000
AXPZ20 KNHC 311036
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE OCT 31 2006

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1030 UTC.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 89W N OF 3N MOVING W 10 KT.  LITTLE 
SIGNIFICANT CONVECTION ASSOCIATED WITH FEATURE AND CONDITIONS 
ALOFT DO NOT APPEAR FAVORABLE FOR ANY DEVELOPMENT AS EASTERLY 
SHEAR CURTAILS DEEP CONVECTION. 

SECOND TROPICAL WAVE ALONG 82W N OF 4N SEEMS TO DRAG MORE 
CONVECTION THAN ITS PREDECESSOR BUT IS MOSTLY DUE TO WIND 
CONVERGENCE OVER MOUNTAINS IN NICARAGUA.  SIMILARLY...CONDITIONS 
ALOFT DO NOT APPEAR CONDUCIVE TO DEVELOPMENT ALTHOUGH EASTERLY 
SHEAR IS NOT AS STRONG AS THE PREVIOUS WAVE.  IT WLY MOVEMENT 
WILL BRING WAVE INTO MORE ADVERSE UPPER CONDITIONS.

...ITCZ...
ITCZ AXIS ALONG  9N83W  8N94W  11N111W  7N130W  8N140W. 
SCATTERED STRONG WITHIN 90 NM OF ITCZ FROM 93W TO 105W AND 
WITHIN 120 NM OF AXIS FROM 107W TO 125W.

...DISCUSSION...
FLAT MID/UPPER LEVEL RIDGE MAINTAINS WEAK QUASI ZONAL FLOW ALOFT 
N OF 20N W OF 120W.  JET CORE OF 85 KT HAS WIDE SWATH OF 
TROPICAL MOISTURE ADVECTING E OVER BAJA CALIFORNIA BUT LITTLE 
ENERGY TO DEVELOP SIGNIFICANT DEEP CONVECTION.  ANTICYCLONE 
CENTER AT 12N133W REMAINS BLOCKING SOUTHERN INTRUSION OF 
UPSTREAM UPPER LEVEL LONGWAVE TROUGH FORCING IT INTO A MORE NELY 
DIRECTION.  

LARGE AMPLITUDE MID/UPPER LEVEL TROUGH OVER CENTRAL PLAINS 
EXTEND S INTO SRN MEXICO AND BRINGS DRY AIR MASS INTO E PAC E OF 
120W...WHICH DOES NOT HELP TROPICAL WAVES MENTIONED ABOVE IN 
THEIR DEVELOPMENT PHASES. 

WEAK UPPER LEVEL ANTICYCLONIC CIRCULATION AT 11N95W SEEMS TO BE 
ONLY FEATURE ENHANCING WESTWARD ADVECTION OF TROPICAL MOISTURE 
FROM COLOMBIA INTO THE E PAC ITCZ...AND THAT DOES NOT SEEM TO BE 
ENOUGH TO DEVELOP ANY TROPICAL SYSTEMS.

ON THE SURFACE...
HIGH PRES CENTER OVER NWRN CORNER OF E PAC BASIN MAINTAINS 
HEALTHY TRADES ACROSS AREA W OF 120W FROM 13N TO 20N.  AS RIDGE 
IS FORCED E BY INCOMING COLD FRONT...PRES GRADIENT TIGHTENS 
AGAINST BAJA CALIFORNIA MOUNTAINS WITH INCREASE IN NW WINDS 
REACHING 20 KT.  WEAK COLD FRONT OVER NW CORNER WILL TEMPORARILY 
INCREASE W WIND TO 20 KT...BUT WILL DIMINISH QUITE FAST.  SWELLS 
MIGHT LINGER FOR ANOTHER 12-24 HRS AFTER WIND DROPS.  

CROSS EQUATORIAL WIND AND SWELLS MOVE INTO E PAC S OF 9N E OF 
123W.  


$$
WALLY BARNES