000
AXPZ20 KNHC 172158
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT DEC 17 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 AXIS FROM 08N83W TO 05N102W THEN ITCZ TO 09N118W 
TO 06N128W TO BEYOND 09N140W.  SCATTERED MODERATE CONVECTION 
WITHIN 120 NM OF AXIS FROM 111W TO 122W.  SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WITHIN 120 NM N AND 60 NM S OF AXIS W 
OF 134W.

...DISCUSSION...

UPPER LEVEL CYCLONE AT 31N119W STRONGLY SUPPORTS SURFACE LOW 
PRES 1018 MB AT 30N117W WITH FRONTAL TROUGH EXTENDING TO 
25N117W.  CYCLONE SHIFT E INLAND SUN EFFECTIVELY DOOMING SURFACE 
LOW PRES AND FRONTAL TROUGH TO DISSIPATE.  WEAK COLD FRONT 
APPROACH NORTHEASTERN BOUNDARY LATE MON WITH STRONG N BREEZE BUT 
IS NOT EXPECTED TO REACH S OF 30N...NEVERTHELESS ITS NW SWELLS 
UP TO 10-11 FT SHOULD EXTEND AS FAR S AS 22N.    

FRESH NE TRADEWINDS W OF 130W DIMINISH SUN BUT ARE EXPECTED TO 
INCREASE EASTWARD IN COVERAGE MON AS HIGH PRES IS SQUEEZED BY 
AFOREMENTIONED APPROACHING COLD FRONT.

GAP WINDS...
GULF OF TEHUANTEPEC...STRONG N BREEZE ACROSS GULF OF TEHUANTEPEC 
EXPECTED TO REACH GALE FORCE TONIGHT.  EVENT BECOMES SHORT LIVED 
AS HIGH PRES OVER GULF OF MEXICO SHIFTS E EASING PRES GRADIENT 
OVER THE ISTHMUS. 

GULF OF PAPAGAYO...SURFACE LOW PRES 1010 MB OVER COLOMBIA FORCE 
STRONG E WINDS OVER WESTERN CARIBBEAN FINDING THEIR WAY ACROSS 
NICARAGUA MOUNTAIN GAPS AND REACH GULF OF PAPAGAYO IN E PAC.  
WINDS EXPECTED TO WEAKEN BY LATE MON AS LOW PRES BECOMES ILL 
DEFINED.

$$
WALLY BARNES