Severe Thunderstorm Warning 178, NWS Tulsa, OK

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
1120 AM CDT TUE MAY 4 1999

RUNNING WAY BEHIND THIS MORNING.  HAVE ISSUED UPDATED ZONES TWICE...
ONCE TO UP POPS TO CATEGORICAL NORTH AND LIKELY SOUTH AND ISSUE
FLASH FLOOD WATCH FOR ALL ZONES...AND SECOND TO HEADLINE THE NEW
TORNADO WATCH UNTIL 4PM FOR THE ENTIRE AREA.  IT LOOKS LIKE THE BEST
TORNADIC THREAT WILL BE IN THE SOUTHERN HALF OF THE AREA WHERE
ATMOSPHERE IS LESS WORKED OVER...WITH HEAVY RAIN AND FLASH FLOODING
THE BIGGEST THREAT IN THE NORTH.  SEVERE HAIL LOOKS TO BE A
POSSIBILITY JUST ABOUT EVERYWHERE.

DID NOT TOUCH SECOND PERIOD AS TIMING OF DRYLINE STILL NOT CERTAIN.
MAY PROLONG SEVERE...HEAVY RAIN THREAT INTO THE EVENING ESPECIALLY
IN EASTERN ZONES WITH FUTURE UPDATES IF NEEDED.

FCSTID = 19

.TUL...
AR...FLASH FLOOD WATCH FOR TODAY ALL ZONES.
OK...FLASH FLOOD WATCH FOR TODAY ALL ZONES.

ARZ001-002-010-011-019-020-029-OKZ049-053>076-051100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
600 AM CDT TUE MAY 4 1999

...A TORNADO WATCH IN EFFECT ACROSS PARTS OF EASTERN OKLAHOMA
UNTIL 11 AM...

A FEW SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS PARTS OF EASTERN OKLAHOMA
THIS MORNING AND AFTERNOON. THIS THREAT WILL SHIFT TO FAR EASTERN
OKLAHOMA NORTHWEST ARKANSAS LATE THIS AFTERNOON AND EVENING.

.SYNOPSIS...
AN UPPER LEVEL TROUGH OF LOW PRESSURE CURRENTLY SITUATED OVER COLORADO
AND NEW MEXICO WILL DEEPEN AND LIFT NORTHEAST INTO KANSAS BY EARLY THIS
EVENING. AN UPPER LEVEL JET STREAK ASSOCIATED WITH THE LOW WAS CURRENTLY
OVER NORTHERN TEXAS. AT THE SURFACE...A DRYLINE LOCATED OVER WESTERN
OKLAHOMA THIS MORNING WILL MOVE EAST AS THE DAY PROGRESSES

.DISCUSSION...
THE UPPER LEVEL JET STREAK CURRENTLY ROTATING AROUND THE LOW WILL ACT AS
SOURCE OF LIFT FOR THE FORMATION OF THUNDERSTORMS ACROSS MUCH OF
OKLAHOMA THIS MORNING. AS A RESULT OF THE POSITIONING OF THIS
FEATURE...A FEW SEVERE STORMS WILL BE POSSIBLE. LARGE HAIL AND DAMAGING
WINDS WILL BE THE LIKELY THREAT BUT A FEW SUPERCELLS WILL BE POSSIBLE
GIVEN CURRENT WIND SHEAR PROFILES.

THE PROGRESSION OF THE UPPER LEVEL LOW AND SURFACE DRYLINE WILL SERVE AS
THE FOCUS FOR A FEW SEVERE STORMS THIS AFTERNOON ACROSS EASTERN
OKLAHOMA. STORMS THAT DO FORM WILL LIKELY EVOLVE INTO A SQUALL LINE AS
THEY MOVE ACROSS EASTERN OKLAHOMA. FORECASTED INSTABILITY INDICATE
DAMAGING WINDS AND LARGE HAIL THE PRIMARY THREATS. WIND PROFILES REMAIN
FAVORABLE FOR ISOLATED EMBEDDED SUPERCELLS AS THE DRYLINE MOVES ACROSS
EASTERN OKLAHOMA. THE SEVERE WEATHER THREAT WILL SHIFT TO FAR EASTERN
OKLAHOMA AND NORTHWEST ARKANSAS BY EARLY EVENING. THE DRYLINE WILL BE
EAST OF NORTHWEST ARKANSAS BY LATE EVENING THUS ENDING THE SEVERE THREAT
OVER ALL OF EASTERN OKLAHOMA AND NORTHWEST ARKANSAS.

.EMERGENCY MANAGEMENT AGENCY AND SPOTTER ACTIVATION...
SPOTTER GROUPS ACROSS ALL OF EASTERN OKLAHOMA AND NORTHWEST ARKANSAS
SHOULD KEEP INFORMED OF THE LATEST WEATHER CONDITIONS.  ACTIVATION MAY
BE NEEDED THIS MORNING AND AFTERNOON ACROSS EASTERN OKLAHOMA...AND
POSSIBLY BY THIS EVENING ACROSS NORTHWEST ARKANSAS.

ARZ001-002-010-011-019-020-029-OKZ049-053>076-051100-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
600 AM CDT TUE MAY 4 1999

...A TORNADO WATCH IN EFFECT ACROSS PARTS OF EASTERN OKLAHOMA
UNTIL 11 AM...

A FEW SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS PARTS OF EASTERN OKLAHOMA
THIS MORNING AND AFTERNOON. THIS THREAT WILL SHIFT TO FAR EASTERN
OKLAHOMA NORTHWEST ARKANSAS LATE THIS AFTERNOON AND EVENING.

.SYNOPSIS...
AN UPPER LEVEL TROUGH OF LOW PRESSURE CURRENTLY SITUATED OVER COLORADO
AND NEW MEXICO WILL DEEPEN AND LIFT NORTHEAST INTO KANSAS BY EARLY THIS
EVENING. AN UPPER LEVEL JET STREAK ASSOCIATED WITH THE LOW WAS CURRENTLY
OVER NORTHERN TEXAS. AT THE SURFACE...A DRYLINE LOCATED OVER WESTERN
OKLAHOMA THIS MORNING WILL MOVE EAST AS THE DAY PROGRESSES

.DISCUSSION...
THE UPPER LEVEL JET STREAK CURRENTLY ROTATING AROUND THE LOW WILL ACT AS
SOURCE OF LIFT FOR THE FORMATION OF THUNDERSTORMS ACROSS MUCH OF
OKLAHOMA THIS MORNING. AS A RESULT OF THE POSITIONING OF THIS
FEATURE...A FEW SEVERE STORMS WILL BE POSSIBLE. LARGE HAIL AND DAMAGING
WINDS WILL BE THE LIKELY THREAT BUT A FEW SUPERCELLS WILL BE POSSIBLE
GIVEN CURRENT WIND SHEAR PROFILES.

THE PROGRESSION OF THE UPPER LEVEL LOW AND SURFACE DRYLINE WILL SERVE AS
THE FOCUS FOR A FEW SEVERE STORMS THIS AFTERNOON ACROSS EASTERN
OKLAHOMA. STORMS THAT DO FORM WILL LIKELY EVOLVE INTO A SQUALL LINE AS
THEY MOVE ACROSS EASTERN OKLAHOMA. FORECASTED INSTABILITY INDICATE
DAMAGING WINDS AND LARGE HAIL THE PRIMARY THREATS. WIND PROFILES REMAIN
FAVORABLE FOR ISOLATED EMBEDDED SUPERCELLS AS THE DRYLINE MOVES ACROSS
EASTERN OKLAHOMA. THE SEVERE WEATHER THREAT WILL SHIFT TO FAR EASTERN
OKLAHOMA AND NORTHWEST ARKANSAS BY EARLY EVENING. THE DRYLINE WILL BE
EAST OF NORTHWEST ARKANSAS BY LATE EVENING THUS ENDING THE SEVERE THREAT
OVER ALL OF EASTERN OKLAHOMA AND NORTHWEST ARKANSAS.

.EMERGENCY MANAGEMENT AGENCY AND SPOTTER ACTIVATION...
SPOTTER GROUPS ACROSS ALL OF EASTERN OKLAHOMA AND NORTHWEST ARKANSAS
SHOULD KEEP INFORMED OF THE LATEST WEATHER CONDITIONS.  ACTIVATION MAY
BE NEEDED THIS MORNING AND AFTERNOON ACROSS EASTERN OKLAHOMA...AND
POSSIBLY BY THIS EVENING ACROSS NORTHWEST ARKANSAS.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TULSA OK
920 AM CDT TUE MAY 04 1999

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

0740 AM    4 N HOMINY                OK    TORNADO
05/04/99   OSAGE                           SPOTTERS REPORTED A
                                           BRIEF TORNADO TOUCHDOWN.

0830 AM    1 S PANAMA                OK    .75 INCH HAIL
05/04/99   LE

0912 AM    5 W HOMINY                OK    60 MPH TSTM GUST
05/04/99   OSAGE

0916 AM    5 W HOMINY                OK    .75 INCH HAIL
05/04/99   OSAGE