[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 160543
SWODY2
SPC AC 160541

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1141 PM CST FRI DEC 15 2006

VALID 171200Z - 181200Z

...NO TSTM AREAS FORECAST...

...SYNOPSIS...
STRONG MID-UPPER LEVEL SHORTWAVE TROUGH IS EVIDENT IN MOISTURE
CHANNEL IMAGERY INVOF 130W...OFFSHORE PACIFIC NW.  AS THIS FEATURE
MOVES INLAND WRN CONUS...HIGH-AMPLITUDE AND POSITIVELY TILTED TROUGH
IS FCST TO EVOLVE.  THIS WILL YIELD LONG FETCH OF SW FLOW ALOFT FROM
 BAJA CA TO GREAT LAKES DAY-2.

MEANWHILE...AT SFC...CYCLOGENESIS ALREADY UNDERWAY IN CENTRAL
ROCKIES WILL CONTINUE WITH APCH OF UPPER TROUGH.  FRONTAL ZONE --
ASSOCIATED WITH NRN STREAM SHORTWAVE NOW OVER SASK -- IS FCST TO
MOVE SLOWLY SWD ACROSS PLAINS STATES AND MS VALLEY THROUGH EARLY
DAY-2.  FRONT THEN SHOULD ACCELERATE SWD OVER CENTRAL/SRN HIGH
PLAINS IN RESPONSE TO WEAK FRONTAL-WAVE CYCLONE MOVING NEWD FROM
SERN NEB/NERN KS REGION TOWARD GREAT LAKES.  MEANWHILE
RESIDUAL/QUASISTATIONARY FRONTAL ZONE WILL LINGER ACROSS ERN
GULF...FL STRAITS AND BAHAMAS.

...FL KEYS...
LOW LEVEL BAROCLINIC ZONE MAY CONTRIBUTE TO CONVECTION OVER FL
STRAITS AND PERHAPS KEYS...WITH SOME BUOYANCY REACHING ICING LEVELS
BASED ON MODEL FCST SOUNDINGS.  HOWEVER...WEAK LAPSE RATES AND LACK
OF MORE ROBUST CONVERGENCE INVOF FRONT SHOULD LIMIT CONVECTIVE
COVERAGE...AND SHOULD KEEP MOST ACTIVITY S OF KEYS.  ALTHOUGH VERY
BRIEF/ISOLATED TSTMS CANNOT BE RULED OUT...POTENTIAL APPEARS TOO
CONDITIONAL/MRGL FOR GEN THUNDER OUTLOOK ATTM.

...SRN PLAINS TO MO...
PREFRONTAL LOW LEVEL WAA REGIME WILL BE WELL UNDERWAY THROUGH
PERIOD...ALONG WITH RETURN FLOW OF PARTIALLY MODIFIED AIR MASS THAT
WILL HAVE FOLLOWED LONG ANTICYCLONIC TRAJECTORIES OVER PORTIONS GULF
OF MEXICO.  RELATED MOISTENING MAY CONTRIBUTE TO DEVELOPMENT OF
PRECIP AND SHOWERS INVOF LOW LEVEL FRONTAL ZONE LATE IN
PERIOD...FROM FROM OK NEWD ACROSS IL.  WITH FLOW ALOFT NEARLY
PARALLEL TO FRONT AND APPARENT ABSENCE OF SIGNIFICANT MID-UPPER
LEVEL ASCENT...LAPSE RATES ALOFT SHOULD REMAIN WEAK.  MODEL FCST
SOUNDINGS INDICATE SOME BUOYANCY IS POSSIBLE BUT MAINLY IN THERMAL
LAYERS SUITABLE FOR WARM-CLOUD PRECIP PRODUCTION.  TSTM PROBABILITY
IS NONZERO BUT VERY WEAK...AND NOT JUSTIFYING GEN FCST ATTM.

..EDWARDS.. 12/16/2006