000
AXPZ20 KNHC 101550
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI APR 10 2009

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 
1530 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE LIES ALONG A LINE FROM 08N83W 
TO 03N100W TO 01N115W TO 03N125W TO 01N140W. SCATTERED MODERATE 
ISOLATED STRONG FROM 04N TO 07N BETWEEN 89W AND 94W.

...DISCUSSION...

A SFC TROUGH IS ANALYZED ON THE 1200 UTC MAP ALONG 91W/92W SOUTH 
OF 9N. A LARGE CLUSTER OF MODERATE TO ISOLATED STRONG CONVECTION 
IS ASSOCIATED WITH THIS TROUGH WHICH IS EMBEDDED IN THE ITCZ. 
THE MOST RECENT QSCAT PASS...1152 UTC...SHOWED SOME WIND SHIFT 
ASSOCIATED WITH THE TROUGH. 

A BROAD AREA OF TRADE WINDS IS BEING ENHANCED ON THE SOUTHERN 
PERIPHERY OF A BROAD SURFACE RIDGE EXTENDING FROM 30N140W TO 
22N115W. NE WINDS OF 20 KT ARE PRESENT FROM 09N TO 21N W OF 130W 
BASED ON AN EARLIER QUIKSCAT PASS. THESE CONDITIONS ARE EXPECTED 
TO SPREAD EWD IN ABOUT 24 HOURS AS THE SFC HIGH ALSO MOVES EWD 
ALONG 31N. SATELLITE IMAGERY AND SCATTEROMETER DATA REVEAL A 
PAIR OF SFC TROUGHS LOCALLY ENHANCING THESE WINDS...THE WESTERN 
TROUGH EXTENDING FROM 08N125W TO 04N127W...WHERE THERE IS A 1009 
MB LOW...TO 01N127W...AND THE EASTERN TROUGH EXTENDING FROM 
16N115W TO 09N117W. THE WEATHER PATTERN ASSOCIATED WITH THE SFC 
LOW IS EXHIBITING SOME BANDING FEATURE BUT CONVECTION IS AT  
MINIMUM WITH ONLY SCATTERED SHOWERS WITHIN AROUND 180 NM OF LOW 
CENTER. ISOLATED SHOWERS ARE ALSO NOTED WITHIN 180 NM E OF THE 
EASTERN TROUGH FROM 11N TO 13N. ANOTHER SFC TROUGH EXTENDS FROM 
30N121W TO 27N123W TO 26N127W. NW TO N WINDS IN THE 20 TO 25 KT 
RANGE AND SEAS UP TO 11 FT IN NW SWELL ARE FOUND IN THE WAKE OF 
THIS TROUGH...WHICH IS EXPECTED TO MOVE EWD REACHING THE 
NORTHERN BAJA PENINSULA/GULF OF CALIFORNIA ON SAT. IN ADDITION...
A NARROW SWATH OF NW WINDS OF 20 KT WITH SEAS TO 9 FT WILL 
PERSIST WITHIN AROUND 120 NM OF THE PACIFIC MEXICAN COAST FROM 
WESTERN GUERRERO TO JALISCO. AS FOR WAVE HEIGHTS...A LARGE AREA 
OF SEAS OF 8 TO 10 FT IN GENERALLY NW SWELL WILL IMPACT MUCH OF 
THE DISCUSSION AREA DURING THE NEXT FEW DAYS...RESULTING FROM 
PREVIOUS STORM COMPLEXES OUTSIDE OF THE FORECAST REGION.

AN UPPER-LEVEL LOW SPINNING NEAR 31N122W SUPPORTS THE TROUGH  
LOCATED W OF THE BAJA PENINSULA. THE SUBTROPICAL JET-STREAM WITH 
CORE WINDS OF 90 TO 110 KT ROUNDS THE BASE OF THIS TROUGH ALONG 
16N140W 20N127W 24N115W THEN ACROSS CENTRAL BAJA INTO NW MEXICO. 
A SECOND WIND MAXIMUM IS NOTED JUST SOUTH OF THE UPPER-LEVEL 
LOW. STRONG SUBSIDENCE AND THE ASSOCIATED DRY AIR MASS IS WITHIN 
THE UPPER-LEVEL TROUGH. FURTHER SOUTH...AN UPPER LEVEL HIGH IS 
CENTERED NEAR 2.5N105N WITH RIDGE EXTENDING TO NEAR THE COAST OF 
N CENTRAL AMERICA...AND OVER SE MEXICO.

GAP WINDS...
INCREASED TRADE WINDS OVER THE CARIBBEAN REGION ARE FORECAST TO 
EXTEND INTO THE GULF OF PAPAGAYO DURING THE NEXT FEW DAYS...WHEN 
SURFACE WINDS ARE EXPECTED TO OCCASIONALLY REACH 20 KT. 

$$
GR