000
AXPZ20 KNHC 092213
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE OCT 09 2007

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 2100 UTC.
  
...TROPICAL WAVE...
TROPICAL WAVE ALONG 137W MOVING W 15 KT AWAY FROM CLUSTER OF 
CONVECTION ALONG ITCZ.

...ITCZ...
INTERTROPICAL CONVERGENCE ZONE...AXIS 12N87W  13N107W  11N116W 
11N130W  12N136W  11N140W.  SCATTERED MODERATE CONVECTION WITHIN 
120 NM OF AXIS E OF 112W AND WITHIN 180 NM OF AXIS FROM 124W TO 
138W.

...DISCUSSION...
NE-SW ELONGATED UPPER LEVEL RIDGE EXTENDING FROM ANTICYCLONE 
OVER SRN TIP OF BAJA CALIFORNIA 23N110W TO SECOND ANTICYCLONE AT 
20N121W THEN CONTINUE TO 13N140W.  WEAK UPPER TROUGH EXTENDS 
FROM AN UPPER LOW OVER SRN CALIFORNIA TO 32N117W THEN TO ANOTHER 
WEAK UPPER CYCLONE NEAR 24N140W.  RIDGE WOULD BLOCK FURTHER S 
INTRUSION OF WEAK COLD FRONT APPROACHING NRN BORDER OF E PAC AND 
WILL STALL IT N OF 25N EVENTUALLY DIFFUSING IT.  AIR MASS VERY 
DRY UNDER RIDGE AND ALONG TROUGH AXIS LEAVING NARROW SWATH OF 
MOISTURE TRAPPED BETWEEN BOTH...ALONG 80 KT JET CORE HEADING NE 
TO NRN BAJA CALIFORNIA AND SW CONUS.  

UPPER LEVEL ANTICYCLONE OVER WRN CARIBBEAN SUPPLIES AMPLE 
TROPICAL MOISTURE TO ITCZ FOR DEEP CONVECTION.  LACK OF 
UPLIFTING MECHANICS CURTAILS ACTIVITY ALONG ITCZ.  

MAIN FEATURE AT THE SURFACE ARE COLD FRONT APPROACHING NRN 
FRINGES OF AREA.  FRONT EXPECTED TO STALL ITS SRN 
INCURSION...SHIFT E TO THE MAINLAND AND DISSIPATE WITHIN NEXT  
48 HRS...LEAVING ONLY LONG PERIOD SWELL TRAINS UP TO 12 FT ON 
ITS TRAIL.  

SW CROSS EQUATORIAL WINDS S OF 12N INCREASING AND BUILDING SEAS 
TO 12 FT BY END OF FORECAST PERIOD. 

$$
WALLY BARNES