336 
 WTNT43 KNHC 241438
 TCDAT3
  
 TROPICAL STORM RINA DISCUSSION NUMBER   4
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
 1100 AM EDT MON OCT 24 2011
  
 VISIBLE SATELLITE IMAGES SHOW THAT RINA HAS BECOME BETTER
 ORGANIZED WITH THE CENTER LOCATED WELL WITHIN THE LARGE AREA
 OF DEEP CONVECTION.  THE LATEST DVORAK DATA T AND CI NUMBERS...
 AND A RECENT AMSU INTENSITY ESTIMATE SUPPORT INCREASING THE 
 INITIAL WIND SPEED TO 40 KT.  AN AIR FORCE RESERVE HURRICANE HUNTER
 AIRCRAFT IS SCHEDULED TO INVESTIGATE THE CYCLONE THIS AFTERNOON AND
 SHOULD PROVIDE A BETTER ASSESSMENT OF THE INTENSITY OF RINA. 
  
 ALTHOUGH THERE IS SOME DRY AIR TO THE NORTHWEST OF THE CYCLONE...
 AN INCREASINGLY FAVORABLE UPPER-LEVEL WIND PATTERN AND VERY WARM
 WATERS OF THE NORTHWESTERN CARIBBEAN SEA SHOULD ALLOW FOR STEADY
 STRENGTHENING DURING THE NEXT 48-72 HOURS.  IN 3 TO 4 DAYS...
 SOUTHERLY SHEAR IS EXPECTED TO INCREASE...AND LATER IN THE
 PERIOD...THE CYCLONE IS FORECAST TO INTERACT WITH A FRONTAL
 BOUNDARY.  THESE CONDITIONS WILL LIKELY LEAD TO SOME WEAKENING OF
 RINA BEFORE THE END OF THE FORECAST PERIOD.  THE UPDATED NHC
 INTENSITY FORECAST IS ABOVE THE PREVIOUS ADVISORY AND LIES BETWEEN
 THE STATISTICAL SHIPS/LGEM GUIDANCE AND THE MORE AGGRESSIVE
 GFDL/HWRF MODELS.
  
 RECENT GEOSTATIONARY AND MICROWAVE SATELLITE FIXES SUGGEST THAT RINA
 IS BEGINNING ITS TURN TOWARD THE LEFT.  THE INITIAL MOTION ESTIMATE
 IS 320/5.  THE CYCLONE SHOULD TURN WEST-NORTHWESTWARD TODAY AS A
 MID-LEVEL RIDGE BUILDS OVER THE NORTHERN GULF OF MEXICO DURING THE
 NEXT 24 HOURS.  AS THIS RIDGE SLIDES EASTWARD IN A COUPLE OF
 DAYS...IT SHOULD ALLOW RINA TO TURN NORTHWESTWARD...THEN NORTHWARD.
 NEAR THE END OF THE FORECAST PERIOD...RINA IS EXPECTED TO TURN
 NORTHEASTWARD AS THE RIDGE RETREATS AND A BROAD TROUGH MOVES OVER
 THE GULF OF MEXICO.  THE MODEL GUIDANCE IS IN SOMEWHAT BETTER
 AGREEMENT THIS CYCLE...WITH THE GFDL AND HWRF SHIFTING SOUTHWARD
 AND KEEPING RINA OVER THE NORTHWESTERN CARIBBEAN SEA DURING THE
 FORECAST PERIOD.  THE NHC FORECAST IS VERY SIMILAR TO THE PREVIOUS
 ADVISORY THROUGH 96 HOURS...BUT NOW SHOWS A SLOW NORTHEASTWARD
 MOTION THEREAFTER.  THE NEW TRACK IS IN GOOD AGREEMENT WITH BOTH
 THE TVCA AND HFIP MULTI-MODEL CONSENSUS.
  
 
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  24/1500Z 17.1N  82.9W   40 KT  45 MPH
  12H  25/0000Z 17.4N  83.4W   50 KT  60 MPH
  24H  25/1200Z 17.6N  84.0W   60 KT  70 MPH
  36H  26/0000Z 17.8N  84.8W   70 KT  80 MPH
  48H  26/1200Z 18.1N  85.7W   80 KT  90 MPH
  72H  27/1200Z 19.2N  87.0W   75 KT  85 MPH
  96H  28/1200Z 20.5N  87.0W   65 KT  75 MPH
 120H  29/1200Z 21.0N  86.0W   55 KT  65 MPH
  
 $$
 FORECASTER BROWN/ROBERTS