[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 010538
SWODY1
SPC AC 010536

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1236 AM CDT TUE AUG 01 2006

VALID 011200Z - 021200Z

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

...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE UPPER
HUDSON VALLEY INTO NRN AND CNTRL NEW ENGLAND...

...SYNOPSIS...

A RATHER LOW-AMPLITUDE...PROGRESSIVE LARGE-SCALE PATTERN WILL EXIST
ACROSS SRN CANADA AND THE NRN TIER OF STATES DURING THE DAY ONE
PERIOD.  WITHIN THIS REGIME...STRONG SHORT WAVE TROUGH OVER WRN
ONTARIO WILL TRANSLATE EWD INTO QUEBEC...EFFECTIVELY LOWERING
HEIGHTS OVER THE ST. LAWRENCE VALLEY DURING THE LATTER HALF OF THE
FORECAST.  MEANWHILE TO THE W...PRIMARY SHORT WAVE TROUGH /NOW OVER
NV/ WILL TEND TO DE-AMPLIFY AS IT LIFTS NEWD INTO THE NRN PLAINS.  A
WEAKER IMPULSE /CURRENTLY OVER THE CNTRL ROCKIES/ WILL PRECEED THE
NV WAVE INTO THE CNTRL PLAINS WHILE SHEAR AXIS OVER NM SLOWLY SHIFTS
EWD INTO THE CNTRL/SRN HIGH PLAINS.

IN THE LOW-LEVELS...NW-SE ORIENTED WARM FRONT WILL LIFT NEWD THROUGH
NEW ENGLAND TODAY WHILE TRAILING FRONTAL BOUNDARY SLOWLY SAGS SWD
THROUGH THE UPPER GREAT LAKES AND CNTRL PLAINS REGIONS.  SURFACE LOW
PRESSURE INITIALLY OVER NWRN KS WILL DEVELOP NEWD ALONG THIS
BOUNDARY INTO THE MID MO VALLEY BY THIS EVENING.

...UPPER GREAT LAKES INTO MID MO VALLEY...

AS MENTIONED ABOVE...WEAKER SHORT WAVE TROUGH /NOW LIFTING NEWD INTO
WY/ WILL PRECEDE PRIMARY WAVE WITH FORCING FOR ASCENT ASSOCIATED
WITH THIS FEATURE SHIFTING EWD INTO PLAINS FAIRLY EARLY IN THE DAY. 
AS A CONSEQUENCE...LATEST SHORT TERM MODEL GUIDANCE SUGGESTS THAT
CONSIDERABLE CLOUDS/PRECIPITATION MAY EXIST NEAR OR JUST N OF
FRONTAL ZONE FROM NEB INTO SRN MN...WHICH COULD LIMIT THE DEGREE OF
DESTABILIZATION.  IT DOES APPEAR THAT AIR MASS S OF FRONTAL ZONE
OVER KS NEWD INTO THE MIDWEST WILL EXPERIENCE STRONG DIABATIC
HEATING...WHICH WHEN COUPLED WITH MODEST BOUNDARY LAYER
MOISTURE...WILL SUPPORT MLCAPES OF 1000-2500 J/KG.

DIURNAL TSTMS ARE EXPECTED TO BECOME INCREASINGLY LIKELY BY MID TO
LATE AFTERNOON ALONG FRONT OR DIFFERENTIAL HEATING/OUTFLOW
BOUNDARIES FROM THE CNTRL HIGH PLAINS NEWD THROUGH THE MID MO VALLEY
INTO WI AND PORTIONS OF LOWER MI.  FORECAST SOUNDINGS INDICATE
MODESTLY STRONG SHEAR THROUGH THE LOWEST 3-5 KM AGL WITH QUITE WEAK
WIND FIELDS ABOVE 6-7 KM AGL...ESPECIALLY OVER THE WRN PORTION OF
SLIGHT RISK AREA.  THIS WOULD SUGGEST THE POTENTIAL FOR SOME UPDRAFT
ROTATION EARLY IN STORM LIFE CYCLES WITH A GRADUAL TRANSITION TO
OUTFLOW DOMINANT MULTICELL CLUSTERS OR A BROKEN LINE.  WARM
THERMODYNAMIC PROFILES AND MODEST MID-LEVEL LAPSE RATES SHOULD LIMIT
LARGE HAIL PRODUCTION WITH THE PRIMARY SEVERE WEATHER THREAT BEING
DAMAGING WINDS.

...NRN/CNTRL NEW ENGLAND...

CLUSTERS OF STRONG TO POTENTIALLY SEVERE STORMS CAPABLE OF LOCALLY
DAMAGING WINDS MAY BE ONGOING AT THE ONSET OF THE FORECAST FROM NERN
NY INTO NRN NEW ENGLAND IN ASSOCIATION WITH LOW-LEVEL WAA OCCURRING
N OF SURFACE WARM FRONT.  THIS ACTIVITY SHOULD SHIFT SEWD OR EWD
THROUGH THE MORNING HOURS.

HEIGHT RISES/INTENSIFYING CAP IN WAKE OF SURFACE WARM FRONTAL
PASSAGE AND WITHIN SLIGHT RIDGING AHEAD OF QUEBEC SHORT WAVE TROUGH
WILL LIKELY SUPPRESS ANY SEVERE CONVECTION THROUGH THE AFTERNOON
HOURS...PERHAPS INTO EARLY EVENING.  HOWEVER WITH TIME...HEIGHT
FALLS ON SERN PERIPHERY OF QUEBEC SHORT WAVE TROUGH SHOULD SUPPORT
AN INCREASE IN TSTM ACTIVITY OVER THE ST. LAWRENCE VALLEY WITH
STORMS BECOMING INCREASINGLY LIKELY ACROSS NRN/CNTRL NEW ENGLAND
TONIGHT.  STRONG WLY DEEP SHEAR OF 40-50 KT INDICATES THE POTENTIAL
FOR EMBEDDED BOWING STRUCTURES CAPABLE OF MAINLY DAMAGING WINDS.

..MEAD/GRAMS.. 08/01/2006