000
AXPZ20 KNHC 241612 CCA
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1540 UTC THU AUG 24 2006

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1515 UTC.

...SPECIAL FEATURES...

AT 24/1500 UTC...HURRICANE ILEANA WAS CENTERED NEAR 20.5N 
114.9W...OR 320 NM WSW OF THE SOUTHERN TIP OF BAJA 
CALIFORNIA...MOVING WNW 9 KT. MAXIMUM SUSTAINED WIND SPEED IS 85 
KT WITH GUSTS TO 105 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 
973 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS 
MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. 

...TROPICAL WAVES...

TROPICAL WAVE ALONG 86W N OF 3N MOVING W 10-15 KT. REMNANT 
NOCTURNAL CONVECTION PERSISTS ALONG THIS WAVE OFF THE PACIFIC 
COAST OF COSTA RICA...WHERE THE WAVE INTERSECTS THE ITCZ. IR 
IMAGERY SHOWS TOPS ARE WARMING AS THE NIGHTTIME CONVECTION 
WEAKENS. HOWEVER...TRENDS ON SATELLITE IMAGERY ALSO SHOWS 
ADDITIONAL CONVECTION CONTINUING MORE TO THE WEST ALONG WITH 
WAVE MOVEMENT.

TROPICAL WAVE ALONG 102W S OF 15N MOVING W 10-15 KT. ACTIVE 
CONVECTION IS FLARING ALONG AND TO THE WEST OF THIS WAVE. IN 
ADDITION...ANIMATED IR IMAGERY CONTINUES TO SHOW INDICATIONS OF 
MID LEVEL ROTATION JUST TO THE WEST. RECENT QUIKSCAT IMAGERY 
DEFINES A CYCLONIC TURNING NEAR 10N99W...ALONG THE ITCZ.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 9N84W 10N99W 19N114W 12N122W 9N140W. 
ISOLATED MODERATE CONVECTION NEAR 9N101W 11N103W 12N117W...AND 
ALONG THE COLOMBIAN PACIFIC COAST. 

SCATTERED STRONG CONVECTION WITHIN 120NM OF 8N85W. 

...DISCUSSION...

FORECAST FOR ILEANA HAS THE HURRICANE ENCOUNTERING COOLER WATERS 
AND INCREASING SHEAR...AND THUS WEAKENING OVER THE NEXT COUPLE 
OF DAYS AS IT MOVES NE. THE SHEARING WILL BE PROVIDED BY A 
PROMINENT UPPER LEVEL LOW PRESSURE SYSTEM CENTERED NEAR 20N130W. 
ASSOCIATED TROUGH EXTENDS FROM SOUTHERN CALIFORNIA TO 9N140W. 
DRY AIR SUBSIDENCE IS EVIDENT ALONG THE TROUGH LINE W OF ILEANA. 
MEANWHILE...AN MID/UPPER RIDGE OVER NRN MEXICO WILL MAINTAIN 
ILEANA ON ITS WSW COURSE. 

CONDITIONS ARE FAVORABLE FOR THE CONVECTION NEAR TROPICAL WAVE 
NEAR 101W TO PERSIST OVER THE NEXT SEVERAL DAYS. GFS AND NOGAPS 
SHOW A WEAK CIRCULATION FORMING WHERE QUIKSCAT DATA ARE SHOWING 
STRONG CYCLONIC TURNING. MOVEMENT WILL BE SLOW HOWEVER AS THIS 
SYSTEM MIGRATES TOWARD AN AREA OF WEAK STEERING FLOW SE OF THE 
DEPARTING ILEANA. GFS AND NOGAPS ALSO DEVELOP A WEAK CIRCULATION 
ALONG THE TROPICAL WAVE NEAR 86W...BUT KEEP IT WEAK AS IT MOVES 
NW ALONG THE CENTAM PACIFIC COAST.

OTHERWISE...SOUTHERLY 10 TO 15 KT CROSS EQUATORIAL FLOW WILL 
PERSIST SOUTH OF 8N FOR THE NEXT SEVERAL DAYS ALONG WITH 
SOUTHERLY SWELL OF 7 TO 8 FT.

$$
EC