000
AXPZ20 KNHC 220928
TWDEP 

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

...SPECIAL FEATURE...

TROPICAL STORM HILARY NEAR 14.7N 98.1W 991 MB AT 0900 UTC SEP 
22 MOVING WNW OR 295 DEG AT 8 KT. MAXIMUM SUSTAINED WINDS 60 KT 
GUSTS 75 KT. TROPICAL STORM FORCE WINDS ARE WITHIN 75 NM NE 
QUADRANT...60 NM NW AND SE QUADRANTS...AND 40 NM SW QUADRANT. 
SEAS 12 FT OR GREATER ARE WITHIN 120 NM E SEMICIRCLE...30 NM SW 
QUADRANT AND 60 NM NW QUADRANT WITH SEAS TO 18 FT. SEE LATEST 
NHC FORECAST ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 
KNHC FOR MORE DETAILS. HILARY IS STARTING TO FORM AN EYE WITH 
CONVECTIVE BANDS ASSOCIATED WITH HILARY ARE NOTED WITHIN 90 NM.
 
...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS FROM 13N108W TO 13N120W TO LOW 
PRES NEAR 10N128W 1010 MB. SCATTERED MODERATE CONVECTION 
PERSISTS WITHIN 90 NM N OF AXIS BETWEEN 120W AND 128W. 

...DISCUSSION... 

SCATTEROMETER DATA SHOW LIGHT TO MODERATE FLOW N OF 15N W OF 
115W ON THE SE SIDE OF A 1021 MB SURFACE HIGH PRES AREA CENTERED 
NEAR 31N140W. WINDSAT DATA FROM 0600 UTC SHOWED AN AREA OF 20 KT 
WINDS W OF A QUASI-STATIONARY TROUGH FROM 13N136W TO 
09N138W...ACCOMPANIED BY SCATTERED MODERATE CONVECTION WITHIN 60 
NM. 20 KT TRADES ARE ALSO NOTED ON ASCAT DATA N OF THE MONSOON 
TROUGH BETWEEN 120W AND 125W...ALONG WITH SMALL CLUSTERS OF 
CONVECTION.

ASCAT DATA FROM 0410 UTC SHOWED FRESH NW TO N WINDS ALONG THE 
COAST OF CENTRAL BAJA...ON THE EASTERN EDGE OF THE SURFACE 
RIDGE. THIS WILL DIMINISH THROUGH 12 HOURS AS THE RIDGE WEAKENS.

DIVERGENCE ALOFT ASSOCIATED WITH A SHARP UPPER TROUGH OVER THE 
SOUTHERN CENTRAL AMERICA IS SUPPORTING CLUSTERS OF CONVECTION 
WITHIN 120 NM OF THE COAST FROM NW COSTA RICA TO EL SALVADOR. 
STRONG CONVECTION PERSISTS TO THE W OF HILARY...MAINLY N OF 15N 
BETWEEN 100W AND 103W.

NW SWELL WITH HEIGHTS TO 10 FT AND PERIODS TO 16 SECONDS 
CONTINUES TO PROPAGATE S OF 32N AND E OF 140W...AND WAVEWATCH 
III SHOWS IT WILL REACH AS FAR E AS 120W AND AS FAR S AS 10N 
WITHIN 36 HOURS BEFORE DECAYING BELOW 8 FT.


$$
CHRISTENSEN