[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 071630
SWODY1
SPC AC 071629

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1129 AM CDT SAT OCT 07 2006

VALID 071630Z - 081200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
DEEP NC UPR LOW EXPECTED TO CONTINUE SSW TROUGH SUNDAY AS HIGH
AMPLITUDE RIDGE PERSISTS OVER THE MS VLY AND MAIN PORTION OF WRN
STATES TROUGH LIFTS NE INTO S CNTRL CANADA.

AT LWR LEVELS...SURFACE TROUGH ASSOCIATED WITH NC LOW SHOULD
REDEVELOP S ACROSS FAR ERN NC/SC THROUGH THE PERIOD...WHILE LOW
ASSOCIATED WITH WRN TROUGH LIFTS RAPIDLY NE ACROSS ND INTO WRN
ONTARIO.

...TIDEWATER VA S INTO FAR ERN NC/OUTER BANKS...
UNUSUAL PATTERN WITH SSW-MOVING NOR'EASTER.  SURFACE AND SATELLITE
DATA SHOW AREA OF MODIFIED TROPICAL AIR MASS /EFFECTIVE WARM SECTOR/
EXTENDING FROM OFF THE SE VA/NC CST WWD IN A NARROWING WEDGE INTO
EXTREME SE VA NEAR ORF.  SSW MOTION OF UPR SYSTEM AND ASSOCIATED
BAND OF DEEP ELY FLOW TO ITS NORTH SUGGEST THAT THE WARM SECTOR WILL
REDEVELOP SSW WITH TIME AS SHALLOW BOUNDARY THAT MOVED JUST OFF THE
NC CST LATE YESTERDAY RETROGRESSES W.

WHILE LITTLE SURFACE DEVELOPMENT IS EXPECTED THROUGH THE PERIOD...
ONSHORE MOVEMENT OF NARROW WARM SECTOR AND ASSOCIATED LOW LEVEL
CONVERGENCE/ENHANCED WIND SHEAR FIELDS MAY BE SUFFICIENT TO SUPPORT
A BAND OR TWO OF THUNDERSTORMS WITH LOW LEVEL ROTATION.  IF THE
GUIDANCE IS TO BE BELIEVED REGARDING FCST SSW WOBBLING OF UPR COLD
POCKET...WARM SECTOR INSTABILITY SHOULD GRADUALLY DIMINISH THROUGH
THE PERIOD AFTER SOME TEMPORARY DESTABILIZATION FROM SURFACE HEATING
OVER EXTREME ERN NC TODAY.

IF INSTABILITY/CONVERGENCE DO NEVERTHELESS PROVE SUFFICIENT TO
SUPPORT SUSTAINED SURFACE-BASED STORMS IN WARM SECTOR...A LOW
PROBABILITY THREAT WILL EXIST FOR BRIEF TORNADOES.  THIS THREAT
SHOULD MOVE SWD FROM TIDEWATER VA/FAR NE NC EARLY THIS AFTN TO THE
HATTERAS AREA LATER TODAY/TONIGHT...TO POSSIBLY THE MHX/ILM AREA
EARLY SUNDAY.

...SW U.S...
DRIER SW FLOW HAS OVERSPREAD MUCH OF AZ IN THE WAKE OF SHORTWAVE
TROUGH NOW LIFTING NE ACROSS WY/MT.  SUBTROPICAL MOISTURE PLUME
WILL...HOWEVER...PERSIST FROM NE SONORA INTO EXTREME ERN AZ AND NM. 
AS UPR TROUGH LINGERS IN THE WEST AND A LOW REDEVELOPS ALONG THE SRN
CA CST...DEEP FLOW WILL SLOWLY BACK TO A MORE SLY
COMPONENT...ALLOWING MOISTURE TO ONCE AGAIN INCREASE ACROSS CNTRL AZ
THIS EVENING.

SHEAR PROFILES HAVE WEAKENED WITHIN THE MOIST PLUME RELATIVE TO
YESTERDAY...BUT HEATING SHOULD BOOST SBCAPE TO AROUND 1000 J/KG. 
SCTD THUNDERSTORMS SHOULD STRENGTHEN/DEVELOP BY AFTN INVOF
HIGHER TERRAIN IN ERN AZ/NM AND FAR SW AZ...WITH POTENTIAL FOR
ISOLATED MARGINALLY SEVERE WIND/HAIL.  SOME OF THIS ACTIVITY COULD 
CONTINUE INTO TONIGHT AND MAY SPREAD FARTHER W INTO AZ AS UPR FLOW
BACKS.

...CNTRL PLNS...
SURFACE HEATING AND CONVERGENCE/WARM ADVECTION ALONG ENHANCED LEE
TROUGH TRAILING SW FROM ND LOW MAY YIELD A FEW STORMS WITH GUSTY
WINDS IN PARTS OF NEB/NE CO AND SE SD LATER TODAY INTO TONIGHT.

..CORFIDI/BOTHWELL.. 10/07/2006