000 WTPZ45 KNHC 150240 TCDEP5 HURRICANE GUILLERMO DISCUSSION NUMBER 11 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP102009 800 PM PDT FRI AUG 14 2009 VISIBLE AND INFRARED SATELLITE IMAGERY REVEALS AN IMPRESSIVE CLOUD PATTERN ASSOCIATED WITH GUILLERMO...WITH MANY OF THE STRUCTURAL CHARACTERISTICS OF A MATURE HURRICANE. THE CYCLONE HAS MAINTAINED A RAGGED...BANDING-TYPE EYE SINCE EARLIER TODAY...THOUGH IT HAS RECENTLY BECOME CLOUD-FILLED. ADDITIONALLY...TWO WELL-ORGANIZED BANDS ARE COILING AROUND A CENTRAL DENSE OVERCAST. EVEN THOUGH DVORAK T-NUMBERS HAVE DECREASED TO 4.5 FROM BOTH TAFB AND SAB AT 00 UTC...THE CONVECTIVE ORGANIZATION OF GUILLERMO HAS IMPROVED IN THE LAST HOUR OR TWO. BASED UPON ITS MOST RECENT SATELLITE APPEARANCE...THE INTENSITY IS HELD AT 85 KT THIS ADVISORY. THE INITIAL MOTION ESTIMATE REMAINS 285/14...ESSENTIALLY NO DIFFERENT THAN BEFORE. GUILLERMO IS MOVING AROUND THE SOUTHWEST SIDE OF A DEEP-LAYER ANTICYCLONE EXTENDING FROM THE SOUTH CENTRAL UNITED STATES INTO THE SUBTROPICAL EAST PACIFIC PAST 140W. THERE HAS BEEN NO CHANGE TO THE TRACK PHILOSOPHY...WITH THIS FEATURE FORECAST TO KEEP GUILLERMO ON A TRACK JUST NORTH OF DUE WEST THROUGH 72 HOURS. THEREAFTER...THE CYCLONE SHOULD BE APPROACHING A WEAKNESS IN THE VICINITY OF THE HAWAIIAN ISLANDS WHICH SHOULD INDUCE A MORE WEST-NORTHWESTWARD COURSE. THE MODEL CONSENSUS HAS EDGED SLIGHTLY NORTH BEYOND 72 HOURS...POSSIBLY IN RESPONSE TO THE AFORMENTIONED WEAKNESS. LAST VISIBLE PICTURES SHOW GUILLERMO PUSHING INTO A DENSE FIELD OF STRATOCUMULUS...INDICATIVE OF PROGRESSIVELY COOLER SEA SURFACE TEMPERATURES AHEAD OF IT. THIS IS THE MAIN FACTOR WHICH SHOULD LEAD TO GRADUAL WEAKENING DURING THE NEXT 24-36 HOURS...EVEN WHILE THE ENVIRONMENTAL SHEAR REMAINS RELATIVELY LOW. THEREAFTER... INCREASING SOUTHWESTERLY SHEAR ASSOCIATED WITH A RETROGRADING MID- TO UPPER-LEVEL TROUGH AROUND 150-160W SHOULD ACCELERATE THE WEAKENING TREND. GUILLERMO IS FORECAST TO BECOME A REMNANT LOW BY THE END OF THE FORECAST PERIOD AND COULD WEAKEN FASTER THAN FORECAST IF THE SHEAR IS AS HIGH AS SHIP MODEL GUIDANCE SUGGESTS. FORECAST POSITIONS AND MAX WINDS INITIAL 15/0300Z 18.3N 130.3W 85 KT 12HR VT 15/1200Z 18.7N 132.3W 80 KT 24HR VT 16/0000Z 19.3N 135.0W 70 KT 36HR VT 16/1200Z 19.9N 137.6W 60 KT 48HR VT 17/0000Z 20.5N 140.2W 50 KT 72HR VT 18/0000Z 22.2N 145.3W 40 KT 96HR VT 19/0000Z 24.0N 150.5W 30 KT 120HR VT 20/0000Z 26.0N 156.0W 25 KT...REMNANT LOW $$ FORECASTER KIMBERLAIN