[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 221242
SWODY1
SPC AC 221239

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0739 AM CDT SAT APR 22 2006

VALID 221300Z - 231200Z

...THERE IS A SLGT RISK OF SVR TSTMS TODAY FROM FL TO SE VA....

...SE ATLANTIC STATES TODAY...
A SMALL MCS IS MOVING NEWD ACROSS NC/VA IN ASSOCIATION WITH AN MCV
IN ADVANCE OF THE PRIMARY MID LEVEL TROUGH OVER GA.  THIS INITIAL
CONVECTION MAY PRODUCE MARGINAL SEVERE GUSTS AND SOME HAIL...THOUGH
THE STORMS COULD MOVE ACROSS THE WARM SECTOR BEFORE SUBSTANTIAL
SURFACE HEATING/DESTABILIZATION CAN TAKE PLACE.  THE PRIMARY SEVERE
STORM THREAT DURING THE DAY SHOULD EVOLVE FROM THE ONGOING
CONVECTION OVER GA/SC IN ASSOCIATION WITH THE PRIMARY MID LEVEL
TROUGH.  THIS ACTIVITY WILL SPREAD NEWD AND SHOULD INTENSIFY BY LATE
MORNING WHILE ENCOUNTERING STRONGER INSTABILITY OVER CENTRAL SC/NC. 
THE COMBINATION OF MODERATE INSTABILITY /MLCAPE VALUES OF 1000-1500
J/KG/ AND 35-45 KT LOW-MID LEVEL FLOW SHOULD SUPPORT A FEW BOWING
LINE SEGMENTS...WHERE DAYTIME DESTABILIZATION OF THE BOUNDARY LAYER
WILL ALLOW STRONGER DOWNDRAFTS AND MORE EFFICIENT MOMENTUM TRANSFER
TO THE SURFACE.  THE SEVERE THREAT SHOULD PERSIST THROUGH LATE
AFTERNOON...AND THEN BEGIN TO DIMINISH THIS EVENING AS THE STRONGER
CONVECTION MOVES OFFSHORE AND THE LOW LEVELS STABILIZE.

THE INFLUENCE OF THE MID LEVEL TROUGH WILL EXTEND OVER N FL...WHERE
ADDITIONAL THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE ALONG THE
OUTFLOW BOUNDARY FROM THE MORNING STORMS ACROSS SW GA/FL PANHANDLE. 
OTHER ISOLATED SEVERE STORMS MAY FORM OVER THE INTERIOR PENINSULA
DURING THE AFTERNOON IN ASSOCIATION WITH SEA BREEZE BOUNDARIES. 
AFTERNOON MLCAPE NEAR 1500 J/KG AND SOMEWHAT ENHANCED VERTICAL SHEAR
ALONG AND E OF THE ATLANTIC COAST SEA BREEZE MAY PROVE SUFFICIENT
FOR STORMS WITH SOME SUPERCELL CHARACTERISTICS.

...SE NM/W TX THIS EVENING/EARLY TONIGHT...
A MID LEVEL SHORTWAVE RIDGE WILL MOVE E OF THE HIGH PLAINS BY
AFTERNOON...WITH SWLY MID LEVEL FLOW CONTRIBUTING TO DEVELOPMENT OF
A LEE TROUGH ACROSS ERN NM.  MEANWHILE...BOUNDARY LAYER DEWPOINTS IN
THE MID 40S TO UPPER 50S WILL SPREAD NWWD FROM THE MIDDLE RIO GRANDE
VALLEY TO SE NM BY AFTERNOON.  THIS MOISTURE...ALONG WITH SURFACE
HEATING THROUGH BREAKS IN A BROAD CIRRUS PLUME...WILL RESULT IN
POTENTIALLY MODERATE INSTABILITY /MLCAPE VALUES OF 1000-1500 J/KG/
BY LATE AFTERNOON NEAR AND IMMEDIATELY E OF THE LEE TROUGH.  WIDELY
SCATTERED THUNDERSTORMS MAY FORM LATE THIS AFTERNOON/EVENING ALONG
THE LEE TROUGH INVOF SE NM...WHERE VERTICAL SHEAR AND INSTABILITY
SHOULD BE AT LEAST MARGINALLY FAVORABLE FOR SUPERCELLS.  THE PRIMARY
SEVERE THREAT WILL BE LARGE HAIL INITIALLY...AND THEN A FEW DAMAGING
GUSTS IF STORMS CAN GROW UPSCALE INTO ONE OR MORE SMALL MCS/S DURING
THE EVENING WHILE SPREADING TOWARD W TX.

...ERN KS/WRN MO LATE TONIGHT...
LOW-LEVEL MOISTURE SHOULD SPREAD NWD FROM TX TO THE ERN KS AREA BY
LATER TONIGHT...WHEN THE LLJ WILL ENHANCE WAA ALONG AND N OF A
BAROCLINIC ZONE ACROSS ERN KS/WRN MO.  THE MOISTENING SHOULD BE
SUFFICIENT FOR ELEVATED CONVECTION LATE TONIGHT...AND STEEP MID
LEVEL LAPSE RATES MAY SUPPORT SOME HAIL WITH THE STRONGER STORMS.  

...SRN LOWER MI AREA THIS AFTERNOON...
SEVERAL SMALLER SCALE WAVES WILL CONTINUE TO ROTATE AROUND THE NRN
WI CLOSED LOW WHILE IT DRIFTS SEWD TO LOWER MI BY TONIGHT.  WITH
DAYTIME HEATING...COLD MID LEVEL TEMPERATURES /NEAR -26 C AT 500 MB/
AND STEEP LOW-MID LEVEL LAPSE RATES WILL SUPPORT L0W-TOPPED
THUNDERSTORMS CAPABLE OF PRODUCING MAINLY SMALL HAIL DURING THE
AFTERNOON.

..THOMPSON/TAYLOR.. 04/22/2006