Severe Thunderstorm Warning 37, NWS Tulsa, OK

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
1020 AM CDT SUN APR 16 1995

14Z SFC MAP SHOWED FRONTAL BOUNDARY FROM SOUTH OF MCI TO EMP TO DDC.
BOUNDARY MOVED NORTH OVERNIGHT BUT HAS NOW BEGUN SAGGING SOUTH AGAIN
DUE TO CONVECTIVE OUTFLOW IN KS. NEW ETA CONTINUES TO ALLOW THE
BOUNDARY TO SAG SOUTH INTO NE OK TONIGHT AS WEAK HIGH PRESSURE BUILDS
INTO THE CENTRAL PLAINS REINFORCING THE SHALLOW COOL AIRMASS NORTH OF
THE BOUNDARY.

AIRMASS ACROSS ERN OK REMAINS CAPPED AND TSTM CHANCES LOOK PRETTY SLIM
TODAY. WILL KEEP POPS IN NE OK JUST IN CASE A STORM CAN GET GOING BUT
WILL LOWER THEM A BIT. STORM CHANCES MAY INCREASE A BIT IN NE OK
TONIGHT AS THE FRONTAL BOUNDARY SAGS BACK INTO THE AREA.

THE BEST CHANCE OF TSTMS AND SEVERE WEATHER SHOULD BE MONDAY INTO
MONDAY EVENING AS THE STRONG UPPER LEVEL STORM MOVES OUT INTO THE
PLAINS. THE TRACK AND TIMING OF THE RESULTANT SFC LOW AND FEATURES ARE
STILL VERY MUCH IN DOUBT WITH WIDELY VARYING MODEL SOLUTIONS OFFERING
LITTLE HELP. THE ECMWF WHICH HAS HANDLED ALL OF THE RECENT SYSTEMS
QUITE WELL IS ABOUT 12 HOURS SLOWER THAN THE OTHER MODELS AND STILL HAS
THE SFC LOW OVER NW KS TUESDAY MORNING. HOWEVER...THIS MAY BE TOO SLOW
THIS TIME SINCE THE NEXT UPSTREAM SHORTWAVE WILL BE FOLLOWING SO
CLOSELY AND SHOULD HELP TO KICK THIS SYSTEM OUT. THE NGM AND AVN ARE
UNDOUBTABLY TOO FAR NORTHWEST WITH THE SFC LOW WHICH LEAVES THE ETA AND
LFM. THE ETA IS SIMILAR TO THE ECMWF...JUST 12 HOURS FASTER...WHILE THE
LFM IS MUCH FURTHER SOUTHEAST WITH THE SFC LOW IN SE KS BY MONDAY
EVENING (PER COORDINATION WITH WES JUNKER AT NMC). THE ANSWER MAY LIE
IN HOW MUCH CONVECTION FORMS NORTH OF THE FRONTAL BOUNDARY AND HELPS
REINFORCE THE BOUNDARY TO THE SOUTH. REGARDLESS...MONDAY LOOKS LIKE IT
COULD BE A VERY ACTIVE DAY ACROSS ERN OK...QUITE POSSIBLY THE MOST
ACTIVE OF THE SPRING WEATHER SEASON THUS FAR.

.TUL...NONE.

PLATE

ARZ001-002-010-011-019-029-OKZ054>077-171200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
115 PM CDT SUN APR 16 1995

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TONIGHT FOR
NORTHEASTERN OKLAHOMA AND THE NORTHWEST CORNER OF ARKANSAS. THE
RISK AREA IS ALONG AND NORTH OF A LINE FROM BRISTOW TO TAHLEQUAH
TO FAYETTEVILLE. THE RISK OF SEVERE WEATHER WILL INCREASE MONDAY.

EARLY THIS AFTERNOON A SURFACE FRONT WAS LOCATED FROM JUST SOUTH OF
EMPORIA KANSAS TO A WEAK SURFACE LOW NORTH OF WICHITA. THE FRONT
THEN EXTENDED SOUTHWEST ACROSS NORTHWEST OKLAHOMA. SOUTH OF THE
FRONT THE ATMOSPHERE IS UNSTABLE...BUT A WARM LAYER OF AIR BETWEEN
5000 AND 10000 FEET IS PROVIDING A CAP FOR THUNDERSTORM
DEVELOPMENT. EXTENSIVE CLOUD COVER WILL MINIMIZE HEATING TODAY.
THUS THUNDERSTORMS ARE NOT EXPECTED TO FORM THIS AFTERNOON.

THE FRONT IS EXPECTED TO SLOWLY MOVE SOUTHWARD OVERNIGHT AND BE
LOCATED ACROSS NORTHEAST OKLAHOMA AND EXTREME NORTHWEST ARKANSAS BY
MORNING. THIS AREA IS WHERE THE CAP IS WEAKEST. CONVERGENCE ALONG
THE FRONT COMBINED WITH WEAK UPPER LEVEL DISTURBANCES MOVING
THROUGH SOUTHWEST FLOW ALOFT MAY RESULT IN THUNDERSTORMS FORMING
TONIGHT...MAINLY AFTER MIDNIGHT. THUNDERSTORMS MAY BECOME SEVERE
WITH LARGE HAIL BEING THE PRIMARY THREAT.

A BETTER CHANCE OF SEVERE THUNDERSTORMS...INCLUDING THE POTENTIAL
FOR TORNADOES...WILL OCCUR MONDAY. A STRONG UPPER LEVEL SYSTEM IS
FORECAST TO MOVE INTO THE PLAINS PUSHING A DRYLINE EASTWARD ACROSS
OKLAHOMA DURING THE DAY. WITH PLENTY OF MOISTURE AND INSTABILITY
ALREADY IN PLACE...AND AN INCREASINGLY FAVORABLE WIND PROFILE...
MONDAY AND MONDAY NIGHT COULD BE VERY ACTIVE FOR SEVERE
THUNDERSTORMS ACROSS EASTERN OKLAHOMA AND NORTHWEST ARKANSAS.

CIVIL DEFENSE AGENCIES AND STORM SPOTTER GROUPS IN THE RISK AREA
SHOULD MONITOR THE LATEST WEATHER INFORMATION AND BE PREPARED FOR
POSSIBLE ACTIVATION TONIGHT. CIVIL DEFENSE AGENCIES AND STORM
SPOTTER GROUPS ACROSS EASTERN OKLAHOMA AND NORTHWEST ARKANSAS
SHOULD LISTEN FOR LATER FORECASTS AND THUNDERSTORM OUTLOOKS AND BE
PREPARED FOR POSSIBLE ACTIVATION MONDAY.

ARZ001-002-010-011-019-029-OKZ054>077-171200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS THUNDERSTORM OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE TULSA OK
230 PM CDT SUN APR 16 1995

...UPDATE...

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
NORTHEAST OKLAHOMA THIS AFTERNOON AND EVENING. THE RISK AREA IS
WEST OF A LINE FROM SOUTH COFFEYVILLE IN NOWATA COUNTY TO MILFAY IN
CREEK COUNTY. A TORNADO WATCH IS IN EFFECT  FOR OSAGE...PAWNEE...
WASHINGTON...NOWATA AND CREEK COUNTIES UNTIL 900 PM.

A WEAKENING CAP AND A WEAK DISTURBANCE IN THE MID LEVELS COMBINED
WITH A FRONT STRETCHING FROM WESTERN OKLAHOMA TO SOUTH CENTRAL
KANSAS HAS RESULTED IN THE RAPID DEVELOPMENT OF THUNDERSTORMS THIS
AFTERNOON ACROSS WESTERN OKLAHOMA...SEVERAL OF WHICH HAVE BEEN
SEVERE. THESE STORMS WERE MOVING NORTHEAST AND MAY AFFECT PARTS OF
NORTHEAST OKLAHOMA THIS AFTERNOON AND EVENING IN AREAS TO THE NORTH
AND WEST OF TULSA. LARGE HAIL AND DAMAGING WINDS ARE POSSIBLE WITH
THESE STORMS. THERE IS ALSO THE POTENTIAL FOR THE DEVELOPMENT OF
TORNADOES.

CIVIL DEFENSE AGENCIES AND STORM SPOTTER GROUPS IN THE TORNADO
WATCH AREA SHOULD BE ACTIVATING NOW.

THERE IS ALSO A SLIGHT RISK OF SEVERE THUNDEdRSTORMS TONIGHT FOR
NORTHEASTERN OKLAHOMA AND THE NORTHWEST CORNER OF ARKANSAS NORTH OF
A LINE FROM BRISTOW TO TAHLEQUAH TO FAYETTEVILLE.