[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 031656
SWODY2
SPC AC 031655

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1155 AM CDT MON JUL 03 2006

VALID 041200Z - 051200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM NEW ENGLAND AND THE MID
ATLANTIC REGION WWD INTO THE OH VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF ERN WY/SWRN
SD/WRN NEB...

...SYNOPSIS...
HIGH AMPLITUDE FLOW PATTERN IS FORECAST TO PROGRESS SLOWLY EWD ON
TUESDAY AS UPPER LOW OVER WRN ONTARIO MOVES TO THE ERN ONTARIO/WRN
QUEBEC BORDER...UPSTREAM RIDGE MOVES OVER THE NRN HIGH PLAINS...AND
A TROUGH REMAINS OVER THE ERN PACIFIC. AT THE SURFACE A BROAD AREA
OF LOW PRESSURE IS FORECAST TO MOVE ACROSS ERN CANADA AND NEW
ENGLAND IN ADVANCE OF THE UPPER LOW...WITH A SURFACE COLD FRONT
EXPECTED TO MOVE SEWD ACROSS NEW ENGLAND...THE LOWER GREAT LAKES AND
MIDDLE MS VALLEY.  IN THE WEST...A SLOW MOVING COLD FRONT WILL MOVE
INTO THE ERN PARTS OF WA AND OREGON.

...NERN STATES ACROSS THE OH VALLEY...
MODELS INDICATE SEVERAL AREAS OF CONVECTION WILL BE OCCURRING DURING
THE MORNING ALONG/AHEAD OF THE COLD FRONT FROM PARTS OF NY/PA WSWWD
ACROSS THE MID MS VALLEY.  CLOUD COVER SPREADING DOWNSTREAM FROM
THIS ACTIVITY COUPLED WITH MODEST LAPSE RATES IS LIKELY TO INHIBIT
STRONG DESTABILIZATION DURING THE DAY AHEAD OF THE FRONT...BUT DEW
POINTS OF 65-70F AND LOCAL AREAS OF ENHANCED DIURNAL HEATING WILL
CONTRIBUTE TO MAXIMUM MLCAPE VALUES OF 1000-1500 J/KG DURING THE
AFTERNOON.  THIS SUGGESTS INTENSIFICATION OF THUNDERSTORMS WILL
OCCUR AS DYNAMIC FORCING FOR LARGE SCALE ASCENT IS ENHANCED BY
DIVERGENCE ALOFT ASSOCIATED WITH RIGHT ENTRANCE REGION WITHIN UPPER
LEVEL JET STREAK MOVING ACROSS THE LOWER GREAT LAKES AND NEW ENGLAND
DURING THE AFTERNOON AND EVENING.

VERTICAL SHEAR PROFILES ARE FORECAST TO BE PRIMARILY
UNIDIRECTIONAL...WITH STRONGEST DEEP LAYER SHEAR OF 35-45 KT IN THE
LOWEST 6 KM EXPECTED OVER NRN PARTS OF THE SLIGHT RISK AREA FROM THE
LOWER GREAT LAKES INTO NRN NEW ENGLAND.  THIS WILL SUPPORT
DEVELOPMENT OF MULTIPLE EMBEDDED LINE SEGMENTS WITH OCCASIONAL BOW
ECHOES AND ATTENDANT THREAT FOR DAMAGING WIND GUSTS...ALONG WITH
HAIL FROM STRONGER CELLS.  ORGANIZED SEVERE POTENTIAL IS EXPECTED TO
GRADUALLY DIMINISH WITH SWD EXTENT ACROSS THE OH VALLEY AND MIDDLE
ATLANTIC REGION WHERE WINDS ALOFT/VERTICAL SHEAR ARE EXPECTED TO
DECREASE.

...ERN WY INTO WRN NEB...
WEAK UPSLOPE LOW LEVEL WINDS ARE FORECAST TO DEVELOP OVER PARTS OF
THE HIGH PLAINS TOMORROW AS SURFACE HIGH PRESSURE BUILDS INTO THE
UPPER MIDWEST. THIS WILL RESULT IN SURFACE DEWPOINTS IN THE 50S 
SPREADING INTO THIS REGION...AND ALTHOUGH MID LEVEL LAPSE RATES ARE
EXPECTED TO BE MODEST AS HEIGHTS RISE OVER THE ROCKIES...ENVIRONMENT
WILL BECOME UNSTABLE WITH MLCAPE OF AROUND 1000 J/KG DURING THE
AFTERNOON.  THUNDERSTORMS SHOULD DEVELOP DURING THE AFTERNOON OVER
THE HIGHER TERRAIN OF WY AND SWRN SD AND MOVE SEWD INTO THE HIGH
PLAINS ALONG THE SRN EDGE OF 20-25 KT NWLY MID LEVEL FLOW.  STRONG
DIRECTIONAL SHEAR WITH HEIGHT SHOULD BE SUFFICIENT TO ENHANCE STORM
ORGANIZATION AND SUPPORT DEVELOPMENT OF A FEW SUPERCELLS WITH LARGE
HAIL AND STRONG WIND GUSTS DURING THE LATE AFTERNOON AND EVENING.

...NRN INTERMOUNTAIN REGION...
STEEP LAPSE RATES ARE EXPECTED TO PERSIST ACROSS THE AREA AS PRIMARY
UPPER TROUGH REMAINS OVER THE ERN PACIFIC.  PLUME OF MID LEVEL
MOISTURE IS EXPECTED TO BE EMBEDDED WITHIN SSWLY FLOW
ALOFT...SUGGESTING POTENTIAL FOR A FEW HIGHER-BASED THUNDERSTORMS TO
DEVELOP DURING THE AFTERNOON AND EVENING.  STEEP LAPSE RATES AND
DEEP WELL-MIXED LAYER SUGGESTS THREAT FOR ISOLATED MICROBURSTS AND
POSSIBLE HAIL...BUT RELATIVELY WEAK DEEP LAYER SHEAR SHOULD LIMIT
OVERALL SEVERE THREAT.

..WEISS.. 07/03/2006