000 AXPZ20 KNHC 090936 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC TUE SEP 09 2008 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 0730 UTC. ...SPECIAL FEATURES... TROPICAL STORM LOWELL IS CENTERED NEAR 20.7N 112.9W...OR ABOUT 120 MILES NW OF SOCORRO ISLAND AND ABOUT 215 MILES SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA AT 0900 UTC. LOWELL IS MOVING NW OR 315 DEG AT 7 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WINDS ARE 45 KT WITH GUSTS TO 55 KT. NUMEROUS MODERATE TO STRONG CONVECTION CAN BE FOUND WITHIN 150 NM NW AND 300 NM SW QUADRANTS OF LOWELL. THE CONVECTION IS SHEARED TO THE W OF THE CENTER DUE TO STRONG E UPPER LEVEL FLOW OVER THE SYSTEM. LOWELL IS FORECAST TO MOVE N TOWARD SOUTHERN BAJA CALIFORNIA OVER THE NEXT TWO DAYS. PLEASE REFER TO THE LATEST NHC PUBLIC ADVISORY UNDER AWIPS HEADER MIATCPEP3 OR WMO HEADER WTPZ33 KNHC AND THE FULL FORECAST ADVISORY UNDER AWIPS HEADER MIATCMEP3 OR WMO HEADER WTPZ23 KNHC FOR MORE DETAILS. ...ITCZ... ITCZ AXIS CAN BE FOUND FROM 09N79W TO 06N90W TO 10N105W TO 14N115W TO 08N140W. SCATTERED MODERATE CONVECTION LIES WITHIN 270 NM S OF AXIS BETWEEN 123W AND 132W AS WELL AS WITHIN 120 NM OF AXIS BETWEEN 81W AND 88W. ...DISCUSSION... SUBTROPICS... MID LEVEL TROUGH ALONG 120W WILL CONTINUE TO AMPLIFY OVER THE NEXT FEW DAYS. IN ADDITION TO STEERING LOWELL TO THE NE...THIS TROUGH WILL ATTRACT SOME OF THE ENERGY ASSOCIATED WITH THE MID LEVEL LOW CURRENTLY E OF THE HAWAIIAN ISLANDS WHICH IS EXPECTED TO BE FORCED NE ITSELF BY ANOTHER AMPLIFYING TROUGH APPROACHING FROM ITS NW. OVERALL...THIS PATTERN WILL SUPPORT MEAN MID LEVEL TROUGHING OVER THE N WATERS OVER THE NEXT FEW DAYS. ALOFT... EXPECT THE UPPER RIDGE AXIS TO REMAIN STRETCHED FROM NEAR 21N140W TOWARD THE MOUTH OF THE GULF OF CALIFORNIA. THE AMPLIFYING TROUGH ALONG 120W WILL FURTHER SEPARATE THE ANTICYCLONES ON EITHER EDGE OF THIS RIDGE AXIS. PRIOR TO THE ARRIVAL OF THE TROUGH...UPPER LEVEL DIFFLUENCE IS EXPECTED OVER THE NEXT 48 HOURS OVER W MEXICO BETWEEN 20N AND 25N IN THE REGION OF MOIST SOUTHERLY LOW LEVEL FLOW ON THE E SIDE OF LOWELL...INCREASING THE PROBABILITY OF CONVECTION THERE OVER THE NEXT FEW DAYS. ELSEWHERE N OF 15N W OF 125W DRY CONDITIONS ARE GENERALLY EXPECTED. TROPICS... THE UPPER LEVEL LOW CURRENTLY PASSING W THROUGH NICARAGUA WILL WEAKEN AND LIKELY LOSE ITS CLOSED CIRCULATION AS IT PUSHES INTO THE PACIFIC. WHILE RELATIVELY DRY CONDITIONS CAN CURRENTLY BE FOUND OVER MUCH OF CENTRAL AMERICA AND THE ADJACENT PACIFIC COASTAL WATERS FROM 10N TO 20N E OF 100W...WITH MOST OF THE AVAILABLE MOISTURE BEING OCCUPIED TO THE NW WITH LOWELL...THERE IS STILL PLENTIFUL LOW LEVEL MOISTURE S OF 10N AND E OF 90W FOR THE DIFFLUENT FLOW ON THE SE EDGE OF THIS UPPER LEVEL LOW/TROUGH TO TAP INTO AS IT PUSHES INTO THE PACIFIC. THEREFORE...EXPECT A HIGHER PROBABILITY OF CONVECTION S OF 10N AND E OF 90W THIS AFTERNOON INTO WED. ELSEWHERE...FAIRLY STRONG NE TO E MID TO UPPER FLOW ON THE S PERIPHERY OF SUBTROPICAL RIDGING COVERS MUCH OF THE TROPICS AND IS INHIBITING DEEP CONVECTION IN THE REGION. CROSS-EQUATORIAL SW SWELL IS PRODUCING A LARGE AREA OF 8-11 FT SEAS BETWEEN 92W AND 130W. THIS SWELL EVENT IS EXPECTED TO SLOWLY SUBSIDE OVER THE NEXT FEW DAYS. $$ SCHAUER CLARK