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000
ACUS02 KWNS 260535
SWODY2
SPC AC 260533

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1233 AM CDT SUN MAY 26 2013

VALID 271200Z - 281200Z

...THERE IS A SLGT RISK OF SVR TSTMS FOR A LARGE PORTION OF THE
PLAINS AND MO RIVER VALLEY...

...SYNOPSIS...
A POWERFUL UPPER JET LOCATED OVER THE ERN PACIFIC WILL ACT TO
REINVIGORATE A LARGE-SCALE TROUGH OVER THE WRN STATES DURING THE
LATTER HALF OF THE DAY 2 PERIOD.  DOWNSTREAM OVER THE CNTRL
U.S...SEVERAL WEAK MID-LEVEL PERTURBATIONS WILL MOVE ACROSS THE
CNTRL-NRN PLAINS INTO THE MIDWEST WHILE THE PRIMARY SHORTWAVE TROUGH
MOVES FROM THE NRN ROCKIES INTO ERN MT BY THE EVENING.
PLACEMENT/TIMING OF THESE SMALLER-SCALE FEATURES IS STILL
UNCERTAIN...BUT STRONG-SEVERE STORM ACTIVITY WILL PROBABLY ASSOCIATE
WITH AT LEAST ONE OF THESE IMPULSES MOVING ACROSS THE CNTRL PLAINS.
AT THE SURFACE...A LOW/TRIPLE POINT OVER WRN KS AND AN ATTENDANT
TROUGH/DRYLINE WILL SERVE TO FOCUS THE PRIMARY SEVERE POTENTIAL
DURING THE AFTERNOON THROUGH THE EVENING HOURS.

...CNTRL PLAINS...
WARM ADVECTION REGIME LIKELY ONGOING MONDAY MORNING OVER THE ERN
NEB/IA/NRN MO ON THE NOSE OF A LLJ WILL PROBABLY YIELD SCTD
SHOWERS/STORMS OVER THIS REGION INVOF OF A NW-SE ORIENTED FRONTAL
ZONE.  STORMS LOCATED ON THE SW FLANK OF THIS CLUSTER MAY POSE AN
ISOLD LARGE HAIL THREAT WHERE ACCESS TO GREATER H7-H5 LAPSE RATES
WOULD BE LOCATED ON THE ERN FRINGE OF THE EML.

MOIST/STRONG SLY LOW LEVEL FLOW WILL ALLOW DEWPOINTS TO RISE INTO
THE MID 60S-70 DEG F E/SE OF THE SURFACE LOW FROM OK INTO KS/SRN NEB
BENEATH AN INITIAL STRONG CAP.  MODELS SHOW MID-LEVEL LAPSE RATES IN
EXCESS OF 8 DEG C/KM AND FORECAST SOUNDINGS SHOW MLCAPE RANGING FROM
2500-4000 J/KG OVER NEB/KS.  N/NE OF THE TRIPLE POINT...BACKED ELY
COMPONENT TO LOW LEVEL FLOW WOULD SUPPORT STRONG DEEP LAYER SHEAR
PROFILES /35-45 KT EFFECTIVE SHEAR/ WELL INTO THE SUPERCELL RANGE.
STRONG HEATING DURING THE DAY WILL CONSIDERABLY WEAKEN THE CAP BY
AFTERNOON LEADING TO ISOLD-SCTD STORMS DEVELOPING.  LARGE TO VERY
LARGE HAIL AND DMGG WINDS ARE POSSIBLE WITH THE INITIAL
ACTIVITY...BUT AN INCREASING TORNADO THREAT MAY MATERIALIZE TOWARDS
THE EVENING AS LOW LEVEL SHEAR INCREASES IN RESPONSE TO AN
INTENSIFYING LLJ AND TEMP/DEWPOINT SPREADS LESSEN.  A POSSIBLE
UPSCALE TRANSITION MAY OCCUR DURING THE EVENING WITH A DMGG WIND
THREAT PERHAPS ENSUING AS STORMS MIGRATE EWD TOWARDS THE MO RIVER.

...NRN PLAINS...
A FRONTAL ZONE DRAPED OVER THE ERN DAKOTAS WILL ACT TO CONFINE THE
GREATER LOW LEVEL MOISTURE WWD OVER THE WRN DAKOTAS WITHIN SELY LOW
LEVEL FLOW AND ADJACENT NERN WY/ERN MT.  THE APPROACH OF THE
SHORTWAVE TROUGH OVER MT DURING PEAK HEATING WILL PROBABLY LEAD TO
ISOLD STORMS DEVELOPING...BOTH NEAR THE BLACK HILLS AND FARTHER NW
IN CLOSER PROXIMITY TO THE UPPER FORCING FOR ASCENT.  WIND PROFILES
WOULD SUPPORT STORM ORGANIZATION...WITH ISOLD LARGE HAIL AND DMGG
WINDS POSSIBLE.

...SRN PLAINS...
THE DRYLINE WILL EXTEND SWD FROM THE TRIPLE POINT LOW THROUGH
PORTIONS OF WRN OK AND INTO W TX DURING THE AFTERNOON.  STRONG
HEATING INVOF OF THE DRYLINE WILL PROMOTE A DEEPLY MIXED BOUNDARY
LAYER FEATURING VERY STEEP SURFACE-H5 LAPSE RATES.  30-35 KT
EFFECTIVE SHEAR SUPPORTIVE OF ORGANIZED DISCRETE STORMS WOULD POSE
AN ATTENDANT LARGE HAIL/SEVERE WIND GUST THREAT WITH THIS ACTIVITY
BEFORE WANING DURING THE EVENING HOURS.

..SMITH.. 05/26/2013