Tornado Warning 37, NWS Norman, OK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORMAN OK
250 PM CDT MON MAY 3 1999

NEGATIVELY TILTED TROF CONTINUES TO DIG SOUTHEASTWARD ACROSS THE
SOUTHWEST US THIS AFTERNOON. AN INITIAL S/WV NOW MOVING ACROSS NEW
MEXICO WILL CONT TO MOVE EAST NORTHEAST ACROSS THE TX PANHANDLE INTO
WESTERN OK AND SOUTHERN KS THIS EVENING. A STRONGER WAVE JUST NOW
CROSSING THE SEIRRA NEVADAS WILL QUICKLY DROP INTO THE BASE OF THE
TROF LATER TONIGHT AND MOVE ACROSS THE AREA ON TUESDAY.

AS ALL THIS IS HAPPENING A DRY LINE NEAR THE TX/OK BORDER WILL
SLOWLY WORK ITS WAY EAST FOR THE FIRST PART OF THIS EVENING. AS
STORMS BECOME ORGANIZED ALONG THE DRY LINE LATER THIS EVENING THEY
WILL MOVE EASTWARD ACROSS THE STATE OVERNIGHT. THEY WILL PROBABLY
ADVANCE AHEAD OF THE DRY LINE...WHICH SHOULD REMAIN ACROSS WESTERN
OK OR RETREAT WESTWARD LATER THIS EVENING IN ANTICIPATION OF THE
MAIN WAVE WHICH COMES OUT ON TUESDAY. AT THAT TIME THE DRY LINE
WHICH WILL BE ALIGNED ALONG THE TX/OK BORDER AND THE PACIFIC COOL
FRONT WHICH WILL BE TRAILING THE DRY LINE INITIALLY WILL MAKE THERE
WAY INTO THE CENTRAL SECTIONS OF OK BY 18Z.

AS THE OVERNIGHT AND EARLY MORNING CONVECTION CONT TO MOVE EAST
EARLY TUESDAY MOST OF WESTERN AND PERHAPS CENTRAL OKLAHOMA WILL END
UP DRY TUESDAY AFTERNOON. THINK THAT BEST CHANCES FOR AFTERNOON
CONVECTION ON TUESDAY WILL BE FROM I-35 EASTWARD. WILL LIKELY KEEP
SOME CHANCES IN CENTRAL AND SOUTHEAST TOMORROW AFTERNOON. OTHERWISE
POPS ON TUESDAY WILL BE FOR LINGERING STORMS FROM TONIGHTS ACTIVITY.

FOR THE EXTENDED MRF TRIES TO CLOSE THE UPPER CIRCULATION OFF AGAIN
OVER THE CENTRAL U.S. AND BRINGS ANOTHER S/WV AROUND THE CIRCULATION
ON THURSDAY. THINK THIS WILL JUST BRING SOME MID AND HIGH LEVEL
CLOUDS TO THE AREA. THE CLOSED LOW SLOWLY MOVES EAST AFTER THAT AND
LEAVES THE SOUTHERN PLAINS DRY WITH A WARMING TREND INTO THE
WEEKEND.

FCSTID = 30
OKC   65  77  52  70 /  70  50  10   0
HBR   61  78  48  74 /  60  30   0   0
SPS   64  81  52  77 /  60  40   0   0
GAG   55  75  45  68 /  30  20   0   0
PNC   63  77  50  68 /  70  50  10   0
DUA   65  78  53  73 /  60  50  20   0

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

OKZ004>048-050>052-TXZ083>090-031930-

THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE NORMAN OK
1230 PM CDT MON MAY 3 1999

THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER THE WESTERN
HALF OF OKLAHOMA AND WESTERN NORTH TEXAS LATER THIS AFTERNOON THROUGH
TONIGHT. THE RISK AREA IS EAST OF A HOLLIS TO BUFFALO LINE AND WEST
OF U.S.HIGHWAY 177. AREAS OF CENTRAL AND SOUTHEAST OKLAHOMA EAST OF
HIGHWAY 177 ARE IN A SLIGHT RISK.

DISCUSSION...AN INTENSIFYING TROUGH OF LOW PRESSURE IN THE UPPER
ATMOSPHERE WAS LOCATED IN CENTRAL ARIZONA EARLY THIS AFTERNOON.
LATER THIS AFTERNOON THE FEATURE WILL BRING STRONG MID-LEVEL WINDS
INTO A FAVORABLE POSITION FOR SEVERE THUNDERSTORM DEVELOPMENT ACROSS
WESTERN OKLAHOMA AND THE WESTERN PART OF NORTH TEXAS. SURFACE MOISTURE
WAS ALSO ABUNDANT ACROSS THE RISK AREA AT NOON AS DEWPOINTS
CONTINUED TO RISE INTO THE UPPER 60S ACROSS SOUTHWEST AND CENTRAL
OKLAHOMA. A DRYLINE WILL STRETCH ACROSS NORTHWEST OKLAHOMA INTO THE
SOUTHEAST TEXAS PANHANDLE LATER THIS AFTERNOON WHICH WILL PROVIDE A
FOCUS FOR THUNDERSTORM DEVELOPMENT INTO THE NIGHT. THESE STORMS
SHOULD EVENTUALLY FORM INTO A SQUALL LINE AS THEY MOVE EAST INTO
CENTRAL OKLAHOMA LATE THIS EVENING.

WIND SHEAR IN THE ATMOSPHERE IS EXPECTED TO BE FAVORABLE FOR STORM
ORGANIZATION AND SOME SUPERCELL THUNDERSTORMS ARE LIKELY.
ALTHOUGH HAIL AND DAMAGING WINDS ARE THE MAIN SEVERE WEATHER
THREATS...THE COMBINATION OF MODERATE INSTABILITY AND MODERATELY
STRONG WIND FIELDS SUGGEST THAT ISOLATED TORNADOES ARE ALSO POSSIBLE
INTO THE MID-EVENING.  AS THE THUNDERSTORMS ORGANIZE INTO A SQUALL
LINE LATER THIS EVENING...THE MAIN SEVERE THREATS WILL BE HAIL
AND STRONG WINDS.

EMERGENCY MANAGERS AND SPOTTER GROUPS ACROSS CENTRAL AND WESTERN
OKLAHOMA AND WESTERN NORTH TEXAS SHOULD BE PREPARED FOR POSSIBLE
ACTIVATION LATER THIS AFTERNOON AND THROUGH THE EVENING.

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
417 PM CDT MON MAY  3 1999

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

0420 PM    WESTERN LAWTON            OK   .88 INCH HAIL
05/03/99   COMANCHE

J

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
436 PM CDT MON MAY  3 1999

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

0435 PM    5 N LAWTON                OK   1.75 INCH HAIL
05/03/99   COMANCHE

J