000
AXPZ20 KNHC 270236
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED APR 27 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 FROM 09N84W TO 05N97W 
TO 08N106W TO 00N127W. NO SIGNIFICANT CONVECTION.

...DISCUSSION...
ALOFT...LARGE UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED 
NEAR 25N114W WITH A RIDGE TO THE SE TO THE SOUTHERN TIP OF BAJA 
CALIFORNIA PENINSULA AND ANOTHER RIDGE TO THE NW TO NEAR 
28N135W. SWLY WINDS OF 25-35 KT ARE SEEN ON THE NORTHERN 
PERIPHERY OF THE RIDGE. WINDS ALOFT RAPIDLY INCREASE OVER N BAJA 
CALIFORNIA AND NORTHERN MEXICO DUE TO THE PRESENCE OF A 
JET-STREAM WITH CORE WINDS OF 110-130 KT OVER THE SW CONUS. 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 WEAKENING CUT-OFF LOW NEAR 22N135W. 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 01N104W 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 14N W OF 115W. 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. AN EARLIER ASCAT PASS ALONG WITH 
SOME SHIP OBSERVATIONS VERIFIED THE EXISTENCE OF THESE WIND 
SPEEDS. TRADE WINDS TO 20 KT ARE ALSO NOTED AROUND THE SOUTHERN 
PERIPHERY OF THE RIDGE FROM 7N-20N W OF 125W. BOTH...WINDS W OF 
THE BAJA PENINSULA AND THE TRADES WILL SLIGHTLY DIMINISH IN 24 
HOURS AS HIGH PRES LOCATED N OF AREA WEAKENS. EXPECT INCREASING 
WINDS AGAIN IN ABOUT 48 HOURS AS HIGH PRES BUILDS IN FROM THE N. 

AS PREVIOUSLY MENTIONED...A SURFACE TROUGH IS NW OF THE 
GALAPAGOS ISLANDS AND EXTENDS FROM 4N89W TO 1N93W CROSSING THE 
EQUATOR AT 98W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION 
IS OBSERVED ON SATELLITE IMAGERY WITHIN 80 NM EITHER SIDE OF 
TROUGH AXIS...BUT MAINLY FROM 1N-3N...AND WHERE THE TROUGH MEETS 
THE EQUATOR. ANOTHER TROUGH IS WITHIN THE ITCZ ALONG 108W FROM 
4N TO 11N. A SMALL CLUSTER OF MODERATE CONVECTION IS ALONG THE 
TROUGH AXIS NEAR 8N. SIMILAR CONVECTION IS NEAR 6N118W.

W OF 110W...REGIONAL WATERS ARE MAINLY DOMINATED BY NW SWELL AND 
NE WIND WAVES RAISING SEAS UP TO 11 FT W OF BAJA CALIFORNIA. E 
OF 110W...CROSS EQUATORIAL LONG PERIOD S TO SW SWELLS ARE NOTED 
WITH SEAS BELOW 8 FT. 

$$
GR