000
AXPZ20 KNHC 121603
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT NOV 12 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

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

MONSOON TROUGH FROM 09N84W TO 06N90W TO 07N94W. ITCZ AXIS FROM 
09N94W TO 11N126W...THEN RESUMES FROM 08N132W TO 10N140W. 
SCATTERED MODERATE CONVECTION NOTED WITHIN 180 NM S OF AXIS 
BETWEEN 125W AND 130W.

...DISCUSSION...

N OF 20N...A COMPLEX SURFACE LOW WITH MINIMUM PRES OF 1005 MB 
CENTERED NEAR 31N123W WILL GRADUALLY WEAKEN AS IT SHIFTS E 
TOWARD NORTHERN BAJA THROUGH MON. AN ASSOCIATED COLD FRONT 
EXTENDING FROM 30N119W TO 20N127W WILL GRADUALLY DISSIPATE 
THROUGH MON AS IT SHIFTS E. A 05 UTC ASCAT SCATTEROMETER PASS 
INDICATED 20 TO 30 KT WINDS WITHIN 180 NM ON THE SOUTHERN HALF 
OF THE LOW PRES. A 09 UTC JASON2 ALTIMETER PASS SHOWED SEAS AS 
HIGH AS 17 FT IN THIS SAME AREA AS WELL...ATTRIBUTABLE IN PART 
TO THE STRONG WINDS...BUT ALSO TO A LARGE AREA OF NW SWELL WITH 
PERIODS OF 10 TO 15 SECONDS PUSHING SE FROM THE N CENTRAL 
PACIFIC. 

FURTHER SOUTH...ASCAT SCATTEROMETER AND ALTIMETER DATA SHOW ONLY 
LIGHT TO MODERATE TRADE WIND FLOW PREVAILS S OF 20N W OF 110W. 
HIGH PRES WILL BUILD N OF THE AREA BEHIND THE EXITING LOW PRES 
AND FRONT SUN INTO MON...ALLOWING TRADE WIND FLOW TO INCREASE TO 
20 KT PRIMARILY FROM 10N TO 20N W OF 130W. IN ADDITION THE 
AFOREMENTIONED NW SWELL WILL ENCOMPASS MUCH OF THE AREA W OF 
11OW OVER THE NEXT 48 HOURS...ALTHOUGH OVERALL SEA HEIGHTS WILL 
SUBSIDE TO NO MORE THAN 11 FT AS THE SWELL DECAYS. 

GULF OF CALIFORNIA...SW WINDS TO 20 KT ARE POSSIBLE OVER THE 
NORTHERN GULF OVER THE NEXT 24 HOURS AHEAD OF THE LOW PRES AND 
WEAKENING COLD FRONT MOVING TOWARD NORTHERN BAJA. 

GULF OF TEHUANTEPEC...COASTAL OBSERVATIONS SHOW WINDS TO 20 
KT...HINTING THAT RESIDUAL GAP WIND FLOW PERSISTS WITH MAX WINDS 
PROBABLY AS HIGH AS 25 KT JUST OFFSHORE. THIS WILL DIMINISH 
THOUGH TODAY AS THE DENSER AIR MASS OVER THE GULF OF MEXICO 
MODIFIES AND SHIFTS E. THE PREVIOUS NEAR STORM FORCE WINDS 
THROUGH TEHUANTEPEC HAVE LEFT A LEGACY OF NE SWELL AS FAR AS 700 
NM TO THE SW OF THE GULF. THIS WILL SUBSIDE TO BELOW 8 FT 
THROUGH MON.

GULF OF PAPAGAYO...ENHANCED GRADIENT FLOW OVER THE SW CARIBBEAN 
ALONG WITH OVERNIGHT DRAINAGE EFFECTS OFF THE HIGH TERRAIN OF 
NORTHERN COSTA RICA MAY ALLOW WINDS TO 20 KT THROUGH THE GULF OF 
PAPAGAYO DURING THE LATE NIGHT AND EARLY MORNING THROUGH 48 
HOURS.  

S OF PANAMA...ENHANCED NORTHERLY FLOW OVER THE SW CARIBBEAN AND 
THE POSSIBLE FORMATION OF A WEAK LOW PRES AREA THERE ALONG THE 
MONSOON TROF MAY ALLOW SW WINDS TO INCREASE TO 20 KT S OF PANAMA 
OVER THE NEXT 48 HOURS...WITH SEAS BUILDING TO 8 FT. GLOBAL 
$$

CHRISTENSEN