000
AXPZ20 KNHC 020937
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE OCT 02 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

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

THE MONSOON TROUGH IS ALONG 12N87W TO 13N95W TO 15N113W THEN 
RESUMES FROM 14N117W TO 11N129W. THE INTERTROPICAL CONVERGENCE 
ZONE AXIS EXTENDS FROM 11N129W TO 10N135W TO 11N140W. SCATTERED 
MODERATE AND ISOLATED STRONG CONVECTION IS FROM 08N TO 11N 
BETWEEN 96W AND 101W. SCATTERED MODERATE AND ISOLATED STRONG 
CONVECTION IS WITHIN 60-120 NM OF THE MEXICAN COAST BETWEEN 93W 
AND 105W.

...DISCUSSION...

A WEAK SURFACE TROUGH IS IN THE NW PORTION OF THE DISCUSSION 
WATERS FROM 31N137W TO 24N137W WITH SCATTERED SHOWERS 
ACCOMPANYING THE TROUGH W OF 134W. THIS FEATURE REPRESENTS A 
DISRUPTION IN AN EXPANSIVE SUBTROPICAL RIDGE DOMINATING THE 
PACIFIC OCEAN N OF 19N W OF 118W. OVERNIGHT SCATTEROMETER PASSES 
INDICATED LIGHT TO MODERATE WINDS ACROSS THE WATERS N OF 10N W 
OF 110W. 

A 1010 MB SURFACE LOW WHICH IS THE REMNANT OF MIRIAM IS CENTERED 
NEAR 17N116W. THE CIRCULATION OF THIS LOW CONTINUES TO CAUSE A 
BREAK IN THE MONSOON TROUGH. ISOLATED TO SCATTERED SHOWERS ARE 
OCCURRING WITHIN 180 NM OF THE CENTER. THE LOW WILL CONTINUE TO 
DRIFT SW THROUGH THE NEXT 24-48 HOURS.

EARLIER ALTIMETER PASSES SUGGESTED A LINGERING AREA OF 8 FT NW 
SWELL ACROSS AN AREA BOUNDED BY A LINE FROM 20N127W TO 29N121W 
TO 29N115W TO 20N120W TO 20N127W...ALTHOUGH THIS SWELL IS 
FORECAST TO DECAY TO LESS THAN 8 FT LATER THIS MORNING.

SW MONSOONAL FLOW REMAINS AT 20 TO 25 KT S OF THE MONSOON TROUGH 
FROM 07N TO 10N BETWEEN 97W AND 102W AS CAPTURED BY OVERNIGHT 
WINDSAT AND ASCAT SCATTEROMETER PASSES. THESE WINDS ARE FORECAST 
TO DIMINISH TO 15 TO 20 KT LATER TODAY. MEANWHILE CROSS- 
EQUATORIAL SW SWELL TO 9 FT REMAINS OVER THE S CENTRAL WATERS S 
OF 07N BETWEEN 100W AND 120W. THIS SWELL TRAIN WILL CONTINUE TO 
SPREAD NORTHWARD REACHING TO 10N BY 24 HOURS...THEN WILL 
GRADUALLY SUBSIDE FROM N TO S BY 48 HOURS.

GAP WINDS...
A COLD FRONT HAS MOVED THROUGH THE SW GULF OF MEXICO AND BAY OF 
CAMPECHE AND STRONG HIGH PRES IS BEGINNING TO BUILD IN BEHIND IT 
ACROSS THE WESTERN GULF AND EASTERN MEXICO. THIS SETUP WILL 
USHER IN FRESH TO STRONG NORTHERLY WINDS IN AND DOWNWIND OF THE 
GULF OF TEHUANTEPEC COMMENCING LATER THIS MORNING...INCREASING 
TO NEAR GALE FORCE DURING THE EARLY MORNING HOURS EACH 
SUCCESSIVE DAY THROUGH THE END OF THE WEEK. IT IS POSSIBLE THAT 
THE WINDS MAY EVEN BRIEFLY REACH GALE FORCE WHICH WILL NEED TO 
BE MONITORED IN CASE A GALE WARNING IS WARRANTED. CYCLONIC 
VORTICITY ASSOCIATED WITH THESE WINDS MAY HELP TO INDUCE THE 
FORMATION AND DEVELOPMENT OF AN AREA OF LOW PRES S AND SW OF THE 
GULF OF TEHUANTEPEC BY LATE WED THROUGH FRI.

MODEL GUIDANCE FORECASTS A 20 TO 25 KT GULF OF PAPAGAYO EVENT 
BEGINNING AT 48 HOURS AS NE TO E TRADES INCREASE AND EXPAND 
WESTWARD IN THE CARIBBEAN SEA. THESE WINDS SHOULD DIMINISH TO 20 
KT OR LESS IN THE GULF OF PAPAGAYO BY THE END OF THE WEEK AS THE 
TRADES RETREAT EASTWARD. 

$$
LEWITSKY