000
AXPZ20 KNHC 092137
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED NOV 09 2011

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 EXTENDS FROM 09.5N85W TO 07N96W TO 08N103W. 
THE ITCZ EXTENDS FROM 08N103W TO 11.5N120W WHERE THERE IS A 
BREAK AS A RESULT OF A SURFACE TROUGH FROM 15N118W TO 10N122W. 
THERE IS SCATTERED MODERATE TO STRONG WITHIN 60 N E OF TROUGH 
AXIS FROM 11N TO 13N. THE ITCZ THEN RESUMES FROM 11N122W TO 
09N131W AND EXTENDS BEYOND 10N140W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION WAS NOTED WITHIN 60 NM S AND 30 NM N OF ITCZ 
AXIS BETWEEN 124W AND 130W.

...DISCUSSION...

A SURFACE HIGH PRESSURE CENTER 1025 MB IS NEAR 32N123W WITH 
RIDGE EXTENDING TO NEAR 21N110W. THE PRESSURE GRADIENT BETWEEN 
THE AREA OF HIGH PRESSURE AND TROUGHING OVER MEXICO IS 
MAINTAINING FRESH TO STRONG NW WINDS OVER THE GULF OF 
CALIFORNIA. THE PRESSURE GRADIENT BETWEEN THE AREA OF HIGH 
PRESSURE AND THE ITCZ IS MAINTAINING FRESH 20 KT TRADES FROM 09N 
TO 20N W OF 118W.

THE HIGH PRESSURE CENTER WILL DRIFT SE WHILE WEAKENING OVER THE 
NEXT 24 TO 48 HOURS. WITH THE AREA OF HIGH PRESSURE 
WEAKENING...WINDS OVER THE GULF OF CALIFORNIA WILL DIMINISH 
BELOW 20 KT LATE THU NIGHT. ADDITIONALLY AS A RESULT OF THE 
WEAKENING HIGH PRESSURE...THE FRESH 20 KT TRADES WILL DIMINISH 
OVER THE W PART OF THE AREA. 

WITH THE HIGH PRESSURE CENTER MENTIONED ABOVE SHIFTING E SINCE 
YESTERDAY...A COLD FRONT A SURFACE COLD FRONT HAS MOVED INTO THE 
FAR NW PART OF THE AREA. CURRENTLY...SEAS REMAIN BELOW 8 FT 
ASSOCIATED WITH THE FRONT...BUT WILL RAPIDLY BUILD IN NW SWELL. 
COMBINED SEAS IN NW SWELLS WILL BUILD TO NEAR 16 FT BY THU 
AFTERNOON OVER THE FAR NW PART OF THE AREA...AND TO 22 FT BY FRI 
AFTERNOON. 

GAP WINDS
GULF OF TEHUANTEPEC...A COLD FRONT OVER THE GULF OF MEXICO WILL 
CONTINUE TO MOVE EASTWARD OVER THE NEXT 24 HOURS...REACHING THE 
BAY OF CAMPECHE TONIGHT. NORTHERLY WINDS BEHIND THE FRONT WILL 
START TO FUNNEL THROUGH THE CHIVELA PASS TONIGHT...AND RAPIDLY 
INCREASE TO GALE FORCE BY THU AFTERNOON...AND JUST BELOW STORM 
FORCE BY LATE THU. WINDS WILL DIMINISH BELOW GALE FORCE FRI 
NIGHT AND FURTHER DIMINISH BELOW 20 KT SAT NIGHT.

$$
AL