000
AXPZ20 KNHC 310932
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN AUG 31 2008

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0915 UTC.

...TROPICAL WAVES...

TROPICAL WAVE ALONG 107 S OF 18N MOVING W 5-10 KT. THE WAVE 
REMAINS EMBEDDED WITHIN THE MONSOON TROUGH WITH LOW-LEVEL 
SW/WESTERLY WINDS REACHING AS FAR N AS 15N. THIS PATTERN HAS 
CAUSED THE WAVE TO SLOW DOWN CONSIDERABLY WITH THE POSSIBILITY 
OF A SURFACE LOW BEGINNING TO FORM ALONG THE AXIS NEAR 16N AS 
INDICATED BY EDGE OF THE SWATH DATA ON THE 0154 UTC QUIKSCAT 
PASS. THE WAVE IS EXPECTED TO CONTINUE MOVING SLOWLY TO THE 
W...BUT THE LOW THAT IS FORMING WILL RETROGRADE ESE AT ABOUT 5 
KT DUE TO THE PREVAILING FLOW. SCATTERED MODERATE/ISOLATED 
STRONG CONVECTION IS FROM 10N-16N BETWEEN 98W-112W.
     
...ITCZ...

ITCZ AXIS IS CENTERED FROM 10N86W TO 12N100W TO 10N120W TO 
09N140W. SCATTERED MODERATE TO STRONG WITHIN 90-120 NM N OF THE 
AXIS BETWEEN 87W AND 91W AND FROM 12N TO 15N BETWEEN 102W AND 
106W. SCATTERED MODERATE ISOLATED STRONG WITHIN 240 NM S OF THE 
AXIS BETWEEN 89W AND 105W...AND WITHIN 90 NM S OF THE AXIS 
BETWEEN 122W AND 127W. 

...DISCUSSION...

TROPICS...
EXTENSIVE UPPER LEVEL ANTICYCLONE OVER THE SUBTROPICS CONTINUES 
TO PRODUCE MAINLY NE/E FLOW ALOFT OVER THE TROPICAL PACIFIC 
WATERS. THE MONSOON TROUGH IS STILL ACTIVE OFF THE MEXICAN COAST 
AND LOW-LEVEL SW/WLY WINDS HAVE PUSHED AS FAR N AS 15N MAINLY E 
OF 120W. LOW-LEVEL CONVERGENCE IS PRODUCING SCATTERED TSTM 
ACTIVITY MAINLY S OF THE TROUGH AXIS...LARGELY DUE TO SPEED 
CONVERGENCE...AND A 30 KT NE JET ALOFT IS AIDING WITH UPPER 
LEVEL DIFFLUENCE. THE SURFACE WIND FIELD...COMBINED WITH SLY 
SWELLS COMING FROM THE SOUTHERN HEMISPHERE...IS PRODUCING 8-10 
FT SEAS OVER THE CENTRAL PART OF THE PACIFIC REGION...AND THESE 
SEAS COULD BUILD AS HIGH AS 12 FT OVER THE NEXT 24-48 HRS. 
ELSEWHERE...CONVECTION IS ORIENTED IN A NARROWER BAND NEAR THE 
ITCZ AXIS W OF 120W.

SUBTROPICS...
A LARGE UPPER LEVEL HIGH IS CENTERED WSW OF THE BAJA PENINSULA 
NEAR 22N125W AND CONTINUES TO BE BOUNDED BY A SHARP UPPER TROUGH 
AXIS STRETCHING FROM SOUTHERN CALIFORNIA DOWN THE GULF OF 
CALIFORNIA TO 23N108W...AND ANOTHER WEAK TROUGH EXTENDING NE/SW 
ACROSS 30N140W. A WEAK COLD FRONT...ESSENTIALLY A NORTHERLY WIND 
SURGE...HAS REACHED NEAR 30N FROM THE N WITH N/NE WINDS EXPECTED 
TO INCREASE OVER THE NORTHERN WATERS OVER THE NEXT 48 HRS. 
NORTHERLY SWELLS ARE ALSO EXPECTED TO CROSS 30N WITH HIGHEST 
SEAS UP TO 13 FT.

$$
COBB