000
AXPZ20 KNHC 062119
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI JAN 06 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 09N84W TO 04N92W. THE  ITCZ 
AXIS EXTENDS FROM 04N92W TO 03N96W TO 09N135W TO BEYOND 07N140W. 
SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 90 NM S OF AXIS 
BETWEEN 117W AND 122W. SCATTERED MODERATE CONVECTION WAS NOTED 
WITHIN 60 NM S OF AXIS BETWEEN 130W AND 135W.

...DISCUSSION...

A 1033 MB HIGH PRES IS CENTERED N OF THE AREA NEAR 39N133W WITH 
RIDGE EXTENDING SE TO NEAR 17N115W. THE PRESSURE GRADIENT 
BETWEEN THE AREA OF HIGH PRESSURE AND LOWER PRESSURE IN THE 
VICINITY OF THE ITCZ TO THE S IS MAINTAINING FRESH TRADEWINDS 
FROM 09N TO 18N W OF 128W AS DEPICTED BY LATEST 1800 UTC ASCAT 
PASS. LARGE LONG PERIOD NW SWELL CONTINUES TO MOVE SE ACROSS THE 
AREA...WITH COMBINED SEAS 8 TO 14 FT CURRENTLY COVERING MUCH OF 
THE AREA W OF 120W. THESE SEAS WILL CONTINUE TO SPREAD SE WHILE 
SLOWLY SUBSIDING THROUGH SUN. 

THE PRESSURE GRADIENT BETWEEN THE HIGH PRESSURE CENTER MENTIONED 
ABOVE AND A TROUGH OVER THE SW UNITED STATES IS PRODUCING FRESH 
NORTHERLY WINDS N OF 27N BETWEEN 120W AND 130W AS DEPICTED BY 
THE LATEST 1828 UTC ASCAT PASS. AS THE AREA OF HIGH PRESSURE 
WEAKENS OVER THE WEEKEND...THESE WINDS WILL DIMINISH BELOW 20 KT 
BY SUN MORNING. 

GULF OF TEHUANTEPEC...WINDS OVER THE GULF OF MEXICO CONTINUE TO 
MODIFY...AND WINDS FUNNELING INTO THE GULF OF TEHUANTEPEC 
CONTINUE TO DIMINISH. CURRENTLY THIS AFTERNOON...FRESH 20 KT 
WINDS ARE NOTED OVER THE GULF OF TEHUANTEPEC...AND ARE 
EXPECTED TO DIMINISH BELOW 20 KT BY THIS EVENING. 

GULF OF PAPAGAYO...FRESH TO STRONG NORTHEASTERLY GRADIENT WIND 
OVER THE WESTERN CARIBBEAN IS FLOWING THROUGH THE GAP IN THE 
TOPOGRAPHY OVER NICARAGUA 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.

ELSEWHERE E OF 110W...N TO NE SWELL ASSOCIATED WITH THE COMBINED 
STRONG GAP FLOW FROM PAPAGAYO AND TEHUANTEPEC COVERS MUCH OF THE 
AREA S OF 15N BETWEEN 90W AND 110W. THESE SWELLS ARE MIXING WITH 
NW SWELL W OF 100W AND CAUSING CONFUSED SEAS. 

HIGH PRESSURE IS FORECAST TO BUILD ACROSS THE GREAT BASIN REGION 
OVER THE WEEKEND. THIS WILL TIGHTEN THE PRES GRADIENT THROUGH 
THE GULF OF CALIFORNIA AND LEAD TO NWLY WINDS INCREASING TO 20 
TO 25 KT BY SUN AFTERNOON. 

$$
AL