000 AXPZ20 KNHC 251529 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC FRI AUG 25 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1545 UTC. ...SPECIAL FEATURE... AT 25/1500 UTC...HURRICANE ILEANA WAS CENTERED NEAR 21.6N 116.9W...OR 380 NM W OF THE SOUTHERN TIP OF BAJA CALIFORNIA...MOVING WNW 4 KT. MAXIMUM SUSTAINED WIND SPEED IS 70 KT WITH GUSTS TO 85 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 983 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. ILEANA HAS WEAKENED SLIGHTLY...AS EVIDENCED BY SATELLITE IMAGERY SHOWING CLOUD TOPS WARMING. MAIN CONVECTION IS CONFINED TO WITHIN 80 NM RADIUS OF THE CENTER...WRAPPING FROM TO THE SOUTHERN TO EASTERN SEMICIRCLE OF THE STORM. SHEARING AND DRY AIR ENTRAINMENT IS CONTAINED ON THE WEST SIDE. HOWEVER...WIND SHEAR IS NOT AS STRONG AS EARLIER...AND ALTHOUGH ILEANA WILL CONTINUE TO WEAKEN OVER COOLER WATERS...IT WILL WEAKEN AT A SLOW PACE THROUGH TODAY. ...TROPICAL WAVES... TROPICAL WAVE ALONG 80W MOVING W AT 10 TO 15 KT. LINGERING OVERNIGHT CONVECTION WAS EVIDENT IN THE BAY OF PANAMA AND ALONG THE COLOMBIAN COAST...ALONG THE WAVE AXIS. THIS CONVECTION WILL LIKELY DIMINISH THROUGH THE DAY...THEN REFLARE TONIGHT OFF THE PACIFIC COAST OF WESTERN PANAMA AND COSTA RICA AS THE WAVE MOVES W. LOW PRESSURE CENTER NEAR 9N87W MOVING W AT 10 TO 15 KT. THIS FEATURE WAS AN OPEN WAVE LAST NIGHT WITH EVIDENCE OF A MID LEVEL CIRCULATION. HOWEVER...MORNING VISIBLE SATELLITE IMAGERY AND QUIKSCAT DATA SUGGEST THAT IS HAS CLOSED OFF IN THE LOWER LEVELS. MAIN CONVECTION REMAINS TO THE WEST OF THIS SYSTEM...ALTHOUGH NEW CONVECTION IS DEVELOPING TO THE SOUTH OF THE SYSTEM AND WRAPPING INWARD. TROPICAL WAVE ALONG 104W S OF 15N MOVING W 10-15 KT. THERE IS CYCLONIC ROTATION IN THE MID CLOUDS ABOUT A CENTER NEAR 10N107W. CONVECTION CONTINUES WITH 200 NM OF THE CENTER. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 9N80W 11N110W 13N120W 9N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 90 NM OF AXIS BETWEEN 85W AND 115W. ...DISCUSSION... UPPER LEVEL LOW PRESSURE IS CENTERED NEAR 22N132W...APPROXIMATELY 800 NM W OF THE CENTER OF ILEANA. ASSOCIATED TROUGH AXIS EXTENDS FROM CALIFORNIA COAST TO NEAR 7N137W. THIS IS RESULTING IN A LARGE AREA OF SUBSIDENT DRY AIR W OF 125W. MID/UPPER RIDGING CONTINUES OVER MEXICO...ALLOWING MODERATE TO STRONG UPPER LEVEL EASTERLY WINDS TO S OF 14N. ACTIVE CONVECTION PERSISTS ALONG THE ITCZ ESPECIALLY NEAR AFOREMENTIONED TROPICAL WAVE LOCATIONS. FOR THE FORECAST FOR THE NEXT SEVERAL DAYS...AS ILEANA PROGRESSES TO THE NW AND WEAKENS OVER COOLER WATER...MAIN AREAS TO WATCH ARE THE CONVECTION SPOTS NEAR THE TROPICAL WAVES AND THE CLOSED LOW NEAR 9N87W. GFS SHOWS UPPER SHEAR WILL RELAX ALLOWING CIRCULATIONS TO DEVELOP OVER THE NEXT 48 HOURS. THE GFS PARTICULARLY DEVELOPS THE WAVE NEAR 104W. THIS IS PLAUSIBLE CONSIDERING THIS IN THE AREA OF LEAST UPPER SHEAR CURRENTLY. HOWEVER...THE SYSTEM IS PROGGED TO HAVE VERY SLOW DEVELOPMENT INTO NEXT WEEK AS IT TRACKS INTO MORE UNFAVORABLE CONDITIONS NEAR THE UPPER TROUGH...FURTHER WEST THAN ILEANA'S CURRENT PATH. THE SECOND AREA TO WATCH WILL BE THE CLOSED LOW NEAR 9N87W. THIS IS PROGGED TO CONTINUE TO SLOWLY DEVELOP THROUGH THE NEXT 72 HOURS...ALTHOUGH MOVING NW AND KEEPING WELL OFFSHORE OF THE CENTAM PACIFIC COAST. $$ CHRISTENSEN