DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 101628
SWODY1
SPC AC 101626

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1126 AM CDT SAT AUG 10 2013

VALID 101630Z - 111200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER CENTRAL/SRN VA INTO NRN
NC...

...CENTRAL/SRN VA INTO NRN NC...
FRONTAL BOUNDARY ACROSS CENTRAL VA WWD INTO KY IS EXPECTED TO SAG
SWD TODAY. THE REGION IS ALONG THE SRN EDGE OF STRONGER WLY FLOW
ALOFT AND WITHIN THE RIGHT ENTRANCE REGION OF A STRONG UPPER LEVEL
JET LOCATED ACROSS THE NERN STATES. THE AIR MASS IS VERY MOIST WITH
PW VALUES AOA 2.0 IN AND SURFACE DEW POINTS IN THE LOW/MID 70S. MID
LEVEL LAPSE RATES ARE MODEST /NEAR 6C PER KM/...HOWEVER HIGH
MOISTURE CONTENT OF LIFTED PARCELS AND STRONG DIABATIC HEATING SOUTH
OF THE FRONT /SURFACE TEMPERATURES MID 80S TO NEAR 90/ ARE RESULTING
IN CONTINUED DESTABILIZATION WITH CAPE OF 2000-3000 J/KG. AREA VAD
WINDS FROM FCX/AKQ AND LWX INDICATE A BAND OF 30-40 KT WESTERLY
WINDS IN THE LOWEST 2-4 KM AGL WHICH WILL ENHANCE STORM ORGANIZATION
AND EWD MOTION. CURRENT STORMS OVER CENTRAL VA HAVE SHOWN SIGNS OF
SLOW INTENSIFICATION...AND ADDITIONAL CONVECTION IS EXPECTED TO
DEVELOP THIS AFTERNOON ACROSS SRN VA/NRN NC WITHIN A WEAKLY CAPPED
ENVIRONMENT....WITH POTENTIAL FOR LOCALLY DAMAGING WIND GUSTS WITH
STRONGER CELLS. SEE MESOSCALE DISCUSSION 1685 FOR ADDITIONAL
DETAILS.

...ARKLATEX ACROSS THE MID SOUTH INTO THE CENTRAL APPALACHIANS...
A VERY MOIST ENVIRONMENT PERSISTS ALONG AND SOUTH OF THE FRONT AND
OUTFLOW BOUNDARIES THAT EXTEND ACROSS THIS REGION. STRONGER HEATING
AND DESTABILIZATION WILL OCCUR IMMEDIATELY SOUTH OF THE COMPOSITE
OUTFLOW BOUNDARIES WHICH MAY SERVE AS THE EFFECTIVE FOCUS FOR NEW
CONVECTIVE DEVELOPMENT. WINDS ALOFT WEAKEN WITH SWD EXTENT
SUGGESTING THAT WEAKLY ORGANIZED AND SOME PULSE STORMS WILL BE THE
PRIMARY CONVECTIVE TYPES WITHIN THIS ENVIRONMENT. ISOLATED SEVERE
WET MICROBURSTS WILL BE POSSIBLE WITH STRONGER ACTIVITY INTO THE
EVENING HOURS.

...ERN MT INTO SD/NRN NEB...
A WEAK SHORTWAVE TROUGH WILL PROGRESS EWD/ESEWD OVER SD TODAY.
ELEVATED CONVECTION ASSOCIATED WITH THIS FEATURE HAS BEEN SLOWLY
WEAKENING AS IT MOVES ACROSS SRN SD. HOWEVER...THERE WILL BE SOME
POTENTIAL FOR INTENSIFICATION OF THE STORMS DURING THE DAY IN
RESPONSE TO SURFACE HEATING AND RESIDUAL 60+ F DEWPOINTS ON THE SRN
FRINGE OF THE ONGOING CONVECTION WITH POTENTIAL FOR ISOLATED SEVERE
STORMS.

OTHER ISOLATED STRONG/SEVERE STORMS MAY FORM THIS AFTERNOON
ACROSS ERN MT IN RESPONSE TO A STRONGER UPSTREAM SHORTWAVE
TROUGH ROTATING SEWD FROM SASKATCHEWAN. THE COMBINATION OF
MARGINAL-MODERATE BUOYANCY AND VERTICAL SHEAR IS EXPECTED TO SUPPORT
ISOLATED STRONG STORMS /POSSIBLY SEVERAL SUPERCELLS/ WITH A RISK OF
LARGE HAIL AND DAMAGING WIND GUSTS. UNCERTAINTY ABOUT STORM
COVERAGE WILL PRECLUDE AN INTRODUCTION OF SLIGHT RISK ATTM.

...PAC NW/NRN ROCKIES...
A CLOSED UPPER LOW WILL CONTINUE TO DRIFT NWD ALONG THE OREGON
COAST THROUGH THE PERIOD. AN INCREASE IN STORM DEVELOPMENT IS
EXPECTED AGAIN THIS AFTERNOON IN THE ZONE OF ASCENT TO THE N/NE OF
THE LOW FROM EXTREME NRN CA ACROSS CENTRAL OREGON TO WA.
WEAK-MODERATE BUOYANCY WILL DEVELOP IN THIS CORRIDOR THIS
AFTERNOON...COINCIDENT WITH SUFFICIENT DEEP-LAYER SLY/SELY VERTICAL
SHEAR FOR ORGANIZED MULTICELL CLUSTERS...AND PERHAPS SOME MARGINAL
SUPERCELL STRUCTURES. THE STRONGEST STORMS WILL BE CAPABLE OF
PRODUCING ISOLATED MARGINALLY SEVERE HAIL AND STRONG/DAMAGING GUSTS
THIS AFTERNOON INTO EARLY TONIGHT.

..WEISS/JIRAK.. 08/10/2013

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