652 
 WTNT43 KNHC 242041
 TCDAT3
  
 HURRICANE RINA DISCUSSION NUMBER   6
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
 500 PM EDT MON OCT 24 2011
  
 VISIBLE SATELLITE IMAGES SHOW SEVERAL BANDS OF DEEP CONVECTION
 WRAPPING AROUND THE CENTER OF RINA AND A SMALL CENTRAL DENSE
 OVERCAST FEATURE. THE HURRICANE HUNTER AIRCRAFT HAS NOT REPORTED
 ANY STRONGER WINDS SINCE THEIR INITIAL PASS INTO THE CENTER JUST
 BEFORE 1800 UTC...AND BASED ON THE EARLIER DATA THE INITIAL
 INTENSITY WILL REMAIN 65 KT. 
  
 RINA WILL BE TRAVERSING VERY WARM WATER AND REMAIN IN A LOW SHEAR
 ENVIRONMENT DURING THE NEXT COUPLE OF DAYS. THE ONLY NEGATIVE
 FACTOR FOR INTENSIFICATION IS AN AREA OF DRY AIR TO THE NORTHWEST
 OF THE CYCLONE. SO FAR...RINA HAS REMAINED WELL INSULATED FROM THE
 DRY AIR AND THE OFFICIAL FORECAST ASSUMES THAT THE DRY AIR WILL NOT
 REACH THE CORE DURING THE NEXT COUPLE OF DAYS. AFTER THAT...
 SOUTHERLY SHEAR IS FORECAST TO INCREASE AND RINA IS ALSO EXPECTED
 TO INTERACT WITH A FRONTAL BOUNDARY THAT MOVES INTO THE
 SOUTHEASTERN GULF OF MEXICO NEAR THE END OF THE FORECAST PERIOD.
 THE INTENSITY FORECAST IS VERY SIMILAR TO THE ONE ISSUED IN THE
 SPECIAL ADVISORY AND IS NEAR THE GFDL AND HWRF GUIDANCE THROUGH 48
 HOURS. AFTER THAT TIME...IT IS CLOSER TO A BLEND OF THE STATISTICAL
 AND DYNAMICAL MODEL GUIDANCE. GIVEN THE RELATIVELY SMALL SIZE OF
 THE HURRICANE...IT WOULD NOT BE SURPRISING TO SEE RAPID CHANGES
 BOTH UP AND DOWN IN ITS INTENSITY.
  
 THE AIRCRAFT FIXES SHOW THAT THE HURRICANE HAS SLOWED DOWN.  A
 BUILDING HIGH PRESSURE RIDGE OVER THE NORTHERN GULF OF MEXICO IS
 EXPECTED TO STEER RINA WESTWARD DURING THE NEXT 24 TO 36 HOURS.
 AS THE RIDGE SLIDES EASTWARD THE HURRICANE SHOULD TURN
 NORTHWESTWARD...THEN NORTHWARD IN 2 TO 3 DAYS.  AFTER THAT...THE
 TRACK GUIDANCE BECOMES QUITE DIVERGENT WITH THE GFDL AND HWRF
 TAKING THE CYCLONE NORTHEASTWARD...AND THE GFS SHOWING AN
 EASTWARD OR EAST-SOUTHEASTWARD MOTION.  FOR NOW...THE NHC FORECAST
 REMAINS BETWEEN THESE TWO EXTREMES AND SHOWS A SLOW EAST-NORTHEAST
 MOTION NEAR THE END OF THE PERIOD.
  
 GIVEN THE EXTREMELY LARGE SPREAD IN THE GUIDANCE...AND THE POOR RUN
 TO RUN CONSISTENCY...THERE IS MUCH LOWER THAN NORMAL CONFIDENCE IN
 THE LONG-RANGE TRACK FORECAST OF RINA. 
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  24/2100Z 17.1N  83.1W   65 KT  75 MPH
  12H  25/0600Z 17.2N  83.7W   75 KT  85 MPH
  24H  25/1800Z 17.3N  84.4W   90 KT 105 MPH
  36H  26/0600Z 17.6N  85.2W  100 KT 115 MPH
  48H  26/1800Z 18.1N  86.0W  105 KT 120 MPH
  72H  27/1800Z 19.8N  87.2W   95 KT 110 MPH
  96H  28/1800Z 21.0N  87.0W   85 KT 100 MPH
 120H  29/1800Z 21.5N  85.0W   75 KT  85 MPH
  
 $$
 FORECASTER BROWN