000
AXPZ20 KNHC 171555
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU DEC 17 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...
THE ITCZ AXIS FLUCTUATES FROM 05N TO 07N BETWEEN SOUTH AMERICA 
AND 140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED 
FROM 05N TO 09N BETWEEN 80W AND 95W AND ALSO FROM 04N TO 09W W 
OF 107W. 

...DISCUSSION...
AN UPPER LEVEL SHORTWAVE RIDGE EXTENDS OVER THE NW PORTION OF 
THE DISCUSSION AREA WITH AXIS FROM 25N125W TO 32N132W. UPPER 
DEBRIS MOISTURE ORIGINATING N OF HAWAII IS STREAMING ALONG THE 
RIDGE W OF 140W THEN FANS OUT OVER THE AREA N OF 27N W OF 125W.

AN UPPER TROUGH EXTENDS ALONG 32N105W TO 12N105W. A BAND OF 
UPPER MOISTURE IS NOTED FROM 21N TO 29N BETWEEN 120W AND 110W. 
OTHERWISE UPPER DRY AIR IS INDICATED N OF 12N W OF 100W.

AT THE LOW LEVELS...A 1024 MB HIGH PRES IS CENTERED NEAR 
30N128W. NE TO E TRADE WINDS AT 20 TO 25 KT CONTINUE ALONG THE 
SOUTHERN PERIPHERY OF THE HIGH PRES...ROUGHLY FROM 05N TO 20N W 
OF 120W. A TROPICAL LOW PRES IS EMBEDDED IN THE THE ITCZ NEAR 
06N115W AND IS EXPECTED TO PERSIST FOR A FEW DAYS ACCOMPANIED BY 
20 TO 25 KT WINDS. NW SWELLS TO 15 FT ARE PROPAGATING SE THROUGH 
THE WATERS W OF 115W AND WILL BE REINFORCED BY A COLD FRONT 
MOVING OVER THE NW PORTION SAT WITH SEAS BUILDING TO ABOUT 18 
FT LATE SAT.

GAP WINDS...NORTHERLY WINDS TO MINIMAL GALE FORCE CONTINUE 
THROUGH THE ISTHMUS OF TEHUANTEPEC AND SHOULD DIMINISH BELOW 
GALE LATE SAT MORNING. NE TO E WINDS OF 20 TO 25 KT ARE STILL 
BRIDGING ACROSS THE GULF OF PAPAGAYO AND ARE EXPECTED TO 
DIMINISH TO LESS THAN 20 KT OVER THE NEXT 24 HOURS. NW WINDS AT 
15 TO 20 KT ARE EXPECTED TO CONTINUE OVER THE NORTHERN GULF OF 
CALIFORNIA FOR THE NEST FEW DAYS.  

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