[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 031251
SWODY1
SPC AC 031249

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0749 AM CDT MON JUL 03 2006

VALID 031300Z - 041200Z

...THERE IS A SLGT RISK OF SVR TSTMS TODAY INTO TONIGHT FROM WI/IA
EWD TO PARTS OF PA/NY....

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING FOR SRN
MT AND NRN/ERN WY....

...UPPER GREAT LAKES AREA THIS AFTERNOON/TONIGHT...
PRIMARY SYNOPTIC FEATURE OF INTEREST THIS PERIOD WILL BE A STRONG
MID LEVEL TROUGH MOVING ESEWD OVER ONTARIO AND THE UPPER GREAT
LAKES. THIS WILL BE ACCOMPANIED BY A SURFACE CYCLONE INVOF JAMES
BAY...AND AN ASSOCIATED COLD FRONT WILL MOVE SEWD FROM THE NRN
PLAINS TO THE GREAT LAKES AND CENTRAL PLAINS BY EARLY TUESDAY. 
LOW-LEVEL MOISTENING/DESTABILIZATION IS EXPECTED TODAY ACROSS THE WI
AREA IN ADVANCE OF THE COLD FRONT AND IN THE WAKE OF MORNING
CONVECTION OVER NRN IL.  THE NET RESULT SHOULD BE AFTERNOON MLCAPE
VALUES OF 1500-2500 J/KG...BASED ON BOUNDARY LAYER DEWPOINTS IN THE
UPPER 60S AND TEMPERATURES OF 85-90 F.

DEBRIS CLOUDINESS FROM THE WEAK CONVECTION OVER NW WI MAY SLOW
SURFACE HEATING SOME TODAY ACROSS NRN WI AND UPPER MI...AND COULD
LIMIT INSTABILITY.  ADDITIONAL THUNDERSTORMS SHOULD DEVELOP ALONG
THE COLD FRONT BY MID AFTERNOON ACROSS WI...AND POSSIBLE WRN UPPER
MI IF CLOUD BREAKS OCCUR.  THIS CONVECTION SHOULD THEN SPREAD ESEWD
ACROSS LOWER MI AND THE NRN PORTIONS OF IL/INDIANA/OH TONIGHT. THE
COMBINATION OF MODERATE INSTABILITY AND 0-6 KM VECTOR SHEAR ORIENTED
ACROSS THE SURFACE FRONT MAY SUPPORT A FEW SUPERCELLS DURING THE
AFTERNOON ACROSS THE WI AREA.  CONVECTION WILL LIKELY EVOLVE INTO
CLUSTERS/ LINE SEGMENTS WHILE MOVING SEWD OVERNIGHT...WITH A
CONTINUED THREAT FOR DAMAGING GUSTS AND LARGE HAIL.

...OH VALLEY INTO PA/NY TODAY...
SEVERAL SMALL SCALE WAVES ARE EMBEDDED IN THE SRN FRINGE OF THE
WLYS...WITH THE MORE PRONOUNCED WAVES NOW MOVING EWD OVER ERN IA AND
CENTRAL/ERN PA.  AT THE SURFACE...A DIFFUSE BAROCLINIC ZONE EXTENDS
FROM IA ACROSS LOWER MI TO NY...WITH A SECONDARY BOUNDARY RELATED TO
OVERNIGHT/ONGOING CONVECTION FROM NRN IL TO SRN OH AND THE NRN
CHESAPEAKE REGION.  A FEW MULTICELL CLUSTERS MAY PERSIST DURING THE
DAY ALONG THE SRN BOUNDARY...SUSTAINED BY SURFACE
HEATING/DESTABILIZATION.  OTHER STORMS MAY ALSO FORM BY MIDDAY/EARLY
AFTERNOON ACROSS CENTRAL NY ALONG THE BAROCLINIC ZONE. DEEP LAYER
WNWLY SHEAR AND MODEST INSTABILITY MAY BE SUFFICIENT FOR FEW
ORGANIZED STORMS CAPABLE OF PRODUCING ISOLATED LARGE HAIL AND
DAMAGING GUSTS.

...NRN ROCKIES AREA TODAY...
A MID LEVEL SHORTWAVE TROUGH OVER ID THIS MORNING WILL CREST THE
RIDGE AND MOVE ESEWD OVER MT/NRN WY BY LATER THIS AFTERNOON INTO
EARLY TONIGHT. MODEST LOW-LEVEL MOISTURE /SURFACE DEWPOINTS IN THE
LOW-MID 50S/ IS PRESENT ACROSS SRN MT AND ERN WY IN THE WAKE OF A
FRONTAL PASSAGE...WHILE AFTERNOON TEMPERATURES SHOULD WARM INTO THE
80S WITH DAYTIME HEATING.  WEAK-MODERATE INSTABILITY AND VERTICAL
SHEAR ARE EXPECTED IN ADVANCE OF THE MID LEVEL WAVE...AND
THUNDERSTORMS SHOULD FORM OVER THE HIGH TERRAIN OF SRN MT BY EARLY
AFTERNOON.  THE MORE INTENSE STORMS MAY DEVELOP SUPERCELL STRUCTURES
AND BE CAPABLE OF PRODUCING LARGE HAIL AND GUSTY WINDS.

..THOMPSON/GUYER.. 07/03/2006