[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 121959
SWODY1
SPC AC 121958

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0258 PM CDT WED JUL 12 2006

VALID 122000Z - 131200Z

...THERE IS A SLGT RISK OF SVR TSTMS SRN PARTS OF THE OH VALLEY INTO
THE MID ATLANTIC...NERN U.S. AND SRN NEW ENGLAND...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE NRN ROCKIES INTO THE
NRN HIGH PLAINS...

...NERN U.S. THROUGH SRN NEW ENGLAND AREA...

A WARM FRONT EXTENDS FROM SRN NEW ENGLAND WWD THROUGH CNTRL NY TO A
SURFACE LOW OVER THE LOWER GREAT LAKES. RICH LOW LEVEL MOISTURE
EXISTS NEAR AND S OF FRONT WITH DEWPOINTS NEAR 70. MOIST...TROPICAL
DEEP LAYER PROFILES WITH WIDESPREAD CLOUDS AND POOR MID LEVEL LAPSE
RATES HAVE RESULTED IN MARGINAL INSTABILITY. SOME BOUNDARY LAYER
WARMING HAS DEVELOPED ALONG SRN EDGE OF THICKER CLOUD SHIELD FROM
ERN PA THROUGH NJ AND EXTREME SRN NEW ENGLAND WITH MLCAPE FROM 500
TO 1000 J/KG. SHORTWAVE TROUGH AND ATTENDANT SURFACE LOW OVER THE
GREAT LAKES WILL MIGRATE ENEWD ALONG THE LOW LEVEL BAROCLINIC ZONE
TOWARD ENGLAND THIS AFTERNOON AND EVENING. AS THIS OCCURS A 40+ KT
LOW LEVEL JET WILL STRENGTHEN NEWD INTO THE NERN U.S. AND SRN NEW
ENGLAND WITH INCREASING LOW LEVEL SHEAR PROFILES. A FEW STORMS WITH
SUPERCELL STRUCTURES HAVE ALREADY BEEN OBSERVED IN WARM SECTOR FROM
NRN NJ INTO SERN NY AND SRN NEW ENGLAND. ADDITIONAL STORMS MAY
DEVELOP THE REMAINDER OF THIS AFTERNOON INTO THE EVENING AS THE
BOUNDARY LAYER CONTINUES TO DESTABILIZE. STRENGTHENING LOW LEVEL
SHEAR WILL MAINTAIN A THREAT FOR A FEW SUPERCELLS WITH LOW LEVEL
MESOCYCLONES AND ISOLATED TORNADOES INTO THE EARLY EVENING. 

...SRN OH AND TN VALLEY THROUGH MID ATLANTIC AREAS...

SEVERAL MULTICELL CLUSTERS CONTINUE DEVELOPING ALONG NUMEROUS
OUTFLOW BOUNDARIES AND IN ASSOCIATION WITH REMNANT MCVS FROM PARTS
OF TN...KY AND INTO WV AND NRN VA. THE ATMOSPHERE HAS BECOME
MODERATELY UNSTABLE IN THESE AREAS OWING TO AMPLE SURFACE HEATING.
PRIMARY THREAT WILL CONTINUE TO BE ISOLATED DAMAGING WIND GUSTS WITH
THE STRONGER STORMS THROUGH EARLY EVENING. 


...ERN ID...MT THROUGH WRN ND...

SCATTERED STORMS ARE CURRENTLY DEVELOPING OVER THE HIGHER TERRAIN OF
SWRN MT INTO SERN ID WITHIN ZONE OF ASCENT ACCOMPANYING A SHORTWAVE
TROUGH ADVANCING EWD THROUGH THE NRN ROCKIES. ACTIVITY WILL BEGIN TO
SPREAD EWD INTO THE HIGH PLAINS OF MT WHERE TEMPERATURES HAVE WARMED
INTO THE 90S AND DEWPOINTS HAVE MIXED INTO THE 50S WITH RESULTING
INVERTED-V BOUNDARY LAYER PROFILES AND STEEP LAPSE RATES.
INSTABILITY IS SOMEWHAT LIMITED OWING TO THE MODEST LOW LEVEL
MOISTURE. THIS SUGGESTS THE PRIMARY THREAT WILL BE ISOLATED DAMAGING
WIND. HOWEVER MARGINALLY SEVERE HAIL COULD ALSO ACCOMPANY THE
STRONGER STORMS.  

FARTHER EAST RICHER LOW LEVEL MOISTURE EXISTS ACROSS THE CNTRL
DAKOTAS...BUT STRONG MIXING HAS RESULTED IN DEWPOINTS FALLING INTO
THE 40S AND 50S OVER THE WRN DAKOTAS. A SURFACE BOUNDARY EXTENDS
FROM WRN SD SWWD INTO ERN MT. A LEE TROUGH EXTENDS NWD THROUGH WRN
SD INTO SWRN ND. STRONG HEATING AND MIXING WITH TEMPERATURES AROUND
100 HAS WEAKENED THE CAP IN THIS AREA...AND THUNDERSTORMS ARE IN THE
PROCESS OF DEVELOPING ALONG THESE BOUNDARIES. INVERTED-V PROFILES
WILL PROMOTE THE THREAT OF ISOLATED DAMAGING WIND WITH THIS
ACTIVITY. MODERATE INSTABILITY AND VERY STEEP LAPSE RATES WILL ALSO
SUPPORT A THREAT FOR HAIL. 


...CNTRL PLAINS...

REFER TO SWOMCD 1489.

..DIAL.. 07/12/2006