000
AXPZ20 KNHC 252130
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN SEP 25 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...SPECIAL FEATURE...

HILARY REMAINS A POWERFUL HURRICANE. AT 2100 UTC...HILARY WAS 
CENTERED NEAR 17.1N 110.3W MOVING W OR 270 DEG AT 9 KT. ESTIMATED
MINIMUM CENTRAL PRESSURE IS 953 MB. MAXIMUM SUSTAINED WINDS ARE 
110 KT GUSTS TO 135 KT. SOME MINOR FLUCTUATIONS IN INTENSITY ARE 
LIKELY IN THE SHORT TERM...BUT THE OVERALL TREND IS TO SLOWLY 
WEAKEN THROUGH TUE. HILARY IS EXPECTED TO MOVE WEST THE NEXT TWO 
DAYS THEN TURN NORTHWARD. NUMEROUS STRONG CONVECTION IS WITHIN 
90 NM E AND 45 NM W SEMICIRCLES. SCATTERED TO NUMEROUS MODERATE 
TO STRONG CONVECTION ELSEWHERE WITHIN 150 NM E AND 90 NM W 
SEMICIRCLES. SWELLS GENERATED BY HILARY EXTEND OUTWARD UP TO 240 
NM FROM THE CENTER...AND ARE AFFECTING PORTIONS OF THE COAST OF 
SOUTHWESTERN MEXICO AND INTO THE SOUTHERN GULF OF CALIFORNIA. 
SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS 
MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. 
 
...ITCZ/MONSOON TROUGH...

MONSOON TROUGH AXIS EXTENDS FROM 12N87W TO 11N90W TO 09N100W 
THEN RESUMES W OF HURRICANE HILARY NEAR 14N116W TO 12N130W TO 
09N140W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION FROM 
05N TO 11N E OF 90W TO THE COAST OF COLOMBIA. SCATTERED MODERATE 
CONVECTION FROM 05N TO 10N BETWEEN 100W AND 104W...AND FROM 10N 
TO 13N BETWEEN 123W AND 130W.

...DISCUSSION... 

HIGH PRES RIDGE EXTENDS SE FROM A 1021 MB HIGH CENTERED NEAR 
27N130W TO NEAR 22N113W. PRESSURE GRADIENT BETWEEN THE HIGH PRES 
AND LOWER PRES OVER MOJAVE DESERT IS SUPPORTING FRESH NW WINDS N 
OF 24N E OF 118W TO THE W COAST OF BAJA CALIFORNIA. LITTLE CHANGE
IS EXPECTED IN THE GENERAL SYNOPTIC PATTERN THE NEXT TWO DAYS AS 
THE HIGH REMAINS NEARLY STATIONARY. A STATIONARY FRONT JUST NW 
OF THE FORECAST AREA CROSSES NEAR 30N140W. 15 KT SW WINDS ARE IN 
THE FAR NW PORTION WITH SEAS TO 8 FT IN NW SWELL AFFECTING THE 
WATERS N OF 29N W OF 138W. LITTLE CHANGE IS EXPECTED THE NEXT 24 
HOURS WITH SEAS SUBSIDING BELOW 8 FT MON. LIGHT TO MODERATE N-NE 
TRADE WINDS DOMINATE THE REGION N OF THE MONSOON TROUGH W OF 
115W...WITH A NARROW ZONE OF 15 TO 20 KT TRADE WINDS BETWEEN 13N 
AND 17N W OF 125W.

SEVERAL WEAK DISTURBANCES EMBEDDED WITHIN THE MONSOON TROUGH ARE 
PRODUCING SCATTERED SHOWERS AND ISOLATED TSTMS ALONG THE TROUGH 
AXIS W OF 122W. MODERATE TO FRESH MONSOONAL FLOW PREVAILS S OF 
THE TROUGH AXIS E OF 95W. MARINE CONDITIONS ELSEWHERE REMAIN 
FAIRLY BENIGN ACROSS THE REGION. LONG PERIOD NW SWELL IS MERGING 
WITH SW SWELL FROM THE SOUTHERN HEMISPHERE MAINLY S OF 05N.

$$
MUNDELL/GR