000
AXPZ20 KNHC 081603
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT DEC 08 2007

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 
1445 UTC.
 
...ITCZ...
INTERTROPICAL CONVERGENCE ZONE AXIS ALONG 8N83W 9N120W 8N140W. 
ISOLATED MODERATE CONVECTION WITHIN 60 NM OF AXIS 122W-137W.  

...DISCUSSION...
LARGE AMPLITUDE UPPER LEVEL LONGWAVE TROUGH EXTEND FROM 32N120W 
TO 10N124W.  JET CORE 115 KT DIGS S ON ITS W SIDE ADVECTING 
LARGE AMOUNTS OF HIGH LATITUDE MOISTURE INTO E PAC. TROUGH 
FORCES DOWNSTREAM MID/UPPER LEVEL RIDGE N OF 20N EASTWARD BUT 
FAILS TO MOVE WELL ANCHORED PORTION OF RIDGE S OF 20N E OF 100W.

UPSTREAM FROM TROUGH...BROAD MID/UPPER LEVEL RIDGE AXIS MOVES 
ALONG 140W WITH ITS CREST PROVIDING PLENTY OF MOISTURE FOR 
TROUGH TO ADVECT INTO E PAC...BUT MAINTAINS DRY AIR MASS S OF 
17N.  SOME MOISTURE ALSO ADVECTED NE TOWARDS CENTRAL MEXICO ON  
E SIDE OF TROUGH BE SECOND BRANCH OF 110 KT JTST.  

AT THE SURFACE...WEAK COLD FRONT INCHES SE FROM 27N115W 21N130W 
23N140W.  STRONG NE WINDS FOLLOW FRONTAL PASSAGE WHICH BRING 
LARGE LONG PERIOD SWELL TRAINS INTO E PAC.  FRONT DIFFUSES 
WITHIN 24 HRS AND DISSIPATES WITHIN 48 HRS ALONG WITH NE WINDS 
BUT SWELLS REMAIN IMPACT ON AREAS N OF 10N AND W OF 110W.

TRADES WILL REMAIN CONFINED TO W OF 120W FROM 10N TO 20N THROUGH 
FORECAST PERIOD AND PAPAGAYO GAP WINDS WILL DIMINISH BUT LINGER 
BEYOND 48 HRS. 

$$
WALLY BARNES