000 WTNT43 KNHC 270835 TCDAT3 HURRICANE RINA DISCUSSION NUMBER 17 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182011 400 AM CDT THU OCT 27 2011 RINA HAS BECOME LESS WELL ORGANIZED ON SATELLITE IMAGERY OVER THE PAST SEVERAL HOURS...WITH THE EXTENT OF COLD CLOUD TOPS DIMINISHING WITHIN A RAGGED-LOOKING CDO FEATURE. THIS SUGGESTS THAT SOME WEAKENING HAS TAKEN PLACE...AND INDEED THE AIR FORCE HURRICANE HUNTERS FOUND THAT THE CYCLONE IS NOW BARELY OF HURRICANE STRENGTH WITH THE PEAK SFMR-OBSERVED SURFACE WINDS OF 62 KT. THE INITIAL WIND SPEED IS SET...PERHAPS GENEROUSLY...AT 65 KT. SOUTH- SOUTHWESTERLY SHEAR OVER RINA IS EXPECTED TO GRADUALLY INCREASE... AND THIS ALONG WITH THE INTERACTION WITH THE YUCATAN PENINSULA AND DRIER AIR SHOULD CAUSE THE SYSTEM TO WEAKEN THROUGHOUT THE FORECAST PERIOD. THE OFFICIAL INTENSITY FORECAST SHOWS MORE WEAKENING THEN THE PREVIOUS ONE FOR DAYS 1-3 AND IS THE SAME AT DAYS 4-5. THIS IS SIMILAR TO THE STATISTICAL-DYNAMICAL DSHIPS MODEL FORECAST. RINA IS MOVING ALONG THE WESTERN SIDE OF A MID-LEVEL HIGH PRESSURE AREA AT ABOUT 325/5. THE TRACK GUIDANCE IS IN GENERAL AGREEMENT ON A NORTHWARD TURN DURING THE NEXT DAY OR SO. IN 36-48 HOURS...THE NORTHWARD MOTION IS EXPECTED TO END AS WEAK MID-LEVEL RIDGING DEVELOPS TO THE WEST OF RINA. BY THE END OF THE FORECAST PERIOD...THE WEAKENING CYCLONE IS LIKELY TO BE DRIVEN SOUTHWARD BY LOW-LEVEL NORTHERLY FLOW ASSOCIATED WITH A FRONT THAT PUSHES THROUGH THE GULF OF MEXICO. THE OFFICIAL TRACK FORECAST IS SOMEWHAT TO THE SOUTH AND WEST OF THE PREVIOUS ONE...BUT NOT NEARLY AS MUCH AS SHOWN BY THE PREPONDERANCE OF THE DYNAMICAL MODELS. FORECAST POSITIONS AND MAX WINDS INIT 27/0900Z 18.8N 86.9W 65 KT 75 MPH 12H 27/1800Z 19.8N 87.0W 60 KT 70 MPH 24H 28/0600Z 21.0N 87.1W 55 KT 65 MPH...INLAND 36H 28/1800Z 21.6N 86.8W 50 KT 60 MPH 48H 29/0600Z 21.9N 86.3W 45 KT 50 MPH 72H 30/0600Z 22.0N 85.5W 40 KT 45 MPH 96H 31/0600Z 21.5N 85.5W 35 KT 40 MPH 120H 01/0600Z 21.0N 85.5W 25 KT 30 MPH $$ FORECASTER PASCH