000
AXPZ20 KNHC 091534
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT APR 09 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 WAS ANALYZED FROM 05N77W 
TO 03N88W THEN RESUMES FROM 04N98W TO 05N116W THEN RESUMES FROM 
06N123W TO 02N140W. NUMEROUS MODERATE AND SCATTERED STRONG 
CONVECTION WAS WITHIN 120 NM EITHER SIDE OF THE AXIS E OF 85W. 
SCATTERED MODERATE AND ISOLATED STRONG CONVECTION WAS FROM 04N 
TO 07N BETWEEN 96W AND 104W AND ALSO WITHIN 90 NM S OF THE AXIS 
BETWEEN 113W AND 117W.

...DISCUSSION...

W OF 110W...AN UPPER LEVEL TROUGH EXTENDS FROM AN UPPER CYCLONE 
CENTERED OVER CENTRAL NEVADA S ACROSS SOUTHERN CALIFORNIA 
THROUGH 32N120W SW TO NEAR 12N130W. WSR-88D RADAR FROM SAN DIEGO 
INDICATES SCATTERED INSTABILITY SHOWERS MOVING INLAND FROM THE 
PACIFIC TO ACROSS NW BAJA CALIFORNIA AND THE SOUTHERN CALIFORNIA 
COASTAL AREAS. AN ACCOMPANYING SURFACE TROUGH EXTENDS FROM 
27N114W TO 19N126W. AN UPPER ANTICYCLONE IS POSITIONED NEAR 
32N143W WITH ASSOCIATED 1030 MB SURFACE HIGH PRES NEAR 34N142W 
EXTENDING A RIDGE AXIS SE ACROSS THE NORTHERN WATERS. EARLIER 
SCATTEROMETER PASSES SHOWED 20 KT NW TO N WINDS BEHIND THE 
SURFACE TROUGH MENTIONED ABOVE IN AN AREA N OF 25N...ALONG WITH 
AN AREA OF 20 KT TRADES FROM 14N TO 22N. THE NORTHERLY WINDS N OF
25N WILL GRADUALLY DIMINISH THROUGH THE NEXT 48 HOURS AS THE 
TROUGH DISSIPATES...WHILE TRADES WILL EXPAND EASTWARD ALL THE 
WAY TO 110W AS HIGH PRES MOVES SE INTO THE AREA. MEANWHILE LARGE
NW SWELLS TO 16 FT WITH WAVE PERIODS OF 13 TO 15 SECONDS ARE 
PROPAGATING ACROSS THE NE WATERS W OF BAJA CALIFORNIA WITH 
SWELLS TO 8 FT REACHING TO 02N. THESE SWELLS WILL GRADUALLY 
DECAY TO 8 TO 10 FT BY 48 HOURS.

OTHERWISE...WEAK 1011 MB SURFACE LOW PRES WAS CENTERED NEAR 
07N120W WITH A TROUGH EXTENDING FROM 11N118W THROUGH THE LOW TO 
03N121W. SCATTERED MODERATE TO STRONG CONVECTION WAS OCCURRING 
WITHIN 120 NM IN THE NE QUADRANT OF THE LOW.

E OF 110W...AN UPPER ANTICYCLONE IS CENTERED OVER 12N89W WITH 
UPPER RIDGING EXTENDING TO 110W ALONG 12N. CLUSTERS OF 
CONVECTION AS DESCRIBED IN THE ITCZ SECTION ABOVE ARE OCCURRING 
ALONG THE ITCZ DUE TO ABUNDANT DEEP LAYER MOISTURE AND UPPER 
DIFFLUENCE ALONG THE SOUTH EDGE OF THE UPPER RIDGING. OTHERWISE 
NE TO E WINDS WILL CONTINUE TO PULSE TO 20 KT IN THE GULF OF 
PAPAGAYO DURING THE NEXT FEW DAYS WITH SEAS REMAINING JUST LESS 
THAN 8 FT.

GULF OF CALIFORNIA...SW WINDS IN THE FAR N GULF HAVE DIMINISHED 
AS A DISSIPATING COLD FRONT STRETCHING FROM SW ARIZONA TO ACROSS 
THE CENTRAL BAJA CALIFORNIA PENINSULA CONTINUES TO THE E. 20 KT 
NORTHERLY WINDS ARE EXPECTED TO COMMENCE IN THE CENTRAL GULF SUN 
MORNING THEN WILL EXPAND TO ENCOMPASS THE MAJORITY OF THE GULF 
MON MORNING AS THE PRES GRADIENT STRENGTHENS BETWEEN BUILDING 
HIGH PRES W OF THE BAJA CALIFORNIA PENINSULA AND A LOW PRES 
SYSTEM MOVING THROUGH SOUTHERN TEXAS AND NE MEXICO. SEAS ARE 
EXPECTED TO REMAIN LESS THAN 8 FT IN THE GULF THROUGH THE PERIOD.

$$
LEWITSKY