000
AXPZ20 KNHC 220301
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU SEP 22 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 
0300 UTC.

...SPECIAL FEATURE...

.TROPICAL STORM HILARY NEAR 14.4N 97.2W 1000 MB AT 0300 UTC SEP 
22 MOVING WNW OR 295 DEG AT 6 KT. MAXIMUM SUSTAINED WINDS 45 KT 
GUSTS 55 KT. TROPICAL STORM FORCE WINDS ARE WITHIN 45 NM NE AND 
45 NM NW QUADRANTS. SEAS 12 FT OR GREATER ARE WITHIN 90 NM E 
SEMICIRCLE ...30 NM SW QUADRANT AND 60 NM NW QUADRANT WITH SEAS 
TO 15 FT. SEE LATEST NHC FORECAST ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. CONVECTIVE BANDS 
ASSOCIATED WITH HILARY ARE STARTING TO WRAP TIGHTLY AROUND THE 
CYCLONE CENTER UNDER A SMALL AREA OF DENSE OVERCAST.
 
...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS FROM PANAMA AT 08N78W TO EL 
SALVADOR AT 13N88W. THERE IS A BREAK NEAR T.S. HILARY. THE 
MONSOON TROUGH BEGINS AGAIN AT 11N109W TO 13N120W TO A 1011 MB 
LOW NEAR 10N129W. SCATTERED MODERATE CONVECTION IS FROM 05N TO 
08N BETWEEN 84W AND 88W. CLUSTERS OF SCATTERED MODERATE TO 
STRONG CONVECTION IS FROM 12N TO 16N BETWEEN 95W AND 101W DUE TO 
HILARY. ISOLATED MODERATE CONVECTION IS FROM 09N TO 12N BETWEEN 
105W AND 110W...AND FROM 09N TO 12N BETWEEN 137W AND 141W.  

...DISCUSSION... 

A 1021 MB HIGH PRES IS NEAR 32N140W...SUPPORTING LIGHT NE TRADES 
N OF 15N W OF 120W. SCATTEROMETER DATA SHOWS WINDS LESS THAN 20 
KT AROUND A SURFACE LOW EMBEDDED WITHIN THE MONSOON TROUGH NEAR 
10N129W. A SURFACE TROUGH IS FROM 13N137W TO 08N139W. NE WINDS 
20 KT ARE FROM 10N TO 13N W OF TROUGH.  

CONVECTION REMAINS VERY ACTIVE OVER A LARGE PORTION OF THE AREA 
AROUND T.S. HILARY.  MODEL GUIDANCE IS IN GOOD AGREEMENT... 
MOVING HILARY WNW S OF MEXICO THROUGH THE WEEKEND. LITTLE CHANGE 
IN THE OVERALL PATTERN IS EXPECTED ELSEWHERE...WITH MODERATE 
N-NE TRADE WINDS N OF THE MONSOON TROUGH AXIS...WHICH WILL 
EXTEND ACROSS THE ENTIRE BASIN ALONG 11-12N W OF HILARY.

$$
FORMOSA