000
AXPZ20 KNHC 080259
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN JAN 08 2012

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS FROM 08N83W TO 04N95W. THE ITCZ 
AXIS EXTENDS FROM 04N95W TO 06N115W TO 08N131W TO BEYOND 
07N140W. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 60 NM S 
OF AXIS BETWEEN 83W AND 87W.

...DISCUSSION...

A 1030 MB HIGH PRES IS CENTERED N OF THE AREA NEAR 38N130W WITH 
RIDGE EXTENDING SE TO NEAR 19N110W. THE PRESSURE GRADIENT 
BETWEEN THE AREA OF HIGH PRESSURE AND LOWER PRESSURE IN THE 
VICINITY OF THE ITCZ IS MAINTAINING FRESH TRADEWINDS FROM 08N TO 
16N W OF 128W. LONG PERIOD NW SWELL WITH PERIODS OF 17-18 
SECONDS ALONG THE LEADING EDGE OF THE SWELL TRAIN CONTINUES TO 
MOVE SE THROUGH THE FORECAST WATERS WITH COMBINED SEAS 8 TO 13 
FT CURRENTLY COVERING MUCH OF THE AREA W OF 110W. THESE SWELLS 
WILL CONTINUE TO PROPAGATE SE...REACHING 95W BY MON 
AFTERNOON...WHILE SLOWLY SUBSIDING. 

THE PRESSURE GRADIENT BETWEEN THE HIGH PRESSURE CENTER MENTIONED 
ABOVE AND TROUGHING ACROSS CALIFORNIA IS PRODUCING FRESH 
NORTHERLY WINDS N OF 29N BETWEEN 120W AND 126W. WINDS WILL 
DIMINISH BELOW 20 KT BY EARLY SUN AS THE AREA OF HIGH PRESSURE 
WEAKENS. 

GULF OF PAPAGAYO...FRESH TO STRONG TRADE WINDS OVER THE WESTERN 
CARIBBEAN ARE FLOWING THROUGH THE GAPS IN THE TOPOGRAPHY OVER 
NICARAGUA AND COSTA RICA INTO THE GULF OF PAPAGAYO. WINDS WILL 
PEAK NEAR 25 KT DURING THE EARLY MORNING HOURS WITH THE ADDED 
COMPONENT OF NOCTURNALLY DRIVEN KATABATIC WINDS AND THEN REDUCE 
TO AROUND 20 KT THROUGHOUT THE DAY AND EVENING HOURS. LITTLE 
CHANGE IN THIS PATTERN IS EXPECTED THROUGH MON. AS THE AREA OF 
HIGH PRESSURE OVER THE SW N ATLC WATERS WEAKENS EARLY NEXT 
WEEK...WINDS OVER THE CARIBBEAN WATERS WILL DIMINISH. THIS WILL 
DIMINISH WINDS FUNNELING INTO THE GULF OF PAPAGAYO... WITH WINDS 
EXPECTED TO FINALLY DIMINISH BELOW 20 KT TUE.

HIGH PRESSURE WILL BUILD ACROSS THE GREAT BASIN REGION OVERNIGHT 
AND SUN. THIS WILL TIGHTEN THE PRES GRADIENT THROUGH THE GULF OF 
CALIFORNIA ON SUN. NWLY WINDS WILL INCREASE TO 20 TO 30 KT BY 
SUN MORNING...WITH FRESH TO STRONG WINDS SPREADING S THROUGH THE 
GULF...REACHING AS FAR S AS 23N BY MON EVENING. 

$$
AL