000
AXPZ20 KNHC 030317
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI APR 03 2009

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 
0330 UTC.

...ITCZ...
THE ITCZ AXIS EXTENDS FROM 08N82W TO 02N100W TO 06N127W TO 
05N140W. ISOLATED MODERATE CONVECTION IS FOUND FROM 04N TO 06N 
BETWEEN 84W AND 90W. 

...DISCUSSION...
ALOFT...AN UPPER-LEVEL TROUGH IS OVER THE NW PORTION OF THE 
FORECAST REGION EXTENDING FROM 30N125W TO 28N140W. W AND SW 
UPPER-LEVEL WINDS AHEAD OF THIS TROUGH...COINCIDENT WITH THE 
SUBTROPICAL JET...ARE TRANSPORTING ABUNDANT MID/TO UPPER LEVEL 
MOISTURE ACROSS MUCH OF THE AREA FROM 10N T0 25N WEST OF 115W . 
A RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE REMAINDER OF THE 
AREA. SUBSIDENCE AND THE ASSOCIATED DRY AIR MASS IS NOTED S OF 
20N EAST OF 115W UNDER THE INFLUENCE OF A RIDGE ANCHORED BY AN 
UPPER-LEVEL HIGH LOCATED JUST SOUTH OF THE GULF OF TEHUANTEPEC 
NEAR 14N94W. THIS RIDGE ALSO ENVELOPS SE MEXICO AND NORTHERN 
CENTRAL AMERICA WHERE MOSTLY FAIR WEATHER PREVAILS.  

AT THE SURFACE...A 1034 MB HIGH CENTERED NW OF DISCUSSION AREA 
NEAR 37N148W EXTENDS A RIDGE THROUGH THE REGION FROM 30N140W TO 
18N109W. THE PRES GRADIENT BETWEEN THE RIDGE AND THE ITCZ HAS 
THE WINDS UP TO 20 KT N OF THE ITCZ WEST OF 130W...AND ALSO TO 
20 KT W OF THE BAJA PENINSULA AS THE RIDGE INTERACTS WITH LOWER 
PRES OVER THE SW CONUS. THE TRADE WINDS ARE EXPECTED TO DIMINISH 
IN ABOUT 24 HOURS AS THE HIGH MOVES SEWD AND WEAKENS. NORTHERLY 
SWELL WILL CONTINUE TO PUSH INTO THE WATERS OFF THE NORTHERN 
BAJA PENINSULA THROUGH THE NEXT 48 HOURS...RANGING FROM 8 TO 12 
FT. LOOKING AHEAD...A COLD FRONT IS FORECAST TO ENTER THE NW 
PORTION OF THE FORECAST REGION ON SUN FOLLOWED BY MODERATE TO 
FRESH NW WINDS AN INCREASING SEAS. LARGE AND LONG PERIOD SWELLS 
FROM THE NW ARE EXPECTED IN THE WAKE OF THE FRONT LATE SUN INTO 
MON...RAISING SEAS TO ABOUT 15 FT.   

$$
GR