000
AXPZ20 KNHC 262139
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE APR 26 2011

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 2100 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE AXIS IS FROM 09N84W TO 05N97W 
TO 07N104W TO 00N119W. NO SIGNIFICANT CONVECTION.

...DISCUSSION...
ALOFT...LARGE UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED 
NEAR 26N117W WITH A RIDGE TO THE SE TO THE SOUTHERN TIP OF BAJA 
CALIFORNIA PENINSULA AND ANOTHER RIDGE TO THE W TO NEAR 27N135W. 
AN UPPER LEVEL TROUGH CROSSES THE FORECAST WATERS MAINLY FROM E 
TO W ALONG 21W/22W AND EXTENDS FROM N CENTRAL MEXICO TO 21N140W 
WITH A CUT-OFF LOW NEAR 21N135W. FURTHER SOUTH...A RIDGE 
DOMINATES THE AREA E OF 105W INCLUDING SE MEXICO AND CENTRAL 
AMERICA. UPPER DIFFLUENCE BETWEEN THIS RIDGE AND AN UPPER LEVEL 
LOW SITUATED NEAR 02N105W IS HELPING TO INDUCE CONVECTION NEAR A 
SURFACE TROUGH LOCATED NW OF THE GALAPAGOS ISLANDS.  

AT THE SURFACE...A RIDGE COVERS THE AREA N OF 10N W OF 110W. THE 
PRES GRADIENT BETWEEN THE RIDGE AND LOW PRES OVER THE SW U.S. IS 
PRODUCING 20-25 KT WINDS NEAR THE COAST OF BAJA CALIFORNIA 
GENERALLY N OF 22N E OF 125W. THE 1802 ASCAT PASS ALONG WITH 
SOME SHIP OBSERVATIONS VERIFIED THE EXISTENCE OF THESE WIND 
SPEEDS FORECAST TO PERSIST OVER THE NEXT COUPLE OF DAYS. TRADE 
WINDS TO 20 KT ARE ALSO NOTED AROUND THE SOUTHERN PERIPHERY OF 
THE RIDGE FROM 7N-20N W OF 125W. 

AS PREVIOUSLY MENTIONED...A SURFACE TROUGH IS NW OF THE 
GALAPAGOS ISLANDS AND EXTENDS FROM 5N89W TO 2N92W CROSSING THE 
EQUATOR AT 95W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION 
IS WITHIN 120 NM E OF TROUGH AXIS. SIMILAR CONVECTION IS ALONG 
THE EQUATOR BETWEEN 96W AND 99W. ANOTHER TROUGH IS WITHIN THE 
ITCZ ALONG 105W FROM 4N TO 11N. ISOLATED TO SCATTERED MODERATE 
CONVECTION IS NEAR THE NORTHERN END OF THE TROUGH AXIS. 

W OF 110W...REGIONAL WATERS ARE MAINLY DOMINATED BY NW SWELL AND 
NE WIND WAVES. E OF 110W...CROSS EQUATORIAL LONG PERIOD S TO SW 
SWELL ARE NOTED RAISING SEAS TO 8 FT IN SMALL AREA S OF 03N 
BETWEEN 82W AND 86W. SEAS WILL SUBSIDE TO LESS THAN 8 FT IN 24 
HOURS.  

$$
GR