000
AXPZ20 KNHC 072116
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT JAN 07 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

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

THE MONSOON TROUGH AXIS EXTENDS FROM 09N83W TO 04.5N93W. THE 
ITCZ AXIS EXTENDS FROM 04.5N93W TO 06N115W TO 07.5N125W TO 
BEYOND 08N140W. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 
120 NM N OF AXIS BETWEEN 130W AND 140W. CONVERGENCE S OF THE 
MONSOON TROUGH IS RESULTING IN SCATTERED MODERATE CONVECTION 
FROM 04N TO 07N BETWEEN 80W AND 83W.

...DISCUSSION...

A 1032 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 
20N W OF 130W. LONG PERIOD NW SWELL WITH PERIODS OF 18-20 
SECONDS ALONG THE LEADING EDGE OF THE SWELL TRAIN CONTINUES TO 
MOVE SE THROUGH THE FORECAST WATERS WITH COMBINED SEAS 8 TO 12 
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 125W...WITH SEAS AS 
HIGH AS 15 FT ALONG THE BORDER AT 30N. 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 IS FLOWING THROUGH THE GAPS IN THE TOPOGRAPHY OVER 
NICARAGUA AND COSTA RICA SPILLING THROUGH 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.

HIGH PRESSURE WILL BUILD ACROSS THE GREAT BASIN REGION TONIGHT 
AND SUN. THIS WILL TIGHTEN THE PRES GRADIENT THROUGH THE GULF OF 
CALIFORNIA ON SUN AND LEAD TO NWLY WINDS INCREASING TO 20 TO 30 
KT BY SUN MORNING...WITH FRESH TO STRONG WINDS SPREADING S 
THROUGH THE GULF SUN NIGHT AND MON...REACHING AS FAR S AS 24N BY 
MON AFTERNOON. 

$$
AL