000
AXPZ20 KNHC 301550
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI SEP 30 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...SPECIAL FEATURE...
TROPICAL DEPRESSION HILARY IS AN EXPOSED LOW-LEVEL CENTER NEAR 
23.0N 121.5W AT 1500 UTC...MOVING NNW OR 330 DEG AT 6 KT WITH A
CENTRAL PRES OF 1005 MB. MAXIMUM SUSTAINED WINDS 30 GUSTS TO 40 
KT. HILARY IS EXPECTED TO CONTINUE TO WEAKEN AND BECOME A 
REMNANT LOW LATER TODAY. SEAS GENERATED BY HILARY WILL CONTINUE 
TO SUBSIDE THROUGH THE WEEKEND. SEE LATEST NHC FORECAST/ 
ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE 
DETAILS. 
 
...ITCZ/MONSOON TROUGH...
MONSOON TROUGH FROM 09N78W TO 09N83W TO 14N96W TO 10N109W TO 
11N125W TO 09N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION WITHIN 180 NM S OF TROUGH BETWEEN 78W AND 
90W...BETWEEN 96W AND 102W...AND BETWEEN 110W AND 125W.

...DISCUSSION...
A COLD FRONT EXTENDS FROM 30N132W TO 25N140W. THE FRONT IS 
ALREADY BEGINNING TO WEAKEN AND IS EXPECTED TO DISSIPATE WITHIN 
THE NEXT 24 TO 36 HOURS. WINDS BEHIND THE FRONT ARE BELOW 20 KT 
AS NOTED IN A 0630Z ASCAT PASS...BUT SEAS ARE NEAR 8 FT IN NW 
SWELL. SEAS ARE EXPECTED TO PEAK AT AROUND 8-9 FT DURING THE 
12-24 HOURS.

FURTHER SOUTH...DESPITE THE PRESENCE OF A WEAK TROUGH NEAR 133W 
S OF 13N...TRADE WIND FLOW REMAINS LIGHT TO MODERATE BETWEEN THE 
MONSOON TROUGH AND 20N W OF 110W...DUE TO WEAK HIGH PRES TO THE 
N. RESIDUAL NORTHERLY SWELL TO 8 FT WILL DECAY THROUGH THE 
REMAINDER OF THE DAY IN THIS SAME AREA.

HIGH PRES ASSOCIATED WITH A COLD FRONT MOVING ACROSS THE GULF OF 
MEXICO THROUGH SAT WILL INDUCE AN ENHANCED PRES GRADIENT 
AND STRONG WINDS IN THE CHIVELAS PASS AND GULF OF TEHUANTEPEC BY 
EARLY SAT. PEAK NORTHERLY WINDS ARE EXPECTED TO REACH 25-30 KT...
BELOW GALE FORCE...LATE SAT NIGHT THROUGH SUN AFTERNOON.

AS HILARY BECOMES A REMNANT LOW AND DISSIPATES OVER THE NEXT 24 
TO 48 HOURS...SEA HEIGHTS WILL STEADILY DIMINISH N OF 20N W OF 
BAJA CALIFORNIA.

$$
CHRISTENSEN