000 WTPZ44 KNHC 252030 TCDEP4 HURRICANE FRANK DISCUSSION NUMBER 17 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP092010 200 PM PDT WED AUG 25 2010 THERE HAD BEEN LITTLE CHANGE IN THE ORGANIZATION OF FRANK THROUGH MUCH OF THE AFTERNOON...ALTHOUGH IN THE LAST HOUR OR SO THE BEGINNINGS OF AN EYE BECAME APPARENT. DVORAK SATELLITE ESTIMATES AT 18Z WERE 65 KT AND THAT WILL BE THE ADVISORY INTENSITY. THE CYCLONE HAS ABOUT 36-48 HOURS LEFT OVER WARM WATER...AND WITH THE SHEAR EXPECTED TO REMAIN RELATIVELY UNCHANGED...SOME ADDITIONAL STRENGTHENING SEEMS LIKELY. THE OFFICIAL FORECAST IS IN GOOD AGREEMENT WITH THE SHIPS AND GFDL MODELS...WITH THE LGEM AND HWRF SHOWING LITTLE TO NO ADDITIONAL DEVELOPMENT. AFTER 48 HOURS...A GRADUAL DECAY OVER COOLER WATERS IS EXPECTED. IT APPEARS AS THOUGH FRANK IS MOVING A LITTLE FASTER NOW...AT 285/11. FRANK IS EXPECTED TO CONTINUE WEST-NORTHWESTWARD FOR THE NEXT COUPLE OF DAYS AROUND THE SOUTHERN PERIPHERY OF A SUBTROPICAL RIDGE OVER NORTHWESTERN MEXICO. LATER IN THE FORECAST PERIOD... FRANK SHOULD SLOW AND TURN NORTHWARD IN RESPONSE TO A LARGE MID-LATITUDE TROUGH FORECAST TO DIG SOUTHWARD OFF THE WEST COAST OF THE U.S. AND BAJA CALIFORNIA. THE MODEL GUIDANCE HAS GENERALLY SHIFTED TO THE WEST AND THE OFFICIAL FORECAST IS NUDGED IN THAT DIRECTION. THERE IS A FAIR AMOUNT OF SPREAD IN THE GUIDANCE AT DAYS 4-5...WITH THE GFDL AND HWRF SHOWING SUBSTANTIAL EASTWARD AND NORTHWARD MOTION...RESPECTIVELY...AND ARE POSSIBLY MAINTAINING TOO COHERENT A VORTEX AT THOSE RANGES. THE GLOBAL MODELS...AND THE OFFICIAL FORECAST...SUGGEST THAT A RELATIVELY WEAK CYCLONE WILL MOVE SLOWLY WITHIN AN ILL-DEFINED LOW-LEVEL STEERING FLOW. FORECAST POSITIONS AND MAX WINDS INITIAL 25/2100Z 17.0N 106.3W 65 KT 12HR VT 26/0600Z 17.4N 107.9W 70 KT 24HR VT 26/1800Z 17.9N 109.7W 75 KT 36HR VT 27/0600Z 18.5N 111.6W 75 KT 48HR VT 27/1800Z 19.0N 113.0W 65 KT 72HR VT 28/1800Z 20.5N 114.5W 55 KT 96HR VT 29/1800Z 21.0N 114.5W 45 KT 120HR VT 30/1800Z 22.0N 114.0W 30 KT $$ FORECASTER FRANKLIN