000 WTPZ45 KNHC 261450 TCDEP5 HURRICANE DARBY DISCUSSION NUMBER 15 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP052010 800 AM PDT SAT JUN 26 2010 COMPACT DARBY HAD CHANGED LITTLE THIS MORNING. ALTHOUGH THE PINHOLE EYE HAS BECOME OBSCURED IN THE ENHANCED INFRARED IMAGERY...AN 0811 UTC AMSR-E MICROWAVE IMAGE INDICATED THAT THE EYE WAS STILL QUITE INTACT NEAR THE SURFACE. ADDITIONALLY...A STRONG BANDING FEATURE WAS EVIDENT OVER THE WEST AND NORTH PORTIONS OF THE SYSTEM. DVORAK INTENSITY ESTIMATES AND AN ADVANCED OBJECTIVE DVORAK TECHNIQUE ESTIMATE SUPPORT MAINTAINING THE ESTIMATE AT 95 KT FOR THIS ADVISORY. EASTERLY SHEAR IS EXPECTED TO GRADUALLY INCREASE OVER DARBY THROUGH THE FORECAST PERIOD...CAUSING THE CYCLONE TO WEAKEN. THE OFFICIAL INTENSITY FORECAST IS BASED ON A BLEND OF THE SHIPS MODEL AND THE LGEM...AND IS SIMILAR TO THE PREVIOUS FORECAST. THE INITIAL MOTION IS ESTIMATED AT 260/3...WITHIN THE EASTERLY MID TO UPPER TROPOSPHERIC STEERING FLOW OF A WEAKENING RIDGE TO THE NORTH OF DARBY. DYNAMICAL MODELS INDICATE THAT THE AFOREMENTIONED RIDGE WILL WEAKEN DURING THE NEXT DAY OR SO...CAUSING THE CYCLONE TO DRIFT OR BECOME STATIONARY. BEYOND THE 36 HOUR PERIOD...AN INCREASING WEAKNESS...POSSIBLY INFLUENCED BY TROPICAL STORM ALEX...SHOULD INDUCE A GRADUAL NORTHEASTWARD MOTION. THIS EVENTUAL TURN TOWARD THE NORTHEAST COULD COME MUCH LATER THAN SUGGESTED...INDICATIVE OF A LARGE SPREAD IN THE MODELS DURING THIS PARTICULAR PERIOD OF THE FORECAST. CONSEQUENTLY...THERE IS LOW CONFIDENCE IN FORECAST TRACK AFTER THE 48 HOUR PERIOD. THE OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS ONE...AND A LITTLE WEST OF THE MULTI-MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INITIAL 26/1500Z 13.4N 102.9W 95 KT 12HR VT 27/0000Z 13.3N 103.5W 90 KT 24HR VT 27/1200Z 13.3N 104.0W 80 KT 36HR VT 28/0000Z 13.5N 104.1W 70 KT 48HR VT 28/1200Z 14.0N 103.7W 65 KT 72HR VT 29/1200Z 14.3N 103.0W 50 KT 96HR VT 30/1200Z 14.7N 102.5W 40 KT 120HR VT 01/1200Z 15.0N 102.3W 30 KT $$ FORECASTER ROBERTS