000
AXPZ20 KNHC 151543
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU APR 15 2010

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...

AXIS ALONG 02N78W TO 08N94W TO 04N105W TO 08N120W TO 06N140W. 
SCATTERED MODERATE FROM 04N TO 06N BETWEEN 90W AND 93W. WIDELY 
SCATTERED MODERATE WITHIN 120 NM  N OF AXIS BETWEEN 105W AND 
135W.

...DISCUSSION...

AN UPPER LEVEL CYCLONE IS POSITIONED N OF THE AREA NEAR 38N137W 
WITH AN UPPER TROUGH EXTENDING FROM THE CYCLONE TO 27N140W. 
ANOTHER LARGER UPPER LEVEL TROUGH EXTENDS OVER THE EASTERN 
PORTION OF THE AREA FROM THE WESTERN GULF OF MEXICO ACROSS SE 
OLD MEXICO NEAR THE GULF OF TEHUANTEPEC TO NEAR 10N95W. 

TO THE S...UPPER LEVEL ANTICYCLONIC FLOW DOMINATES THE REMAINDER 
OF THE DISCUSSION AREA WITH ONE ANTICYCLONE CENTERED JUST W OF 
THE AREA NEAR 10N130W AND A SECOND ANTICYCLONE CENTERED NEAR 
10N140W. A RIDGE AXIS EXTENDS GENERALLY ALONG 10N W OF 110W. 
UPPER LEVEL DIFFLUENT FLOW TO THE S-SE OF THE ANTICYCLONE 
CENTERS IS ENHANCING CONVECTION IN THE ITCZ W OF 110W.

A 130-150 KT SUBTROPICAL JET ENTERS THE DISCUSSION AREA NEAR 
25N140W EXTENDING TO THE NE NEAR 32N120W NEAR THE NORTHERN BAJA 
PENINSULA ADVECTING MID TO UPPER LEVEL MOISTURE AROUND THE 
NORTHERN PERIPHERY OF THE ABOVE MENTIONED RIDGE TOWARD THE SW 
UNITED STATES.

AT THE SURFACE...THE ABOVE MENTIONED NORTHERN UPPER LEVEL 
CYCLONE AND TROUGH ARE SUPPORTING A SURFACE LOW PRES CENTER OF 
1005 MB NEAR 33N139W WITH A COLD FRONT EXTENDING FROM THE LOW 
CENTER TO 32N140W TO 20N144W. S-SW WINDS OF 20 TO 25 KT N OF 25N 
WITHIN 180 NM E OF THE FRONT WILL PERSIST THROUGH THE NEXT 24 
HOURS THEN MOVE N OF THE AREA. ANOTHER LOW AND COLD FRONT WILL 
MOVE INTO THE NW PORTION OF THE AREA BETWEEN IN 36 HOURS WITH 
ANOTHER ROUND OF S-SW WINDS OF 20-25 KT AHEAD OF IT BETWEEN 
36-48 HOURS.  

MEANWHILE A TIGHT PRES GRADIENT EXISTS FROM 10N TO 15N BETWEEN 
115W AND 135W AND IS RESULTING IN NE TRADES OF 20 KT. RESULTANT 
SHORT PERIOD NE WIND WAVES ARE COMMINGLING WITH LONG PERIOD NW 
SWELL AND CROSS EQUATORIAL LONG PERIOD SW SWELL THAT HAS BEEN 
PROPAGATING N ACROSS THE DISCUSSION AREA FOR SEVERAL DAYS 
RESULTING IN CONFUSED SEAS WHERE THE DIFFERENT WAVE GROUPS ARE 
INTERSECTING.

$$
FORMOSA