000 WTPZ42 KNHC 090847 TCDEP2 HURRICANE GILMA DISCUSSION NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL EP072012 200 AM PDT THU AUG 09 2012 YESTERDAY AFTERNOON...A SERIES OF MICROWAVE IMAGES FROM THE FNMOC SATELLITE DATA TROPICAL CYCLONE PAGE INDICATED THAT THE EYEWALL OF GILMA WAS PARTIALLY OPEN IN THE NORTH PORTION. RECENTLY...A 0400 UTC SSMIS OVERPASS REVEALED A FULLY CLOSED EYEWALL...ALBEIT...A LITTLE THIN IN THE NORTHWEST QUADRANT. BASED ON THE INNER CORE IMPROVEMENT DURING THE PAST SEVERAL HOURS...AND A BLEND OF THE TAFB AND SAB SATELLITE INTENSITY ESTIMATES...THE INITIAL INTENSITY IS RAISED TO 70 KT. THERE ARE NO CHANGES TO THE INTENSITY FORECAST PHILOSOPHY. A WEAKENING TREND IS EXPECTED TO COMMENCE IN 24 HOURS OR SO AS THE CYCLONE TRAVERSES A SHARP GRADIENT OF DECREASING SSTS AND MOVES INTO A LESS FAVORABLE THERMODYNAMIC ENVIRONMENT. THE OFFICIAL NHC INTENSITY FORECAST IS BASICALLY A COMPROMISE OF THE LGEM AND FLORIDA STATE SUPERENSEMBLE MODELS AND CALLS FOR GILMA TO BECOME A REMNANT LOW IN 4 DAYS. THE INITIAL MOTION IS ESTIMATED TO BE 285/6. A MID- TO UPPER- TROPOSPHERIC LOW AND AN ASSOCIATED TROUGH EXTENDING SOUTHWESTWARD FROM THE SOUTHERN TIP OF BAJA CALIFORNIA APPEARS TO BE ERODING THE RIDGE SITUATED TO THE NORTH OF GILMA. CONSEQUENTLY...THIS SYNOPTIC FEATURE HAS CAUSED THE CYCLONE TO SLOW ITS FORWARD SPEED DURING THE PAST 12 HOURS...AND THE LARGE-SCALE MODELS INDICATE THAT THIS WEAKENED STEERING PATTERN WILL PERSIST THROUGH THE ENTIRE FORECAST PERIOD. A SUBSEQUENT TURN TOWARD THE NORTHWEST IS ALSO EXPECTED LATER TODAY AS A RESULT OF THE AFOREMENTIONED GROWING WEAKNESS IN THE RIDGE. AROUND DAY 4...GILMA IS FORECAST TO TURN BACK TOWARD THE WEST-NORTHWEST WITHIN THE EASTERLY LOW-LEVEL FLOW AS A WEAK...SHALLOW SYSTEM. THE NHC FORECAST FOR THIS ADVISORY LIES BETWEEN THE PREVIOUS ONE AND THE TVCE MULTI-MODEL CONSENSUS. THE 34-KT AND 50-KT WIND RADII WERE SLIGHTLY ADJUSTED BASED ON A 0452 UTC ASCAT PASS. FORECAST POSITIONS AND MAX WINDS INIT 09/0900Z 16.2N 118.6W 70 KT 80 MPH 12H 09/1800Z 16.7N 119.2W 70 KT 80 MPH 24H 10/0600Z 17.4N 119.9W 65 KT 75 MPH 36H 10/1800Z 18.1N 120.5W 55 KT 65 MPH 48H 11/0600Z 18.8N 121.0W 45 KT 50 MPH 72H 12/0600Z 19.9N 121.7W 35 KT 40 MPH 96H 13/0600Z 20.6N 122.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 14/0600Z 20.6N 124.5W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ FORECASTER ROBERTS