000 ABPZ20 KNHC 172343 TWOEP TROPICAL WEATHER OUTLOOK NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 500 PM PDT THU SEP 17 2009 FOR THE EASTERN NORTH PACIFIC...EAST OF 140 DEGREES WEST LONGITUDE.. THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON TROPICAL STORM MARTY...LOCATED ABOUT 305 MILES SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA. AN AREA OF LOW PRESSURE LOCATED ABOUT 150 MILES WEST-SOUTHWEST OF ZIHUATANEJO MEXICO IS PRODUCING LIMITED SHOWER AND THUNDERSTORM ACTIVITY NEAR THE CENTER OF CIRCULATION. HOWEVER...ENVIRONMENTAL CONDITIONS STILL APPEAR FAVORABLE FOR DEVELOPMENT AS THIS SYSTEM MOVES WEST-NORTHWESTWARD AROUND 10 MPH DURING THE NEXT COUPLE OF DAYS. THERE IS A MEDIUM CHANCE...30 TO 50 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE NEXT 48 HOURS. $$ FORECASTER BERG