000
AXPZ20 KNHC 311559
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN AUG 31 2008

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 
1515 UTC.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 108W FROM 07N-18N MOVE W 10 KT CONTINUES 
WITH MINOR CONVECTION ALONG AXIS WHILE CLUSTERS OF DEEP 
CONVECTION REMAIN FAR BEHIND UNDER AREA OF MODERATE DIFFLUENCE.
WAVE EMBEDDED WITHIN SURFACE MONSOON TROUGH AND UNDER ELY SHEAR 
ALOFT CURTAILING SIGNIFICANT CYCLONIC ORGANIZATION.  MODEL 
GUIDANCE HAVE PULL BACK FROM THE PREVIOUS FORMATION OF LOW PRES 
CENTER ALONG WAVE AND CONTINUE WEAKENING WAVE TO OBLIVION.  

...ITCZ...
ITCZ AXIS ALONG 10N85W TO 12N108W TO 08N140W.  SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM OF 04N79W AND 
FROM 07N-11N BETWEEN 90W-138W. 

...DISCUSSION...
BROAD UPPER LEVEL ANTICYCLONE CENTERED AT 22N107W STRETCHES 
ALONG 20N-22N LITERALLY THROUGH ENTIRE E PAC N OF ITCZ.  
ASSOCIATED MODERATE TO STRONG SUBSIDENCE MAINTAINS A VERY DRY 
AIR MASS N OF 18N W OF 110W.  ADD A MODERATE STEADY NE-E FLOW TO 
SHEAR ANY SIGNS OF DEEP CONVECTION AND WE FIND A VERY MOIST BUT 
TAME ITCZ WITH ONLY SCATTERED MODERATE CONVECTION MAINLY S OF 
AXIS.  

ELSEWHERE AT THE SURFACE...
WHILE MODEL GUIDANCE NO LONGER ORGANIZE LOW PRES ALONG WAVE...
IT DOES FORM IT MORE TO THE E NEAR AREA OF DEEP CONVECTION UNDER 
DIFFLUENT FLOW ALOFT.  LOW PRES CENTER THEN DRIFTS NE INTO 
COOLER WATERS AND STABLE AIR MASS AND WEAKENS.  

HIGH PRES CENTER 1032 MB WELL N OF AREA AT 43N142W COMBINES WITH 
1000 MB LOW PRES OVER NRN CALIFORNIA TO CREATE AREA OF GALE 
FORCE WINDS JUST N OF 32N WITH STRONG NLY WINDS SPILLING INTO 
FORECAST AREA N OF 24N WITH ACCOMPANYING LARGE LONG PERIOD 
SWELLS.  

SW WIND FIELD S OF MONSOON TROUGH COMBINED WITH CROSS 
EQUATORIAL SWELLS ARE CAUSING 8-10 FT SEAS S OF 10N E OF 130W 
LIKELY LASTING THROUGH FORECAST PERIOD. 

$$
WALLY BARNES