000
AXPZ20 KNHC 210350
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE DEC 21 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

.ITCZ...
AXIS FROM 03N78W TO LOW PRES 1009 MB AT 07N88W TO 04N97W TO 
13N116W TO 06N140W.  NO SIGNIFICANT CONVECTION.

.DISCUSSION...
MOST OF BASIN REMAINS FAIRLY DRY ALOFT AS AXIS OF UPPER LEVEL 
TROUGH AND BROAD DOWNSTREAM RIDGE COVER MOST OF E PAC WITH 
SUBSIDING AIR MASS.  MAIN MOISTURE ADVECTION HAPPENS ALONG NW 
CORNER W OF TROUGH ALOFT RIDING 145 KT JET CORE THAT SUPPORTS 
COLD FRONT PRESENTLY FROM 32N120W TO 22N140W.  EVEN ITCZ SUFFERS 
FROM LACK OF MOISTURE WITH NO SIGNIFICANT CONVECTION IN SPITE OF 
GOOD LOW LEVEL CONVERGING WINDS NEAR LOW PRES CENTER AT 07N88W 
AND WEAK SURFACE TROUGH ALONG 120W FROM 09N TO 15N.  BOTH 
FEATURES EXPECTED TO FURTHER WEAKEN WITHIN NEXT 24-48 HRS.  

COLD FRONT AND ASSOCIATED LONG PERIOD NW 12-16 FT SWELLS ARE 
MAIN CONCERN THROUGH PERIOD.  ENERGY SURGE WITHIN 24 HRS EXPANDS 
STRONG NW WINDS SPREADING SWELLS SE AS FAR AS 118W.  FRONT ALSO 
KICKS SW WINDS WITHIN GULF OF CALIFORNIA BUT SHOULD REMAIN N OF 
30N.  

LOW PRES AT 07N88W ENHANCE DOWNSLOPE DRAINAGE WINDS TONIGHT JUST 
E OF GULF OF PAPAGAYO INCREASING FROM MODERATE TO A FRESH 
BREEZE.  WINDS LIKELY WEAKEN DURING DAYTIME HOURS AND AS LOW 
PRES PULLS FURTHER W OF 90W.   
        
$$
WALLY BARNES