000
AXPZ20 KNHC 161000
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON APR 16 2007

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 ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...
AXIS 6N77W  7N91W  5N102W  7N115W  4N126W  4N140W.  SCATTERED 
MODERATE ISOLATED STRONG WITHIN 90 NM OF AXIS FROM 101W TO 113W. 
SCATTERED MODERATE WITHIN 60 NM N OF AXIS W OF 123W.

...DISCUSSION...
MID/UPPER LEVEL CYCLONIC VORTEX N OF AREA CUTTING OFF FROM MAIN 
LONGWAVE TROUGH OVER SRN CALIFORNIA NEAR 36N116W.  JET CORE OF 
110 KT ROUNDS ITS BASE...BUT HAS WEAKENED SIGNIFICANTLY FROM 
YESTERDAY'S 150 KT.  TROUGH AXIS DIGS SW TO 20N126W 17N140W.  
VERY DRY AIR MASS DUE TO SUBSIDENCE ALOFT FOLLOWS WITHIN 150 NM 
OF TROUGH AXIS.  LARGE AMPLITUDE RIDGE FOLLOWS UPSTREAM WITH 
ONLY SIGNS OF MOISTURE N OF 27N127W.  SECOND BROADER RIDGE 
CENTERED OVER SOUTH AMERICA DOWNSTREAM OF TROUGH ADVECTS WIDE 
SWATH OF MOISTURE INTO TROPICAL E PAC S OF 15N AND IS PUT TO USE 
BY ITCZ FOR ITS CONVECTION WITH SMALL AREA OF DIFFLUENCE ALOFT E 
OF 120W ENHANCING DEEP CONVECTION.

MODERATE WESTERLIES ALOFT S OF 12N W OF 120W MAINTAIN STEADY 
SUPPLY OF TROPICAL MOISTURE FOR ITCZ ACTION.

...AT THE SURFACE...
HEALTHY HIGH PRES CENTER 34N136W 1034 MB HAS WELL ANCHORED RIDGE 
EXTENDS ITS INFLUENCE TO 17N115W LIMITING VERTICAL DEVELOPMENT 
OF CLOUDS.  BKN TO OVERCAST LOW LEVEL STRATIFIED CLOUD SEEN OVER 
REGION.  

GAP WINDS...SHORT LIVED GALE IN GULF OF TEHUANTEPEC EXPECTED TO 
LAST ANOTHER 12 HRS BEFORE SUBSIDING TONIGHT.

$$
WALLY BARNES