000 WTNT43 KNHC 251436 TCDAT3 HURRICANE RINA DISCUSSION NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182011 1100 AM EDT TUE OCT 25 2011 THE SATELLITE PRESENTATION OF RINA CONTINUES TO IMPROVE...WITH A SMALL EYE SEEN IN AN 1128 UTC SSMIS PASS AND RECENT VISIBLE IMAGERY. THE INITIAL INTENSITY IS INCREASED TO 90 KT FOR THIS ADVISORY BASED 12Z DVORAK DATA-T NUMBERS FROM TAFB AND SAB. THE HURRICANE IS SITUATED OVER A REGION OF VERY HIGH OCEAN HEAT CONTENT AND THE UPPER-LEVEL OUTFLOW IS WELL ESTABLISHED...ESPECIALLY TO THE NORTH. BASED ON THE FAVORABLE ENVIRONMENT...STRENGTHENING TO MAJOR HURRICANE INTENSITY APPEARS LIKELY. THE NEW NHC FORECAST HAS BEEN ADJUSTED UPWARD IN THE SHORT TERM AND IS IN GOOD AGREEMENT WITH THE ICON INTENSITY CONSENSUS MODEL THROUGH 36 HOURS. AFTER 48 HOURS... WEAKENING SHOULD BEGIN AS THE CYCLONE EXPERIENCES INCREASING SOUTHWESTERLY VERTICAL WIND SHEAR. AT DAYS 4 AND 5 THE NEW NHC FORECAST IS A LITTLE LOWER THAN THE PREVIOUS ONE...TRENDING TOWARD THE LATEST RUN OF THE LGEM MODEL. THE INITIAL MOTION ESTIMATE IS 285/03...AS RINA CONTINUES TO MOVE SLOWLY WEST-NORTHWESTWARD TO THE SOUTH OF A WEAKENING MID-LEVEL RIDGE. IN ABOUT 3 DAYS A LARGE MID/UPPER-LEVEL TROUGH WILL MOVE INTO THE EASTERN UNITED STATES...AND A RIDGE WILL STRENGTHEN TO THE NORTHEAST OF PUERTO RICO. THIS EVOLUTION OF THE PATTERN SHOULD RESULT IN RINA TURNING NORTHWESTWARD AND NORTHWARD AS IT APPROACHES THE YUCATAN PENINSULA...AND THEN TURNING EASTWARD AS THE CYCLONE WEAKENS LATE IN THE PERIOD. THE BIGGEST CHANGE TO THE TRACK FORECAST IS A FASTER FORWARD SPEED THROUGH 48 HOURS...WITH THE NHC TRACK LYING A LITTLE TO THE RIGHT OF THE CENTER OF THE GUIDANCE ENVELOPE...BUT TO THE LEFT OF THE GFS. AT DAYS 3 THROUGH 5...LITTLE CHANGE WAS MADE TO THE OFFICIAL FORECAST GIVEN THE LARGE SPREAD IN THE TRACK GUIDANCE. AT THE END OF THE PERIOD THE NHC FORECAST IS CLOSEST TO THE GFS ENSEMBLE MEAN AND A LITTLE NORTH OF THE FSU SUPERENSEMBLE. GIVEN THE LARGE SPREAD IN THE MODEL SOLUTIONS IN THE EXTENDED RANGE...THE CONFIDENCE IN THE LATTER PART OF THE TRACK FORECAST REMAINS LOW. BASED ON THE FASTER TRACK FORECAST...HURRICANE AND TROPICAL STORM WARNINGS ARE NOW REQUIRED FOR A PORTION OF THE YUCATAN PENINSULA. FORECAST POSITIONS AND MAX WINDS INIT 25/1500Z 17.4N 83.9W 90 KT 105 MPH 12H 26/0000Z 17.7N 84.7W 100 KT 115 MPH 24H 26/1200Z 18.2N 85.6W 105 KT 120 MPH 36H 27/0000Z 19.1N 86.5W 100 KT 115 MPH 48H 27/1200Z 20.2N 87.0W 100 KT 115 MPH 72H 28/1200Z 22.0N 86.5W 80 KT 90 MPH 96H 29/1200Z 22.5N 84.5W 60 KT 70 MPH 120H 30/1200Z 22.5N 83.5W 50 KT 60 MPH...INLAND $$ FORECASTER BRENNAN