[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 160554
SWODY1
SPC AC 160552

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1252 AM CDT TUE MAY 16 2006

VALID 161200Z - 171200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SRN FL PENINSULA...

...SYNOPSIS...

AMPLIFIED LARGE-SCALE PATTERN WILL CONTINUE THROUGH THE DAY ONE
PERIOD WITH LONG WAVE TROUGHING IN THE E AND A RIDGE INTO THE W. 
UPPER LOW NOW OVER THE CNTRL APPALACHIANS WILL LIFT NEWD TOWARD THE
ST. LAWRENCE VALLEY WITH LONG WAVE TROUGH BECOMING MORE ELONGATED AS
SHORT WAVE TROUGH DIGS SEWD ACROSS THE NRN GULF OF MEXICO.  SEVERAL
OTHER WEAK PERTURBATIONS ARE FORECAST TO ROTATE THROUGH THE
LARGER-SCALE TROUGH FROM THE GREAT LAKES THROUGH THE MS RIVER
VALLEY.

IN THE LOW-LEVELS...SURFACE CYCLONE ATTENDANT TO UPPER LOW WILL
DEVELOP NEWD THROUGH ERN NEW ENGLAND INTO THE ST. LAWRENCE VALLEY. 
TRAILING COLD FRONT WILL CONTINUE TO PUSH EWD INTO THE ATLANTIC WITH
SWRN EXTENSION SLOWLY SAGGING SWD THROUGH THE CNTRL AND SRN FL
PENINSULA.  AN ADDITIONAL COLD FRONTAL SURGE IS FORECAST TO MOVE SWD
THROUGH THE MID MS/LOWER OH VALLEYS SWD THROUGH THE MID SOUTH AND
TN/LOWER MS VALLEYS.

...S FL...

REGIONAL RADAR AND LIGHTNING DATA INDICATE ACTIVE CONVECTION ACROSS
THE CNTRL AND ERN GULF BASIN...SUGGESTING THAT STORMS WILL LIKELY BE
ONGOING AT 16/12Z WITHIN PRE-FRONTAL AIR MASS OVER THE CNTRL/SRN
PENINSULA.  LARGE-SCALE FORCING AHEAD OF MCV SHIFTING EWD THROUGH
THE CNTRL GULF COUPLED WITH HEIGHT FALLS ASSOCIATED WITH SHORT WAVE
TROUGH DIVING SEWD TOWARD THE NRN GULF SHOULD MAINTAIN CLUSTERS OF
TSTMS THROUGH THE FORECAST PERIOD ALONG AND S OF FRONTAL ZONE.

CONSIDERABLE CLOUDS AND PRECIPITATION WILL TEND TO LIMIT
DESTABILIZATION...THOUGH THE PRESENCE OF A MOIST LOW-LEVEL AIR MASS
/I.E. DEWPOINTS IN THE 60S TO LOWER 70S/ SHOULD CONTRIBUTE TO
MLCAPES OF AROUND 1000 J/KG.  MODESTLY STRONG DEEP-LAYER SPEED SHEAR
WILL BE SUPPORTIVE OF A FEW SEVERE STORMS CAPABLE OF MAINLY LARGE
HAIL AND DAMAGING WINDS.  BEST POTENTIAL FOR SUPERCELLS AND A COUPLE
OF TORNADOES WILL EXIST AHEAD OF SURFACE LOW WHICH IS FORECAST TO
SHIFT EWD ACROSS THE SRN PENINSULA THIS EVENING OWING TO LOCALLY
ENHANCED LOW-LEVEL SHEAR.

...MID SOUTH INTO LOWER MS VALLEY...

COLD MID-LEVEL TEMPERATURES /I.E. -20 C AT 500 MB/ COUPLED WITH
DIABATIC HEATING ARE EXPECTED TO CONTRIBUTE TO THE DEVELOPMENT OF
STEEP LOW TO MID-LEVEL LAPSE RATES AND WEAK CONVECTIVE INSTABILITY
AHEAD OF SECONDARY FRONTAL SURGE THIS AFTERNOON.  A FEW OF THE
STRONGER STORMS WILL BE CAPABLE OF HAIL /SOME APPROACHING SEVERE
LEVELS/ AND GUSTY WINDS INTO THE EVENING HOURS.

...MIDWEST...

A SECONDARY REGION OF TSTMS WILL BE POSSIBLE TODAY AHEAD OF
VORTICITY LOBE ROTATING SEWD OUT OF THE GREAT LAKES.  IT APPEARS
THAT CLOUD COVER WILL BE MORE WIDESPREAD THAN POINTS TO THE
S...EFFECTIVELY LIMITING LAPSE RATES AND RESULTANT DEGREE OF
DESTABILIZATION.  NONETHELESS...SOME SMALL HAIL WILL BE POSSIBLE
WITH THE MORE INTENSE STORMS.

...ERN NEW ENGLAND...

DEEP-LAYER FORCING WILL INCREASE ACROSS THE REGION TODAY WITH
APPROACH OF SURFACE AND UPPER-LEVEL LOWS. TSTMS ARE EXPECTED TO
BECOME INCREASINGLY LIKELY BY AFTERNOON FROM VICINITY OF LOW SWD
ALONG COLD FRONT.  CURRENTLY...IT APPEARS THAT INSTABILITY WILL
REMAIN QUITE WEAK...THOUGH THE STRONG FORCING FOR ASCENT AND
INCREASING VERTICAL SHEAR MAY SUPPORT A FEW VIGOROUS STORMS CAPABLE
OF GUSTY WINDS AND SMALL HAIL.

..MEAD/TAYLOR.. 05/16/2006