000
AXPZ20 KNHC 240300
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT SEP 24 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 
0315 UTC.

...SPECIAL FEATURE...

HURRICANE HILARY WAS NEAR 16.7N 104.0W AT 0300 UTC MOVING W OR
280 DEG AT 8 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 940 MB. 
MAXIMUM SUSTAINED WINDS ARE 125 KT WITH GUSTS TO 150 KT MAKING 
HILARY A CATEGORY FOUR HURRICANE ON THE SAFFIR-SIMPSON SCALE. 
SATELLITE PRESENTATION CONTINUES TO BE RATHER IMPRESSIVE AS A 
SMALL WARM EYE OF ABOUT 15 NM IS EVIDENT THIS EVENING. HILARY IS 
EXPECTED TO MAINTAIN ITS CURRENT INTENSITY FOR THE NEXT TWO TO 
THREE DAYS AS THE HURRICANE WILL REMAIN OVER WARM WATERS AND 
ENCOUNTER LITTLE SHEAR. NUMEROUS STRONG CONVECTION IN BANDS IS 
LOCATED WITHIN 80 NM OF THE CENTER. IN ADDITION NUMEROUS STRONG 
CONVECTION IS LOCATED WITHIN 70 NM EITHER SIDE OF A LINE FROM 
19N105W TO 15N107W. SEE LATEST NHC FORECAST ADVISORY UNDER 
AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS.
 
...ITCZ/MONSOON TROUGH...

MONSOON TROUGH AXIS 10N85W TO 06N93W...RESUMES 15N110W TO 
12N125W TO 10N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS LOCATED N OF 04N BETWEEN 80W AND 84W AND FROM 09N 
TO 12N BETWEEN 126W AND 129W. 

...DISCUSSION... 

A MIDDLE/UPPER LEVEL CYCLONIC CIRCULATION IS POSITIONED IN THE 
VICINITY OF 24N140W. SOUTHWESTERLY WINDS TO THE SE OF THE 
CIRCULATION ARE RELATIVELY STRONG WITH SATELLITE CLOUD DRIFT 
WINDS INDICATING SPEEDS UP TO 60 KNOTS. THE CIRCULATION IS 
FORECAST TO MOVE NE OVER THE NEXT COUPLE OF DAYS AND SLOWLY 
WEAKEN. A STRONG MIDDLE/UPPER LEVEL TROUGH IS APPROACHING THE NW 
PART OF THE DISCUSSION AREA. AN ASSOCIATED COLD FRONT WILL 
PRODUCE WINDS OF 20 KNOTS OR SO EITHER SIDE OF THIS FEATURE. 
ANOTHER MIDDLE/UPPER LEVEL CYCLONIC CIRCULATION IS CENTERED OFF 
THE CENTRAL CALIFORNIA COAST NEAR 35N124W WITH ASSOCIATED 
CYCLONIC FLOW EXTENDING SOUTHWARD TO 28N BETWEEN 118W AND 128W. 
AT THE SURFACE A 1020 MB HIGH IS CENTERED NEAR 29N133W.

BROAD ANTICYCLONIC FLOW ALOFT COVERS A LARGE AREA FROM ROUGHLY 
12N TO 23N BETWEEN 115W AND 135W. E OF 100W FLOW ALOFT IS MAINLY 
EASTERLY WITH MODERATE WIND SPEEDS IN THE 25 TO 40 KNOT RANGE.

$$
CAB