000
AXPZ20 KNHC 040321
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED AUG 04 2010

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.

...ITCZ...

ITCZ AXIS ALONG 09N79W TO 07N92W TO 10N103W TO 11N110W TO 
09N118W TO 11N126W TO 10N129W TO 10N138W. SCATTERED MODERATE AND 
ISOLATED STRONG CONVECTION IS WITHIN 60 NM EITHER SIDE OF THE 
AXIS BETWEEN 82W AND 84W. SCATTERED MODERATE AND ISOLATED STRONG 
CONVECTION IS WITHIN 150 NM N OF THE AXIS AND 120 NM S OF THE 
AXIS BETWEEN 107W AND 120W.

...DISCUSSION...

AN UPPER LEVEL ANTICYCLONE IS OVER THE FAR NW WATERS NEAR 
24N137W WITH AN UPPER RIDGE EXTENDING TO THE NE TO NEAR 32N130W 
AND TO THE SW TO 22N140W. MODERATE TO STRONG UPPER LEVEL 
SUBSIDENCE AND AN IMPLIED DRY AIR MASS IS NOTED MAINLY N OF 15N 
AND W OF 125W. ANOTHER UPPER LEVEL ANTICYCLONE IS CENTERED OVER 
THE SOUTH CENTRAL UNITED STATES AND HAS A RIDGE AXIS EXTENDING 
SW ACROSS NORTHERN MEXICO AND THE SOUTHERN BAJA PENINSULA TO 
NEAR 21N123W. IN BETWEEN THE TWO ANTICYCLONES THERE IS AN 
INVERTED TROUGH THAT REACHES FROM 26N125W TO 11N135W. 

EASTERLY/ZONAL FLOW PREVAILS ACROSS THE REMAINDER OF THE 
DISCUSSION AREA IN THE DEEP TROPICS. UPPER LEVEL MOISTURE 
RESULTING FROM ITCZ CONVECTION IS BEING ADVECTED TO THE WEST AS 
A RESULT OF THE PERSISTENT EASTERLY WINDS. AFTERNOON/EVENING 
CONVECTION THAT DEVELOPED OVER MEXICO AND CENTRAL AMERICA IS 
ALSO BEING ADVECTED JUST OFFSHORE INTO THE E PACIFIC WITH THE
EASTERLY FLOW.

AT THE SURFACE...A WEAK AREA OF 1010 MB LOW PRES IS POSITIONED 
ALONG THE ITCZ NEAR 13N108W...OR ABOUT 425 NM SOUTHWEST OF 
MANZANILLO MEXICO...WITH A SURFACE TROUGH EXTENDING FROM 15N107W 
THROUGH THE LOW TO 11N108W. AN EARLIER ASCAT SCATTEROMETER PASS 
INDICATED NE 20 KT WINDS IN THE NW QUADRANT AND S TO SW 20 KT 
WINDS IN THE SE AND S QUADRANTS ALTHOUGH ANY 20 KT WINDS NOW 
APPEAR TO BE CONFINED TO S OF THE ITCZ FROM 05N TO 09N BETWEEN 
105W AND 115W. THIS LOW AND TROUGH ARE PRODUCING AN AREA OF 
DISORGANIZED SHOWERS AND THUNDERSTORMS. THIS SYSTEM IS MOVING 
W-NW AROUND 8 KT AND UPPER LEVEL WINDS ARE EXPECTED TO REMAIN 
UNFAVORABLE FOR DEVELOPMENT. THERE IS A LOW CHANCE OF THIS 
SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

A SURFACE TROUGH EMBEDDED IN THE ITCZ EXTENDS FROM 13N127W TO 
08N128W. SCATTERED MODERATE CONVECTION IS WITHIN 180 NM W OF THE 
TROUGH AXIS. ANOTHER WEAK SURFACE TROUGH IS ABOUT TO EXIT THE 
AREA TO THE W EXTENDING FROM 12N138W TO 08N139W. SCATTERED 
SHOWERS ARE NOTED EITHER SIDE OF THE TROUGH AXIS.

CROSS EQUATORIAL SOUTHERLY SWELLS CONTINUE TO AFFECT THE 
SOUTHERN PORTION OF THE BASIN MAINLY S OF 10N AND WILL CONTINUE 
UP TO 8 TO 9 FT THROUGH 48 HOURS.

$$
LEWITSKY