000
AXPZ20 KNHC 282144
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED NOV 28 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS FROM 06N77W TO 08N86W TO 07N96W THEN ITCZ TO 
06N112W TO 07N118W TO 07N133W TO BEYOND 08N140W.  SCATTERED 
MODERATE TO STRONG CONVECTION WITHIN 90 NM OF AXIS E OF 84.  
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 45 NM OF 
AXIS FROM 90W TO 105W.

...DISCUSSION...
ALOFT...DEEP LAYER CYCLONE HAS PULLED N-NW TO 44N142W DRAGGING 
LONGWAVE TROUGH TO 34N140W TO 14N153W.  TROUGH SUPPORTS WEAK 
COLD FRONT EXTENDING FROM 32N124W TO 30N126W TO 23N140W.  STRONG 
SUBSIDENCE DRIES AIR MASS W OF TROUGH WHILE 85 KT JET CORE 
ADVECTS ABUNDANT TROPICAL MOISTURE...CONVECTIVE DEBRIS FROM 
ITCZ... ACROSS BASIN UNTO CENTRAL BAJA CALIFORNIA AND MEXICO.  
SLANTED RIDGE CREST FROM TIP OF BAJA CALIFORNIA TO 00N130W 
PROVIDES LARGE REGION OF DIVERGENT FLOW ALOFT...BUT WITH BROAD 
SURFACE HIGH PRES 1023 MB UPLIFTING MECHANICS ARE NIL.  

MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTEND FROM CENTRAL MEXICO TO 
13N103W TO 00N100W WITH VERY DRY AIR MASS W OF AXIS CURTAILING 
ANY ITCZ W OF 105W.  PLENTY OF TROPICAL MOISTURE FROM SOUTH 
AMERICA INTRUDES INTO E PAC ALONG MONSOON TROUGH/ ITCZ LATITUDES 
WITH SCATTERED MODERATE TO STRONG CONVECTION NOTED E OF 97W.  

...ELSEWHERE AT THE LOWER LEVELS...
COLD FRONT FROM 30N126W TO 23N140W BRING FRESH WESTERLIES AND 
LARGE...18-20 FT...LONG PERIOD NW SWELLS BEHIND IT SPREADING S 
TO REACH 10N W OF 120W BY LATE FRI.  HIGH PRES CENTER 1023 MB AT 
26N119W BLOCKS EASTERLY INTRUSION OF COLD FRONT WHICH LOST UPPER 
LEVEL SUPPORT WHEN AFOREMENTIONED CYCLONE SHIFTED N.  COLD FRONT 
THEN DISSIPATES BY THU.

GULF OF TEHUANTEPEC...
N-NE GALE FORCE WINDS HAVE PEAKED NEAR STORM FORCE EARLIER TODAY 
AND ARE EXPECTED TO SLOWLY DIMINISH FURTHER THROUGH LATE THU. 
SEAS EXPECTED TO SUBSIDE BELOW 8 FT BY FRI.  

GULF OF PAPAGAYO...
FRESH NE-E TRADES EXPECTED TO BECOME A STRONG BREEZE LATE 
TONIGHT AND THU THEN DIMINISH BY LATE FRI AS LOW PRES CENTER 
1007 MB OVER COLOMBIA WEAKENS.  

$$
WALLY BARNES