000
AXPZ20 KNHC 201551
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU AUG 20 2009

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1530 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 89W N OF 04N INTO CENTRAL AMERICA 
MOVING W AT 15-20 KT. WIDELY SCATTERED MODERATE CONVECTION IS 
FROM 05N-08N BETWEEN 87W-90W...AND FROM 10N-12N BETWEEN 87W-89W.
 
A TROPICAL WAVE IS ALONG 116W FROM 07N-16N MOVING W AT 10 KT. 
BROAD CYCLONIC TURNING IS NOTED NEAR 11N116W. SCATTERED MODERATE 
CONVECTION IS FROM 09N-13N BETWEEN 114W-119W. 

A TROPICAL WAVE IS ALONG 130W FROM 08N-17N MOVING W AT 10 KT. 
SCATTERED MODERATE CONVECTION IS FROM 09N-11N BETWEEN 
130W-133W...AND FROM 12N-15N BETWEEN 125W-133W.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG 08N78W 
11N90W 09N100W 12N120W 13N130W 10N140W. SCATTERED MODERATE 
CONVECTION IS ALONG THE COAST OF COLOMBIA FROM 04N-08N BETWEEN 
77W-80W. SIMILAR CONVECTION IS FROM 04N-05N BETWEEN 81W-83W. 
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 09N-13N 
BETWEEN 92W-96W. SCATTERED MODERATE CONVECTION IS ALSO FROM 
11N-12N BETWEEN 101W-103W.

SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS NOTED N OF 
THE ITCZ OVER THE GULF OF TEHUANTEPEC FROM 13N-16N BETWEEN 
93W-97W.

...DISCUSSION...

A 1027 MB HIGH IS NW OF THE AREA NEAR 37N148W. A RIDGE AXIS 
EXTENDS SE TO 33N140W TO THE S COAST OF BAJA CALIFORNIA AT 
23N117W. 10-15 KT NE WINDS ARE NOTED IN VICINITY OF THE RIDGE. 
IN THE TROPICS...05-10 KT TRADES ARE PREDOMINATELY E OF 120W 
HOWEVER...15 KT NE WINDS ARE DOWNSTREAM OF THE GULF OF PAPAGAYO 
AND WILL PREVAIL FOR THE NEXT FEW DAYS. TRADES ARE ALSO 10-15 KT 
W OF 120W. THE GULF OF TEHUANTEPEC HAS CONVECTION AS MENTIONED 
ABOVE. FURTHER W...SCATTERED SHOWERS ARE ALONG THE COAST OF 
MEXICO FROM ACAPULCO TO MAZATLAN. SSMI TOTAL PRECIPITABLE WATER 
ALSO SHOWS CONSIDERABLE MOISTURE N OF 03N FROM ECUADOR TO BAJA 
CALIFORNIA AT 110W. THE SAME SSMI MOISTURE EXTENDS W ALONG THE 
ITCZ FROM 03N -17N W OF 110W TO BEYOND 140W.  

LONG PERIOD SOUTHERLY SWELLS AT A PERIOD OF 18 SECONDS ARE 
EXPECTED TO REACH THE COAST OF CENTRAL AMERICA S OF THE BAJA 
PENINSULA TONIGHT AND REACH SOUTHERN CALIFORNIA FRI NIGHT.     

IN THE UPPER LEVELS...
AN UPPER LEVEL LOW IS CENTERED AT 19N138W. A SECOND UPPER LEVEL 
LOW IS CENTERED AT 32N123W. AN UPPER LEVEL HIGH IS IN BETWEEN 
CENTERED NEAR 22N128W. FURTHER E...ZONAL FLOW IS FROM 80W TO 
110W. STRONG SUBSIDENCE IS NOTED N OF 17N BETWEEN 110W-140W. 
CONSIDERABLE UPPER LEVEL MOISTURE IS OVER THE REMAINDER OF THE 
AREA NAMELY OVER CENTRAL AMERICA AND THE TROPICS FROM 03N-17N. 

$$
FORMOSA