000
AXPZ20 KNHC 090930
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE AUG 09 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.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH IS ALONG 10N86W TO 10N97W TO 15N110W TO 
10N130W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 
10N130W TO 06N140W. SCATTERED MODERATE TO STRONG CONVECTION IS 
WITHIN 180 NM S OF THE MONSOON TROUGH BETWEEN 92W AND 96W AND 
ALSO WITHIN 120 NM S OF THE MONSOON TROUGH BETWEEN 97W AND 102W. 
SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 
60-120 NM EITHER SIDE OF THE MONSOON TROUGH BETWEEN 118W AND 
122W.

...DISCUSSION...

A NEARLY STATIONARY LARGE MID TO UPPER LEVEL CYCLONIC 
CIRCULATION IS NW OF THE AREA NEAR 31N149W. A LARGE UPPER LEVEL 
ANTICYCLONE IS OVER NW MEXICO NEAR 31N113W. SOUTHERLY FLOW 
EXISTS BETWEEN THE CYCLONIC AND ANTICYCLONIC CIRCULATIONS N OF 
15N W OF 127W ADVECTING AND DISPLACING MOISTURE ASSOCIATED WITH 
THE REMNANTS OF EUGENE TO THE N THROUGH NE. UPPER LEVEL 
DIFFLUENCE ON THE SOUTHERN PERIPHERY OF THE ANTICYCLONE IS 
AIDING CONVECTIVE DEVELOPMENT OVER NW MEXICO PUSHING W OF THE 
BAJA CALIFORNIA PENINSULA N OF 20N W TO 125W. ELSEWHERE 
ALOFT...LIGHT TO MODERATE EASTERLY FLOW COVERS THE MAJORITY OF 
THE REMAINDER OF THE TROPICS.

AT THE SURFACE...1030 MB HIGH PRES IS CENTERED NW OF THE AREA 
NEAR 37N150W WITH AN ATTENDANT RIDGE EXTENDING INTO THE AREA 
NEAR 32N135W TERMINATING NEAR 25N120W. THE 1012 MB REMNANT LOW 
OF EUGENE IS CENTERED NEAR 19.5N138W. A TIGHT PRES GRADIENT 
REMAINS BETWEEN THE LOW CIRCULATION AND THE RIDGING TO THE NE OF 
IT WITH A 0606 UTC ASCAT SCATTEROMETER PASS CAPTURING NE-E 20-25 
KT WINDS WITHIN 300 NM IN THE NW SEMICIRCLE OF THE LOW. THIS 
AREA OF WINDS IS ACCOMPANIED BY 8-11 FT MIXED NE AND SE SWELL. 
THE LOW WILL DEGENERATE INTO A TROUGH BY 24 HOURS AS IT BEGINS 
TO MOVE W OF THE AREA WITH A SMALL AREA OF 20 KT WINDS AND SEAS 
TO 9 FT LINGERING FROM 20N TO 24N W OF 136W...DIMINISHING BY 36 
HOURS.

A DECAYING SET OF CROSS-EQUATORIAL SOUTHERLY SWELL RESIDES FROM S
OF 10N W OF 110W WITH SEAS TO 9 FT. THESE SEAS WILL SUBSIDE TO 8 
FT IN 24 HOURS WHILE BECOMING CONFINED TO S OF 03N BETWEEN 110W 
AND 125W. BY 48 HOURS...A NEW SET OF SW SWELL TO 9 FT WILL CROSS 
THE EQUATOR PROPAGATING TO S OF 03N BETWEEN 95W AND 120W. 
MEANWHILE...MODEL GUIDANCE SHOWS SW FLOW INCREASING TO 20 KT S 
OF THE MONSOON TROUGH FROM 08N TO 13N BETWEEN 114W AND 125W IN 
24 HOURS THEN DIMINISHING BY 48 HOURS WITH 8 FT SEAS LINGERING 
FROM 10N TO 14N BETWEEN 116W AND 124W.

$$
LEWITSKY