000
AXPZ20 KNHC 290319
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU SEP 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 
0245 UTC.

...SPECIAL FEATURE...

HILARY WAS DOWNGRADED TO A TROPICAL STORM AT 0300 UTC NEAR 
19.6N119.3W WITH ESTIMATED MINIMUM CENTRAL PRESSURE OF 988 MB. 
MAXIMUM SUSTAINED WINDS WERE 60 KT WITH GUSTS TO 75 KT. NUMEROUS 
MODERATE TO STRONG CONVECTION WAS NOTED WITHIN 120 NM NE 
SEMICIRCLE OF CENTER. WHILE SCATTERED MODERATE CONVECTION WAS 
NOTED WITHIN 90 NM SW SEMICIRCLE OF CENTER. HILARY CONTINUES TO 
SLOWLY WEAKEN...AND AS HILARY BEGINS TO TRACK OVER COOLER WATER 
TEMPERATURES...A MORE RAPID RATE OF WEAKENING IS EXPECTED. 
HILARY IS FORECAST TO WEAKEN TO A POST TROPICAL REMNANT LOW 
FRIDAY. SWELLS GENERATED BY HILARY ARE AFFECTING THE WEST COAST 
OF BAJA CALIFORNIA...THE SOUTHERN GULF OF CALIFORNIA...AND 
ADJACENT PORTIONS OF SOUTHWEST MEXICO...CAUSING HIGH SURF AND 
LIFE-THREATENING RIP CURRENT CONDITIONS. SEE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC 
FOR MORE DETAILS. 
 
...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE SW CARIBBEAN ACROSS S 
NICARAGUA ENTERING THE E PACIFIC NEAR 12N86W EXTENDING W TO 
10N108W WHERE IT ENDS. THERE IS NO ITCZ OR MONSOON TROUGH FROM 
108W TO 135W AS A RESULT OF THE CIRCULATIONS AROUND HURRICANE 
HILLARY AND A SMALL LOW PRESSURE CENTER NEAR 11N133W. THE ITCZ 
STARTS NEAR 10N135W AND EXTENDS W OF 09N140W. SCATTERED MODERATE 
WITHIN 45 NM OF ITCZ AXIS W OF 135W. 

...DISCUSSION... 

A 1010 MB LOW PRES CENTER WAS CENTERED NEAR 11N133W WITH LITTLE 
TO NO CONVECTION ASSOCIATED WITH IT. THE CIRCULATION AROUND THIS 
FEATURE...COMBINED WITH THE CIRCULATION AROUND TROPICAL STORM 
HILARY HAS LIMITED THE COVERAGE OF THE MONSOON TROUGH AND ITCZ 
OVER THE AREA AS MENTIONED ABOVE. THE LOW IS FORECAST TO REMAIN 
NEARLY STATIONARY THROUGH THE FORECAST PERIOD. 

LONG PERIOD NW SWELL OF 9 TO 10 FT PREVAILS ACROSS THE NW 
PORTION OF THE AREA AND WILL CONTINUE TO MERGE WITH SWELL FROM 
HILARY OVER THE NEXT FEW DAYS TO CREATE CONFUSED SEAS N OF 15N 
AND W OF 130W. NW SWELL WILL BE REINFORCED BY A COLD FRONT 
FORECAST TO ENTER THE NW PART OF THE AREA LATE THU 
AFTERNOON/EARLY EVENING.  

$$
AL