000
AXPZ20 KNHC 300230
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT APR 30 2011

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ANALYZED FROM 04N77W 
TO 04N100W TO 08N117W TO 05N140W. SCATTERED MODERATE CONVECTION 
IS NOTED WITHIN 150 NM EITHER SIDE OF AXIS FROM 105W TO 110W. 
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 120 
NM N OF AXIS BETWEEN 126W AND 128W.

...DISCUSSION...
A SMALL BUT VERY WELL DEFINED UPPER LEVEL CYCLONE CENTERED NEAR 
28N137W CONTINUES TO LIFT N-NE ACROSS THE FAR NW CORNER OF THE 
AREA. AN UPPER LEVEL TROUGH EXTENDS FROM THIS CYCLONE TO ABOUT 
23N138W. A FEW SHOWERS ARE AROUND THE LOW CENTER. THE REMAINDER 
OF THE FORECAST AREA TO THE E REMAINS UNDER THE INFLUENCE OF A 
BROAD AND FLAT UPPER LEVEL RIDGE. COMPUTER MODEL SUGGESTS THAT 
THE UPPER LEVEL CYCLONE WILL MOVE EWD ACROSS THE N WATERS SAT 
THROUGH MON WHILE DEEPENING. THE RIDGE WILL DRIFT EWD AND 
CONTINUE TO AFFECT THE AREA E OF 110W.

A DEEP LAYER RIDGE N OF AREA AND ALONG 140W SUPPORTS A 1038 MB 
HIGH PRES CENTER NEAR 41N134W. THIS SURFACE HIGH WILL MOVE NE 
AND SLIGHTLY WEAKEN DURING THE NEXT 24 HOURS. FRESH TO STRONG 
NORTHERLY WINDS PERSIST S OF THE HIGH PRES N OF 20N. AN EARLIER  
WINDSAT PASS...AND THE MOST RECENT ASCAT PASS VERIFIED THE 
EXISTENCE OF THESE WIND SPEEDS. THIS WEATHER PATTERN WILL 
PERSIST THIS SAT BUT WINDS ARE FORECAST TO DIMINISH BY SUN AS 
HIGH PRES WEAKENS. SEAS OF 8 TO 12 FT IN NW SWELL ARE NOTED OFF 
OF THE NORTHERN BAJA COAST. A DIFFLUENT PATTERN ALOFT BETWEEN 
THE AFOREMENTIONED RIDGE AND AN UPPER LEVEL CYCLONE SITUATED 
NEAR 4N106W IS HELPING TO INDUCE MODERATE  CONVECTION WITHIN 150 
NM EITHER SIDE OF THE ITCZ FROM 105W TO 110W...AND NEAR THE 
NORTHERN END OF A SURFACE TROUGH THAT EXTENDS FROM 12N116W TO 
4N119W.  

GULF OF CALIFORNIA...NW WINDS WILL INCREASE OVER THE NORTHERN 
PORTION OF THE GULF BETWEEN LOW PRES OVER NW MEXICO AND HIGH 
PRES OVER THE NE PACIFIC BY SAT MORNING AND THEN SPREAD S TO 25N 
THROUGH LATE SUN...BUILDING SEAS OF 6-7 FT. 

GAP WINDS...
WINDS HAVE DIMINISHED TO BELOW 20 KT THROUGH THE GULF OF 
TEHUANTEPEC. CURRENTLY...IXTEPEC IN OAXACA MEXICO IS REPORTING 
SUSTAINED WINDS OF ONLY 10 KT. 

FURTHER S...NE FLOW THROUGH THE GULF OF PAPAGAYO WILL PULSE UP 
AND DOWN AT OR BELOW 20 KT THROUGHOUT THE NEXT COUPLE OF DAYS. 

$$
GR