Severe Thunderstorm Warning 243, NWS Norman, OK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
820 PM CDT MON MAY 8 2000

MINOR CHANGES MADE TO ZONES TO REFLECT LATEST TRENDS.  MAIN ACTION
CONTINUES WITH ELEVATED CONVECTION IN NORTHERN OKLAHOMA...WELL NORTH
OF FRONT FROM SHAWNEE TO NEAR WALTERS. MAIN THREATS FROM THESE
STORMS WILL BE LARGE HAIL AND LOCALLY HEAVY RAINFALL/FLOODING.

00Z RAOB DATA SHOWS CONTINUATION OF COOLING TREND NOTED ALOFT
EARLIER THUS POTENTIAL STILL EXISTS FOR SURFACE BASED STORMS TONIGHT
AS SHORT WAVE BRUSHES ACROSS THE AREA. OKLAHOMA MESONET CONTINUES TO
INDICATE STRONG LOW-LEVEL SOUTHEAST FLOW ACROSS SOUTHERN OKLAHOMA
RESULTING IN STRONG CONVERGENCE ALONG THE SLOWLY ADVANCING COLD
FRONT. ADAS CAPE VALUES REMAIN ABOVE 3K J/KG ACROSS SOUTH THUS IF
ENOUGH MID LEVEL COOLING OCCURS STORMS MAY STILL DEVELOP RAPIDLY WITH
POTENTIAL FOR SUPERCELL STRUCTURE GIVEN IMPROVED SHEAR THIS EVENING.

..16..

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

OKZ004>048-050>052-TXZ083>090-082200-

THUNDERSTORM OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE NORMAN OK
343 PM CDT MON MAY 8 2000

THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON
AND EARLY TONIGHT OVER PARTS OF CENTRAL AND NORTHEAST OKLAHOMA...
NORTH AND EAST OF A LINE FROM SEMINOLE TO CHICKASHA TO BINGER TO
PERRY. ALSO... THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TONIGHT
NORTH AND EAST OF A LINE FROM COALGATE TO SNYDER TO HINTON TO BRAMAN.
SEVERE WEATHER WATCHES MAY BE NEEDED IN PARTS OF THESE AREAS BEFORE
SUNSET.

DISCUSSION...THUNDERSTORM DEVELOPMENT WILL BE LIKELY BY 7 PM ALONG
AND NEAR A SLOW MOVING COLD FRONT EXTENDING FROM NEAR CUSHING TO
OKLAHOMA CITY TO SNYDER LATE THIS AFTERNOON. WHILE NORTH WINDS
CONTINUE NORTH AND WEST OF THE FRONT... SURFACE WINDS ARE EXPECTED TO
BACK FROM SOUTHWESTERLY TO MORE SOUTHERLY TO THE SOUTH AND EAST OF
THE FRONT. THESE CHANGES WILL LEAD TO INCREASING CONVERGENCE ALONG
THE FRONT... AND A MORE FAVORABLE VERTICAL WIND PROFILE FOR SEVERE
THUNDERSTORMS BY EARLY EVENING. WINDS AT MID AND UPPER LEVELS ALSO
WILL CONTINUE TO STRENGTHEN...FURTHER ENHANCING VERTICAL SHEAR.

MUCH OF WESTERN AND NORTH CENTRAL OKLAHOMA HAS COOLED AND STABILIZED
BEHIND THE COLD FRONT. BUT THE AIR REMAINS WARM...HUMID AND VERY
UNSTABLE ALONG AND SOUTHEAST OF THE SURFACE BOUNDARY. A STRONG CAP OF
WARM AIR SEVERAL THOUSAND FEET ABOVE THE GROUND IS EXPECTED TO
WEAKEN THROUGH THIS EVENING... RESULTING IN AN INCREASING CHANCE
OF THUNDERSTORM DEVELOPMENT THROUGH THE EVENING. ANY STORMS THAT
INITIATE BEFORE SUNSET ARE LIKELY TO INTENSIFY QUICKLY... AND MAY
PRODUCE VERY LARGE HAIL... DAMAGING WINDS... AND POSSIBLY
TORNADOES.

FURTHER WEAKENING OF THE CAP IS EXPECTED AFTER DARK AS AN UPPER
LEVEL STORM SYSTEM APPROACHES THE AREA FROM THE SOUTHERN ROCKIES.
AS A RESULT... MORE WIDESPREAD THUNDERSTORM DEVELOPMENT IS EXPECTED
TONIGHT ACROSS MUCH OF CENTRAL AND NORTHERN OKLAHOMA. LARGE HAIL AND
VERY HEAVY RAINFALL WILL BE THE MAIN THREATS LATER TONIGHT...
ESPECIALLY ACROSS NORTH CENTRAL OKLAHOMA.

SPOTTER GROUPS OVER CENTRAL AND SOUTHWEST OKLAHOMA... FROM AS FAR
SOUTH AND WEST AS LAWTON AND SURROUNDING AREAS... NORTHEAST ACROSS
MUCH OF CENTRAL OKLAHOMA... SHOULD BE PREPARED FOR POSSIBLE
ACTIVATION AT ANY TIME THROUGH THIS EVENING.

24

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
729 PM CDT MON MAY 8 2000

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

0710 PM    TONKAWA                   OK   1.00 INCH HAIL
05/08/00   KAY                            PUBLIC REPORT

0725 PM    4 WNW MARLAND             OK   .75 INCH HAIL
05/08/00   NOBLE                          PUBLIC REPORT

JL

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
807 PM CDT MON MAY 8 2000

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

0742 PM    HENNESSEY                 OK   1.00 INCH HAIL
05/08/00   KINGFISHER                     REPORTED BY POLICE DEPT.

0740 PM    4 SSE BILLINGS            OK   .88 INCH HAIL
05/08/00   NOBLE                          PUBLIC REPORT

0750 PM    4 E GARBER                OK   .75 INCH HAIL
05/08/00   GARFIELD                       PUBLIC REPORT
                           0
JL

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
812 PM CDT MON MAY 08 2000

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

0810 PM    3 S GARBER                OK   1.25 INCH HAIL
05/08/00   GARFIELD                       HAM RADIO REPORT

JL

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
836 PM CDT MON MAY 8 2000

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

0820 PM    6 S BILLINGS              OK   1.00 INCH HAIL
05/08/00   NOBLE                          PUBLIC REPORT

0815 PM    MARSHALL                  OK   1.00 INCH HAIL
05/08/00   LOGAN                          REPORTED BY EOC

0805 PM    8 S PONCA CITY            OK   1.00 INCH HAIL
05/08/00   KAY                            PUBLIC REPORT

0835 PM    3 N HENNESSEY             OK   .88 INCH HAIL
05/08/00   KINGFISHER                     PUBLIC REPORT

0830 PM    HAYWARD                   OK   .75 INCH HAIL
05/08/00   GARFIELD                       PUBLIC REPORT

JL