[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 011257
SWODY1
SPC AC 011255

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0755 AM CDT TUE AUG 01 2006

VALID 011300Z - 021200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER NERN NY AND NRN /CNTRL NEW
ENGLAND...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LWR MO VLY TO THE UPR
GRT LKS...

...SYNOPSIS...
SUBTROPICAL UPR RIDGE WILL ELONGATE E TO THE MID ATLANTIC CST THIS
PERIOD AS BELT OF STRONG WLY FLOW ASSOCIATED WITH NRN ONTARIO
SHORTWAVE TROUGH OVERSPREADS CNTRL QUEBEC AND THE LWR ST LAWRENCE
VLY.  IN THE WEST...TROUGH OVER THE NRN GRT BASIN SHOULD CONTINUE
ENE TO THE NRN PLNS WHILE A SERIES OF WEAKER IMPULSES MOVE NEWD IN
BELT OF ENHANCED FLOW EXTENDING FROM THE SRN HI PLNS TO THE UPR MS
VLY.

SURFACE LOW ACCOMPANYING THE ONTARIO DISTURBANCE SHOULD TRACK E
ACROSS QUEBEC...ALLOWING NW-SE ORIENTED WARM FRONT NOW IN WRN NEW
ENGLAND TO REDEVELOP E INTO NRN AND CNTRL ME BY LATE IN THE DAY. 
FARTHER W...TRAILING COLD FRONT WITH WAVES EXPECTED TO DRIFT SLOWLY
S/SE ACROSS THE CNTRL PLNS...THE MID/UPR MS VLY AND THE UPR GRT LKS.


...NE NY INTO NRN/CNTRL NEW ENGLAND...
CLUSTERS OF TSTMS SHOULD CONTINUE TO FORM INVOF WARM FRONT OVER SW/S
CNTRL QUEBEC TODAY...WHERE 30+ KT WARM/MOIST WLY LLJ WILL MOST
STRONGLY IMPINGE ON BOUNDARY.  MORE ISOLATED DEVELOPMENT MAY ALSO
OCCUR SWD INTO NERN NY AND WRN/NRN NEW ENGLAND...WHERE HEIGHT RISES
ASSOCIATED WITH ELONGATING RIDGE WILL TEND TO SUPPRESS DEVELOPMENT
...BUT SUBSTANTIAL DIFFERENTIAL HEATING WILL EXIST.  THE AXIS OF
DEVELOPMENT LIKELY WILL SHIFT E WITH TIME WITH MOTION OF FRONT.

BY EARLY EVENING...COMBINATION OF DIURNAL HEATING AND LARGE SCALE
ASCENT ON SRN FRINGE OF QUEBEC SHORTWAVE IMPULSE SHOULD SUPPORT
INCREASED STORM DEVELOPMENT ALONG BOTH THE WARM FRONT...AND ALONG
COLD FRONT SETTLING S OVER THE ST. LAWRENCE VLY.  THIS ACTIVITY
SHOULD CONTINUE E/ESE ACROSS NRN NEW ENGLAND TONIGHT/EARLY
WEDNESDAY.

GIVEN MODERATE TO STRONG /30-40 KT/ DEEP W TO NWLY CLOUD-LAYER
FLOW...AND MODEST DIRECTIONAL SHEAR...EMBEDDED SUSTAINED STORMS/
SUPERCELLS APPEAR LIKELY.  ASSOCIATED BOWING SEGMENTS COULD YIELD
DAMAGING WIND AND POSSIBLY A TORNADO...IN ADDITION TO VERY HEAVY
RAIN...AS PWS REMAIN AROUND 2 INCHES.

...MID MO VLY TO UPR GRT LKS...
STORM OUTFLOW/LOW LEVEL DIVERGENCE ASSOCIATED WITH WEAK IMPULSE
LIFTING NE ACROSS THE CNTRL PLNS LIKELY WILL MITIGATE SEVERE THREAT
OVER PARTS OF NEB AND IA TODAY.  HOWEVER...AIR MASS E OF OUTFLOW
BOUNDARY/COLD FRONT SHOULD DESTABILIZE WITH DAYTIME HEATING.  MLCAPE
TO 2500 J/KG WILL BE POSSIBLE OVER KS...AND FROM ERN IA INTO
CNTRL/SRN WI AND LWR MI.

WHILE ELEVATED STORMS COULD POSE A LIMITED SEVERE THREAT LATER TODAY
INTO TONIGHT INVOF FRONT OVER CNTRL/ERN NEB INTO ERN SD...GREATER
CHANCE FOR SEVERE SHOULD ACCOMPANY MORE SURFACE-BASED ACTIVITY FROM
ERN IA INTO WI/LWR MI. FORECAST SOUNDINGS INDICATE
MODERATELY STRONG SHEAR THROUGH THE LOWEST 3-5 KM AGL...WITH WEAK
WINDS ABOVE 6-7 KM...ESPECIALLY OVER THE WRN PART OF SLIGHT RISK
AREA.  THIS SUGGESTS THE POTENTIAL FOR UPDRAFT ROTATION EARLY IN
STORM LIFE CYCLES...BUT WITH A FAIRLY RAPID EVOLUTION TO OUTFLOW
DOMINANT MULTICELL CLUSTERS/BROKEN LINES.  WARM THERMODYNAMIC
PROFILES AND MODEST MID-LEVEL LAPSE RATES SHOULD LIMIT LARGE HAIL
POTENTIAL...WITH THE PRIMARY SEVERE THREAT BEING DAMAGING WIND.

...SERN U.S...
WWD-MOVING UPR IMPULSE MAY ENHANCE POTENTIAL FOR A CLUSTER OR TWO OF
DIURNAL PULSE STORMS WITH LOCALLY DAMAGING WIND IN MS/AL AND THE FL
PANHANDLE REGION.

..CORFIDI/GRAMS.. 08/01/2006