000
AXPZ20 KNHC 140934
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED SEP 14 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...

MONSOON TROUGH EXTENDS FROM 12N87W TO 08N95W TO 11.5N106W TO 
11N121W. ITCZ AXIS EXTENDS FROM 11N121W TO 09N140W. SCATTERED 
MODERATE ISOLATED STRONG N OF 12N BETWEEN 95W AND 100W. 

...DISCUSSION...
SURFACE HIGH PRESSURE 1028 MB IS CENTERED NEAR 37N140W HAS RIDGE 
EXTENDING SE TO NEAR 20N113W. THE PRESSURE GRADIENT BETWEEN THE 
HIGH PRESSURE AND THE ITCZ IS SUPPORTING FRESH 20 KT TRADES FROM 
10N TO 17N W OF 135W AS DEPICTED BY THE LATEST 0700 UTC ASCAT 
PASS. THIS AREA OF HIGH PRESSURE WILL MAINTAIN OVER THE FORECAST 
PERIOD KEEPING THIS SMALL AREA OF FRESH 20 KT TRADES.  

GAP WINDS...CYCLONIC FLOW AROUND A TROPICAL WAVE OVER THE 
YUCATAN PENINSULA IS MAINTAINING NE WINDS OVER THE SW GULF OF 
MEXICO. THESE WINDS AREA FUNNELING THROUGH THE CHIVELA PASS 
MAINTAINING 20 TO 25 KT WINDS OVER THE GULF OF TEHUANTEPEC. AS 
THE TROPICAL WAVE SHIFTS FURTHER WESTWARD...THESE WINDS ARE 
EXPECTED TO DIMINISH BELOW 20 KT TONIGHT. WITH THE MONSOON 
TROUGH SHIFTED FURTHER SOUTH...THE TROPICAL WAVE WILL CONTINUE 
TO PROPAGATE WESTWARD THROUGH THE FORECAST PERIOD. THE TROPICAL 
WAVE WILL START TO INTERACT WITH THE MONSOON TROUGH WITHIN THE 
NEXT 48 HOURS. THIS INTERACTION WILL INCREASE CONVECTION AND IN 
TURN WILL FRESHEN THE MONSOONAL FLOW FROM 05N TO 10N BETWEEN 95W 
AND 113W BY LATE THU NIGHT. 

SOUTHERLY CROSS EQUATORIAL SWELL RESULTING WITH COMBINED SEAS TO 
9 FT CONTINUE OVER THE TROPICAL WATERS S OF 09N W OF 110W. 

$$
AL