000
AXPZ20 KNHC 021539
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON APR 02 2012

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE ITCZ AXIS EXTENDS FROM 08N121W TO BEYOND 04N140W. SCATTERED 
MODERATE CONVECTION WITHIN 60 NM EITHER SIDE OF THE AXIS BETWEEN 
127W AND 132W.

...DISCUSSION...

A MID TO UPPER LEVEL RIDGE EXTENDING FROM NEAR HAWAII TO THE 
NORTHERN ROCKIES IS SHIFT EAST AHEAD OF A DEEP LAYER TROUGH 
DIGGING ACROSS THE N CENTRAL PACIFIC. A 1032 MB SURFACE HIGH 
CENTERED NEAR 32N130W IS STARTING TO WEAKEN AHEAD OF AN 
APPROACHING COLD FRONT TO THE NW OF THE DISCUSSION AREA. FURTHER 
EAST...A MID LEVEL SHORT WAVE TROUGH CONTINUES TO PUSH SE 
THROUGH THE SOUTHERN EXTENT OF THE BAJA CALIFORNIA PENINSULA AND 
GULF OF CALIFORNIA. AN ASSOCIATED COLD FRONT THAT HAD EXTENDED 
FROM N CENTRAL MEXICO TO NEAR 25N120W HAS LARGELY DISSIPATED 
WEST OF THE CENTRAL GULF OF CALIFORNIA. ALTHOUGH THE AIRMASS 
BEHIND THE FRONT HAS MODIFIED AND THE FRONT HAS DISSIPATED...THE 
GRADIENT BETWEEN THE 1032 MB SURFACE HIGH AND DEEP LOW PRES OVER 
THE ROCKIES IS RESULTING IN FRESH TO STRONG WINDS OFF THE COAST 
OF NORTHERN BAJA. SCATTEROMETER DATA OVER THE PAST SEVERAL HOURS 
ALSO SHOWED A BROAD AREA OF FRESH TRADE WIND FLOW MAINLY N OF 
08N W OF 115W. SHIP AND ALTIMETER DATA SHOW THE NW SWELL IS 
CONTINUING TO SUBSIDE....BUT HEIGHTS TO 16 FT ARE STILL NOTED N 
OF 25N E OF 130W. SEAS TO 8 FT ARE NOTED AS FAR SOUTH AS 03N.

THE COLD FRONT NW OF THE AREA WILL SHIFT SE AND SAG SOUTH OF 32N 
BY MID WEEK BEFORE DISSIPATING. THE SURFACE HIGH NEAR 32N130W 
WILL DISSIPATE...ALLOWING THE WINDS TO DIMINISH TONIGHT THROUGH 
WED. FURTHER SOUTH...AN UPPER LOW NEAR 18N132W CONTINUES TO MOVE 
EAST...AND WILL REACH 18N115W BY WED. TRADE WIND CONVERGENCE 
ALONG WITH UPPER FORCING ASSOCIATED WITH THE UPPER LOW IS 
PROVIDING ENOUGH LIFT TO SUPPORT MODEST CONVECTION ALONG THE 
ITCZ BETWEEN 127W AND 132W. DESPITE PERSISTENT UPPER DIVERGENT 
FLOW SE OF THE LOW OVER THE NEXT COUPLE OF DAYS...THE DIMINISHED 
TRADE WINDS TUE AND WED WILL NOT PROVIDE ENOUGH LOW LEVEL 
CONVERGENCE TO ALLOW ANY SIGNIFICANT CONVECTION TO PERSIST IN 
THE DEEP TROPICS W OF 110W. 

FURTHER EAST...A NEGATIVELY TILTED UPPER TROUGH PERSISTS FROM 
10N95W TO 04N85W...DIRECTLY OVER A SURFACE TROUGH FROM CENTRAL 
COSTA RICA TO 04N98W. SURFACE LOW AROUND THE TROUGH CONTINUES TO 
BE LESS THAN 10 KT. HOWEVER ENOUGH UPPER FORCING REMAINS IN 
PLACE TO ALLOW INTENSIFYING CONVECTION SE OF THE UPPER 
TROUGH...N OF 02N BETWEEN 80W AND 88W. GFS AND ECMWF GUIDANCE 
BOTH SHOW THE UPPER TROUGH SLOWLY MIGRATING NE THROUGH 
TUE...WITH THE GFS SLIGHTLY SLOWER. THE CONVECTION IN THIS AREA 
WILL LIKELY PERSIST AT LEAST ANOTHER 24 HOURS...THEN PROBABLY 
WEAKEN. 

GULF OF CALIFORNIA...HIGH PRES BUILDING OVER THE GREAT BASIN 
TODAY WILL ALLOW FRESH TO STRONG WINDS TO FUNNEL DOWN THE 
NORTHERN HALF OF THE GULF OF CALIFORNIA. AN OSCAT PASS FROM 0730 
UTC SHOWED ONLY 15 KT WINDS AT THAT TIME...BUT THIS HAS PROBABLY 
ALREADY STARTED TO INCREASE AND WILL REACH 20 TO 25 KT TODAY. 
THE WINDS WILL DIMINISH BELOW 20 KT OVERNIGHT AS THE HIGH PRES 
TO THE NORTH WEAKENS.
$$
CHRISTENSEN