000
AXPZ20 KNHC 221517
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI SEP 22 2006

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1445 UTC.

...ITCZ...
INTERTROPICAL CONVERGENCE ZONE...8N77W 14N96W 11N110W 11N120W 
8N130W 10N140W. SCATTERED MODERATE N OF 14N BETWEEN 92W AND 97W. 
SCATTERED MODERATE WITHIN 120 NM OF THE AXIS BETWEEN 120W AND 
126W...AND W OF 137W.

DIMINISHING CLUSTER OF MODERATE CONVECTION IN GULF OF 
TEHUANTEPEC.

TROPICAL LOWS...
A 1010 MB LOW NEAR 16N107W REMAINING STNRY. ISOLATED MODERATE 
CONVECTION IS SHEARED TO THE WEST OF THE LOW LEVEL CIRCULATION.

...DISCUSSION...
UPPER LOW PRESSURE CENTERED NEAR 26N130W CONTINUES TO MAKE SLOW 
PROGRESS TO THE NE. SW FLOW BETWEEN THIS FEATURE AND AN UPPER 
RIDGE NEAR 24N117W IS PROVIDING UPPER EXHAUST TO A LARGE CLUSTER 
OF MODERATE TSTMS ALONG THE ITCZ FROM 7N TO 12N BETWEEN 120W AND 
135W. OTHERWISE STABLE AIRMASS REMAINS IN PLACE N OF 17N UNDER 
UPPER LOW AND ASSOCIATED BOUNDARY LAYER RIDGE. THE RIDGE WILL 
WEAKEN AS LOW PRESSURE OVER THE SW U.S. RETROGRADES OFF THE 
COAST THIS WEEKEND. QUIKSCAT IMAGERY FROM LATE YESTERDAY EVENING 
SHOWED CONTINUED MODERATE TO FRESH TRADES N OF 14N AND W OF 
125W. THESE WINDS WILL LIKELY DIMINISH THROUGH TONIGHT AS THE 
BOUNDARY LAYER RIDGE WEAKENS. HOWEVER...PERSISTENT STRONG N 
WINDS N OF THE AREA FROM THE PAST COUPLE OF DAYS IS ALLOWING 
RESIDUAL LARGE SWELL MAINLY N OF 23N THROUGH THE WEEKEND.

MEANWHILE...THE WEAK CIRCULATION NEAR 16N107W IS WELL DEPICTED 
ON RECENT QUIKSCAT IMAGERY. ELY SHEAR ON SRN PERIPHERY OF UPPER 
RIDGE OVER MEXICO IS HOLDING CONVECTION ON THE WRN SIDE OF THIS 
CIRCULATION AND CONTINUES TO INHIBIT DEVELOPMENT. 
OTHERWISE...ASIDE FROM DIMINISHING OVERNIGHT ACTIVITY IN THE 
GULF OF TEHUANTEPEC...COASTAL CONVECTION REMAINS LIMITED FOR 
NOW. ELY WINDS MAY INCREASE THIS WEEKEND HOWEVER AS RIDGE BUILDS 
TO THE N. MAY SEE MODEST INCREASE IN GULF OF PAPAGAYO BY SAT AS 
EVIDENCED BY STRONGER ELY WINDS IN SATELLITE AND QUIKSCAT 
IMAGERY OVER SW CARIBBEAN.

CROSS-EQUATORIAL FLOW PERSISTS S OF THE ITCZ. FRESH SELY FLOW IS 
AIDING CONVERGENCE TO CONVECTION ALONG ITCZ BETWEEN 120W AND 
135W. NWW3 IS DEPICTING LARGE SLY SWELL BETWEEN 95W AND 125W S 
OF 10N STARTING THIS WEEKEND.

$$
CHRISTENSEN