000
AXPZ20 KNHC 291602
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU NOV 29 2012

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS FROM 06N77W TO 08N85W TO 07N102W THEN ITCZ 
TO 06N110W TO 07N130W TO BEYOND 08N140W.  SCATTERED MODERATE TO 
STRONG CONVECTION WITHIN 90 NM OF AXIS E OF 98W.

...DISCUSSION...
ALOFT...LARGE DEEP LAYER CYCLONE WELL N OF REGION NEAR 47N139W 
DRAGS LONGWAVE TROUGH TO 32N136W TO 15N145W.  TROUGH SUPPORTS 
COLD FRONT APPROACHING NW CORNER OF E PAC ENTERING TONIGHT.   
DRY AIR MASS SWATH S OF 30N ALONG TROUGH AXIS WITH 65 KT JET 
CORE DOWNSTREAM ADVECTING PLENTY OF TROPICAL MOISTURE TO 
SOUTHERN HALF OF BAJA CALIFORNIA AND CENTRAL MEXICO.  MID TO 
UPPER LEVEL RIDGE CREST TILTS WITH INCOMING TROUGH BUT BLOCKS 
ANY FURTHER EASTWARD INTRUSION BY TROUGH SINCE SUPPORTING 
CYCLONE HAS MOVED TOO FAR NORTH.   

MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTEND FROM OAXACA MEXICO TO 
07N109W TO 00N108W WITH VERY DRY AIR MASS W OF AXIS N OF 
ITCZ/MONSOON TROUGH.  TROPICAL MOISTURE FROM SOUTH AMERICA  
INTRUDES INTO E PAC ALONG MONSOON TROUGH/ITCZ LATITUDES WITH 
SCATTERED MODERATE TO STRONG CONVECTION NOTED E OF 100W.  

...ELSEWHERE AT THE LOWER LEVELS...
APPROACHING COLD FRONT USHERS STRONG SOUTHWESTERLY BREEZE N OF 
28N W OF 130W AND PUSHES LARGE...18-21 FT...LONG PERIOD NW 
SWELLS SPREADING S TO REACH EQUATOR W OF 128W BY LATE SAT. 
HIGH PRES CENTER 1021 MB AT 26N120W BLOCKS EASTERLY INTRUSION OF 
AFOREMENTIONED COLD FRONT WHICH LACKS UPPER LEVEL SUPPORT WHEN 
DEEP LAYER CYCLONE SHIFTED N.  COLD FRONT THEN DISSIPATES FRI.

GULF OF TEHUANTEPEC...
N-NE GALE FORCE WINDS HAVE STARTED DIMINISHING AND ARE EXPECTED 
BECOME STRONG BREEZE THROUGH REMAINING OF FORECAST PERIOD.  SEAS 
EXPECTED TO SUBSIDE BELOW 8 FT LATE SAT.  

GULF OF PAPAGAYO...
STRONG BREEZE CROSSING INTO BASIN THROUGH MOUNTAIN GAP EXPECTED 
TO DIMINISH TO A MODERATE BREEZE FRI AS 1010 MB LOW PRES CENTER 
OVER COLOMBIA WEAKENS.  

$$
WALLY BARNES