[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 151942
SWODY1
SPC AC 151939

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0139 PM CST FRI DEC 15 2006

VALID 152000Z - 161200Z

...NO SVR TSTM AREAS FORECAST...

...S FL AND THE KEYS...

MESOANALYSIS AND VISIBLE SATELLITE IMAGERY INDICATE ONE LOW LEVEL
BOUNDARY ALONG THE FL STRAITS AND A SECONDARY WEAKER CONFLUENCE ZONE
FROM NEAR PBI SWWD TOWARD EYW.  DESPITE A MOIST LOW-LEVEL AIR
MASS...CONSIDERABLE CLOUDS AND WEAK LAPSE RATES HAVE LIMITED
DESTABILIZATION WITH MLCAPES AOB 500 J/KG.  STILL SOME THREAT OF
ISOLATED TSTMS WILL EXIST THIS AFTERNOON AND TONIGHT OWING TO
PERSISTENT LOW-LEVEL CONVERGENCE ALONG THESE BOUNDARIES...AND
PERHAPS INCREASED LARGER-SCALE FORCING ASSOCIATED WITH WEAK IMPULSE
EVIDENT IN WATER VAPOR IMAGERY OVER WRN CUBA.

...HUDSON VALLEY INTO WRN NEW ENGLAND...

RADAR AND LIGHTNING DATA INDICATE THAT CONVECTION HAS RECENTLY
DEEPENED SUFFICIENTLY TO SUPPORT TSTM DEVELOPMENT.  AIR MASS REMAINS
DRY...HOWEVER DAYTIME HEATING HAS CONTRIBUTED TO THE DEVELOPMENT OF
STEEP LOW-LEVEL LAPSE RATES AND RESULTANT WEAK CONDITIONAL
INSTABILITY.  EXPECT ONGOING CONVECTION TO PERSIST AHEAD OF COLD
FRONT INTO WRN NEW ENGLAND THIS EVENING...DRIVEN BY THE MARGINAL
INSTABILITY AND STRONG FORCING AHEAD OF MIGRATORY SHORT WAVE TROUGH.
ACTIVITY SHOULD TEND TO DISSIPATE LATER THIS EVENING AS LOW-LEVEL
LAPSE RATES WEAKEN.

...PACFIC NW COAST...

NEXT STRONG SYSTEM NEAR 42N/134W IS FORECAST TO DIG SEWD ACROSS THE
ERN PACIFIC TONIGHT WITH LOW-LEVEL ONSHORE FLOW WEAKENING IN
RESPONSE TO APPROACH OF ATTENDANT SURFACE CYCLONE.  BOTH RUC
OBJECTIVE FIELDS AND VISIBLE SATELLITE IMAGERY SUGGEST THAT LAPSE
RATES ARE QUITE STEEP...THOUGH LARGE-SCALE FORCING FOR ASCENT WILL
REMAIN MARGINAL.  SOME POTENTIAL FOR A FEW LIGHTNING STRIKES WILL
EXIST THIS AFTERNOON INTO EVENING...HOWEVER THIS THREAT APPEARS TOO
MARGINAL TO WARRANT A GENERAL THUNDER AREA.

...NRN ROCKIES INTO GREAT BASIN...

SOME POTENTIAL WILL EXIST FOR A FEW LIGHTNING STRIKES WITHIN POST
FRONTAL AIR MASS OWING LARGELY TO STRONG MID-LEVEL COOLING AND
RESULTANT STEEPENING LAPSE RATES.  THIS THREAT IS EXPECTED TO REMAIN
QUITE LIMITED AND NO THUNDER AREA WILL BE INCLUDED.

..MEAD.. 12/15/2006