000
AXPZ20 KNHC 312157
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN AUG 31 2008

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2115 UTC.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 108W FROM 08N-17N MOVE W 10 KT CONTINUES 
WITH MINOR CONVECTION ALONG AXIS N OF 15N WHILE CLUSTERS OF DEEP 
CONVECTION REMAIN FAR BEHIND UNDER AREA OF MODERATE DIFFLUENCE 
AND WEAK SURFACE TROUGH.  WAVE EMBEDDED WITHIN SURFACE MONSOON 
TROUGH AND UNDER ELY SHEAR ALOFT CURTAILING SIGNIFICANT CYCLONIC 
ORGANIZATION.  MODEL GUIDANCE NO LONGER ASSOCIATED DEVELOPMENT 
OF LOW PRES CENTER ALONG WAVE.  

...ITCZ...
ITCZ AXIS ALONG 10N86W TO 11N94W TO 12N102W TO 10N113W TO 
08N126W TO 08N140W.  SCATTERED MODERATE CONVECTION WITHIN 120 NM 
S OF ITCZ FROM 110W TO 120W AND WITHIN 30 NM OF AXIS W OF 130W.

...DISCUSSION...
BROAD COMPLEX UPPER LEVEL RIDGE WITH ANTICYCLONIC CENTERS AT 
23N104W...22N120W AND 21N127W.  RIDGE STRETCHES ALONG 20N-22N 
E-W ACROSS ENTIRE E PAC.  ASSOCIATED MODERATE TO STRONG 
SUBSIDENCE MAINTAINS VERY DRY AIR MASS N OF 20N W OF 110W AND 
FROM 13N20N W OF 115W.  MODERATE STEADY NE-E FLOW AND ELY SHEAR 
CURTAILS ANY SIGNS OF DEEP CONVECTION.  ONLY AREA OF DEEP 
CONVECTION UNDER MODERATE DIFFLUENT FLOW NEAR 15N104W.  VERY 
MOIST BUT TAME ITCZ WITH ONLY SCATTERED MODERATE CONVECTION 
MAINLY S OF AXIS.  

ELSEWHERE AT THE SURFACE...
MODEL GUIDANCE NO LONGER ORGANIZE LOW PRES ALONG WAVE...IT DOES 
FORM IT EMBEDDED IN WEAK TROUGH NEAR AREA OF DEEP CONVECTION AT 
104W UNDER DIFFLUENT FLOW ALOFT.  LOW PRES CENTER THEN DRIFTS NE 
INTO COOLER WATERS AND STABLE AIR MASS AND WEAKENS.  

HIGH PRES CENTER 1031 MB WELL N OF AREA AT 41N140W COMBINES WITH 
997 MB LOW PRES OVER NEVADA TO CREATE AREA OF GALE FORCE WINDS 
ALONG COAST OF CALIFORNIA 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