000
AXPZ20 KNHC 050323
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI SEP 05 2008

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

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

...ITCZ...

ITCZ AXIS IS CENTERED IS CENTERED FROM 10N86W TO 11N100W TO 
12N117W TO 07N140W. NUMEROUS MODERATE/ISOLATED STRONG CONVECTION 
FROM 06N-15N BETWEEN 82W-105W. NUMEROUS MODERATE/ STRONG FROM 
13N-19N BETWEEN 103W-108W.

...DISCUSSION...

TROPICS...
A STRONG MONSOON TROUGH LIES JUST OFFSHORE THE COAST OF MEXICO 
AND CENTRAL AMERICA...EXTENDING ROUGHLY FROM COSTA RICA UP THE 
COAST TO PUERTO VALLARTA MEXICO. EARLIER QUIKSCAT DATA INDICATED 
WIDESPREAD...ENHANCED SW TO W WINDS S OF THE TROUGH AXIS OVER A 
LARGE PART OF THE TROPICAL E PACIFIC W OF 110W. LOW-LEVEL SPEED 
CONVERGENCE AND WEAK CYCLONIC SHEAR ALONG THE AXIS ARE PRODUCING 
SCATTERED CONVECTION ALONG THE LENGTH OF THE TROUGH AS WELL AS 
OVER COASTAL SECTIONS OF SOUTHERN MEXICO. A MORE CONCENTRATED 
AREA OF CONVECTION WITH CLOUD TOP TEMPERATURES TO -70C TO -80C 
HAS FORMED IN ASSOCIATION WITH A SHARP CYCLONIC TURNING NOTED IN 
EARLIER QUIKSCAT DATA NEAR 15N102W...WHICH MAY BE A PRECURSOR
TO A BROAD AREA OF SURFACE LOW PRESSURE. ALTHOUGH THESE CLOUD 
TOPS HAVE COLLAPSED THIS EVENING...GLOBAL MODELS SHOW LOW 
PRESSURE PERSISTING OVER THIS AREA WHILE HEADING ON A MOSTLY W 
TO WNW COURSE AT 5 TO 10 KT OVER THE NEXT FEW DAYS.  SIMILAR TO 
THE LAST TWO SYSTEMS...JULIO AND KARINA...THIS NEXT PROSPECT FOR 
DEVELOPMENT WILL HAVE TO CONTEND WITH STRONG NE TO E VERTICAL 
SHEAR...WHICH COULD HAMPER DEVELOPMENT.

W OF 115W...THE ITCZ AXIS IS MORE WELL-DEFINED DUE TO PRONOUNCED 
CONVERGENCE BETWEEN THE CROSS-EQUATORIAL FLOW AND A RESUMPTION 
OF EASTERLY TRADES. HOWEVER...LIMITED ATMOSPHERIC MOISTURE ALOFT 
IS PRODUCING VIRTUALLY NO ORGANIZED DEEP CONVECTION. IN GENERAL 
...UPPER LEVEL WINDS ARE NE/EASTERLY OVER THE REGION...ADVECTING 
MOISTURE OUTFLOW FROM THE COASTAL CONVECTION WWD TO NEAR 120W.

ELSEWHERE...SW 6-9 FT SWELLS HAVE BEEN SUBSIDING ACROSS MUCH OF 
THE AREA...EXCEPT OVER NEAR AND S OF THE MONSOON TROUGH AXIS 
WHERE STRONG WINDS HAVE KEPT WAVE HEIGHTS LOCALLY HIGHER. 
HOWEVER...A NEW SE SWELL TRAIN IS ALREADY CROSSING THE EQUATOR 
OVER THE SW AND A GROUP OF SW SWELL SHOULD BEGIN ARRIVING 
TONIGHT AND FRI OVER THE ENTIRE REGION. THE ACTIVE SWELL REGIME 
COMBINED WITH ENHANCED MONSOONAL FLOW SHOULD CONTINUE TO FAVOR 8 
TO 11 FT WAVE HEIGHTS OVER NEARLY THE ENTIRE TROPICAL PACIFIC 
WATERS.


SUBTROPICS...
A STRONG UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 24N113W WITH 
AN ELONGATED RIDGE AXIS EXTENDING FROM N/CNTRL MEXICO TO 
20N140W. AN UPPER-LEVEL TROUGH AXIS CONTINUES TO SIT OVER THE NW 
WATERS FROM 30N136W TO 25N140W AND CONFLUENCE CONTINUES TO 
PRODUCE MODERATE/STRONG SUBSIDENCE NW OF A LINE FROM THE SRN TIP 
OF BAJA CALIFORNIA TO 10N140W. THE REMNANTS OF TROPICAL 
DEPRESSION KARINA ARE VISIBLE NEAR 20N114W OR ABOUT 290 NM SW OF 
THE SOUTHERN TIP OF BAJA CALIFORNIA PENINSULA BUT IS NOT 
PRODUCING ANY DEEP CONVECTION. WHAT REMAINS LARGELY CONSISTS OF 
A SWIRL OF LOW CLOUDS WITH SOME EMBEDDED SHOWERS WITHIN 120 NM 
OF ITS CENTER.

GALE FORCE WINDS OFF THE CALIFORNIA COAST CONTINUE TO PRODUCE 
8-11 FT N/NORTHEASTERLY SWELLS WHICH HAVE PROPAGATED INTO THE 
AREA NW OF A LINE FROM 30N125W TO 22N140W. THESE SWELLS ARE 
EXPECTED TO SUBSIDE WITHIN THE NEXT 24 HRS...LEAVING A SMALL 
AREA OF LINGERING SWELLS OVER THE NW PART OF THE AREA FOR THE 
NEXT COUPLE OF DAYS.

$$
KIMBERLAIN/BERG