunderstorm Warning 239, NWS Norman, OK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
815 PM CDT SUN MAY 26 2002

UPDATED ZONES SENT TO INCREASE POPS ACROSS MOST OF FORECAST AREA.
GENERALLY WENT CATEGORICAL ACROSS THE WESTERN 1/3RD OF OKLAHOMA AND
WESTERN NORTH TEXAS...DECREASING FURTHER EAST AND SOUTHEAST. LINE OF
STORMS FROM SOUTHERN KANSAS DOWN INTO WEST TEXAS SHOULD MAINTAIN
THEMSELVES NEXT FEW HOURS BASED ON AREA RAOBS. 00Z OUN AND FWD
SOUNDINGS WOULD BE QUITE SCARY IF WIND SHEAR WERE BETTER. AT ANY
RATE...VERY STEEP MID LEVEL LAPSE RATES EVIDENT...SO EXPECT ACTIVITY
TO HOLD ITS OWN INTO THE OVERNIGHT HOURS. WITH SUCH STEEP LAPSE
RATES...TIME OF YEAR...AND RELATIVELY WEAK SURFACE BASED INVERSIONS
EXPECTED...WILL BE MONITORING FOR NON-CONVECTIVE WIND EVENT /HEAT
BURSTS/.

OTHERWISE...WILL FRESHEN UP HAZARDOUS WEATHER OUTLOOK SHORTLY TO
REFLECT CURRENT THINKING/TRENDS.

FCSTID = 11

-----------------

THE NEXT FEW DAYS ARE SHAPING UP TO BE RATHER WET ACROSS PARTS OF
OK. WITH A MOIST BOUNDARY LAYER IN PLACE AND A RELATIVELY FAVORABLE
VERTICAL THERMAL PROFILE FOR SHOWER AND THUNDERSTORM DEVELOPMENT,
ONLY MODEST LIFTING WILL BE NECESSARY TO GENERATE RAIN. THE FIRST
EPISODE COMES TONIGHT AS STORMS THAT FORM ON THE NM-TX DRYLINE ARE
EXPECTED TO DRIFT ACROSS THE PANHANDLE AND INTERSECT THE LOW-LEVEL
JET OVERNIGHT IN WESTERN OK. AN MCS MAY EVOLVE, MOST LIKELY OVER NW
OK AND MOVE ACROSS THE NORTHERN HALF OF THE STATE LATE TONIGHT. THEN
BY MONDAY AFTERNOON/EVENING, THE UPPER LOW, INDICATED IN W/V OVER
SOUTHERN CA EARLY THIS AFTERNOON, WILL BRING SYNOPTIC SCALE LIFT TO
GENERATE SHOWERS AND STORMS IN THE WEST THAT SHOULD AGAIN SPREAD
EAST DURING THE EVENING AND NIGHT.

MODEL FORECASTS HAVE BEEN QUITE CONSISTENT IN FORECASTING THIS UPPER
LOW TO CUT-OFF FROM THE MAIN FLOW OVER OK MONDAY NIGHT AND MEANDER
ACROSS THE STATE INTO THURSDAY. THUS, POPS REMAIN IN THE FORECAST
FOR ALL AREAS THROUGH WEDNESDAY, WITH THURSDAY BEING THE TRANSITION
DAY. ALTHOUGH PERIODS BEYOND THURSDAY ARE DRY, THE EXIT OF SYSTEMS
LIKE THIS OFTEN IS NOT WELL FORECAST BY NUMERICAL MODELS.

FCSTID =09
OKC   66  80  67  76 /  40  50  40  40
HBR   65  83  66  77 /  50  40  50  40
SPS   67  84  67  80 /  40  40  40  40
GAG   63  82  63  76 /  70  40  70  40
PNC   65  80  66  76 /  60  70  50  40
DUA   66  82  67  77 /  20  40  40  40

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

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
836 PM CDT SUN MAY 26 2002

TIME (CDT) .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0835 PM    7 W BUFFALO               OK   60 MPH WIND GUST
05/26/02   HARPER                         PUBLIC REPORT

FM

OKZ004>048-050>052-TXZ083>090-270700-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
840 PM CDT SUN MAY 26 2002

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 INCLUDES THOSE LOCATIONS WEST OF A LINE
EXTENDING FROM PONCA CITY...TO OKLAHOMA CITY...TO WAURIKA...TO
ARCHER CITY TEXAS. IN ADDITION TO THE CITIES ALREADY LISTED...THIS
RISK AREA INCLUDES ENID...WOODWARD...WEATHERFORD...LAWTON...AND
ALTUS IN OKLAHOMA. IN TEXAS...IT INCLUDES THE CITIES OF WICHITA
FALLS...VERNON...QUANAH...AND SEYMOUR.

TIMING...
THE MOST LIKELY TIME FOR SEVERE THUNDERSTORMS WILL BE FROM NOW
THROUGH 2 AM.

IMPACTS...
HAIL LARGER THAN GOLFBALLS AND WIND GUSTS OVER 65 MPH WILL BE
POSSIBLE WITH THE STRONGEST STORMS. THIS WOULD RESULT IN DAMAGE TO
AUTOMOBILES AND TENDER VEGETATION FROM LARGE HAIL...AND TO
OUTBUILDINGS...TREES...AND FENCES FROM DAMAGING WINDS.

RECOMMENDED ACTIONS...
STORM SPOTTER GROUPS AND EMERGENCY MANAGEMENT PERSONNEL ACROSS THE
RISK AREA SHOULD PLAN FOR SEVERE WEATHER OPERATIONS FROM NOW UNTIL
2 AM. PERSONS CAMPING OUT THIS HOLIDAY WEEKEND SHOULD ALSO SEEK OUT
ADEQUATE SHELTER IN CASE SEVERE WEATHER MOVES INTO YOUR AREA.

DISCUSSION...
A LINE OF SHOWERS AND STRONG TO SEVERE THUNDERSTORMS IS EXPECTED TO
MOVE EASTWARD ACROSS MUCH OF OKLAHOMA AND WESTERN NORTH TEXAS
THROUGH THE OVERNIGHT HOURS. ALTHOUGH WIND SHEAR IS ONLY MODERATE AT
BEST...STRONG INSTABILITY EXISTS OVER THE AREA. AS A STRONG UPPER
STORM SYSTEM MOVES CLOSER TO THE AREA...CONDITIONS WILL BE
FAVORABLE FOR THE ONGOING THUNDERSTORM ACTIVITY TO MAINTAIN ITS
STRENGTH FOR SEVERAL MORE HOURS.

THREAT TABLE...
VALID THROUGH 700 AM CDT MON MAY 27.
PROBABILITY OF THUNDERSTORMS OCCURRING IN THE
              NWS NORMAN COUNTY WARNING AREA...100 PERCENT.
PROBABILITY OF SEVERE STORMS IF STORMS OCCUR...60 PERCENT.

OTHER HAZARDOUS WEATHER...
ASIDE FROM THE SEVERE WEATHER THREAT...NO OTHER HAZARDOUS WEATHER IS
EXPECTED THROUGH TONIGHT.