000
AXPZ20 KNHC 190345
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

MONSOON TROUGH AXIS FROM 08N83W TO 07N95W THEN ITCZ TO 05N110W 
TO 10N122W TO 08N135W TO BEYOND 08N140W.  SCATTERED MODERATE 
CONVECTION WITHIN 60 NM OF AXIS FROM 125W TO 128W. 

...DISCUSSION...

DEEP LAYERED UPPER CYCLONE OVER FAR SOUTHERN ARIZONA AT 34N113W 
WILL BE ACCELERATING E AND OUT OF AREA LATE TONIGHT DRAGGING ITS 
ATTENDANT SURFACE LOW PRES 1010 MB AND DISSIPATING TROUGH WITH 
IT.  SECOND AND STRONGER CYCLONE MOVES INTO SAME AREA EARLY TUE 
WITH A SIMILAR CONFIGURATION.  UPPER LEVEL TROUGH AXIS FROM 
FIRST CYCLONE MAINTAIN DRY AIR MASS N OF 22N FROM 110W TO 130W 
WHILE ABUNDANT MOISTURE SURROUNDS DEEP CYCLONE WITHIN 240 NM OF 
CENTER.  STRONG CONVECTION ASSOCIATED WITH CYCLONE SPREADING E 
OF FORECAST AREA JUST N OF 30N BY END OF FORECAST PERIOD.  
SECOND CYCLONE WHILE MORE INTENSE IS EXPECTED TO REMAIN ON A 
SLIGHTLY MORE NORTHERLY TRACK THAN THE FIRST SO ITS FRONTAL 
BOUNDARY WINDS MIGHT NOT REACH S OF 30N...BUT ITS LONG PERIOD  
NW SWELL ARE EXPECTED TO REACH AS FAR S AS 20N.    

HIGH PRES CENTER 1026 MB AT 29N129W ALLOWS FRESH TRADES TO 
EXPAND EASTWARD TO 110W MON AS RIDGE EXTENDS FURTHER E.  FRESH 
NW BREEZE FROM 18N TO 22N E OF 108W EXPECTED TO DIMINISH MON 
NIGHT AS RIDGE SLIDE E. 

GAP WINDS...
GULF OF TEHUANTEPEC...PRESENT GALE EVENT EXPECTED TO DIMINISH 
LATE TONIGHT AS HIGH PRES OVER SE CONUS SHIFTS EASTWARD REDUCING 
PRES GRADIENT BY EARLY MON.   

GULF OF PAPAGAYO...PRES GRADIENT FORCING FRESH TO STRONG WINDS 
ACROSS NICARAGUA INTO GULF OF PAPAGAYO WITH SPEEDS REACHING NEAR 
GALE FORCE EARLIER TODAY.  WINDS BEGIN TO DIMINISH LATE TONIGHT 
AS HIGH PRES OVER E ATLC SHIFTS EASTWARD...BUT REMAIN AS FRESH 
BREEZE THROUGH AT LEAST EARLY TUE...BEFORE DIMINISHING TO A 
MODERATE BREEZE LATE TUE.

$$
WALLY BARNES