000 WTPZ43 KNHC 020233 TCDEP3 TROPICAL STORM ERICK DISCUSSION NUMBER 6 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP082007 800 PM PDT WED AUG 01 2007 IT HAS BEEN VERY DIFFICULT TO LOCATE THE CENTER OF ERICK IN BOTH CONVENTIONAL AND MICROWAVE SATELLITE IMAGERY THIS EVENING. THE IMAGERY SUGGESTS THAT THE LOW LEVEL CIRCULATION HAS BECOME ELONGATED AND LESS DEFINED. HOWEVER...A MID-LEVEL CIRCULATION IS CLEARLY EVIDENT TO THE SOUTHWEST OF THE ESTIMATED LOW-LEVEL CENTER...AND IT WOULD NOT BE SURPRISING IF REFORMATION OCCURS IN THAT AREA. THE LATEST DVORAK SATELLITE INTENSITY ESTIMATES REMAIN UNCHANGED AND THE INITIAL INTENSITY REMAINS AT 35 KT. NORTHEASTERLY SHEAR CONTINUES TO INHIBIT STRENGTHENING. HOWEVER...THE MODELS SUGGEST THAT THE SHEAR COULD RELAX DURING THE COUPLE OF DAYS...ALLOWING SOME STRENGTHENING. LATER IN THE FORECAST PERIOD...THE CYCLONE WILL BE MOVING OVER COOLER WATERS WHICH SHOULD HALT ANY ADDITIONAL DEVELOPMENT. THE INITIAL MOTION ESTIMATE IS 275/10. ERICK IS FORECAST TO CONTINUE WEST TO WEST-NORTHWESTWARD SOUTH OF A MID-LEVEL RIDGE. MOST OF THE TRACK GUIDANCE AGREES ON THIS SCENARIO BUT WITH VARYING FORWARD SPEEDS. THE 12Z ECMWF SHOWS VERY LITTLE MOTION DURING THE FORECAST PERIOD AS ANOTHER CYCLONE DEVELOPS TO THE EAST OF ERICK. THIS SOLUTION APPEARS TO BE UNREALISTIC AT THIS TIME. THE OFFICIAL TRACK IS A LITTLE FASTER THAN INDICATED IN THE PREVIOUS ADVISORY BUT IS SLOWER THAN THE GFDL AND HWRF MODELS. FORECAST POSITIONS AND MAX WINDS INITIAL 02/0300Z 13.4N 128.6W 35 KT 12HR VT 02/1200Z 13.6N 130.0W 35 KT 24HR VT 03/0000Z 13.9N 131.7W 40 KT 36HR VT 03/1200Z 14.1N 133.4W 45 KT 48HR VT 04/0000Z 14.4N 135.3W 45 KT 72HR VT 05/0000Z 14.8N 138.8W 45 KT 96HR VT 06/0000Z 14.9N 142.5W 40 KT 120HR VT 07/0000Z 15.0N 146.0W 40 KT $$ FORECASTER BROWN