[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 180556
SWODY2
SPC AC 180555

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1255 AM CDT SUN JUN 18 2006

VALID 191200Z - 201200Z

...THERE IS A SLGT RISK OF SVR TSTMS MON ACROSS PARTS OF THE NRN
APPALACHIANS INTO NEW ENGLAND....

...THERE IS A SLGT RISK OF SVR TSTMS LATE MON/MON NIGHT ACROSS PARTS
OF THE NRN ROCKIES INTO THE NRN PLAINS AND PARTS OF THE MID MO
VALLEY....

A HIGH LATITUDE BLOCKING PATTERN WILL PERSIST THROUGH THIS FORECAST
PERIOD ACROSS THE NORTHEAST PACIFIC/ALASKA AND NORTHWEST CANADA. 
AND...MODELS INDICATE THAT THE SOUTHERN BRANCH OF THE ASSOCIATED
SPLIT FLOW WILL REMAIN LARGELY ZONAL...AND GENERALLY NEAR OR JUST
SOUTH THE CANADIAN/U.S. BORDER.  A COUPLE OF BROADER SCALE
TROUGHS...WITH ASSOCIATED SMALLER SCALE IMPULSES...ARE EMBEDDED
WITHIN THIS REGIME...AND ARE PROGGED TO REMAIN PROGRESSIVE.  

IN TANDEM WITH TROUGHING IN THE NORTHERN STREAM...LEAD TROUGH IS
FORECAST TO DEVELOP EAST SOUTHEAST OF THE UPPER MISSISSIPPI
VALLEY/UPPER GREAT LAKES REGION MONDAY...THROUGH MUCH OF THE
REMAINDER OF THE GREAT LAKES AND OHIO VALLEY BY EARLY TUESDAY. AS
THIS OCCURS...AN UPSTREAM TROUGH IS FORECAST TO ADVANCE ACROSS THE
NORTHERN INTERMOUNTAIN REGION/NORTHERN ROCKIES AND NORTHERN HIGH
PLAINS...AHEAD OF A STRONG MID/UPPER JET STREAK NOSING ACROSS THE
NORTHEAST PACIFIC TOWARD THE PACIFIC NORTHWEST COAST.

...GREAT LAKES/OHIO VALLEY INTO THE NORTHEAST...
AHEAD OF MAIN UPPER TROUGH...CONFIDENCE IS GROWING THAT A
SIGNIFICANT IMPULSE...FROM WEAKENING TROUGH NOW SOUTH OF MAIN BELT
OF WESTERLIES...WILL ACCELERATE NORTHEASTWARD INTO THE UPPER OHIO
VALLEY BY 12Z MONDAY...BEFORE CONTINUING INTO/THROUGH THE ST.
LAWRENCE VALLEY/NORTHERN NEW ENGLAND.  BELT OF STRONGER LOWER/MID-
LEVEL FLOW /ON THE ORDER OF 30-40 KTS/ SEEMS LIKELY TO ACCOMPANY
THIS FEATURE...ALONG WITH NARROW TONGUE OF VERY MOIST AIR....
INCLUDING SURFACE DEW POINTS AS HIGH AS 70F. ALTHOUGH MID-LEVEL
LAPSE RATES WILL BE WEAK...MODELS SUGGEST INFLUX OF MOISTURE AND
DAYTIME HEATING WILL CONTRIBUTE TO MIXED LAYER CAPE OF 1000-2000
J/KG...FROM THE NORTH CENTRAL APPALACHIANS THROUGH THE HUDSON/
CHAMPLAIN VALLEY.  

ZONE OF ENHANCED MID-LEVEL FORCING IS EXPECTED TO BE SUFFICIENT FOR
THE DEVELOPMENT OF A SOLIDIFYING CONVECTIVE LINE BY MONDAY
AFTERNOON.  AND...GIVEN POSSIBLE DESTABILIZATION AND FAVORABLE WIND
FIELDS...POTENTIAL WILL EXIST FOR DAMAGING WINDS TO ACCOMPANY
LOCALLY HEAVY RAINFALL WITH RELATIVELY FAST MOVING STORMS.

ELSEWHERE...FORCING ON TAIL END OF MAIN...DIGGING UPPER TROUGH MAY
SUPPORT ADDITIONAL SCATTERED VIGOROUS STORMS AHEAD OF COLD
FRONT...THROUGH THE OHIO VALLEY LATE MONDAY AFTERNOON/EVENING. 
MOISTURE/LOW-LEVEL CONVERGENCE IN WAKE OF IMPULSE LIFTING THROUGH
THE NORTHEAST IS UNCERTAIN...AND IT STILL APPEARS MOST PROBABLE THAT
ANY SEVERE HAIL/WIND EVENTS WILL BE FAIRLY LOCALIZED AND LIMITED TO
PERIOD NEAR/SHORTLY AFTER PEAK HEATING.

...NORTHERN ROCKIES THROUGH NORTHERN/CENTRAL PLAINS...
MOISTURE RETURN IN DEVELOPING FAVORABLE UPSLOPE FLOW REGIME THROUGH
THE HIGH PLAINS STILL APPEARS LIKELY TO BE SOMEWHAT MARGINAL FOR
VIGOROUS CONVECTIVE DEVELOPMENT.  HOWEVER...LAPSE RATES ARE EXPECTED
TO BECOME STEEP AND SUPPORTIVE OF SEVERE HAIL/WIND...AS FORCING
ASSOCIATED WITH OROGRAPHY AND APPROACHING TROUGH GENERATE DEEP
CONVECTION.  INITIATION IS EXPECTED BY LATE MONDAY AFTERNOON ACROSS
THE MOUNTAINS OF SOUTHWEST MONTANA AND WYOMING...BEFORE SPREADING
THROUGH SOUTHERN MONTANA AND NORTHEASTERN WYOMING...NEAR 40-50 KT
MID-LEVEL JET STREAK...MONDAY EVENING. 

STRONG MID-LEVEL WARMING SOUTHEAST OF UPPER TROUGH...THROUGH MUCH OF
THE NORTH CENTRAL PLAINS...WILL PROVIDE STRONG CAPPING. 
HOWEVER...EVENTUALLY...LOW/MID-LEVEL WARM ADVECTION ON EDGE OF CAP
WILL PROBABLY SUPPORT AN EVOLVING CONVECTIVE CLUSTER AS MID-LEVEL
JET NOSES INTO THE NORTHERN PLAINS MONDAY NIGHT.  THIS STILL APPEARS
MOST LIKELY NEAR THE NORTH DAKOTA/SOUTH DAKOTA BORDER AREA...WHERE
SIZABLE LOW/MID-LEVEL TEMPERATURE DEW POINT SPREADS WILL CONTRIBUTE
TO POTENTIAL FOR DAMAGING WIND GUSTS...IN ADDITION TO LARGE
HAIL...DESPITE PRESENCE OF DEEPENING RADIATIONAL INVERSION LAYER.  

OTHER STORMS...PRIMARILY WITH LARGE HAIL POTENTIAL...APPEAR POSSIBLE
LATE MONDAY NIGHT AS LIFT STRENGTHENS ON EDGE OF STRONGER CAPPING
EAST OF THE MID MISSOURI VALLEY.

..KERR.. 06/18/2006