000 WTPZ45 KNHC 060235 TCDEP5 TROPICAL DEPRESSION FIVE-E DISCUSSION NUMBER 2 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP052008 800 PM PDT SAT JUL 05 2008 SATELLITE IMAGERY AND EARLIER ASCAT DATA SUGGEST THAT TROPICAL DEPRESSION FIVE-E HAS A STRUCTURE SIMILAR TO THE MONSOON CYCLONES OF THE WESTERN NORTH PACIFIC AND NORTH INDIAN OCEANS. THE SCATTEROMETER DATA SHOWED AN AREA OF 20-25 KT WINDS ABOUT 70-80 N MI FROM THE CENTER OF THE CYCLONE...AND A SECOND LARGE AREA OF 20-25 KT WESTERLY WINDS WELL TO THE SOUTH AND SOUTHWEST OF THE CENTER. THE DEPRESSION IS PRODUCING WIDESPREAD STRONG...BUT DISORGANIZED...CONVECTION. SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB REMAIN 25 KT...SO THAT REMAINS THE INITIAL INTENSITY. THE CENTER IS HARD TO PINPOINT...AND THE INITIAL MOTION IS A RATHER UNCERTAIN 315/6. THE DEPRESSION IS ON THE SOUTHWEST SIDE OF A WEAK LOW/MID-LEVEL RIDGE AND STRONG UPPER-LEVEL RIDGE...WHICH THE LARGE-SCALE MODELS FORECAST TO PERSIST THROUGH THE FORECAST PERIOD. THE TRACK GUIDANCE SHOWS A SIGNIFICANT SPREAD...WITH THE GFS... UKMET...HWRF...AND NOGAPS FORECASTING THE SYSTEM TO MAKE LANDFALL ON THE MEXICAN COAST NEAR OR WEST OF ACAPULCO...WHILE THE GFDL... ECMWF...AND CANADIAN MODELS FORECAST A WEST-NORTHWESTWARD MOTION NEAR THE COAST. THE FORECAST TRACK CALLS FOR A SLOW NORTHWESTWARD MOTION FOR THE FIRST 24-48 HR...FOLLOWED BY A WEST-NORTHWESTWARD MOTION. THE NEW FORECAST TRACK IS SIMILAR TO THE OLD TRACK AFTER SOME ADJUSTMENT FOR THE INITIAL POSITION...AND LIES BETWEEN THE GFDL AND THE ECMWF. IT SHOULD BE NOTED JUST ABOUT ANY MOTION TO THE RIGHT OF THE TRACK WOULD BRING THE CENTER ONTO THE MEXICAN COAST. THERE IS ALSO A CHANCE OF SOME ERRATIC MOTION DURING THE FIRST 24 HR AS THE SYSTEM CONSOLIDATES. UPPER-LEVEL EASTERLY FLOW ON THE SOUTH SIDE OF THE RIDGE IS PRODUCING 20-25 KT OF VERTICAL WIND SHEAR OVER THE CENTER...AND THE LARGE-SCALE MODELS FORECAST THIS CONDITION TO PERSIST FOR AT LEAST 72 HR. THIS COMBINED WITH THE SPRAWLING NATURE OF THE SYSTEM SUGGESTS THAT INTENSIFICATION SHOULD BE SLOW...IF IT OCCURS AT ALL. THE ONLY GUIDANCE CALLING FOR SIGNIFICANT STRENGTHENING IS THE SHIPS MODEL...WHICH CALLS FOR A PEAK INTENSITY OF 53 KT IN 60 HR. GIVEN THE SIMILARITY OF THE SYSTEM TO A MONSOON CYCLONE...WHICH CAN INTENSIFY IN THIS TYPE OF ENVIRONMENT...THE INTENSITY FORECAST CALLS FOR MODEST STRENGTHENING AS A COMPROMISE BETWEEN THE SHIPS AND LGEM MODELS. AN ALTERNATIVE SCENARIO IS THAT THE CYCLONE WILL DISSIPATE IF IT MAKES LANDFALL OVER THE MOUNTAINS OF SOUTHWESTERN MEXICO. FORECAST POSITIONS AND MAX WINDS INITIAL 06/0300Z 14.5N 100.0W 25 KT 12HR VT 06/1200Z 15.0N 100.3W 30 KT 24HR VT 07/0000Z 15.7N 100.8W 35 KT 36HR VT 07/1200Z 16.4N 101.4W 40 KT 48HR VT 08/0000Z 17.0N 102.2W 40 KT 72HR VT 09/0000Z 18.0N 104.0W 40 KT 96HR VT 10/0000Z 19.0N 106.0W 45 KT 120HR VT 11/0000Z 20.5N 109.5W 45 KT $$ FORECASTER BEVEN