000
AXPZ20 KNHC 020238
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI SEP 02 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 
0215 UTC.

...ITCZ/MONSOON TROUGH...
MONSOON TROUGH FROM 10N85W TO 10N92W THEN RESUMES AT 16N101W TO 
18N121W TO 12N140W. SCATTERED MODERATE ISOLATED STRONG FROM 04N 
TO 11N BETWEEN 82W AND 88W. SCATTERED MODERATE WITHIN 90 NM S OF 
LINE FROM 07N90W TO 07N97W.

...DISCUSSION...
AN UPPER LEVEL TROUGH DOMINATES THE NW CORNER OF THE FORECAST 
AREA AND EXTENDS FROM A CUT-OFF LOW NEAR 29N130W TO A BASE AT 
15N135W. AN ANTICYCLONIC CIRCULATION ANCHORED OVER CENTRAL 
MEXICO HAS A RIDGE EXTENDING SW TO A COL NEAR 14N117W. NE WINDS 
TO THE S OF THIS RIDGE ARE NOTED E OF 110W. DIFFLUENCE 
ASSOCIATED WITH THESE WINDS ALOFT ARE HELPING TO INDUCE 
CONVECTION S OF WESTERN PANAMA AND COSTA RICA.   

STRONG HIGH PRESSURE CENTERED NW OF THE AREA NEAR 41N144W 1032 
MB HAS RIDGE EXTENDING SE TO NEAR 25N125W. THE UPPER LEVEL 
TROUGH OVER THE NW PART OF THE AREA IS HELPING TO WEAKEN THE 
RIDGE. AS A RESULT...WINDS IN ASSOCIATION WITH THIS RIDGE HAVE 
DIMINISHED BELOW 20 KT. HOWEVER...SEAS N OF 20N REMAIN IN THE 8 
TO 11 FT RANGE IN A MIX OF N AND SW SWELL. THE SWELL HEIGHTS ARE 
EXPECTED TO GRADUALLY SUBSIDE OVER THE NEXT COUPLE OF DAYS.

FRESH 20 KT MONSOONAL SW FLOW WITH SEAS TO 11 FT IN SW SWELL 
PREVAILS FROM 10N TO 13N BETWEEN 104W AND 114W. ELSEWHERE CROSS 
EQUATORIAL SW SWELL IS NOTED S OF 20N BETWEEN 80W AND 125W 
RESULTING IN COMBINED SEAS OF 8 TO 10 FT. THE MONSOONAL FLOW IS 
FORECAST TO SLIGHTLY INCREASE TO 25 KT BY LATE SAT.

DISORGANIZED CLOUDINESS AND SHOWERS ASSOCIATED WITH THE REMNANTS 
OF TROPICAL DEPRESSION EIGHT-E...CONTINUE ALONG THE SOUTHWESTERN 
COAST OF MEXICO AND ADJACENT WATERS PARTICULARLY FROM 17N TO 21N 
E OF 108W. A TROUGH IS ANALYZED FROM SOUTHERN BAJA CALIFORNIA TO 
NEAR 18N106W ON THE 0000 UTC SURFACE MAP. AN EARLIER ASCAT PASS 
SHOWED THE WIND SHIFT ASSOCIATED WITH THE TROUGH WHICH IS 
FORECAST TO GRADUALLY DISSIPATE DURING THE NEXT COUPLE OF DAYS. 
AT THE SAME TIME...EXPECT SOME INCREASE IN WINDS JUST W OF THE 
BAJA CALIFORNIA PENINSULA AS PRES GRADIENT TIGHTENS ACROSS THE 
AREA. MARINE GUIDANCE SUGGESTS NW WINDS OF 20 KT AND SEAS TO 8 
FT.

$$
GR