[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 170549
SWODY2
SPC AC 170548

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1248 AM CDT MON APR 17 2006

VALID 181200Z - 191200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE MID / LOWER MO VALLEY
SEWD INTO THE TN VALLEY...

...SYNOPSIS...

HIGH AMPLITUDE LARGE-SCALE PATTERN WILL CONTINUE ACROSS THE CONUS
THROUGH THE DAY TWO PERIOD...CHARACTERIZED BY OMEGA BLOCK FROM THE
WRN ATLANTIC WWD INTO THE PLAINS.  WRN PART OF THIS BLOCK IS
MID-LEVEL TROUGH WHICH WILL INTENSIFY AND FORM A CLOSED LOW OVER THE
NRN PLAINS.

IN THE LOW-LEVELS...OCCLUSION OF NRN-MOST SURFACE LOW WILL OCCUR
TUESDAY MORNING OVER THE ERN DAKOTAS AS STRONG COLD FRONT OVERTAKES
NRN EXTENSION OF WARM OR QUASI-STATIONARY BOUNDARY STRETCHING FROM
THE MID MO VALLEY SEWD INTO THE TN VALLEY AND SERN STATES.  A
SECONDARY SURFACE LOW IS EXPECTED TO DEVELOP AT THE PROGRESSIVE COLD
FRONTAL OCCLUSION POINT SEWD FROM NWRN MO TUESDAY AFTERNOON INTO THE
WRN TN VALLEY LATE MONDAY NIGHT.

...MID AND LOWER MO VALLEY INTO THE TN VALLEY...

17/00Z SOUNDINGS FROM CRP/LCH INDICATE THAT LOW-LEVEL MOISTURE
PROFILES ARE SLOWLY IMPROVING ACROSS THE NWRN GULF COAST WITH LOWEST
MEAN MIXING RATIOS OF 13-15 G/KG.  WHILE THIS RICH A BOUNDARY-LAYER
AIR MASS WILL NOT LIKELY BE ADVECTED NWD INTO THE CNTRL LOW
PLAINS...IT DOES APPEAR THAT 60-65 F DEWPOINTS WILL BE POSSIBLE INTO
MO BY TUESDAY AFTERNOON...CONTRIBUTING TO MLCAPES OF 2000-2500 
J/KG.

STRONG DEEP-LAYER FORCING FOR ASCENT AHEAD OF EVOLVING UPPER LOW
WILL LIKELY SUPPORT AN INCREASE IN ELEVATED TSTMS DURING THE DAY
NEAR AND E OF OCCLUDED FRONT FROM PORTIONS OF ERN SD/SWRN MN SWD
INTO ERN NEB AND WRN IA.  RATHER STEEP MID-LEVEL LAPSE RATES AND
STRONG LOW-LEVEL WARM ADVECTION WILL CONTRIBUTE TO POCKETS OF
MODERATE INSTABILITY FOR ELEVATED PARCELS WITH STRONGEST STORMS
CAPABLE OF MAINLY SEVERE HAIL.

SURFACE-BASED STORM DEVELOPMENT IS EXPECTED BY MID TO LATE AFTERNOON
NEAR SECONDARY SURFACE LOW AND OCCLUSION POINT OVER NWRN MO. 
DESPITE THE STRONGEST MID AND HIGH-LEVEL WIND FIELDS REMAINING
FARTHER TO THE NW IN CLOSER PROXIMITY OF UPPER SYNOPTIC
SYSTEM...VERTICAL SHEAR PROFILES WILL BE SUPPORTIVE OF SEVERE STORMS
INCLUDING SUPERCELLS.  THE WARM SECTOR IS EXPECTED TO BE RATHER
NARROW AT THIS INITIATION POINT WITH ANY STORMS QUICKLY MOVING EWD
ACROSS NW-SE ORIENTED STATIONARY OR WARM FRONT INTO A MUCH MORE
STABLE ENVIRONMENT.

ADDITIONAL STORMS MAY ALSO DEVELOP BY LATE AFTERNOON/EARLY EVENING
SWD ALONG COLD FRONT OR PRE-FRONTAL TROUGH/DRY LINE OVER FAR
E-CNTRL/SERN KS INTO SWRN MO.  HERE...WARM SECTOR WILL BE WIDER
THOUGH MARGINAL DEEP-LAYER SHEAR AND STRONG LINEAR FORCING ALONG
COLD FRONT MAY PROMOTE A RAPID TRANSITION TO OUTFLOW-DOMINANT MCS
WITH THE MAIN THREATS BEING LARGE HAIL AND DAMAGING WINDS.

THE THREAT OF PRIMARILY DAMAGING WINDS AND SEVERE HAIL IS EXPECTED
TO DEVELOP SEWD INTO THE WRN TN VALLEY OVERNIGHT IN ASSOCIATION WITH
WEAKENING MIGRATORY SURFACE LOW.

...NRN FL INTO SWRN GA...

MOIST BOUNDARY-LAYER CONDITIONS ARE EXPECTED TO CONTRIBUTE TO A
MODERATELY UNSTABLE AIR MASS TUESDAY AFTERNOON ALONG WEAK BACK DOOR
FRONT SLOWLY SAGGING SWWD.  WHILE MID-LEVEL LAPSE RATES ARE NOT
EXPECTED TO BE PARTICULARLY STEEP...MODERATELY STRONG UNIDIRECTIONAL
VERTICAL SHEAR MAY SUPPORT A FEW ORGANIZED STORMS CAPABLE OF
ISOLATED DAMAGING WINDS AND PERHAPS A BRIEF TORNADO.

..MEAD.. 04/17/2006