000
AXPZ20 KNHC 021604
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE OCT 2 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

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

MONSOON TROUGH EXTENDS FROM 08N78W TO 12N92W TO 10N105W TO 
14N116W TO 10N127W. ITCZ EXTENDS FROM 10N127W TO 11N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION FROM 08N TO 11N 
BETWEEN 96W AND 101W. SCATTERED MODERATE TO STRONG CONVECTION N 
OF THE MONSOON TROUGH...FROM 14N TO 17N BETWEEN 98W AND 105W.

...DISCUSSION...

A WEAK TROUGH FROM 29N137W TO 22N140W IS A SLIGHT DISRUPTION IN 
AN EXPANSIVE SUBTROPICAL RIDGE THAT COVERS A LARGE PORTION OF 
THE PACIFIC OCEAN SOUTH OF THE ORE/CAL BORDER TO NEAR 20N... 
BETWEEN 120W AND 150W. REMNANT LOW CONTINUES TO WEAKEN NEAR 
16N116W...AND IS EXPECTED BECOME A DIFFUSE OPEN TROUGH TONIGHT. 
SCATTEROMETER DATA ACROSS THE REGION SHOWS LIGHT TO MODERATE 
WINDS NEARLY EVERYWHERE IN THE EASTERN NORTH PACIFIC...EXCEPT 
FOR ENHANCED S-SW WINDS SOUTH OF THE MONSOON TROUGH BETWEEN 92W 
AND 101W. PERSISTENT CROSS-EQUATORIAL SW SWELL OF 5-6 FT ALONG 
WITH 15-20 KT WINDS IN THIS AREA IS GENERATING A SMALL AREA OF 8 
FT COMBINED SEAS FROM 05N TO 09N BETWEEN 100W AND 115W. 5 TO 7 FT
COMBINED SEAS PREVAIL OVER THE REMAINDER OF THE DISCUSSION AREA.

EXPECT VERY LITTLE SIGNIFICANT CHANGE OVER MOST OF THE DISCUSSION
AREA THE NEXT 24 HOURS. THE LARGE RIDGE WILL WEAKEN SLIGHTLY AND 
RETREAT NORTHWARD WHILE THE CONVERGENCE ZONE REMAINS CONVECTIVELY
ACTIVE BETWEEN 90W AND 130W. HIGH PRES BUILDING BEHIND A COLD 
FRONT ACROSS ISTHMUS OF TEHUANTEPEC WILL BRING FRESH TO STRONG N 
WINDS THIS AFTERNOON AND EARLY TONIGHT. BY EARLY WED MORNING N-NE
WINDS WILL PEAK AT 25-30 KT WITH SEAS BUILDING TO 10-11 FT W-SW 
OF THE GULF OF TEHUANTEPEC. WINDS WILL UNDERGO DIURNAL PULSING...
WITH HIGHEST WINDS DURING THE EARLY MORNING EACH DAY THROUGH FRI.
CYCLONIC VORTICITY ASSOCIATED WITH THIS AREA OF FRESH TO STRONG 
WINDS SPILLING OUT OF THE GULF OF TEHUANTEPEC MAY HELP INDUCE 
DEVELOPMENT OF AREA OF LOW PRES S AND SW OF THE HIGH WIND AREA 
BY THU. THE 0600 GFS MODEL RUN SHOWS TROPICAL CYCLOGENESIS NEAR 
13N101W THU MORNING...BUT NONE OF THE OTHER GLOBAL MODELS ARE AS 
AGGRESSIVE AS THE GFS...AND THE LATEST GFS APPEARS TO BE EXTREME
ANOMALY COMPARED TO PREVIOUS RUNS...SO USING A BLEND OF 0000 UTC 
GFS ECMWF AND UKMET INSTEAD.

$$
MUNDELL