Severe Thunderstorm Warning 15, NWS Tulsa, OK

EASTERN OKLAHOMA/NORTHWEST ARKANSAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TULSA OK
315 AM CST THU FEB 17 2000

MAJOR STORM SYSTEM TO AFFECT THE AREA TODAY AND TONIGHT. FRONTAL
BOUNDARY TO THE SOUTH HAS NOW FINALLY STALLED NEAR A TYLER TO WACO
TO FORT STOCKTON LINE. SURFACE CYCLOGENESIS NOW UNDERWAY IN
SOUTHEAST COLORADO AND AS THIS LOW SLIDES SOUTHEAST TODAY...THE
WESTERN END OF THE FRONTAL BOUNDARY WILL SURGE NORTHWARD.

ALREADY SEEING QUITE A BIT OF SHOWER AND THUNDERSTORM ACTIVITY
BREAKING OUT THIS MORNING MAINLY NORTH OF INTERSTATE 40 SO FAR. SOME
NEW CONVECTION ALSO GETTING GOING SOUTHEAST OF DALLAS JUST NORTH OF
THE FRONTAL BOUNDARY. WITH RICH GULF MOISTURE FLOWING NORTH OVER THE
SHALLOW COOL AIR AT THE SURFACE...SHOWERS AND THUNDERSTORMS SHOULD
CONTINUE TO INCREASE TODAY ACROSS EASTERN OKLAHOMA AND NORTHWEST
ARKANSAS. THIS WILL HELP TO REINFORCE THE COOL LOW LEVEL AIRMASS AND
THE FRONTAL BOUNDARY SHOULD REMAIN SOUTH OF THE RED RIVER TODAY. AS
A RESULT...LITTLE TEMPERATURE RECOVERY IS EXPECTED TODAY.

FOLLOWED AN ETA/AVN COMPROMISE ON THE TRACK OF THE SURFACE LOW
TONIGHT WHICH IS IN LINE WITH THE 06Z ETA RUN. THE REAL JUICY AIR IS
ONLY LIKELY TO MAKE IT INTO THE SOUTHWEST PART OF OUR FORECAST AREA
OVERNIGHT BEFORE THE DRYLINE/PACIFIC COLD FRONT SURGES EAST THROUGH
THE AREA LATE TONIGHT. WE SHOULD STILL SEE WIDESPREAD SHOWERS AND
THUNDERSTORMS OVERNIGHT WITH MOST OF THE ACTIVITY ENDING BY LATE
TONIGHT. TEMPERATURES OVERNIGHT WILL LIKELY RISE SEVERAL DEGREES IN
MOST AREAS BEFORE FALLING LATE AFTER THE COLD FRONTAL PASSAGE.

EXTENT OF SEVERE WEATHER ACROSS OUR FORECAST AREA IS REALLY IN
QUESTION. ELEVATED HAILERS WILL BE THE MAIN THREAT EXCEPT IN THE
SOUTHWEST PART OF THE FORECAST AREA WHERE SURFACE BASED CONVECTION
MAY BE POSSIBLE TONIGHT. FOR NOW WILL FOREGO THE MENTION OF SEVERE
IN THE ZONES AS THE WORST OF THE WEATHER SHOULD BE WEST AND SOUTH OF
OUR FORECAST AREA THIS AFTERNOON AND EVENING.

MAY SEE SOME CLEARING LATE TONIGHT BUT WRAPAROUND CLOUDINESS WILL
SPREAD BACK OVER MCUH OF THE AREA EARLY FRIDAY. THESE CLOUDS SHOULD
DECREASE SOME DURING THE AFTERNOON AS THE STORM SYSTEM PULLS RAPIDLY
AWAY FROM THE AREA AND SURFACE HIGH PRESSURE BUILDS IN.

HAVE NOT LOOKED MUCH AT THE EXTENDED YET BUT WILL TAKE A LOOK BEFORE
ISSUANCE TIME TO SEE IF ANY CHANGES ARE NEEDED.

GENERALLY WENT COOLER THAN MOST GUIDANCE TEMPERATURES THROUGH THE
FORECAST PERIOD.

FCSTID = 5
TUL   52  40  47  22 /  70  70   5   0
FSM   50  47  54  27 /  70  80  10   0
MLC   55  43  50  24 /  70  70   5   0
BVO   50  37  45  20 /  70  70   5   0
FYV   50  46  50  21 /  70  80  10   0
BYV   47  45  50  21 /  70  80  10   0
MIO   50  40  46  21 /  70  80   5   0
MKO   53  42  48  23 /  70  70   5   0
F10   52  40  47  22 /  70  70   5   0
HHW   58  46  53  27 /  70  70  10   0

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

PLATE

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.