000
AXPZ20 KNHC 282141
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON DEC 28 2009

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...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...05N77W 
TO 07N90W TO 05N104W TO 08N123W TO 05N140W. SCATTERED MODERATE 
WITHIN 60 NM EITHER SIDE OF AXIS E OF 88W. NO DEEP CONVECTION. 

...DISCUSSION...

ALOFT...A STRONG SHORTWAVE TROUGH IS APPROACHING THE W COAST OF 
BAJA CALIFORNIA GENERATING MULTILAYER CLOUDS WITH EMBEDDED AREAS 
OF MAINLY LIGHT RAIN. THIS CLOUDINESS IS ALSO AFFECTING THE 
WESTERN COAST OF MAINLAND MEXICO PARTICULARLY NORTH OF PUERTO 
VALLARTA. THE SHORTWAVE IS FORECAST TO MOVE EAST ACROSS NORTHERN 
MEXICO AND THE SW CONUS BY TUE. A ZONAL FLOW PREVAILS ALONG MUCH 
OF THE REMAINDER OF THE FORECAST AREA. AN UPPER ANTICYCLONE 
CENTERED OVER THE CENTRAL CARIBBEAN DOMINATES CENTRAL AMERICA 
AND THE EPAC E OF 91W. PATCHES OF MIDDLE TO UPPER LEVEL MOISTURE 
ARE MOVING AROUND THE WESTERN PERIPHERY OF THIS ANTICYCLONE. 

THE WEAK SURFACE LOW THAT WAS NEAR 24N132W THIS MORNING HAS 
DISSIPATED...AND A SURFACE RIDGE IS BUILDING ACROSS THE AREA. 
THE RIDGE IS ANCHORED ON A 1023 MB HIGH LOCATED NEAR 31N135W. A 
BROAD AREA OF FRESH TO STRONG TRADE WINDS IS NOTED N OF THE ITCZ 
TO 20N W OF 125W. THESE CONDITIONS WILL PERSIST THROUGH AT LEAST 
WED AS THE HIGH PRES REMAINS JUST N OF THE LOCAL REGION.

GAP WINDS...
GULF OF TEHUANTEPEC...N WINDS OF 20 KT ARE EXPECTED TO SPREAD S 
AND W AND INCREASE TO 20 TO 30 KT BY TONIGHT.

GULF OF PAPAGAYO...E WINDS OF 20 KT ARE EXPECTED TO INCREASE TO 
20 TO 30 KT AND SPREAD WEST BY TONIGHT.

SEA CONDITIONS ARE DOMINATED BY LONG PERIOD NW SWELL (WAVE 
PERIODS OF UP TO 18 SECONDS) WITH SIGNIFICANT WAVE HEIGHTS AS 
HIGH AS 16 FT PARTICULARLY OVER THE NW CORNER OF THE AREA. THIS 
SWELL EVENT WILL CONTINUE TO SPREAD SE REACHING NEAR 91W IN 
ABOUT 48 HOURS.

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