705 
 WTNT43 KNHC 261457
 TCDAT3
  
 HURRICANE RINA DISCUSSION NUMBER  13
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
 1000 AM CDT WED OCT 26 2011
 
 RINA HAS A SOMEWHAT RAGGED APPEARANCE THIS MORNING.  THE EYE IS NOT
 APPARENT IN VISIBLE IMAGERY...AND DATA FROM THE RADARS AT BELIZE
 CITY AND ON THE TRMM SATELLITE SUGGEST THE EYEWALL HAS LOST SOME
 DEFINITION.  WHILE THE EYEWALL CLOUD TOP TEMPERATURES ARE COLDER
 THAN -80C...THE OVERALL AMOUNT OF CONVECTION ASSOCIATED WITH THE
 CYCLONE HAS DECREASED DURING THE PAST SEVERAL HOURS.  IN
 ADDITION...THE OUTFLOW HAS DIMINISHED SINCE YESTERDAY...AND
 ANALYSES FROM CIMSS AT THE UNIVERSITY OF WISCONSIN SUGGEST 15-20 KT
 OF SOUTHERLY VERTICAL WIND SHEAR.  THE INITIAL INTENSITY IS KEPT AT
 95 KT FOR THIS ADVISORY...BUT THIS COULD BE GENEROUS AND IT IS
 QUITE POSSIBLE THAT THE NOAA HURRICANE HUNTER AIRCRAFT ABOUT TO
 REACH THE STORM WILL FIND RINA HAS WEAKENED.
  
 THE RECENT CENTER FIXES INDICATE THAT RINA HAS TURNED TOWARD THE
 RIGHT DURING THE PAST SEVERAL HOURS WITH THE INITIAL MOTION NOW
 290/4.  RINA IS CURRENTLY EMBEDDED IN A MID-LEVEL RIDGE...WITH A
 STRONG LOW-LEVEL RIDGE NORTH OF THE HURRICANE AND AN UPPER-LEVEL
 ANTICYCLONE TO ITS EAST OVER THE CENTRAL CARIBBEAN.  THE DYNAMICAL
 MODELS FORECAST THE RIDGES TO THE NORTH AND WEST TO WEAKEN DURING
 THE NEXT 48-72 HOURS AS A TROUGH IN THE WESTERLIES AND ASSOCIATED
 COLD FRONT MOVE INTO THE GULF OF MEXICO.  THIS EVOLUTION SHOULD
 CAUSE RINA TO GRADUALLY TURN NORTHWARD NEAR THE EAST COAST OF THE
 YUCATAN PENINSULA.  THE TRACK GUIDANCE IS IN GOOD AGREEMENT ON THIS
 PART OF THE FORECAST...AND THE NEW FORECAST TRACK IS SIMILAR TO THE
 OLD ONE.  AFTER 72 HOURS...RINA IS EXPECTED TO MOVE INTO AN
 ENVIRONMENT WHERE THE MID/UPPER-LEVEL FLOW TRIES TO STEER THE
 CYCLONE NORTHEASTWARD WHILE THE LOW-LEVEL FLOW TRIES TO STEER IT
 SOUTHWARD OR SOUTHWESTWARD.  THIS SHOULD CAUSE RINA TO SHEAR
 APART...BUT THE MODELS DISAGREE ON WHEN THIS WILL HAPPEN AND THUS
 ARE IN POOR AGREEMENT ON THE FORECAST TRACK.  THE ECMWF AND
 CANADIAN WEAKEN RINA VERY QUICKLY AND KEEP THE LOW-LEVEL REMNANT
 NEAR YUCATAN...WHILE THE GFDL FORECASTS A STRONGER CYCLONE TO CROSS
 SOUTH FLORIDA INTO THE ATLANTIC.  THE OTHER MODELS ARE BETWEEN
 THESE EXTREMES.  THE LATTER PORTION OF THE NEW FORECAST TRACK IS
 SIMILAR TO THE PREVIOUS TRACK...IN BEST AGREEMENT WITH THE GFS AND
 NOGAPS MODELS.  HOWEVER...THIS IS A LOW CONFIDENCE FORECAST.
  
 SINCE THE OUTFLOW IS LESS IMPRESSIVE THAN 24 HOURS AGO AND THE SHEAR
 IS FORECAST TO INCREASE FURTHER...IT APPEARS THAT RINA HAS RUN OUT
 OF TIME TO INTENSIFY.  THE INTENSITY FORECAST NOW CALLS FOR THE
 HURRICANE TO GRADUALLY WEAKEN DURING THE NEXT 12-24 HOURS...WITH A
 FASTER WEAKENING AT 36-48 HOURS DUE TO LAND INTERACTION.  DUE TO
 THE UNCERTAINTY OF JUST HOW QUICKLY RINA WILL SHEAR APART OVER THE
 GULF OF MEXICO...THE FORECAST KEEPS RINA A HURRICANE THROUGH 72
 HOURS AND A TROPICAL STORM THROUGH 120 HOURS IN BEST AGREEMENT WITH
 THE SHIPS AND LGEM MODELS.  HOWEVER...IT IS POSSIBLE THAT THE
 CYCLONE COULD WEAKEN MUCH FASTER THAN CURRENTLY FORECAST.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  26/1500Z 17.9N  85.5W   95 KT 110 MPH
  12H  27/0000Z 18.5N  86.2W   95 KT 110 MPH
  24H  27/1200Z 19.5N  87.0W   90 KT 105 MPH
  36H  28/0000Z 20.8N  87.1W   80 KT  90 MPH...INLAND
  48H  28/1200Z 22.0N  87.0W   75 KT  85 MPH...OVER WATER
  72H  29/1200Z 23.0N  85.0W   65 KT  75 MPH
  96H  30/1200Z 23.5N  83.0W   55 KT  65 MPH
 120H  31/1200Z 23.5N  82.5W   45 KT  50 MPH
  
 $$
 FORECASTER BEVEN