000
AXPZ20 KNHC 021557
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE SEP 02 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 1445 UTC.

...SPECIAL FEATURE...
PREVIOUS LOW PRES HAS INTENSIFIED WITH CYCLONIC TURNING TAKING A 
HOLD IN SPITE OF ADVERSE UPPER LEVEL ENVIRONMENT.  TROPICAL 
STORM KARINA AT 19.3N111.5W 1000 MB MOVING W-NW AT 8 KNOTS.  
SCATTERED TO NUMEROUS STRONG DEEP CONVECTION CONFINED TO WITHIN 
150 NM OF CENTER IN W SEMICIRCLE AS ELY WIND SHEAR CURTAILS ITS 
CHANCES OF FURTHER DEVELOPMENT.  COOL SEA SURFACE TEMPERATURES 
AND CONTINUOUS SHEAR EXPECTED TO CURTAIL FURTHER DEVELOPMENT 
KEEPING KARINA AS MINIMAL TROPICAL STORM AND SHOULD WEAKEN AFTER 
24-36 HRS.

...ITCZ...
ITCZ AXIS ALONG 10N84W TO 11N108W TO 09N120W TO 07N140W.  
SCATTERED MODERATE WITHIN 120 NM S OF AXIS FROM 87W-137W.

...DISCUSSION...
REINFORCED MID-UPPER LEVEL ANTICYCLONE CENTERED JUST W OF TIP OF 
BAJA CALIFORNIA AT 25N115W EXTEND W ALONG 22N-23N TO 21N136W.
VERY DRY AIR MASS UNDER RIDGE UMBRELLA N OF 23N AND N OF 10N W 
OF 120W DUE TO MODERATE TO STRONG SUBSIDENCE CURTAILING MOST 
SIGNIFICANT DEEP CONVECTION FROM DEVELOPING...ALBEIT TROPICAL 
STORM KARINA SITTING AT THE EDGE WITH LARGE SWATH OF MOIST AIR.  
MAIN TROPICAL MOISTURE SWATH S OF ITCZ AND ASSOCIATED WITH 
MONSOONAL TROUGH N OF 13N E OF 100W.

LARGE AMPLITUDE LONGWAVE TROUGH AXIS FROM 32N133W TO 14N140W 
EXTEND DRY SLOT TO WRN FRINGES OF FORECAST REGION. 

ELSEWHERE AT THE SURFACE...
HIGH PRES CENTER 1029 MB AT 39N141W HAS RIDGE COVERING AREA N OF 
22N113W WITH KARINA RIGHT AT ITS EDGE.  LOW PRES TROUGH OVER 
COAST OF NRN CALIFORNIA PRODUCING N GALE FORCE WINDS N OF 
FORECAST AREA WHICH SPILL INTO E PAC S OF 32N WITH 20-25 KT 
WINDS AND 9 FT  N-NE WINDS OF 20 KT OVER N AND NW PORTIONS OF 
AREA WITH SEAS UP TO 13 FT IN NE SWELL.  THESE CONDITIONS 
FORECAST TO SLOWLY SUBSIDE OVER NEXT 48 HOURS.

SW WIND FIELD S OF MONSOON TROUGH COMBINED WITH CROSS EQUATORIAL 
SWELLS CAUSING 8-11 FT SEAS S OF ITCZ FROM 91W-122W.  CONDITIONS 
LIKELY LAST THROUGH THROUGH FORECAST PERIOD BEFORE SUBSIDING.  

$$
WALLY BARNES