000
AXPZ20 KNHC 082131
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT SEP 08 2007

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 87W N OF 4N MOVING W 15 KT. SCATTERED 
MODERATE CONVECTION WITHIN 150 NM E OF WAVE FROM 5N AND 7N.

TROPICAL WAVE ALONG 110W N OF 5N MOVING W 10-15 KT. NO 
SIGNIFICANT CONVECTION NOTED WITH THIS WAVE.

TROPICAL WAVE ALONG 120W FROM 4N-17N MOVING W 10-15 KT. NO 
SIGNIFICANT CONVECTION.

...ITCZ...
ITCZ AXIS CENTERED ALONG 9N84W 8N94W 13N100W 11N116W 13N124W 
9N140W. SCATTERED MODERATE CONVECTION FROM 60 TO 180 NM S OF THE 
AXIS BETWEEN 82W AND 86W. SCATTERED MODERATE CONVECTION WITHIN 
60 AND 180 NM S OF THE AXIS. SCATTERED MODERATE WITHIN 60 NM N 
OF AXIS BETWEEN 130W AND 135W. 

...DISCUSSION...
E OF 110W...MAIN FORECAST ISSUE IN THE NEAR TERM IS THE 
PERSISTENCE OF THE REMNANT LOW OF FELIX...NOW OFF THE MEXICAN 
COAST NEAR MANZANILLO. THIS LOW WAS ABLE TO SURVIVE MOVING 
THROUGH THE CENTRAL MEXICAN MOUNTAINS DUE TO UPPER SUPPORT 
PROVIDED BY AN UPPER TROUGH TO THE NW OF THE LOW...NOW OVER THE 
SOUTHERN GULF OF CALIFORNIA. THE LOW SHOWS A WELL DEFINED 
CIRCULATION ON SATELLITE IMAGERY...BUT THIS MAY BE MOSTLY IN THE 
MID LEVELS. SCATTEROMETER ALONG WITH LAND BASED AND SHIP 
OBSERVATIONS SHOW WINDS AROUND ANY SURFACE LOW IS STILL FAIRLY 
WEAK. THE LOW MAY INTENSIFY SLIGHTLY SHORTLY IN THE NEAR 
TERM...BUT WITH THE UPPER SUPPORT WANING...NO SIGNIFICANT 
REDEVELOPMENT IS EXPECTED AT THIS TIME. UPPER RIDGING BUILDING 
BEHIND THE UPPER TROUGH IS PROVIDING NELY SHEAR ACROSS SRN 
MEXICO AND NRN CENTRAL AMERICA. SLY CONVERGENT FLOW HAS 
INCREASED SLIGHTLY ALONG THE ITCZ S OF THE REMNANT LOW OF FELIX. 
HOWEVER...CONVECTION REMAINS LIMITED DUE TO MODERATE NELY SHEAR. 
SHEAR IS CONSIDERABLY LESS FURTHER S...OVER COSTA RICA AND 
PANAMA...WHERE CONVECTION HAS INCREASED SLIGHTLY ALONG THE ITCZ. 
RESIDUAL 8 FT SWELL PERSISTS E OF THE GALAPAGOS...ALTHOUGH WILL 
LIKELY DIMINISH OVER THE NEXT 24 HOURS. NWLY FLOW WILL LIKELY 
INCREASE OFF THE BAJA COAST SUN INTO MON AS SURFACE HIGH PRES 
BUILDS TO THE W.
  
W OF 110W...BROAD UPPER TROUGH EXTENDS FROM 30N130W TO 
19N122W...MAINTAIN FAIRLY DRY AIR ACROSS MOST OF THE AREA. S OF 
THIS...UPPER RIDGE EXTENDS FROM CENTRAL MEXICO TO 16N123W TO 
22N140W. SELY FLOW ALOFT ON THE S SIDE OF THIS RIDGE AXIS IS 
ENHANCING SOME CONVECTION ALONG THE ITCZ AS MENTIONED ABOVE. 
OTHERWISE...DRY AND SUBSIDENT AIR PREVAILS.  SURFACE HIGH PRES 
1016 MB WILL IS CENTERED NEAR 26N120W...WITH A WEAK TROUGH TO 
THE W EXTENDING FROM 30N124W TO 24N127W. MODERATE TO FRESH NELY 
FLOW IS EVIDENT ON SCATTEROMETER AND SHIP OBSERVATIONS PUSHING 
INTO THE AREA W OF THE TROUGH...ACCOMPANIED BY UP TO 10 FT 
SWELL. THIS WILL GRADUALLY DIMINISH THROUGH MON. 

$$
CHRISTENSEN