000
AXPZ20 KNHC 301006
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...SPECIAL FEATURE...
TROPICAL DEPRESSION HILARY IS AN EXPOSED LOW-LEVEL CENTER NEAR 
22.5N 121.4W AT 0900 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 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 EXTENDS FROM 11N86W TO 13N97W TO 11N109W TO 
13N126W TO LOW PRES NEAR 11N133W...THEN AS ITCZ TO 11N140W. 
SCATTERED MODERATE CONVECTION WITHIN 180 NM S OF TROUGH AXIS 
BETWEEN 113W AND 123W.

...DISCUSSION...
A COLD FRONT HAS MOVED INTO NW PORTION FROM 30N134W TO 26N140W. 
THE FRONT IS ALREADY BEGINNING TO WEAKEN AND IS EXPECTED TO 
DISSIPATE WITHIN 24 HOURS. WINDS BEHIND THE FRONT ARE BELOW 20 
KT...BUT SEAS ARE NEAR 8 FT IN NW SWELL. SEAS ARE EXPECTED TO 
PEAK AT AROUND 8-9 FT DURING THE 12-24 HOURS.

WEAK LOW PRES CENTER 1012 MB NEAR 11N133W HAS WINDS TO 20 KT 
WINDS WITHIN 60 NM N OF ITS CENTER. THE LOW WILL DISSIPATE WITHIN
THE NEXT 12-24 HOURS...WITH WINDS AND SEAS DIMINISHING.

HIGH PRES ASSOCIATED WITH A COLD FRONT MOVING INTO THE GULF OF 
MEXICO LATER TODAY AND 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. CONSENSUS MODEL GUIDANCE INDICATES THE NEXT AREA
FAVORABLE FOR POSSIBLE TROPICAL CYCLOGENESIS WILL SHIFT SOUTH OF 
GUATEMALA BY SUN...WHICH MAY GET AN EXTRA KICK OF VORTICITY FROM 
WINDS GENERATED UPSTREAM THROUGH THE GULF OF TEHUANTEPEC BY MON.

$$
MUNDELL