000
AXPZ20 KNHC 310920
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON OCT 31 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 0900 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH WAS ANALYZED FROM 09N84W TO LOW PRES NEAR 
08N85W TO 07N90W TO 07N106W. INTERTROPICAL CONVERGENCE ZONE WAS 
ANALYZED FROM 07N106W TO LOW PRES NEAR 08N113W TO LOW PRES 
09N126W TO 07N140W. SCATTERED MODERATE CONVECTION WITHIN 120 NM 
OFF COAST OF COAST RICA AND WESTERN PANAMA. SCATTERED MODERATE 
CONVECTION WITHIN 45 NM N OF AXIS BETWEEN 122W AND 126W. 

...DISCUSSION...

GULF OF TEHUANTEPEC...A HIGH RESOLUTION ASCAT PASS FROM 04 UTC 
SHOWED WINDS TO 30 KT THROUGH THE GULF OF TEHUANTEPEC. THIS IS 
DUE TO A RENEWED SURGE OF COOLER AND DRIER AIR THAT PUSHED 
THROUGH THE ISTHMUS OVER THE PASSED SEVERAL HOURS...AND WINDS 
WILL LIKELY INCREASE TO GALE FORCE LATER TO THIS MORNING. THE 
GALE CONDITIONS WILL DIMINISH THROUGH EARLY TUE AS THE AIRMASS 
TO THE NORTH MODIFIES. LOOKING AHEAD...TEHUANTEPEC WINDS WILL 
CONTINUE TO DIMINISH THROUGH MID WEEK...THEN INCREASE AGAIN BY 
LATE THU AS ANOTHER COLD SURGE MOVES THROUGH THE SW GULF OF 
MEXICO.

N TO NE SWELL GENERATED BY THE STRONG GAP WIND FLOW THROUGH 
TEHUANTEPEC WILL CONVERGE WITH 7 TO 8 FT SW MOVING INTO THE AREA 
FROM S OF THE EQUATOR CREATING AN AREA OF CONFUSED SEAS FROM 07N 
TO 12N BETWEEN 95W AND 100W. 

CLUSTERS OF SHOWERS AND THUNDERSTORMS PERSIST APPROXIMATELY 120 
NM OFF THE COAST OF COSTA RICA AND WESTERN PANAMA. THIS IS 
RELATED TO A STATIONARY LOW OVER THE FAR SW CARIBBEAN. SHIP DATA 
SHOW SW TO W WINDS OCCASIONAL REACHING 20 KT IN THE FLOW 
CONVERGING INTO THIS LOW S OF PANAMA. 

ASCAT DATA FROM 0545 UTC SHOWED A SWATH OF 20 KT TRADES ACTIVE 
FROM 12N TO 20N W OF 125W...BETWEEN WEAK LOW PRES ALONG THE ITCZ 
NEAR 09N127W...AND HIGH PRES BUILDING FROM THE N CENTRAL PACIFIC 
INTO THE NE PACIFIC. ASCAT DATA ALSO SHOWED N WINDS ALREADY 
STARTING TO INCREASE OFF THE CENTRAL CALIFORNIA COAST AHEAD OF 
THE HIGH PRES. SHIP OBSERVATIONS INDICATE N TO NE WINDS TO 20 KT 
ARE PUSHING S OF 30N BETWEEN 125W AND 135W. GLOBAL MODELS 
SUGGEST INCREASED NE WINDS OVER THE AREA N OF 25N W OF 125W 
THROUGH THE 24 TO 36 HOURS...FOLLOWED BY NW SWELL OF 8 TO 10 FT 
AND PERIODS TO 14 SECONDS THROUGH EARLY WED IN A BROAD AREA FROM 
THE NORTHERN BAJA COAST TO 10N140W. 

BY MID WEEK...THE HIGH PRES OVER THE NE PACIFIC WILL BUILD OVER 
THE GREAT BASIN...RESULTING IN FUNNELING WINDS AROUND 20 TO 30 
KT OVER THE NORTHERN GULF OF CALIFORNIA WED.

$$
CHRISTENSEN