[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 280909
SWODY2
SPC AC 280907

DAY 2 CONVECTIVE OUTLOOK RESENT 4
NWS STORM PREDICTION CENTER NORMAN OK
0307 AM CST TUE NOV 28 2006

VALID 291200Z - 301200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM SERN KS/SWRN MO SWD INTO
N-CNTRL AND NERN TX...

...SYNOPSIS...

A PROGRESSIVE WAVE TRAIN IS FORECAST FROM THE NERN PACIFIC AND WRN
CANADA EWD INTO CNTRL CANADA AND THE N-CNTRL TIER OF STATES. 
MEANWHILE...A SLOWER EWD MOVEMENT OF DEEP...LOW LATITUDE TROUGH IS
EXPECTED FROM THE SRN ROCKIES INTO THE SRN HIGH PLAINS.  IN THE
LOW-LEVELS...SURFACE COLD FRONT INITIALLY FROM LOW PRESSURE OVER
LAKE SUPERIOR SWWD TO SECONDARY LOW PRESSURE OVER THE TX S PLAINS
WILL PUSH SEWD THROUGH THE PERIOD...EXTENDING FROM CNTRL LOWER MI TO
THE LOWER RIO GRANDE VALLEY BY THURSDAY MORNING.

...LOWER MO VALLEY SWD INTO NERN TX...

28/00Z SOUNDINGS WITHIN LOW-LEVEL MOISTURE AXIS ACROSS THE SRN
PLAINS INDICATE THAT PRE-FRONTAL AIR MASS IS ALREADY WEAKLY TO
MODERATELY UNSTABLE WITH MUCAPES OF 500-1000 J/KG.  PERSISTENT SLY
FLOW AHEAD OF COLD FRONT WILL RESULT IN A FURTHER INCREASE IN
BOUNDARY-LAYER MOISTURE ACROSS THE SLIGHT RISK AREA...SUPPORTING
MUCAPES OF 1000-1500 J/KG BY WEDNESDAY AFTERNOON.  INSTABILITY IS
FORECAST TO DECREASE WITH NEWD EXTENT WITH MUCAPES OF 500-800 J/KG
MORE LIKELY TOWARD THE LOWER MO VALLEY.

TSTMS ARE EXPECTED TO BE ONGOING WEDNESDAY MORNING ALONG FRONT OVER
PORTIONS OF IA WITHIN WEAKLY UNSTABLE AIR MASS.  INCREASING HEIGHT
FALLS/DYNAMIC LARGE-SCALE FORCING FOR ASCENT SHOULD SUPPORT SWWD
STORM DEVELOPMENT ALONG/AHEAD OF FRONT BY AFTERNOON AS BOUNDARY
LAYER BECOMES INCREASINGLY UNSTABLE.  VERTICAL SHEAR PROFILES ALONG
LENGTH OF FRONTAL ZONE WILL BE QUITE FAVORABLE FOR ORGANIZED STORMS
INCLUDING SUPERCELLS GIVEN 50-65 KT OF EFFECTIVE BULK SHEAR. 
CURRENTLY...IT APPEARS THAT INSTABILITY WILL REMAIN QUITE MARGINAL
ACROSS NRN AND CNTRL MO...WHICH COULD POTENTIALLY LIMIT A MORE
SUBSTANTIAL SEVERE THREAT.  MODEL TRENDS WILL BE MONITORED AND AN
UPGRADE TO SLIGHT RISK MAY BE NECESSARY IN LATER OUTLOOKS.

AN APPARENT GREATER SEVERE STORM THREAT WILL EXIST FROM SERN KS/SWRN
MO SSWWD INTO THE ERN HALF OF OK AND N-CNTRL/NERN TX WHERE AIR MASS
IS FORECAST TO BECOME MORE UNSTABLE.  SUPERCELLS ARE POSSIBLE GIVEN
THE STRONGLY SHEARED ENVIRONMENT...THOUGH CONVECTION SHOULD TEND TO
EVOLVE TO MORE OF A LINEAR STRUCTURE OWING TO THE ANAFRONTAL
CHARACTERISTICS OF THE COLD FRONT.  DAMAGING WINDS AND SEVERE HAIL
APPEAR TO BE THE MAIN THREATS WITH THE STRONGEST STORMS.

MORE BROKEN...CELLULAR STORM DEVELOPMENT WILL BE POSSIBLE LATE
WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT SWD ALONG TROUGH OR DRYLINE
ATTENDANT TO COLD FRONT INTO N-CNTRL AND CNTRL TX.  SHEAR PROFILES
WILL BE QUITE SUPPORTIVE OF SUPERCELLS CAPABLE OF LARGE HAIL AND
PERHAPS A COUPLE OF TORNADOES OWING TO THE ANTICIPATED MORE DISCRETE
NATURE OF THE STORMS.  ACTIVITY SHOULD EVOLVE INTO A QUASI-LINEAR
MCS OVERNIGHT AS COLD FRONT OVERTAKES TROUGH/DRYLINE WITH ASSOCIATED
WIND/HAIL THREAT DEVELOPING TOWARD THE ARKLATEX.

..MEAD.. 11/28/2006