Severe Thunderstorm Warning 39, NWS Tulsa, OK

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
235 AM CST THU FEB 11 1999

PROBLEM(S) OF THE DAY:
WHAT TYPE(S) OF SEVERE WEATHER WILL OCCUR?
WILL THE CONVECTION BE SCATTERED OR NUMEROUS?

CONVECTION STARTING TO FIRE NOW ACROSS CENTRAL KANSAS JUST BEHIND THE
COLD FRONT AS AIRMASS REMAINS CAPPED AHEAD OF THE FRONT. EXPECT
CONVECTION TO CONTINUE DEVELOPING SOUTH INTO OKLAHOMA AND EVENTUALLY
TO FORM JUST AHEAD OF THE FRONT AS UPPER FORCING INCREASES ALLOWING
THE CAP TO WEAKEN. THESE STORMS SHOULD QUICKLY BECOME SEVERE AND
ORGANIZE INTO A SQUALL LINE WITH HIGH WIND DAMAGE POTENTIAL. SOME
HAIL POTENTIAL MAINLY WITH STORMS BEHIND THE COLD FRONT.

STORMS SHOULD BE MOVING ALONG AT A GOOD ENOUGH CLIP THAT RAIN AMOUNTS
SHOULD BE LIMITED TO AROUND AN INCH AT ANY GIVEN LOCATION SO WILL NOT
ISSUE A FLASH FLOOD WATCH. COLD FRONT SHOULD MOVE EAST OF THE AREA BY
EARLY AFTERNOON BUT WILL SEE SOME CONVECTION LINGER FOR A FEW HOURS
FOLLOWING FRONTAL PASSAGE. WILL KEEP LOW POPS INTO THE EVENING IN FAR
SOUTHEAST OKLAHOMA AND NOT MENTION PRECIPITATION ELSEWHERE TONIGHT AS
WRAPAROUND PRECIPITATION NOW LOOKS LIKE IT WILL STAY TO THE NORTH.

TEMPERATURES WILL TUMBLE AND WINDS WILL INCREASE FROM THE NORTHWEST
FOLLOWING FRONTAL PASSAGE. WINDS MAY FLIRT WITH WIND ADVISORY
CRITERIA FOR A BRIEF TIME BUT THE DURATION OF THE STRONGER WINDS IS
NOT EXPECTED TO BE LONG SO WILL JUST OPT FOR CAUTION ON AREA LAKES.

NO PROBLEMS WITH THE FORECAST IN THE LATER PERIODS AS PACIFIC HIGH
BUILDS INTO THE AREA CLEARING SKIES OVERNIGHT. SEASONABLE FEBRUARY
WEATHER THEN EXPECTED FRIDAY AND SATURDAY WITH A MORE SIGNIFICANT
WARMUP SUNDAY AND MONDAY AHEAD OF THE NEXT STORM SYSTEM. ECMWF
SHOWING A STRONGER SYSTEM NOW MONDAY SO WILL INTRODUCE A CHANCE OF
SHOWERS AND THUNDERSTORMS AT THAT TIME. NO ARCTIC AIR IS IN SIGHT AT
THIS TIME.

GUIDANCE TEMPERATURES OF NO VALUE TODAY WITH CURRENT READINGS MUCH
ABOVE THE FORECAST MAXIMUMS AND FRONT ONLY EXPECTED INTO AREAS
NORTHWEST OF TULSA BY 13Z. AVN MOS TOO COLD TONIGHT AT TULSA WITH
NORTHWEST BREEZES HOLDING TEMPERATURES UP SOME. NGM MOS LOOKS TOO
WARM FRIDAY THOUGH DESPITE PACIFIC NATURE OF AIRMASS WITH AVN MOS
LOOKING BETTER.

FIRST PERIOD NUMBERS BELOW ARE SUBJECT TO CHANGE PRIOR TO RELEASE
TIME.

FCSTID = 5
TUL   68  22  47  25 /  90  10   0   0
FSM   72  26  46  23 / 100  10   0   0
MLC   70  24  48  24 /  90   5   0   0
BVO   60  20  47  23 /  80  10   0   0
FYV   70  23  44  20 / 100  10   0   0
IDB   75  28  48  22 / 100  20   0   0
BYV   70  23  44  20 / 100  10   0   0
MIO   69  22  46  22 / 100  10   0   0
MKO   70  24  48  24 /  90   5   0   0
F10   68  22  47  25 /  90  10   0   0
HHW   73  26  49  23 /  90  10   0   0

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

PLATE

--------------------
EXPERIMENTAL OUTPUT:

HAZARDOUS WEATHER EXPECTED NEXT 24 HOURS: LIKELIHOOD SEVERE
THUNDERSTORMS
NGM CONFIDENCE:  8 ON A SCALE OF 0 TO 10
ETA CONFIDENCE:  8 ON A SCALE OF 0 TO 10
AVN CONFIDENCE:  6 ON A SCALE OF 0 TO 10
FCST CONFIDENCE: 8 ON A SCALE OF 0 TO 10

ARZ001-002-010-011-019-020-029-OKZ049-053>076-121200-

EASTERN OKLAHOMA/NORTHWEST ARKANSAS HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
600 AM CST THU FEB 11 1999

...ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE THROUGH 11 AM ACROSS
MOST OF EASTERN OKLAHOMA WEST OF A SILOAM SPRINGS TO WILBURTON LINE...

...ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE THROUGH 3 PM ACROSS
NORTHWEST ARKANSAS AND FAR SOUTHEAST OKLAHOMA...

...BLUSTERY CONDITIONS EXPECTED TODAY...

A POWERFUL UPPER STORM SYSTEM CURRENTLY OVER WESTERN KANSAS WILL
CONTINUE TO MOVE THROUGH THE CENTRAL PLAINS TODAY AND EARLY
TONIGHT.  ASSOCIATED WITH THIS SYSTEM IS A STRONG COLD FRONT WHICH
WAS LOCATED ALONG A TOPEKA TO PONCA CITY TO CHILDRESS TEXAS LINE
EARLY THIS MORNING. A DRY LINE ALSO EXTENDED FROM NEAR ENID
SOUTHWARD TO WICHITA FALLS. THIS FRONT AND DRY LINE WILL MOVE
RAPIDLY EASTWARD THROUGH THE AREA TODAY PRODUCING WIDESPREAD SHOWERS
AND THUNDERSTORMS.

ALONG THE COLD FRONT AND THE DRY LINE...A LINE OF SHOWERS AND
THUNDERSTORMS CONTINUED TO DEVELOP ALONG A PONCA CITY TO DUNCAN LINE
EARLY THIS MORNING. THESE STORMS ARE EXPECTED TO INTENSIFY TO NEAR
SEVERE LEVELS THIS MORNING AS THE UPPER LEVEL SYSTEM MOVES CLOSER...
WITH DAMAGING STRAIGHT-LINE WINDS THE PRIMARY THREAT.

INSTABILITY ACROSS THE AREA REMAINS FAIRLY HIGH THIS MORNING BUT NOT
QUITE AS HIGH AS PREVIOUSLY EXPECTED. THUS...THE THREAT OF LARGE
HAIL GREATER THAN 1 INCH AND SUPERCELL THUNDERSTORMS HAS DIMINISHED
AND ARE NOT EXPECTED TO DEVELOP TODAY.

EMERGENCY MANAGEMENT ORGANIZATIONS AND STORM SPOTTER GROUPS MAY NEED
ACTIVATION THIS MORNING AND EARLY AFTERNOON.

AS THE PRECIPITATION AND ASSOCIATED COLD FRONT MOVE ACROSS THE AREA...
NORTHWEST WINDS GUSTING UP TO 40 MPH WILL DRIVE MUCH COLDER AIR
INTO THE AREA. TEMPERATURES WILL PLUMMET INTO THE 40S IMMEDIATELY
BEHIND THE FRONT AND CONTINUE TO DROP DURING THE DAY. WITH THE
STRONG WINDS...WIND CHILL VALUES WILL DROP INTO THE TEENS. THE
PRECIPITATION IS EXPECTED TO END BEFORE TEMPERATURES REACH THE
FREEZING MARK...THUS NO SNOW IS EXPECTED ACROSS THE AREA.

THIS OUTLOOK IS INTENDED TO PROVIDE GUIDANCE TO EMERGENCY MANAGEMENT
AGENCIES AND STORM SPOTTER GROUPS CONCERNING TORNADOES...SEVERE
THUNDERSTORMS...HIGH WIND EVENTS...FLOODING AND WINTER WEATHER.
INFORMATION CONCERNING OTHER HAZARDS CAN BE FOUND IN OTHER PRODUCTS
ISSUED BY THE NATIONAL WEATHER SERVICE OFFICE IN TULSA.

p

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TULSA OK
846 AM CST THU FEB 11 1999

OKZ055-056-060-066-111545-

THE SEVERE THUNDERSTORM WATCH IS NO LONGER IN EFFECT FOR THE
FOLLOWING COUNTIES IN

EASTERN OKLAHOMA.
         OKMULGEE            TULSA               NOWATA
         WASHINGTON

THE THREAT OF SEVERE WEATHER HAS MOVED EAST OF THESE COUNTIES.

OKZ057-058-061>063-067>070-072-ARZ001-002-010-011-019-020-111900-

SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 100 PM CST
THURSDAY FOR THE FOLLOWING COUNTIES IN

EASTERN OKLAHOMA...
         CHEROKEE            CRAIG               DELAWARE
         MAYES               MUSKOGEE            OTTAWA
         ADAIR               ROGERS              SEQUOYAH
         WAGONER

NORTHWEST ARKANSAS.
         BENTON              CRAWFORD            FRANKLIN
         MADISON             CARROLL             WASHINGTON

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TULSA OK
940 AM CST THU FEB 11 1999

OKZ057-061-062-067-070-111640-

THE SEVERE THUNDERSTORM WATCH IS NO LONGER IN EFFECT FOR THE
FOLLOWING COUNTIES IN

EASTERN OKLAHOMA.
         MAYES               CRAIG               MUSKOGEE
         ROGERS              WAGONER

THE THREAT OF SEVERE WEATHER HAS MOVED EAST OF THESE COUNTIES.

OKZ058-063-068-069-072-ARZ001-002-010-011-019-020-111900-

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 100 PM CST
THIS AFTERNOON FOR THE FOLLOWING COUNTIES IN

EASTERN OKLAHOMA...
         ADAIR               CHEROKEE            DELAWARE
         OTTAWA              SEQUOYAH

NORTHWEST ARKANSAS.
         BENTON              CRAWFORD            FRANKLIN
         MADISON             CARROLL             WASHINGTON

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TULSA OK
1034 AM CST THU FEB 11 1999

OKZ058-063-068-111734-

THE SEVERE THUNDERSTORM WATCH IS NO LONGER IN EFFECT FOR THE
FOLLOWING COUNTIES IN

EASTERN OKLAHOMA.
         CHEROKEE            DELAWARE            OTTAWA

THE THREAT OF SEVERE WEATHER HAS MOVED EAST OF THESE COUNTIES.

OKZ069-072-ARZ001-002-010-011-019-020-111900-

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 100 PM CST
THURSDAY FOR THE FOLLOWING COUNTIES IN

EASTERN OKLAHOMA...
         ADAIR               SEQUOYAH

NORTHWEST ARKANSAS.
         BENTON              CRAWFORD            FRANKLIN
         MADISON             CARROLL             WASHINGTON AR

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TULSA OK
1039 AM CST THU FEB 11 1999

OKZ069-072-111739-

THE SEVERE THUNDERSTORM WATCH IS NO LONGER IN EFFECT FOR THE
FOLLOWING COUNTIES IN

EASTERN OKLAHOMA.
         ADAIR               SEQUOYAH

THE THREAT OF SEVERE WEATHER HAS MOVED EAST OF THESE COUNTIES.

ARZ001-002-010-011-019-020-111900-

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 100 PM CST
THURSDAY FOR THE FOLLOWING COUNTIES IN

NORTHWEST ARKANSAS.
         BENTON              CRAWFORD            FRANKLIN
         MADISON             CARROLL             WASHINGTON