000
AXPZ20 KNHC 310248
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN AUG 31 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 
0230 UTC.

...TROPICAL WAVES...

TROPICAL WAVE ALONG 106W 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. 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 09N80W TO 12N97W TO 09N116W TO 
12N133W TO 10N140W. SCATTERED MODERATE CONVECTION FROM 08N-12N 
BETWEEN 85W-95W. SCATTERED MODERATE FROM 07N-10N BETWEEN 
116W-133W.

...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 16N 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 12-13 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 TROUGH LYING 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.

$$
BERG