000
AXPZ20 KNHC 231557
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED DEC 23 2009

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

...ITCZ...
ITCZ AXIS IS ALONG 08N79W TO 05N103W TO 08N122W TO 07N140W. 
ISOLATED STRONG CONVECTION IS NEAR 07N121W. 

...DISCUSSION...
AN UPPER LEVEL TROUGH W OF THE AREA ALONG 145W IS PRECEDED BY A 
SWATH OF UPPER MOISTURE WITHIN 180 NM OF LINE 32N140W TO 16N142W.
A SECOND UPPER TROUGH IS FILLING ALONG 100W OVER OLD MEXICO.   
AN UPPER ANTICYCLONE IS CENTERED OVER THE TROPICS NEAR 01N127W 
WITH A RIDGE EXTENDING N TO A CREST AT 31N127W. A LARGE MOISTURE 
PLUME IS OBSERVED WITHIN THE RIDGE...FROM 15N TO 30N BETWEEN 
135W AND 115W...THEN CONTINUES E IN UPPER WESTERLY FLOW ACROSS 
OLD MEXICO AND THE GULF OF MEXICO FROM 15N TO 25N BETWEEN 115W 
AND 85W. AN UPPER TROUGH EXTENDING S ALONG THE E COAST OF CONUS 
CONTINUES S ACROSS CENTRAL AMERICA TO A BASE AT 07N90W. DRY 
UPPER AIR IS INDICATED OVER THE DISCUSSION AREA S OF 15N E OF 
90W.
 
AT THE SURFACE...A COUPLE OF EMBEDDED SURFACE TROUGHS ARE NOTED 
WITHIN IN THE ITCZ ALONG 123W AND 137W. OTHERWISE HIGH PRES 
COVERS THE AREA N OF 17N W OF 117W. ELY TRADES OF 20 KT ARE ON 
THE ON THE SOUTHERN PERIPHERY OF THE RIDGE WITH SOUTHERLY WINDS 
AT 20 TO 25 KT OVER THE NW WATERS IN ADVANCE OF AN APPROACHING 
COLD FRONT IN ABOUT 54 HOURS. NORTHERLY FLOW AT 20 KT IS FOUND 
NE OF THE RIDGE ACROSS THE BAJA PENINSULA INTO THE GULF OF 
CALIFORNIA.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE
  
$$
NELSON