000
AXPZ20 KNHC 110325
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE AUG 11 2009

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 
0300 UTC.

...SPECIAL FEATURES...
AT 11/0300 UTC...TROPICAL DEPRESSION NINE-E IS NEAR 15.1N 125.4W 
OR ABOUT 995 NM...1845 KM...WEST-SOUTHWEST OF THE SOUTHERN TIP 
OF BAJA CALIFORNIA MOVING WEST OR 275 DEGREES AT 10 KT. MAXIMUM 
SUSTAINED WINDS ARE 30 KT WITH GUSTS TO 40 KT. ESTIMATED MINIMUM 
CENTRAL PRES IS 1007 MB. SEE LATEST NHC FORECAST/ ADVISORY UNDER 
AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. 
STRONG SHEARING WINDS FROM AN UPPER-LEVEL TROUGH WITH AXIS ALONG 
125W ARE IMPACTING THE TROPICAL CYCLONE WITH THE CENTER TOTALLY 
EXPOSED TO THE W OF THE DEEP CONVECTION. THE DEPRESSION IS 
STEERED BY THE LOW-LEVEL EASTERLY FLOW DUE TO THE THE 
INCREASINGLY SHALLOW NATURE OF THIS SYSTEM EXPECTED TO BECOME A 
REMNANT LOW IN ABOUT 72 HOURS OR SO.  

A WEAK LOW PRES 1010 MB...ASSOCIATED WITH A TROPICAL WAVE...HAS 
DEVELOPED NEAR 12N106W. THIS SYSTEM IS PRODUCING A LARGE AREA OF 
DISORGANIZED SHOWERS AND THUNDERSTORMS. 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 95W N OF 05N MOVING W 10-15 KT. NO DEEP 
CONVECTION IS ASSOCIATED WITH THIS SYSTEM. 

TROPICAL WAVE ALONG 106W N OF 04N MOVING W 10-15 KT HAS EMBEDDED 
LOW PRES 1010 MB AS MENTION ABOVE UNDER SPECIAL FEATURES. A 
LARGE AREA OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION 
IS ASSOCIATED WITH THIS FEATURE.  

TROPICAL WAVE FROM 08N140W TO 15N136W MOVING W NEAR 15 KT. 
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS NEAR THE 
INTERSECTION OF THE WAVE WITH THE ITCZ. AN EARLIER ASCAT PASS 
INDICATED S WINDS OF 20 KT JUST S OF THE ITCZ TO 10N AND W OF 
135W. MODEL GUIDANCE SUGGESTS THE DEVELOPMENT OF A WEAK 1010 MB 
LOW PRES ALONG THE WAVE AXIS.  
  

...ITCZ...
THE ITCZ AXIS IS ALONG 06N78W TO 11N104W TO 08N120W TO 13N137W. 
SCATTERED MODERATE WITHIN 160 NM S OF AXIS FROM 86W TO 95W. 
SIMILAR CONVECTION IS FOUND NEAR 07N122W...AND NEAR 06N124W. 
SCATTERED MODERATE TO ISOLATED STRONG WITHIN 100 NM N OF AXIS W 
OF 137W. 

...DISCUSSION...

W OF 115W...
A RIDGE/TROUGH/RIDGE PATTERN ALOFT DOMINATES MUCH OF THE AREA. A 
RIDGE COVERS THE W PORTION OF THE FORECAST AREA WHILE THE TROUGH 
AXIS IS ALONG 125W EXTENDING FROM AN UPPER-LEVEL LOW NEAR 
27N125W TO 15N125W. ANOTHER UPPER-LEVEL ANTICYCLONIC CIRCULATION 
IS CENTERED OVER NW MEXICO EXTENDING A RIDGE MAINLY SOUTH TO 
NEAR 10N AND E OF 115W. AT THE SURFACE A RIDGE IS LOCATED 
ROUGHLY N OF 20N W OF 120W. 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 9 FT. THESE WINDS ARE FORECAST TO 
DIMINISH TO 20 KT LATE TODAY.

CROSS-EQUATORIAL SE SWELLS CONTINUE TO AFFECT THE SOUTHERN 
PORTION OF THE FORECAST AREA PARTICULARLY S OF 10N BETWEEN 100W 
AND 110W. THESE CONDITIONS ARE EXPECTED TO GRADUALLY SUBSIDE 
DURING THE NEXT 24 TO 48 HOURS.  

$$
GR