000 AXPZ20 KNHC 102156 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC MON AUG 10 2009 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. ...SPECIAL FEATURE... TROPICAL DEPRESSION NINE-E AT 15.1N 124.2W OR ABOUT 1075 NM W-SW OF SOUTHERN TIP OF BAJA CALIFORNIA MOVING W AT 10 KT AT 2100 UTC AUG 10. MAXIMUM SUSTAINED WIND 30 WITH GUSTS TO 40 KT. ESTIMATED MINIMUM CENTRAL PRES 1007 MB. STRONG SHEARING WINDS FROM UPPER LEVEL TROUGH FORCED CONVECTION TO MOVE SE OF CENTER EXPOSING IT IN THE NW CORNER. SCATTERED MODERATE TO STRONG CONVECTION IN SQUALLS WITHIN 90 NM E QUADRANT. LOW LEVEL CIRCULATION FAIRLY SMALL AND HARD FOR MODEL GUIDANCE TO DETERMINE ITS TRACK...BUT DUE TO THE HOSTILE SHEARING NOT EXPECTED TO ABATE SOON THE SYSTEM IS NOT EXPECTED TO INTENSIFY. SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. WEAK LOW PRES 1010 MB AT 11N106W UNDER SMALL UPPER LEVEL ANTICYCLONE PROVIDING MODERATE DIFFLUENCE ALOFT AND ENHANCING CONVECTION AND DEVELOPMENT OF CYCLONIC ORGANIZATION. MODEL GUIDANCE SOLUTION STRENGTHENS SYSTEM WHICH COULD BECOME TROPICAL CYCLONE WITHIN 48 HR OR LESS. ...TROPICAL WAVES... TROPICAL WAVE ALONG 94W N OF 05N MOVING W 10-15 KT HAS LOST MOST OF ITS ASSOCIATED CONVECTION DUE TO ADVERSE UPPER ENVIRONMENT UNDER STRONG AND DRY NE SHEAR ALOFT. WAVE EXPECTED TO APPROACH LESS HOSTILE CONDITIONS LATE IN FORECAST PERIOD WITH BETTER CHANCES OF CONVECTION MAINLY N OF ITCZ. TROPICAL WAVE ALONG 106W N OF 04N MOVING W 10-15 KT HAS EMBEDDED LOW PRES 1010 MB AS MENTION ABOVE UNDER SPECIAL FEATURES. LARGE AREA OF SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 120 NM EITHER SIDE OF WAVE AXIS N OF ITCZ. TROPICAL WAVE FROM 08N140W TO 16N134W MOVING W 15 KT. WAVE AXIS ASSOCIATED WITH MODERATE TO STRONG TRADES AND SCATTERED MODERATE ISOLATED STRONG CONVECTION AS ANTICYCLONE WITH GOOD DIFFLUENT FLOW ALOFT ENHANCES DEVELOPMENT ALONG AND N OF ITCZ1. MODEL GUIDANCE BUILDS THEN MAINTAINS LOW PRES CENTER 1010 MB ON W-SW DRIFT FOR NEXT 48 HR. NEW TROPICAL WAVE JUST CROSSED INTO E PAC FROM WRN CARIBBEAN NOW ALONG 87W N OF 05N. WHILE NOT IN FAVORABLE UPPER LEVEL ENVIRON WAVE BRINGS ABUNDANT MOISTURE FROM WRN CARIBBEAN AND MAINTAINS CONVECTION WITHIN 90 NM EITHER SIDE OF AXIS. WAVE EXPECTED TO ENTER HOSTILE CONDITIONS ALOFT WHICH SHOULD CURTAIL ANY SIGNIFICANT DEVELOPMENT WITHIN NEXT 48 HR. ...ITCZ... AXIS ALONG...07N81W TO 09N97W TO 11N104W TO 07N117W TO 12N135W TO 11N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 100 NM S OF AXIS FROM 113W-116W. SCATTERED MODERATE TO STRONG CONVECTION WITHIN 150 NM S AND 60 NM N OF AXIS FROM 134W-140W. ...DISCUSSION... BROAD ANTICYCLONE CENTERED AT 20N135W MAINTAINS A DRY STABLE ATMOSPHERE OVER AREA N OF 15N W OF 122W. SECOND...AND WEAKER... ANTICYCLONE AT CENTERED AT 10N135W PRODUCES GOOD OUTFLOW FOR CONVECTION ASSOCIATED WITH TROPICAL WAVE ALONG 137W. DEEP LAYER CYCLONE CENTERED AT 26N125W EXTEND DRY SLOT N OF 20N W OF 115W. IT IS THIS DRY STRONG NW FLOW WHICH IS IMPINGING ON T.D. NINE-E AND CURTAILING ITS MORE AGGRESSIVE DEVELOPMENT AND POSSIBLY ENHANCE ITS DEMISE. THIRD UPPER LEVEL ANTICYCLONE OVER MAINLAND MEXICO ADVECTS ABUNDANT TROPICAL MOISTURE FROM CONTINENT INTO E PAC FEEDING IT TO TROPICAL WAVE ALONG 106W WHILE ITS DRIER STRONGER NE WINDS SHEAR N PORTIONS OF WAVE ALONG 94W. ELSEWHERE AT THE SURFACE... FRESH TO STRONG TRADE WINDS CROSS FROM CARIBBEAN SEA THROUGH GULF OF PAPAGAYO INTO E PAC WITH FRESH TO STRONG NE-E WINDS E OF 92W BUT DIMINISHING THROUGH NEXT 48 HR. CROSS EQUATORIAL SWELLS BUILD SEAS TO 9 FT S OF 07N FROM 95W-120W SUBSIDES GRADUALLY THROUGH NEXT 48 HR. $$ WALLY BARNES