000
AXPZ20 KNHC 110915
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE AUG 11 2009

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 
0900 UTC.

...SPECIAL FEATURES...

TROPICAL DEPRESSION NINE-E NEAR 15.1N 126.4W OR ABOUT 1000 
NM...1850 KM...SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA 
MOVING WEST OR 270 DEGREES AT 10 KT. MAXIMUM SUSTAINED WINDS ARE 
30 KT WITH GUSTS TO 40 KT. ESTIMATED MINIMUM CENTRAL PRES IS 
1006 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. SHEARING WINDS 
FROM AN UPPER-LEVEL TROUGH WITH AXIS ALONG 125W ARE IMPACTING 
THE TROPICAL CYCLONE. AS A RESULT MOST OF THE CONVECTION IS EAST 
OF THE CENTER WITH SCATTERED MODERATE TO STRONG CONVECTION 
WITHIN 60 NM OF CENTER EXCEPT WITHIN 120 NM IN THE EAST 
QUADRANT. THE SYSTEM IS FORECAST TO BECOME A MINIMAL TROPICAL 
STORM TONIGHT THEN CHANGE LITTLE AS IT CONTINUES TO MOVE WEST.

WEAK LOW 11N109W 1010 MB MOVE WEST 10 TO 15 KT. THIS SYSTEM IS 
PRODUCING A LARGE AREA OF SHOWERS AND THUNDERSTORMS THAT IS 
SOMEWHAT ORGANIZED BY LOW LEVEL CYCLONIC FLOW. SCATTERED 
MODERATE WITH ISOLATED STRONG CONVECTION IS WITHIN 120 NM OVER 
THE SE SEMICIRCLE. FURTHER TO THE NORTH ASSOCIATED WITH THE 
TROPICAL WAVE MENTIONED BELOW SCATTERED MODERATE WITH ISOLATED 
STRONG CONVECTION IS WITHIN 60 NM OF THE POINT 14N108W.
UPPER-LEVEL CONDITIONS ARE EXPECTED TO BECOME MORE FAVORABLE FOR 
DEVELOPMENT OF THIS SYSTEM DURING THE NEXT COUPLE OF DAYS AS IT 
MOVES GENERALLY WESTWARD AROUND 10 TO 15 KT.

...TROPICAL WAVES...

TROPICAL WAVE ALONG 96W N OF 05N MOVE W 10-15 KT. ONLY ISOLATED 
MODERATE CONVECTION IN THE ITCZ IS NEAR THE WAVE AXIS.

TROPICAL WAVE ALONG 108W/109W FROM 06N TO 19N MOVING W 10-15 KT.
THE WAVE HAS AN EMBEDDED LOW MENTIONED ABOVE UNDER SPECIAL 
FEATURES. CONVECTION ASSOCIATED WITH THIS FEATURE IS ALSO 
MENTIONED ABOVE.
 
TROPICAL WAVE FROM 08N141W TO 16N135W MOVING W 10-15 KT. 
SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 60 NM OF THE 
POINT 13N137W. THE CONVECTION SEEMS TO BE SOMEWHAT ORGANIZED BY 
LOW LEVEL CYCLONIC FLOW. THERE IS DIFFLUENT FLOW OVER THIS 
FEATURE. 

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...06N77W 
TO 07N110W TO 09N140W. SCATTERED MODERATE WITH ISOLATED STRONG 
CONVECTION IS WITHIN 90 NM EITHER SIDE OF THE ITCZ AXIS FROM 
112W TO 125W. 

...DISCUSSION...

A RIDGE COVERS THE AREA WEST OF 133W. THE AREA IS DRY AND CLOUD 
FREE SOUTH OF 25N WITH MOIST MIDDLE AND UPPER LEVELS WITH BROKEN 
HIGH CLOUDS NORTH OF 25N. 

EAST OF THE RIDGE A TROUGH WITH AND AXIS ALONG 127W EXTENDS EAST 
TO 117W. THIS AREA IS ALSO DRY AND CLOUD FREE IN THE MIDDLE AND 
UPPER LEVELS. 

FROM 117W TO 95W LARGE RIDGE COVERS THE AREA NORTH OF THE ITCZ. 
THIS AREA ID DIFFLUENT ALOFT WITH WIDESPREAD MULTI LEVEL 
OVERCAST TO BROKEN CLOUDS WITH EMBEDDED AREAS OF CONVECTION. 

TROUGH EXTENDS FROM 95W TO 88W. THIS AREA IS DRY AND CLOUDS FREE 
IN THE MIDDLE AND UPPER LEVELS. 

WEAK RIDGE IS EAST OF 88W WITH DIFFLUENT FLOW ALOFT. THE MIDDLE 
AND UPPER LEVELS ARE MOIST BUT THERE ARE FEW CLOUDS IN THIS 
AREA.

AT THE SURFACE A RIDGE IS LOCATED ROUGHLY N OF 23N W OF 115W.
NE WINDS OF 20 KT ARE NOTED ON THE SOUTHERN PERIPHERY OF THE 
RIDGE W OF 130W. 

GAP WINDS...
NE TO E WINDS OF 20 KT CONTINUE TO FUNNEL THROUGH THE GULF OF 
PAPAGAYO RAISING SEAS TO 8 FT. THESE WINDS ARE FORECAST TO 
CONTINUE THROUGH THE NEXT COUPLE OF DAYS.

CROSS-EQUATORIAL SE SWELLS CONTINUE TO AFFECT THE SOUTHERN 
PORTION OF THE FORECAST AREA MOSTLY S OF 10N. THESE CONDITIONS 
ARE EXPECTED TO GRADUALLY SUBSIDE DURING THE NEXT 24 TO 48 
HOURS.  

$$
LL