[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 051242
SWODY1
SPC AC 051241

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0741 AM CDT THU OCT 05 2006

VALID 051300Z - 061200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
A MORE AMPLIFIED PATTERN WILL EVOLVE OVER THE CONUS THROUGH TOMORROW
 AS A MID LEVEL RIDGE BUILDS OVER THE PLAINS DOWNSTREAM FROM THE
CLOSED LOW OVER CA...AND A SEPARATE SHORTWAVE TROUGH OVER WRN
ONTARIO/LAKE SUPERIOR DIGS SEWD TO THE UPPER OH VALLEY/CENTRAL
APPALACHIANS.  THE PRIMARY THUNDERSTORM THREAT AREAS WILL BE ACROSS
A BROAD SWATH OF THE GREAT BASIN IN ADVANCE OF THE CA LOW...AND
INVOF THE SRN APPALACHIANS IN ADVANCE OF THE DIGGING TROUGH.

...GREAT BASIN THROUGH TONIGHT...
A BROAD PLUME OF MID LEVEL MOISTURE FROM THE ERN PACIFIC WILL
PERSIST OVER AZ/UT AND ADJACENT STATES WITHIN THE WARM CONVEYOR BELT
E OF THE SLOW MOVING LOW NEAR THE CENTRAL CA COAST.  A BELT OF 45-65
KT SLY/SSWLY MID LEVEL FLOW WILL COINCIDE WITH THE MOISTURE
PLUME...RESULTING IN SUFFICIENT DEEP LAYER VERTICAL SHEAR FOR
ORGANIZED/PERSISTENT THUNDERSTORMS THROUGH THE PERIOD FROM WRN AZ
NWD OVER UT/NV TO SRN ID.  HOWEVER...WIDESPREAD CLOUDS AND POOR MID
LEVEL LAPSE RATES WITHIN THE MOISTURE PLUME WILL TEND TO LIMIT THE
DEGREE OF INSTABILITY. POCKETS OF SURFACE HEATING WITHIN CLOUD
BREAKS MAY ALLOW SUFFICIENT DESTABILIZATION FOR SUPERCELLS AND/OR
SHORT BOWING SEGMENTS WITH LARGE HAIL AND DAMAGING GUSTS. 
HOWEVER...ANY SUCH FAVORED AREAS OF SURFACE HEATING...AS WELL AS
EMBEDDED SPEED MAXIMA TO HELP FOCUS THUNDERSTORM DEVELOPMENT...ARE
DIFFICULT TO DISCERN AT THIS TIME.  THEREFORE...A LARGE AREA OF 5%
HAIL/WIND PROBABILITIES WILL BE MAINTAINED...ALONG WITH THE
POSSIBILITY OF AN UPGRADE TO PORTIONS OF THIS AREA DURING THE DAY IF
THE THREAT BECOMES MORE FOCUSED/APPARENT. 

...NRN CA/S CENTRAL ORE TODAY...
SCATTERED THUNDERSTORMS WILL LIKELY CONTINUE THROUGH THE DAY FROM
N/NE CA INTO SRN ORE IN THE REGION OF PRONOUNCED ASCENT N/NE OF THE
CLOSED LOW ALONG THE CENTRAL CA COAST. THOUGH VERTICAL SHEAR WILL
BE RELATIVELY WEAK...COOL MID LEVEL TEMPERATURES AND STEEP LAPSE
RATES MAY SUPPORT MARGINALLY SEVERE HAIL IN THE STRONGER STORMS.

...ERN TN/KY INTO NC/VA THIS AFTERNOON/EARLY TONIGHT...
A SURFACE COLD FRONT WILL CONTINUE SLOWLY SEWD ACROSS TN/KY TO THE
SRN APPALACHIANS LATE TODAY...AND SWD ACROSS VA INTO NC.  THE FRONT
WILL BE ACCOMPANIED BY A WEAK MID LEVEL TROUGH TODAY OVER THE SRN
APPALACHIANS...WHILE WEAK CYCLOGENESIS IS EXPECTED OVER THE
CAROLINAS ALONG THE FRONT AND IN ADVANCE OF A STRONGER/LARGER SCALE
WAVE DIGGING TOWARD THE CENTRAL APPALACHIANS BY LATE TONIGHT. 
SCATTERED THUNDERSTORMS ARE EXPECTED TODAY INTO TONIGHT ALONG THE
FRONT. AFTERNOON MLCAPE VALUES OF 1000-1500 J/KG ACROSS ERN TN/SE
KY MAY SUPPORT A FEW STRONG STORMS...BUT THE OVERALL SEVERE THREAT
WILL BE LIMITED BY BOTH RELATIVELY WEAK MID LEVEL LAPSE RATES AND
VERTICAL SHEAR IN THE WARM SECTOR FROM ERN TN/KY INTO THE CAROLINAS
THIS AFTERNOON.  SOMEWHAT STRONGER VERTICAL SHEAR IS EXPECTED ALONG
AND IMMEDIATELY N OF THE E-W FRONT ACROSS SRN VA/NRN NC THIS
AFTERNOON INTO EARLY TONIGHT...BUT WEAK INSTABILITY WILL KEEP ANY
SEVERE STORM THREAT QUITE MARGINAL IN THIS AREA.

..THOMPSON/TAYLOR.. 10/05/2006