000
AXPZ20 KNHC 290311
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON AUG 29 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 11N86W TO 18N108W TO LOW PRES 
18N123W TO 12N131W...THEN ITCZ TO 11N140W. SCATTERED MODERATE 
CONVECTION WITHIN 210 NM S OF TROUGH BETWEEN 103W AND 112W.

...DISCUSSION...
WEAK LOW PRES EVIDENT NEAR 18N123W LACKS CONVECTION AND DOES NOT 
HAVE SIGNIFICANT WINDS OR SEAS ASSOCIATED WITH IT. WW3 WAVE MODEL
AND GFS GLOBAL MODEL SHOW A LINEAR AREA OF HIGHER WINDS AND SEAS 
BETWEEN 105W AND 120W FROM 10N TO 15N...BUT COMBINATION OF ASCAT 
WINDSAT AND JASON ALTIMETRY PASSES WITHIN THE PAST SIX HOURS 
INDICATE WINDS ARE LESS THAN 20 KT AND SEAS LESS THAN 8 FT ACROSS
THE ENTIRE AREA. ADJUSTED HIGH SEAS FORECAST TO ACCOUNT FOR HIGH 
BIAS IN MODEL DATA IN THE 18Z RUN.

VERY LITTLE OF CONCERN OTHERWISE OVER THE DISCUSSION AREA EXCEPT 
FOR VERY LONG PERIOD MODERATE SW SWELL THAT WILL BEGIN TO SWEEP 
NORTHWARD ACROSS THE EQUATOR MONDAY BETWEEN 115W AND 135W. SEAS 
WILL BUILD TO A MAX OF 11-12 FT NEAR EQ125W MONDAY NIGHT...BUT 
OF GREATEST CONCERN IS 20-22 SEC PERIOD AT LEADING EDGE OF SWELL 
TRAIN...WHICH COULD CAUSE LARGE WAVES AND HEAVY SURF WHEN IT 
REACHES THE COAST OF CENTRAL AMERICA TUE NIGHT AND WEDNESDAY.

$$
MUNDELL