000
AXPZ20 KNHC 071534
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT MAY 07 2011

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 
1500 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 07N89W TO 
07N109W TO 05N125W TO 06N140W. SCATTERED MODERATE TO ISOLATED 
STRONG CONVECTION IS NOTED WITHIN 220 NM N OF AXIS BETWEEN 99W 
AND 107W. SIMILAR CONVECTION IS NEAR 08N132W. A SURFACE TROUGH 
IS WITHIN THE ITCZ AND EXTENDS FROM 11N106W TO 05N110W. A 
CLUSTER OF MODERATE TO ISOLATED STRONG CONVECTION IS NEAR THE 
NORTHERN END OF THE TROUGH AXIS FROM 10N TO 13N BETWEEN 105W AND 
108W. 

...DISCUSSION...

FEW SHIP OBSERVATIONS AND ASCAT DATA SHOW MAINLY 15 TO 20 KT 
TRADE WIND FLOW OVER MUCH OF THE AREA W OF 120W...BETWEEN A 1030 
MB HIGH PRES CENTER N OF HAWAII...AND THE WEAK SURFACE TROUGH 
ALONG THE ITCZ MENTIONED IN THE ITCZ SECTION. SEAS ARE ESTIMATED 
TO BE 6 TO 8 FT IN THIS AREA. IN ADDITION...WINDS OFF THE 
CENTRAL AND SOUTHERN BAJA CALIFORNIA COAST ARE REACHING 20 KT 
BETWEEN THE HIGH PRES OVER THE PACIFIC AND 1005 MB LOW PRES NOW 
LOCATED OVER N CENTRAL MEXICO. THE NW FLOW OFF BAJA CALIFORNIA  
WILL PERSIST ALONG THE ENTIRE COAST THROUGH AT LEAST MON AS A 
TROUGH DIGS OVER WESTERN MEXICO. THE TRADE WINDS WILL GRADUALLY 
DIMINISH BELOW 20 KT BY MON AS TROUGHING ALONG THE ITCZ WEAKENS. 

A DIFFLUENT PATTERN ALOFT BETWEEN AN UPPER-LEVEL TROUGH 
STRETCHING FROM 19N121W TO 10N113W TO THE EQUATOR AT 109W AND A 
BROAD ANTICYCLONE EXTENDING FROM THE CENTRAL CARIBBEAN THROUGH 
NORTHERN CENTRAL AMERICA INTO THE EPAC IS HELPING TO MAINTAIN 
CONVECTION N OF THE ITCZ BETWEEN 99W AND 107W...AND NEAR THE 
NORTHERN END OF THE AFOREMENTIONED SURFACE TROUGH. ANOTHER UPPER 
LEVEL TROUGH IS OVER THE NW CORNER OF THE FORECAST AREA. A 
CUT-OFF LOW IS FORECAST TO FORM ALONG THIS TROUGH BY LATE SUN. 

GAP WINDS...
A SURFACE TROUGH OVER THE SW GULF OF MEXICO IS RESULTING IN 
RESIDUAL FUNNELING WINDS THROUGH THE GULF OF TEHUANTEPEC...AS 
SHOWN BY THE MOST RECENT ASCAT PASS. THESE WINDS WILL DIMINISH 
BELOW 20 KT THROUGH LATE TODAY. 

FURTHER SOUTH...THE SAME ASCAT PASS AND A SHIP OBSERVATION  
SHOWED 20 TO 25 KT WINDS PERSISTING THROUGH THE GULF OF PAPAGAYO 
PROBABLY IN ASSOCIATION WITH A WEAK CYCLONIC CIRCULATION TO THE 
S NEAR 8N87W AND ALONG THE ITCZ. MODEL GUIDANCE INDICATES THAT 
THIS NE FLOW WILL CONTINUE TO PULSE UP AND DOWN AT OR BELOW 20 
KT THROUGHOUT THE NEXT FEW DAYS.  

GULF OF CALIFORNIA...
SOME OF THE GLOBAL MODELS SUGGEST INCREASING WINDS TO 20 KT OVER 
THE NORTHERN GULF OF CALIFORNIA BY LATE SUN...BETWEEN HIGH PRES 
OVER THE EASTERN PACIFIC AND DIGGING THROUGH ACROSS THE SW CONUS.
SEAS WILL REMAIN BELOW 8 FT DUE TO LIMITED FETCH IN THAT AREA. 

$$
GR