391 
 WTNT43 KNHC 240243
 TCDAT3
  
 TROPICAL STORM RINA DISCUSSION NUMBER   2
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
 1100 PM EDT SUN OCT 23 2011
  
 EARLIER REPORTS FROM AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT
 INDICATED BELIEVABLE SFMR WINDS OF 33-35 KT OUTSIDE OF THE
 CONVECTION IN THE SOUTHWESTERN QUADRANT OF THE CYCLONE...BUT THESE
 WINDS COULD HAVE BEEN GUSTS. THE AIRCRAFT ALSO HAD TO AVOID STRONG
 THUNDERSTORMS TO THE NORTH OF THE CENTER AND WAS... THEREFORE...
 UNABLE TO SAMPLE THE WINDS IN THAT AREA. SINCE THEN... HOWEVER...
 DEEP CONVECTION HAS INCREASED MARKEDLY IN THE NORTHERN SEMICIRCLE
 AND CONVECTION HAS ALSO DEVELOPED IN THE SOUTHWESTERN QUADRANT...
 WHICH IS LIKELY HELPING TO SUSTAIN THE STRONGER WINDS IN THAT
 REGION AS REPORTED PREVIOUSLY. UW-CIMSS ADT ESTIMATES HAVE BEEN
 STEADILY INCREASING...AND THE MOST RECENT 2-HOUR AVERAGE IS T2.7/39
 KT. AS A RESULT...THE DEPRESSION HAS BEEN UPGRADED TO TROPICAL
 STORM RINA...THE SEVENTEENTH NAMED STORM OF THE SEASON.
  
 RINA IS FORECAST TO REMAIN OVER SSTS OF NEAR 30C FOR THE NEXT 72-96
 HOURS. IN ADDITION...DURING THE 24-48 HOUR TIME PERIOD...THE
 CYCLONE WILL BE MOVING OVER SOME VERY HIGH UPPER-OCEAN CONTENT THAT
 IS MORE THAN 10 TIMES THE VALUE THE STORM IS CURRENTLY TRAVERSING.
 THE UPPER-LEVEL OUTFLOW HAS BEEN STEADILY INCREASING AND IS
 EXPECTED TO IMPROVE EVEN MORE THROUGH 72 HOURS AS RINA MOVES UNDER
 AN UPPER-LEVEL RIDGE AXIS THAT WILL PRODUCE OUTFLOW CHANNELS TO THE
 NORTH AND SOUTH. SO THERE IS PLENTY OF HEAT AND VENTILATION
 AVAILABLE FOR STRENGTHENING TO OCCUR. THE ONLY POSSIBLE INHIBITING
 FACTOR IS VERY DRY MID-LEVEL AIR LOCATED OVER THE SOUTHERN GULF OF
 MEXICO AND YUCATAN CHANNEL...WHICH COULD BE ENTRAINED INTO THE
 CYCLONE AT 48 HOURS AND BEYOND. AS A RESULT...THE INTENSITY
 FORECAST WILL REMAIN ON THE CONSERVATIVE SIDE AND LIES CLOSE TO THE
 INTENSITY CONSENSUS MODEL ICON...AND THE STATISTICAL-DYNAMICAL
 MODEL...LGEM.
  
 THE INITIAL MOTION ESTIMATE IS 335/7 KT BASED ON RECON FIXES. THE
 FORECAST TRACK DEPENDS HEAVILY ON THE INTENSITY FORECAST. SINCE THE
 OFFICIAL INTENSITY FORECAST IS MUCH MORE ROBUST THAN WHAT THE
 GFS...NOGAPS...CANADIAN...AND GFDL MODELS ARE FORECASTING FOR THE
 NEXT 48 HOURS AND BEYOND...THOSE MODEL SOLUTIONS OF A WESTWARD OR
 EVEN WEST-SOUTHWESTWARD MOTION FROM THE CURRENT POSITION HAVE BEEN
 DISCOUNTED. IN CONTRAST...THE HWRF AND UKMET MODELS ARE FORECASTING
 A STRONGER AND DEEPER CYCLONE THROUGHOUT THE THE FORECAST PERIOD...
 WHICH LOOKS MORE LIKELY GIVEN THE RECENT UPWARD TRENDS IN SATELLITE
 AND UPPER-AIR DATA. AS A RESULT...THE EXPECTED FORECAST SCENARIO
 CALLS FOR RINA TO MOVE NORTHWESTWARD THROUGH A WEAKNESS IN THE
 SUBTROPICAL RIDGE FOR THE NEXT 12 HOURS OR SO. AS A VIGOROUS
 SHORTWAVE TROUGH CURRENTLY MOVING EASTWARD ACROSS THE CENTRAL AND
 EASTERN GULF OF MEXICO PASSES EAST OF FLORIDA TOMORROW...THE RIDGE
 SHOULD BUILD BACK IN TO THE NORTH OF RINA...FORCING THE CYCLONE ON
 A SLOW WEST-NORTHWESTWARD TRACK UNTIL DAY 4. AFTER THAT...ANOTHER
 STRONG SHORTWAVE TROUGH IS FORECAST TO DIG SOUTHEASTWARD FROM THE
 SOUTHERN PLAINS AND INTO THE GULF OF MEXICO...WHICH IS EXPECTED TO
 WEAKEN THE SUBTROPICAL RIDGE ONCE AGAIN AND ALLOW RINA TO TURN
 NORTHWARD NEAR THE YUCATAN PENINSULA. THE OFFICIAL FORECAST TRACK
 LIES TO THE RIGHT OF THE PREVIOUS ADVISORY TRACK AND THE CONSENSUS
 MODELS..AND IS CLOSE TO A BLEND OF THE UKMET...HWRF...AND ECMWF
 MODEL TRACKS.
  
 IN THE SHORT TERM...HEAVY RAINFALL AND FLOODING WILL BE SIGNIFICANT
 THREATS FOR NORTHERN HONDURAS WHERE 8-15 INCHES OF RAIN HAVE
 ALREADY FALLEN DURING THE PAST 3 DAYS.
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  24/0300Z 16.4N  82.2W   35 KT  40 MPH
  12H  24/1200Z 16.8N  82.6W   40 KT  45 MPH
  24H  25/0000Z 17.3N  83.4W   45 KT  50 MPH
  36H  25/1200Z 17.5N  84.3W   50 KT  60 MPH
  48H  26/0000Z 17.7N  85.1W   55 KT  65 MPH
  72H  27/0000Z 17.9N  86.2W   60 KT  70 MPH
  96H  28/0000Z 18.9N  87.4W   65 KT  75 MPH
 120H  29/0000Z 20.0N  87.4W   65 KT  75 MPH
  
 $$
 FORECASTER STEWART