000
AXPZ20 KNHC 092130
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
2205 UTC MON DEC 09 2013

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.

...SPECIAL FEATURES...

GULF OF CALIFORNIA GALE...STRONG RIDGING OVER THE GREAT BASIN 
HAS PRODUCED NEAR GALE NORTHERLY WINDS OVER THE NORTHERN GULF OF 
CALIFORNIA. THESE WINDS WILL REACH GALE FORCE BY TONIGHT OVER 
THE NORTHERN GULF OF CALIFORNIA WITH SEAS BUILDING TO 10 FT. THE 
STRONG NW WINDS WILL SPREAD ALONG THE LENGTH OF THE GULF OF 
CALIFORNIA THROUGH TUE...THEN GRADUALLY DIMINISH FROM NORTH TO 
SOUTH THROUGH MID WEEK. 

GULF OF TEHUANTEPEC GALE...A STRONG COLD FRONT WILL MOVE THROUGH 
THE WESTERN GULF OF MEXICO ON TUESDAY. COOL DENSE AIR BEHIND THE 
FRONT WILL FUNNEL THROUGH THE CHIVELA PASS INTO THE GULF OF 
TEHUANTEPEC BY TUE AFTERNOON. WINDS WILL RAPIDLY INCREASE TO 
GALE FORCE BY TUE NIGHT. THE STRONG HIGH PRES N OF THE AREA 
RESULTING FROM THE COLD DENSE AIR WILL ALLOW THE GALE FORCE 
WINDS IN THE GULF OF TEHUANTEPEC TO PERSIST INTO FRIDAY...WITH 
SLIGHTLY STRONGER CONDITIONS DURING THE OVERNIGHT HOURS DUE TO 
DRAINAGE EFFECTS. SEAS WILL BUILD QUICKLY TO 9 FT BY LATE 
TUE...REACHING AS HIGH AS 14-15 FT BY WED. THE PERSISTENT GAP 
WIND FLOW WILL ALSO PRODUCE A PLUME OF SHORT PERIOD NE SWELL IN 
EXCESS OF 8 FT REACHING AS FAR WEST AS 105W BY LATE THURSDAY. 

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

THE MONSOON TROUGH EXTENDS FROM 09N84W TO 07N100W WHERE LOW 
LEVEL WINDS SUGGEST A TRANSITION TO ITCZ WHICH EXTENDS TO 
10N118W TO BEYOND 08N140W. SCATTERED MODERATE CONVECTION 
WAS NOTED WITHIN 150 NM S OF ITCZ BETWEEN 125W AND 135W.

...DISCUSSION... 

GULF OF PAPAGAYO...BRIEF PULSING OF WINDS TO 20 KT CAN BE 
EXPECTED OVER THE NEXT COUPLE OF NIGHTS...WITH SOME POTENTIAL 
FOR STRONGER GAP FLOW LATER IN THE WEEK. WINDS WILL PEAK DURING 
THE OVERNIGHT AND EARLY MORNING HOURS WITH THE ADDED COMPONENT 
OF NOCTURNAL DRAINAGE FLOW.

LOW PRESSURE OF 1020 MB CENTERED N OF THE AREA NEAR 31N125W 
EXTENDS A COLD FRONT INTO THE AREA NEAR 30N125W THEN EXTENDING 
TO 28N130W TO 29N140W.  THE LOW PRES AND ASSOCIATED COLD FRONT 
IS FORECAST TO MOVE FARTHER SOUTH TONIGHT. THE PRESSURE GRADIENT 
BETWEEN THE LOW AND HIGH PRES TO THE NW WILL PRODUCE AN AREA OF 
FRESH TO STRONG WINDS N OF THE FRONT WITH BUILDING SEAS TO 11 FT 
IN NW SWELL. THE LOW AND THE FRONT BOTH ARE FORECAST TO 
DISSIPATE BY WED WITH FRESH NORTHERLY FLOW BEHIND THE FRONT 
DIMINISHING. 

WEAK SURFACE RIDGING ALONG 27N IS SUPPORTING FRESH TO STRONG 
TRADES FROM 09N TO 22N W OF 130W AND FROM 12N TO 16N BETWEEN 
122W AND 130W. THE TRADE WIND CONVERGENCE IS AIDING AREAS OF 
CONVECTION ALONG THE ITCZ BETWEEN 125W AND 135W. THE AREAL 
COVERAGE OF TRADE WINDS ARE EXPECTED TO DIMINISH SLIGHTLY INTO 
TUE AS THE HIGH PRESSURE RIDGE CONTINUES TO WEAKEN.  

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AL