DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 030603
SWODY1
SPC AC 030600

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0100 AM CDT THU OCT 03 2013

VALID 031200Z - 041200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF NEB INTO
IA...

...SYNOPSIS...

UPPER TROUGH WILL AMPLIFY ACROSS THE WRN U.S. BEFORE ADVANCING EWD
INTO THE CNTRL ROCKIES BY THE END OF THE PERIOD. BROAD SWLY TO WLY
FLOW WILL PERSIST DOWNSTREAM FROM THIS FEATURE ACROSS MUCH OF THE
PLAINS AND MS VALLEY REGION. LEAD SHORTWAVE TROUGH NOW LOCATED OVER
THE CNTRL PLAINS WILL DEAMPLIFY FURTHER AS IT SHIFTS NEWD THROUGH
THE MS AND OH VALLEYS. A MORE SUBTLE IMPULSE OVER THE SWRN STATES
WILL EJECT NEWD INTO THE CNTRL PLAINS THURSDAY AFTERNOON.

AT THE SFC A BAROCLINIC ZONE WILL STRETCH FROM NRN PORTIONS OF THE
OH VALLEY WWD INTO THE UPPER MS VALLEY THEN SWWD THROUGH CNTRL NEB.
A LEE TROUGH WILL PERSIST ACROSS THE CNTRL AND SRN HIGH PLAINS WITH
A DRYLINE EXTENDING THROUGH WRN TX INTO NWRN KS WHERE IT WILL
INTERSECT THE SWRN EXTENSION OF THE BAROCLINIC ZONE. THIS BOUNDARY
MAY LIFT A LITTLE FARTHER NWD AS A WARM FRONT THROUGH NEB OVERNIGHT
AS A LEE CYCLONE DEEPENS OVER THE CNTRL HIGH PLAINS.

...CNTRL PLAINS AREA...

STORMS WILL LIKELY BE ONGOING 12Z THURSDAY FROM SERN NEB INTO IA AND
NWRN MO PROMOTED BY A STRONG SLY LLJ. THIS ACTIVITY IS EXPECTED TO
GRADUALLY SHIFT EWD AND WEAKEN. RESIDUAL OUTFLOW BOUNDARY FROM THE
EARLY STORMS MAY LIFT BACK NWD INTO SERN NEB. IN WAKE OF THE MORNING
ACTIVITY...BOUNDARY LAYER RECOVERY IS LIKELY ACROSS CNTRL/ERN NEB AS
MID-UPPER 60S DEWPOINTS RETURN NWD THROUGH PRE-FRONTAL WARM SECTOR
BENEATH PLUME OF WARM AIR /10C AT 700 MB/ AT BASE OF THE EWD
ADVECTING ELEVATED MIXED LAYER. WHILE THESE PROCESSES WILL RESULT IN
DESTABILIZATION WITH 1500-2000 J/KG MLCAPE POSSIBLE...AREAS OF
CLOUDS WILL LIMIT EXTENT OF DIABATIC WARMING WHICH IN ADDITION TO
THE ELEVATED MIXED LAYER WILL LIKELY CONTRIBUTE TO A STOUT CAP OVER
THE WARM SECTOR DURING THE DAY.

THIS REGION WILL ALSO REMAIN WEST OF FORCING ASSOCIATED WITH LEAD
SHORTWAVE TROUGH WITH ONLY WEAK/SUBTLE FORCING ATTENDING THE
SECONDARY IMPULSE DURING THE AFTERNOON. POTENTIAL FOR A STRONG CAP
SUGGESTS SURFACE BASED THUNDERSTORM INITIATION IN WARM SECTOR COULD
BE PROBLEMATIC. A FEW STORMS MAY DEVELOP FARTHER WEST DURING THE
AFTERNOON IN THE UPSLOPE REGIME ACROSS THE CNTRL HIGH PLAINS OF CO
AND WY. BEST CHANCE FOR MORE ROBUST DEVELOPMENT MAY BE DELAYED UNTIL
EVENING AS THE LLJ STRENGTHENS AND INITIATES STORMS NORTH OF THE
EFFECTIVE BOUNDARIES INCLUDING RESIDUAL OUTFLOW BOUNDARY AND FARTHER
NORTH ALONG PRIMARY BAROCLINIC ZONE. EFFECTIVE VERTICAL SHEAR MAY BE
SUFFICIENT FOR SOME SUPERCELL STRUCTURES...BUT TENDENCY WILL BE FOR
STORMS TO LIFT NEWD INTO THE COOLER BOUNDARY LAYER. ISOLATED LARGE
HAIL APPEARS TO BE THE MAIN THREAT OVERNIGHT...BUT STRONG WIND GUSTS
AND A TORNADO CANNOT BE RULED OUT...ESPECIALLY WITH ANY NEAR SFC
BASED STORMS INITIATING ON THE BOUNDARY.

..DIAL/SMITH.. 10/03/2013

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