000
AXPZ20 KNHC 030240
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT SEP 03 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 
0215 UTC.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH IS ALONG THE PACIFIC COASTS OF CENTRAL 
AMERICA THEN RESUMES AT 15N106W TO 15125W TO 13N140W. SCATTERED 
MODERATE CONVECTION IS NOTED N OF 10N W OF 120W AND S OF THE 
MONSOON TROUGH...AND FROM 09N TO 11N BETWEEN 105W AND 120W. 
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 60 NM 
OF THE COASTS OF COSTA RICA AND WESTERN PANAMA.  

...DISCUSSION...
ALOFT...BROAD MIDDLE TO UPPER LEVEL TROUGH COVERS THE AREA N OF 
17N BETWEEN 120W AND 142W WITH A CUT-OFF LOW NEAR 29N132W. UPPER 
LEVEL RIDGING EXTENDS NEARLY E TO W ACROSS MEXICO AND INTO EPAC 
ALONG 21N-22N...WITH TWO UPPER ANTICYCLONES...ONE IS NEAR 
23N108W AND THE SECOND ONE IS NEAR 24N114W. SOUTH TO THIS 
RIDGE...NE TO E FLOW ALOFT PERSISTS...YIELDING LIGHT TO MODERATE 
SHEAR ALOFT ACROSS THE DEEP TROPICS.

AT THE SURFACE...HIGH PRES REMAINS CENTERED WELL N OF THE 
DISCUSSION AREA...WITH A 1029 MB HIGH NEAR 44N137W. A WEAK 
SURFACE RIDGE EXTENDS SE TO NEAR 25N120W PRODUCING MILD PRESSURE 
GRADIENT ACROSS THE LOCAL AREA. WINDS BELOW 20 KT ARE NOTED 
UNDER THE INFLUENCE OF THE RIDGE WITH SEAS TO 9 FT IN NLY SWELL. 

THE REMNANTS OF T.D. EIGHT-E ARE NOTED ON VISIBLE SATELLITE 
IMAGERY JUST W OF THE MARIAS ISLANDS PRODUCING DISORGANIZED 
CLOUDINESS AND A FEW SHOWERS WITH A SMALL AND WELL DEFINED  
SWIRL OF LOW CLOUDS NEAR 22N107.5W. 

FURTHER SOUTH...BROAD MONSOONAL FLOW IS OCCURRING ACROSS THE 
AREA MAINLY FROM 8N TO 11N AND E OF 135W. WINDS ARE GENERALLY AT 
10 TO 15 KT WITH A FEW SMALL AREAS OF 15-20 KT. SCATTEROMETER 
DATA PROVIDED OBSERVATIONS OF THESE WIND SPEEDS. THIS PATTERN IS 
FORECAST TO PERSIST DURING THE NEXT COUPLE OF DAYS.   

LONG PERIOD CROSS EQUATORIAL SWELL CONTINUES TO DOMINATE THE 
REGIONAL WATERS AND WILL GRADUALLY FADE THROUGH TONIGHT. 

$$
GR