[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 290535
SWODY2
SPC AC 290533

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1233 AM CDT SAT JUL 29 2006

VALID 301200Z - 311200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE UPPER MS
VALLEY INTO THE GREAT LAKES...

...SYNOPSIS...

LARGE UPPER RIDGE CENTERED OVER THE CNTRL U.S. WILL DOMINATE MOST OF
THE COUNTRY...WITH STRONGER BELT OF WLYS REMAINING OVER THE NRN TIER
STATES. A POSITIVELY TILTED SHORTWAVE TROUGH WILL AMPLIFY INTO THE
PACIFIC NW THEN EJECT NEWD INTO SWRN CANADA. A BROAD...LOW AMPLITUDE
UPPER TROUGH WILL PERSIST ACROSS SERN CANADA INTO THE NERN STATES.
POTENTIAL ALSO WILL EXIST FOR A SERIES OF SMALLER SCALE VORTICITY
MAXIMA TO MOVE THROUGH THE BELT OF STRONGER FLOW. A COLD FRONT WILL
MOVE INTO THE NERN STATES...BUT SHOULD STALL DURING THE DAY. THIS
BOUNDARY WILL EXTEND NWWD THROUGH THE GREAT LAKES AREA AND TO A
SURFACE LOW ACROSS ND. THE WRN PORTION OF THIS BOUNDARY WILL LIFT
NWD AS A WARM FRONT. A COLD FRONT WILL ALSO MOVE THROUGH ERN MT INTO
ND.

...NERN ND THROUGH NRN MN AND GREAT LAKES AREA...

STRONGER BELT OF WLYS WILL MAINTAIN LAPSE RATE PLUME AS FAR EAST AS
THE GREAT LAKES. RICH LOW LEVEL MOISTURE WILL PERSIST ALONG AND S OF
THE FRONT WITH DEWPOINTS IN THE UPPER 60S TO AROUND 70. THESE
FACTORS WILL CONTRIBUTE TO POTENTIAL FOR STRONG INSTABILITY WHERE
SURFACE HEATING DEVELOPS. PRIMARY UNCERTAINTIES ARE TIMING OF
INDIVIDUAL VORT MAXES AND EVOLUTION OF ONGOING CONVECTION. MODELS
SUGGEST THAT STORMS MAY BE ONGOING WITHIN ZONE OF WARM ADVECTION
FROM PARTS OF THE UPPER MS VALLEY INTO THE GREAT LAKES AREA EARLY
SUNDAY. THIS ACTIVITY WILL SPREAD SEWD AND POTENTIAL WILL EXIST FOR
NEW DEVELOPMENT ALONG ASSOCIATED OUTFLOW BOUNDARIES DURING THE
AFTERNOON. ON THE LARGER SCALE...HEIGHTS ARE FORECAST TO BUILD FROM
THE NRN PLAINS INTO THE UPPER MS VALLEY WITHIN ZONE OF LOW LEVEL
WARM AIR ADVECTION. RISING HEIGHTS AND PRESENCE OF EML SUGGEST
THUNDERSTORM INITIATION MAY OCCUR FARTHER N THAN PREVIOUS DAYS. NEW
INITIATION MAY WAIT UNTIL EVENING AS THE LOW LEVEL JET
INCREASES...ENHANCING LIFT N OF BAROCLINIC ZONE FROM NRN
MN...EXTREME NRN WI INTO THE UPPER PENINSULA OF MI. VERTICAL SHEAR
IN THE 0-6 KM LAYER ON THE ORDER OF 40 KT WILL SUPPORT ORGANIZED
STORM STRUCTURES INCLUDING SUPERCELLS...ESPECIALLY IF STORMS DEVELOP
EARLY ENOUGH TO BE NEAR SURFACE BASED. LARGE HAIL AND DAMAGING WIND
WILL BE THE PRIMARY THREATS. 


...ERN PORTIONS OF THE OH VALLEY THROUGH NERN U.S....

STORMS MAY DEVELOP IN MORE WEAKLY CAPPED WARM SECTOR FROM OH INTO PA
AND WRN NY S OF FRONT EXPECTED TO EXTEND FROM NW-SE ACROSS A PORTION
OF NEW YORK. THE ATMOSPHERE IN THIS REGION WILL BECOME MODERATELY
UNSTABLE DURING THE AFTERNOON. STRONGEST FLOW IN THE 0-6 KM LAYER
WILL REMAIN FARTHER NE ON COOL SIDE OF THE FRONT WITH MODEST DEEP
LAYER VERTICAL SHEAR AND MID LEVEL LAPSE RATES IN WARM SECTOR. A FEW
MULTICELL STORMS CAPABLE OF PRODUCING ISOLATED STRONG TO DAMAGING
WIND GUSTS WILL BE THE MAIN THREAT.  

...SWRN U.S....

UPPER LOW OVER THE SWRN STATES IS FORECAST TO MOVE LITTLE THROUGH
THIS PERIOD. STORMS WILL LIKELY DEVELOP OVER THE HIGHER TERRAIN AS
OROGRAPHIC FORCING AND HEATING INCREASE DURING THE AFTERNOON. THE
THERMODYNAMIC ENVIRONMENT WITH MODERATE INSTABILITY AND STEEP LAPSE
RATES WILL SUPPORT THE POTENTIAL FOR ISOLATED DAMAGING WIND GUSTS
AND HAIL WITH THE STRONGER STORMS.

..DIAL.. 07/29/2006