000
AXPZ20 KNHC 072134
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT MAR 07 2009

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 
2300 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...06N77W TO 
04N80W TO 03N105W TO 04N140W. THERE IS NO SIGNIFICANT CONVECTION 
ALONG THE ITCZ. 

...DISCUSSION...

W OF 110W...A SHARP MID/UPPER LEVEL TROUGH EXTENDS FROM SOUTHERN 
CALIFORNIA TO 30N125W TO ROUGHLY 27N140W. A 100 KT JET STREAK IS 
EVIDENT SOUTH OF THE TROUGH IN SATELLITE DERIVED WIND 
INFORMATION. DIVERGENCE ALOFT ASSOCIATED WITH THE RIGHT REAR 
PORTION OF THE JET STREAK AND AHEAD OF ANOTHER JET ACROSS HAWAII 
IS SUPPORTING A WEAK SURFACE TROUGH ALONG ROUGHLY 132W FROM 15N 
TO 20N. THE SURFACE TROUGH WILL NOT MOVE APPRECIABLY THROUGH 48 
HOURS AND WILL GRADUALLY WEAKEN. OTHERWISE A SURFACE RIDGE 
EXTENDS FROM 30N140W TO SOUTH OF BAJA. A QUIKSCAT PASS FROM 15Z 
SHOWS 20 TO 25 KT BETWEEN THE SURFACE TROUGH THE RIDGE. A JASON 
ALTIMETER PASS FROM 17Z SHOWED 8 TO 10 FT SEAS S OF 25N W OF 
130W. THIS IS THE RESULT OF THE ENHANCED TRADES...AS WELL AS 
PERSISTENT LONG PERIOD NW SWELL PROPAGATING THROUGH THE AREA. 
SHIP OBSERVATIONS AND SCATTEROMETER DATA ALSO SHOW FRESH 
NORTHERLY WINDS OFF THE BAJA COAST...ON THE EASTERN EDGE OF THE 
SURFACE RIDGE. MEANWHILE...THE SW TO W WINDS IN THE MID AND 
UPPER LEVELS ARE ADVECTING A PLUME OF TROPICAL MOISTURE OVER THE 
SURFACE RIDGE...RESULTING IN WIDESPREAD CLOUDINESS FROM 10N TO 
20N...AS WELL AS POCKETS OF LIGHT RAIN AS NOTED ON AN EARLIER 
SHIP REPORT. THE POSITION AND CHARACTER OF THE MID/UPPER TROUGH 
WILL CHANGE LITTLE THROUGH 48 HOURS. WINDS OFF BAJA WILL 
DIMINISH AS THE SURFACE RIDGE WEAKENS SLIGHTLY...OTHERWISE 
LITTLE CHANGE IS EXPECTED.

E OF 110W...MAIN ISSUE REMAINS STRONG GAP FLOW THROUGH THE GULF 
OF PAPAGAYO AND ADJACENT WATERS TO THE WEST. SCATTEROMETER DATA 
FROM EARLIER IN THE DAY SHOWED 20 TO 30 KT WINDS 
CONTINUING...DUE TO STRONG TRADES IN THE SW CARIBBEAN. 
DRAINAGE FLOW ENHANCES THE OVERALL FLOW IN THE EARLY MORNING. 
CONVERGENCE OF THE PAPAGAYO GAP WINDS WITH SOUTHERLY FLOW S OF 
04N IS SPARKING MODEST CONVECTION ALONG THE ITCZ BETWEEN 85W AND 
95W. MODERATE TO FRESH NORTHERLY FLOW PERSISTS THROUGH THE 
ISTHMUS OF PANAMA AND INTO THE GULF OF PANAMA AS WELL. FURTHER 
NORTH...GAP WIND FLOW THROUGH THE GULF OF TEHUANTEPEC IS 
DIMINISHING BELOW 20 KT. SEAS TO 8 FT CONTINUE MAINLY S OF 10N W 
OF 100W...MAINLY DUE TO A MIX OF NW SWELL WITH NE SWELL FROM THE 
PAPAGAYO WINDS.

$$
CHRISTENSEN