Severe Thunderstorm Warning 20, NWS Tulsa, OK

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION...CORRECTION
   (TO LAST SENTENCE IN FIRST PARAGRAPH)
NATIONAL WEATHER SERVICE TULSA OK
1010 AM CST THU FEB 17 2000

15Z SURFACE ANALYSIS INDICATES WARM FRONT ACROSS NORTHEAST AND NORTH
CENTRAL TEXAS ROUGHLY BETWEEN THE RED RIVER AND INTERSTATE 20.
SOLID DECK OF CLOUDS NORTH OF WARM FRONT AND EAST TO NORTHEASTERLY
SURFACE WINDS OVER ARKANSAS WILL KEEP THE FRONTAL BOUNDARY FROM
LIFTING RAPIDLY NORTHWARD DURING THE DAY.  HOWEVER...12Z H8 ANALYSIS
INDICATES STRONG LOW LEVEL JET HAS FORMED IN WESTERN OKLAHOMA WHICH
MAY TEND TO LIFT THE WESTERN PORTIONS OF THE WARM FRONT.  DO NOT
EXPECT WARM FRONT TO LIFT MUCH FARTHER NORTH THAN CHOCTAW COUNTY IN
EASTERN OKLAHOMA THIS AFTERNOON...SO MAXIMUM TEMPERAURES MAY RISE
MUCH EXCEPT PERHAPS IN THE FAR SOUTHEAST.

12Z H5 ANALYSIS INDICATES STRONG UPPER LEVEL SYSTEM ACROSS THE
SOUTHERN ROCKIES WITH COLD AIR POCKET ALOFT WHICH SHOULD MOVE
THROUGH THE AREA TONIGHT.  EXPECT THIS TO BE THE PRIMARY TRIGGER FOR
ANOTHER ROUND OF SEVERE WEATHER TONIGHT...ESPECIALLY AS WARM FRONTAL
BOUNDARY LIFTS NORTHWARD INTO EASTERN OKLAHOMA.  AM RELUCTANT TO
PLAY DOWN THE ROUND OF CURRENT SEVERE WEATHER IN THE MEANTIME.  WILL
WAIT UNTIL AROUND NOON AND ADJUST CURRENT FORECAST AT THAT TIME.

FCSTID = 11

.TUL...
AR...NONE.
OK...NONE.

ARZ001-002-010-011-019-020-029-OKZ049-053>076-181200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
630 AM CST THU FEB 17 2000

...A FEW SEVERE THUNDERSTORMS ARE EXPECTED ACROSS EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS TODAY AND TONIGHT...

.SYNOPSIS...
AN UPPER-LEVEL DISTURBANCE OVER THE SOUTHWEST U.S. EARLY THIS
MORNING WILL MOVE INTO THE SOUTHERN PLAINS BY LATE THIS
AFTERNOON...AS SURFACE LOW PRESSURE DEVELOPS OVER THE TEXAS
PANHANDLE.  A WARM FRONT EXTENDING SOUTHEASTWARD FROM THE SURFACE
LOW WILL MOVE NORTHWARD INTO SOUTHEAST OKLAHOMA THIS EVENING AS THE
SURFACE LOW MOVES ACROSS NORTHERN OKLAHOMA.  THE SURFACE LOW
PRESSURE CENTER WILL MOVE RAPIDLY NORTHEAST AFTER MIDNIGHT...
ALLOWING A COLD FRONT TO PASS THROUGH MUCH OF THE AREA BY MORNING.

.PRIMARY HAZARD...
SCATTERED THUNDERSTORMS OVER FAR SOUTHEAST OKLAHOMA ARE EXPECTED TO
SPREAD NORTHWARD ACROSS ALL OF EASTERN OKLAHOMA AND NORTHWEST
ARKANSAS BY MIDDAY.  PERIODS OF THUNDERSTORMS ARE EXPECTED TO
CONTINUE THROUGH THE AREA THROUGH THE AFTERNOON AND EVENING BEFORE
ENDING LATE TONIGHT.  A FEW OF THE STORMS ARE EXPECTED TO REACH
SEVERE LEVELS WITH LARGE HAIL THE PRIMARY THREAT.

.DISCUSSION...
WITH THE WARM FRONT SOUTH OF THE AREA...A COOL AIRMASS WILL REMAIN
IN PLACE ACROSS THE REGION.  HOWEVER...AS THE UPPER-LEVEL
DISTURBANCE APPROACHES...PLENTIFUL LOW-LEVEL MOISTURE WILL BE LIFTED
OVER THE COOLER AIR THROUGHOUT THE DAY.  THIS LIFT WILL COMBINE
WITH CONSIDERABLE ELEVATED INSTABILITY TO PRODUCE PERIODS OF
THUNDERSTORMS THROUGHOUT THE DAY AND EVENING.

GIVEN THE ELEVATED NATURE OF THESE STORMS...LARGE HAIL WILL BE THE
PRIMARY SEVERE WEATHER THREAT.  HOWEVER...IF THE WARM FRONT MAKES IT
INTO SOUTHEAST OKLAHOMA THIS EVENING...SUPERCELLS WITH MORE
SIGNIFICANT SEVERE WEATHER WILL BE POSSIBLE.  AT THIS TIME IT LOOKS
AS THOUGH SUPERCELLS...IF ANY...WOULD BE CONFINED TO AREAS NEAR THE
RED RIVER BEGINNING AFTER 7 PM THIS EVENING AND LASTING INTO THE
EARLY MORNING HOURS.  A COLD FRONT IS EXPECTED TO SWEEP SOUTHEAST
ACROSS THE AREA LATE TONIGHT...BRINGING AN END TO THE SEVERE WEATHER
THREAT.

.SPOTTER ACTIVATION...
SPOTTER ACTIVATION WILL LIKELY BE REQUIRED ACROSS THE ENTIRE AREA BY
MIDDAY.  AN UPDATED OUTLOOK WILL BE ISSUED AROUND 1 PM.

FOR A GRAPHICAL DEPICTION OF THIS OUTLOOK AND MORE INFORMATION FROM
THE NATIONAL WEATHER SERVICE IN TULSA...VISIT WWW.NWSTULSA.NOAA.GOV.