000
AXPZ20 KNHC 082120
TWDEP 

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

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

THE MONSOON TROUGH AXIS EXTENDS FROM 06N77W TO 05.5N84W TO 
04N89W. THE ITCZ AXIS EXTENDS FROM 04N89W TO 02.5N94W TO 08N130W 
TO BEYOND 07N140W. SCATTERED MODERATE CONVECTION WAS NOTED 
WITHIN 60 NM S OF AXIS E OF 82W. SCATTERED MODERATE CONVECTION 
WAS NOTED WITHIN 120 NM N OF AXIS BETWEEN 128W AND 135W.

...DISCUSSION...

A 1028 MB HIGH PRES CENTER WAS LOCATED N OF THE AREA NEAR 
39N128W WITH RIDGE EXTENDING SE TO NEAR 20N113W. THE PRESSURE 
GRADIENT BETWEEN THE AREA OF HIGH PRESSURE AND LOWER PRESSURE IN 
THE VICINITY OF THE ITCZ IS MAINTAINING FRESH TO STRONG 
TRADEWINDS FROM 08N TO 17N W OF 128W...WHICH ARE PROVIDING LOW 
LEVEL FORCING FOR THE CONVECTION MENTIONED ABOVE. LONG PERIOD NW 
SWELL WITH PERIODS OF 16-18 SECONDS ALONG THE LEADING EDGE OF 
THE SWELL TRAIN CONTINUES TO MOVE SE THROUGH THE FORECAST 
WATERS...WITH COMBINED SEAS 8 TO 10 FT CURRENTLY COVERING MUCH 
OF THE AREA W OF 100W. THESE SWELLS WILL CONTINUE TO PROPAGATE 
SE...REACHING THE GALAPAGOS ISLANDS ALONG 91W BY MON 
AFTERNOON...THEN THE NW COAST OF S AMERICA MON NIGHT...WHILE 
SLOWLY SUBSIDING. 

GULF OF PAPAGAYO...FRESH 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 AT 20 
TO 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 EARLY 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 ACROSS THE GULF OF PAPAGAYO...WITH 
WINDS EXPECTED TO FINALLY DIMINISH BELOW 20 KT MON NIGHT.

GULF OF CALIFORNIA...HIGH PRESSURE OVER THE GREAT BASIN REGION 
HAS TIGHTENED THE PRES GRADIENT ACROSS THE NORTHERN GULF OF 
CALIFORNIA. NWLY WINDS OF 20 TO 30 KT PREVAIL N OF 27N. WINDS 
WILL SPREAD S THROUGH THE ENTIRE LENGTH OF THE GULF BY MONDAY 
MORNING.

$$
AL