DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 072008
SWODY1
SPC AC 072006

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0306 PM CDT SAT JUL 07 2012

VALID 072000Z - 081200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM OH EASTWARD TO THE
MID-ATLANTIC AND SOUTHERN NEW ENGLAND STATES...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SRN MO...NW AR...AND
EXTREME ERN OK...

HAVE ADJUSTED THE SOUTHERN SLIGHT RISK AREA TO ACCOUNT FOR AN AREA
OF CONCENTRATED STG/SVR STORMS FROM NORTHWEST AR NORTHWARD INTO
SOUTHERN MO. SLOW WESTWARD MOVEMENT WILL RESULT IN A RATHER CONFINED
THREAT AREA BUT WITH A CONTINUED WIND DAMAGE THREAT THROUGH
REMAINDER OF AFTERNOON HOURS. HAVE MAINTAINED A LARGE AREA OF 5
PERCENT WIND PROBABILITIES SURROUNDING SLIGHT RISK AREAS GIVEN
WIDESPREAD NATURE OF UNCAPPED AND WELL-MIXED BOUNDARY LAYER.

ALSO TRIMMED SLIGHT RISK OVER NORTHEAST U.S. BASED ON CURRENT
LOCATION OF LINE OF SVR TSTMS AND STABILIZING EFFECTS OF EARLIER
STORMS FARTHER EAST.

..BUNTING.. 07/07/2012

.PREV DISCUSSION... /ISSUED 1126 AM CDT SAT JUL 07 2012/

...OH INTO SRN NEW ENGLAND AND MID ATLANTIC STATES...
A BAND OF STRONG/SEVERE STORMS HAS INTENSIFIED ALONG THE SRN EDGE OF
A MCS MOVING ESEWD ACROSS WRN/CENTRAL NY. THIS IS OCCURRING ALONG
THE NRN GRADIENT OF AN EML PLUME/CAPPING INVERSION THAT HAS SPREAD
EWD INTO THE MID ATLANTIC REGION. VISIBLE IMAGERY SHOWS BREAKS IN
CLOUDS AHEAD OF THE CONVECTIVE SYSTEM FROM PA INTO NJ AND SERN NY
WHICH SHOULD PERMIT STRONG DIABATIC HEATING AND DESTABILIZATION TO
OCCUR IN THE PRE-STORM ENVIRONMENT...WITH SBCAPE REACHING 2000-2500
J/KG THIS AFTERNOON. THE ACTIVITY IS IMMEDIATELY SOUTH OF A STRONG
WNWLY MID/UPPER LEVEL JET...AND WITH AREA VAD PROFILES INDICATING
40-50 KT FLOW ABOVE 3-4 KFT AGL FROM NRN PA INTO SRN NY...FAST STORM
MOTION AND STEEPENING LOW LEVEL LAPSE RATES WILL ENHANCE POTENTIAL
FOR DAMAGING WIND GUSTS TO OCCUR INTO THE EVENING HOURS.

ALTHOUGH CAPPING APPEARS TO BE STRONGER WITH WWD EXTENT INTO
OH...INTENSE DIABATIC HEATING AND WEAK CONVERGENCE ALONG A SWD
SAGGING FRONT WILL RESULT IN GRADUAL WEAKENING OF THE CAP. THIS
WILL PROVIDE POTENTIAL FOR ADDITIONAL STORM DEVELOPMENT THIS
AFTERNOON NEAR THE FRONT WHERE THE AIR MASS WILL BE VERY UNSTABLE
/MLCAPE REACHING 2500-3500 J PER KG/. WNWLY FLOW ALOFT OF 25-30 KT
WILL RESULT IN SUFFICIENT VERTICAL SHEAR FOR A FEW MULTICELL
CLUSTERS/LINEAR SEGMENTS TO FORM...WITH STRONGER STORMS CAPABLE OF
PRODUCING DAMAGING WIND GUSTS AND POSSIBLY SEVERE HAIL.

...LOWER MS VALLEY TO THE OZARKS...
WATER VAPOR IMAGERY INDICATES A CYCLONIC FEATURE ROTATING WNWWD
ALONG THE MID/UPPER LEVEL MOISTURE DISCONTINUITY OVER THE TN VALLEY.
THIS MAY ENHANCE CONVECTIVE DEVELOPMENT ALONG THE DISCONTINUITY FROM
THE MID-SOUTH/LOWER MS VALLEY INTO THE OZARKS THIS
AFTERNOON...ESPECIALLY WHERE REGIONS OF STRONGER HEATING AND
DESTABILIZATION TAKE PLACE. ALTHOUGH ELY MID LEVEL FLOW IS
GENERALLY WEAK...STRONGER UPPER LEVEL ESELY WINDS OVER THE NRN/ERN
PARTS OF THE SLIGHT RISK AREA MAY PROMOTE DEVELOPMENT OF A FEW
ORGANIZED MULTICELL CONVECTIVE CLUSTERS THIS AFTERNOON...WITH
ACTIVITY SPREADING WWD WITH TIME. STRONGER STORMS WILL HAVE
POTENTIAL TO PRODUCE LOCALLY DAMAGING WIND GUSTS.

...CENTRAL HIGH PLAINS INTO KS...
MOIST UPSLOPE FLOW WILL SUPPORT THE DEVELOPMENT OF CLUSTERS OF
THUNDERSTORMS ALONG THE HIGHER TERRAIN...WHICH WILL LIKELY DEVELOP
EWD DURING THE EVENING. STEEP LAPSE RATES WILL SUPPORT A RISK FOR
LOCALIZED DAMAGING WINDS AND HAIL WITH THE STRONGEST STORMS...THOUGH
WEAK DEEP SHEAR SHOULD PRECLUDE THE DEVELOPMENT OF A MORE
SUBSTANTIAL/ORGANIZED SEVERE THREAT. FARTHER EAST...A FEW STORMS
MAY DEVELOP ALONG/NORTH OF THE FRONT WITHIN A DEEPLY MIXED PBL.
STEEP LAPSE RATES SUGGEST POTENTIAL FOR ISOLATED DOWNBURSTS TO
OCCUR.

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