000 WTNT43 KNHC 250246 TCDAT3 HURRICANE RINA DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182011 1100 PM EDT MON OCT 24 2011 RINA IS BECOMING BETTER ORGANIZED. THE HURRICANE HAS MAINTAINED A NEARLY CIRCULAR CENTRAL DENSE OVERCAST THE LAST SEVERAL HOURS... WITH A LARGE AREA OF CLOUD TEMPERATURES LOWER THAN -70C. A 0137 UTC SSMIS OVERPASS ALSO SHOWED A CLOSED LOW- TO MID-LEVEL EYE IN THE DEEPEST CONVECTION. WATER VAPOR IMAGERY INDICATES AN IMPRESSIVE OUTFLOW CHANNEL TO THE NORTH...WITH GOOD OUTFLOW NOTED ELSEWHERE. DVORAK INTENSITY ESTIMATES ARE 4.0 FROM TAFB AND SAB AND THE LATEST ADT VALUE IS 4.3/73 KT. BASED UPON THESE DATA...THE INITIAL INTENSITY IS SET AT 70 KT. RINA IS LIKELY TO INTENSIFY FURTHER DURING THE NEXT COUPLE OF DAYS AS IT TRAVERSES THE VERY WARM WATERS OF THE NORTHWEST CARIBBEAN SEA IN AN ENVIRONMENT OF RELATIVELY LOW SHEAR. THE ONE CAVEAT TO THIS FORECAST IS THAT DRY AIR LURKING IN THE NEAR-STORM ENVIRONMENT COULD POTENTIALLY BE A LIMITING FACTOR. BEYOND 60 HOURS...THE ATMOSPHERIC ENVIRONMENT IS FORECAST TO BECOME INCREASINGLY LESS FAVORABLE AS RINA ENCOUNTERS STRONG SOUTHWESTERLY SHEAR AND ADDITIONAL DRY AIR IMPINGES ON THE CIRCULATION. THE CYCLONE COULD ALSO INTERACT WITH LAND AS IT PASSES NEAR OR OVER THE YUCATAN PENINSULA IN 72-96 HOURS. THE OFFICIAL FORECAST FOLLOWS THE PREVIOUS ONE AND CALLS FOR ADDITIONAL STRENGTHENING IN THE SHORT TERM...FOLLOWED BY STEADY WEAKENING AFTER 48 HOURS. THE INTENSITY FORECAST REMAINS ABOVE THE STATISTICAL-DYNAMICAL INTENSITY GUIDANCE THROUGH 48 HOURS BUT IS IN GOOD AGREEMENT AFTER THIS TIME. IT SHOULD BE NOTED THAT THE ECMWF CONTINUES TO FORECAST RINA TO DISSIPATE IN THE 3 TO 5 DAY TIME FRAME...WHILE THE GFS/UKMET GLOBAL MODELS IMPLY MORE WEAKENING THAN SHOWN IN THE OFFICIAL FORECAST. THE LAST COUPLE OF AIRCRAFT AND SATELLITE FIXES INDICATE THAT RINA HAS MOVED LITTLE AND THE INITIAL MOTION ESTIMATE IS 295/03. LITTLE CHANGE HAS BEEN MADE TO THE PREVIOUS FORECAST TRACK. GLOBAL MODELS ARE IN REASONABLY GOOD AGREEMENT THAT RINA WILL TURN TOWARD THE NORTHWEST AND THEN THE NORTH-NORTHWEST IN 36-72 HOURS ON THE WESTERN SIDE OF A MID-LEVEL RIDGE LOCATED OVER THE NORTHERN CARIBBEAN. AFTER THIS TIME...THERE IS CONSIDERABLE SPREAD IN THE TRACK GUIDANCE. THE HWRF/GFDL/UKMET ACCELERATE RINA NORTHEASTWARD OVER OR NEAR SOUTH FLORIDA...WHEREAS THE GFS TURNS THE CYCLONE SOUTHWARD IN THE NORTHWEST CARIBBEAN. THE MODEL SPREAD IS IN PART RELATED TO THE PREDICTED VERTICAL DEPTH OF RINA. A STRONGER CYCLONE...AS INDICATED BY THE GFDL/HWRF...WOULD LIKELY BE STEERED BY THE DEEP-LAYER SOUTHWESTERLY FLOW...WHILE A WEAKER/SHALLOWER SYSTEM WOULD BE PUSHED SOUTHWARD IN LOW-LEVEL NORTHERLY FLOW. SINCE RINA IS FORECAST TO WEAKEN...PERHAPS MORE SIGNIFICANTLY THAN FORECAST...THE OFFICIAL TRACK PLACES MORE WEIGHT ON THE WEAKER GFS SOLUTION. GIVEN THE LARGE SPREAD IN THE MODEL SOLUTIONS IN THE EXTENDED RANGE...THE CONFIDENCE IN THE LATTER PART OF THE TRACK FORECAST REMAINS LOW. FORECAST POSITIONS AND MAX WINDS INIT 25/0300Z 17.2N 83.3W 70 KT 80 MPH 12H 25/1200Z 17.3N 83.9W 75 KT 85 MPH 24H 26/0000Z 17.5N 84.8W 90 KT 105 MPH 36H 26/1200Z 17.9N 85.6W 100 KT 115 MPH 48H 27/0000Z 18.7N 86.3W 100 KT 115 MPH 72H 28/0000Z 20.9N 87.2W 85 KT 100 MPH...INLAND 96H 29/0000Z 22.2N 85.8W 75 KT 85 MPH 120H 30/0000Z 22.0N 84.0W 65 KT 75 MPH $$ FORECASTER KIMBERLAIN