[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 271702
SWODY2
SPC AC 271701

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1201 PM CDT SUN AUG 27 2006

VALID 281200Z - 291200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...

STRONG TROUGH...ANCHORED BY UPPER LOW ALONG THE NWRN BRITISH
COLUMBIA COAST...WILL DIG SEWD TOWARD THE PACIFIC NW COAST WITH
RESULTANT AMPLIFICATION OF DOWNSTREAM RIDGING OVER THE N-CNTRL CONUS
INTO CANADIAN PRAIRIES.  AS THIS OCCURS UPPER LOW OVER THE CNTRL
PLAINS WILL BECOME BLOCKED BETWEEN RIDGE OVER THE ROCKIES AND
SUBTROPICAL RIDGE OFF THE SERN U.S. COAST...WITH SYSTEM GRADUALLY
SHEARING INTO INCREASINGLY CONFLUENT FLOW OVER THE OH VALLEY AND
LOWER GREAT LAKES.

IN THE LOW-LEVELS...SURFACE LOW OVER THE MID MS VALLEY WILL DEVELOP
ENEWD ALONG BAROCLINIC ZONE ACROSS THE OH VALLEY.  THE ERN EXTENSION
OF THIS BOUNDARY WILL STRETCH EWD TO THE MIDDLE ATLANTIC
COAST...WHILE TRAILING PORTION EXTENDS SWWD TO THE SRN HIGH PLAINS.

...MID MS VALLEY EWD ACROSS THE OH VALLEY TO THE MID ATLANTIC
COAST...

A MOIST AND UNSTABLE LOW-LEVEL AIR MASS COUPLED WITH THE PRESENCE OF
THE SURFACE BOUNDARY AND WEAK IMPULSES EMANATING FROM CNTRL PLAINS
TROUGH WILL SUPPORT SCATTERED TSTM DEVELOPMENT ACROSS THE REGION
MONDAY INTO MONDAY NIGHT.  WHILE LAPSE RATES ARE FORECAST TO REMAIN
POOR AND NEAR MOIST ADIABATIC...POCKETS OF STRONGER DIABATIC HEATING
SHOULD SUPPORT LOCALLY STRONGER INSTABILITY WITH MLCAPES INCREASING
TO 1000-1500 J/KG.  ASIDE FROM THE POOR LAPSE RATES...IT APPEARS
THAT ANY ORGANIZED SEVERE THREAT WILL BE LIMITED BY THE MARGINAL
VERTICAL SHEAR AS THE STRONGER MID AND HIGH-LEVEL FLOW WILL REMAIN N
OF THE PRIMARY BAROCLINIC ZONE.

POTENTIAL WILL EXIST FOR ISOLATED...STRONG TO MARGINALLY SEVERE TSTM
CLUSTERS WITH THE PRIMARY SEVERE THREAT BEING LOCALLY DAMAGING
WINDS.

...ARKLATEX INTO CNTRL NM...

COMPARATIVELY STRONGER BOUNDARY LAYER HEATING IS FORECAST ACROSS
PORTIONS OF CNTRL/SRN TX MONDAY WITH TEMPERATURES WARMING INTO THE
90S AHEAD OF SURFACE FRONT AND ANY RESIDUAL OUTFLOW BOUNDARIES. 
WHEN COUPLED WITH DEWPOINTS IN THE 60S TO LOWER 70S...AIR MASS
SHOULD BECOME MODERATELY UNSTABLE WITH MLCAPES OF 1500-2500 J/KG. 
RELATIVELY WEAK CAPPING SHOULD ALLOW TSTMS TO INCREASE IN COVERAGE
AND INTENSITY THROUGH THE AFTERNOON FROM CNTRL/SRN AR SWWD INTO
CNTRL TX.  HERE TOO...VERTICAL SHEAR WILL REMAIN RELATIVELY
WEAK...EFFECTIVELY LIMITING STORM ORGANIZATION.  STILL...POTENTIAL
WILL EXIST FOR MULTICELL CLUSTERS CAPABLE OF DAMAGING WINDS.

FARTHER TO THE W...POST-FRONTAL UPSLOPE REGIME IS FORECAST TO BECOME
ESTABLISHED IN THE LEE OF THE SRN ROCKIES WITH TSTMS EXPECTED BY
AFTERNOON ALONG THE HIGHER TERRAIN OF CNTRL NM.  DESPITE A DRIER
LOW-LEVEL AIR MASS THAN POINTS TO THE E...THE DEVELOPMENT OF STEEP
LOW TO MID-LEVEL LAPSE RATES WILL SUPPORT POCKETS OF MODERATE
INSTABILITY WITH MLCAPES OF 500-1000 J/KG.  WHILE RELATIVELY STRONG
VEERING IS FORECAST IN THE LOWEST 3 KM AGL...WIND FIELDS AND
RESULTANT SHEAR MAGNITUDE WILL REMAIN MARGINAL.  A FEW ORGANIZED
STORMS /PERHAPS EXHIBITING SOME MID-LEVEL ROTATION/ WILL BE POSSIBLE
WITH THE PRIMARY SEVERE THREAT BEING SEVERE HAIL.

..MEAD.. 08/27/2006