DAY2SVR: Nws Storm Prediction Center Norman Ok

ACUS02 KWNS 200550
SWODY2
SPC AC 200548

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1248 AM CDT MON AUG 20 2012

VALID 211200Z - 221200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
AN AMPLIFIED LARGE-SCALE UPPER-LEVEL TROUGH WILL PERSIST FROM SERN
CANADA TO THE GULF COAST...ALTHOUGH THE HEIGHT GRADIENT WILL BEGIN
TO RELAX. AN EMBEDDED SHORT WAVE IMPULSE SHOULD PROGRESS FROM THE
MIDWEST TO THE CNTRL APPALACHIANS BY EARLY WED. A QUASI-STATIONARY
FRONT WILL REMAIN ANCHORED FROM THE MID-ATLANTIC TO THE CNTRL GULF
COAST. IN THE NORTHWEST...A DAMPENING SHORT WAVE TROUGH WILL IMPINGE
ON AN UPPER-LEVEL RIDGE AND SHOULD REACH THE NRN ROCKIES/SRN
CANADIAN ROCKIES BY 12Z/WED.

...NRN ROCKIES...
AS MID-LEVEL HEIGHT FALLS AND LARGE-SCALE ASCENT OVERSPREAD THE
REGION...ISOLATED ELEVATED TSTMS MAY BE ONGOING 12Z/TUE ALONG THE
LOBE OF LEADING ASCENT IN ERN WA/NERN ORE. ACTIVITY WILL BECOME
SURFACE-BASED AND DIURNALLY INCREASE IN COVERAGE ACROSS THE NRN
ROCKIES AS THE BOUNDARY LAYER DEEPENS AMIDST A WEAKLY BUOYANT AIR
MASS. CONSENSUS OF GUIDANCE STILL SUGGESTS THAT A BELT OF 35-45 KT
SWLYS AT 500 MB MAY LARGELY LAG THE LOBE OF LEADING ASCENT...WHICH
BREEDS UNCERTAINTY OVER THE DEGREE OF JUXTAPOSITION BETWEEN THE
STRONGER DEEP-LAYER SHEAR AND WHERE GREATER TSTM COVERAGE OCCURS.
NEVERTHELESS...STEEP LOW/MID-LEVEL LAPSE RATES AND NEARLY
STRAIGHT-LINE HODOGRAPHS SHOULD SUPPORT MARGINAL SPLITTING SUPERCELL
STRUCTURES CAPABLE OF ISOLATED SEVERE HAIL/WIND.

...SOUTH ATLANTIC COASTAL PLAIN...
SEVERAL PRECEDING DAYS OF CONVECTION WILL MAINTAIN POOR MID-LEVEL
LAPSE RATES AND RESULT IN ONLY A WEAKLY BUOYANT AIR MASS WHERE
POCKETS OF STRONGER HEATING OCCUR ON TUE. MID-LEVEL SWLYS SHOULD
SUBSIDE SLIGHTLY RELATIVE TO D1...BUT THE REGION WILL REMAIN WITHIN
THE RIGHT ENTRANCE REGION OF A STRONG UPPER-LEVEL JET CENTERED FROM
THE PIEDMONT TO THE NEW ENGLAND COAST. THIS SHOULD FOSTER SEVERAL
CONVECTIVE CLUSTERS WITH A PRIMARY RISK OF LOCALIZED DAMAGING WINDS.

..GRAMS.. 08/20/2012

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.