000
AXPZ20 KNHC 192200
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON DEC 19 2011

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 FROM 07N81W TO 08N89W THEN ITCZ TO 07N112W TO 09N127W TO 
09N140W.  ISOLATED MODERATE CONVECTION WITHIN 90 NM OF AXIS FROM 
96W TO 114W.  SCATTERED MODERATE TO STRONG CONVECTION WITHIN 90 
NM OF AXIS W OF 137W. 

...DISCUSSION...
BROAD UPPER LEVEL RIDGE AXIS EXTENDS FROM ANTICYCLONE CENTER AT 
11N110W TO 32N130W PRODUCING DIFFLUENT FLOW WHICH ENHANCES 
SCATTERED MODERATE CONVECTION ALONG ITCZ FROM 103W TO 108W.  
WEAKENING JET STREAM...NOW DOWN TO 95 KT...RIDES OVER CREST OF 
RIDGE ADVECTING ABUNDANT MOISTURE UNTO NORTHWESTERN MEXICO AND N 
PART OF BAJA CALIFORNIA.  UPPER LAYER TROUGH EXTENDS FROM STRONG 
WELL DEFINED CYCLONE NEAR FOUR CORNERS THROUGH CENTRAL MEXICO TO 
GUATEMALA AND INTO E PAC NEAR 10N92W.  MODERATE TO STRONG 
SUBSIDENCE MAINTAINS DRY STABLE AIR AT MID AND UPPER LEVELS 
WITHIN 10 DEG W OF TROUGH AXIS.

SECOND DEEP LAYER CYCLONE APPROACHES COAST OF SOUTHERN 
CALIFORNIA TUE AND MAY REPEAT THE IMPACT OF THE AFOREMENTIONED 
CYCLONE BUT AT A SLIGHTLY MORE NORTHERN LATITUDE BEYOND FORECAST 
PERIOD. 

ELSEWHERE AT THE LOW LEVELS...
HEALTHY HIGH PRES CENTER 1035 MB N OF AREA COVER E PAC N OF ITCZ 
W OF 103W BRINGING STEADY FLOW OF E-NE FRESH BREEZE TRADES W OF 
120W THROUGH FORECAST PERIOD.   LONG PERIOD NW SWELLS UP TO 
10-11 FT PRODUCED BY DISSIPATED COLD FRONT SPREAD S TO 10N 
THROUGH TUE.  

GAP WINDS...
PREVIOUS GALE FORCE WINDS HAVE NOW DIMINISHED BUT LIKELY REMAIN 
AS FRESH N BREEZE THROUGH NEXT 6-12 HRS AS ITS SOURCE AIR MASS 
SHIFT EASTWARD.

GULF OF PAPAGAYO STRONG NE BREEZE CONTINUES UNABATED AS ATLC 
HIGH PRES NE OF AREA CONTINUES TO FORCE STRONG TRADES ACROSS 
ENTIRE CARIBBEAN.  WINDS FUNNEL ACROSS NICARAGUA MOUNTAIN PASSES 
AND EMERGE ON E PAC FROM 09N TO 11N.
 
$$
WALLY BARNES