965 
 WTNT43 KNHC 240832
 TCDAT3
  
 TROPICAL STORM RINA DISCUSSION NUMBER   3
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL182011
 500 AM EDT MON OCT 24 2011
  
 THE CLOUD PATTERN OF RINA HAS NOT BECOME BETTER ORGANIZED OVER THE
 PAST SEVERAL HOURS. THERE IS ONE LARGE CLUSTER OF DEEP CONVECTION
 JUST TO THE NORTH OF THE ESTIMATED CENTER POSITION WITH A COUPLE OF
 ADJACENT SMALLER CLUSTERS...BUT NOT MUCH EVIDENCE OF CURVED BANDS.
 VERY LITTLE THUNDERSTORM ACTIVITY IS CURRENTLY OCCURRING OVER THE
 SOUTHERN HALF OF THE CIRCULATION. THE INITIAL WIND SPEED IS HELD AT
 35 KT IN AGREEMENT WITH THE LATEST OBJECTIVE DVORAK INTENSITY
 ESTIMATES FROM UW/CIMSS. RINA IS IN AN ENVIRONMENT OF MODERATE
 SOUTH-SOUTHEASTERLY VERTICAL BUT IS EXHIBITING FAIRLY WELL-DEFINED
 UPPER-LEVEL OUTFLOW OVER ALL BUT THE SOUTHEASTERN QUADRANT OF THE
 CIRCULATION. THE SHIPS GUIDANCE INDICATES THAT A SLIGHT LESSENING
 OF THE SHEAR COULD OCCUR IN THE NEXT COUPLE OF DAYS. TOTAL
 PRECIPITABLE WATER IMAGERY ALONG WITH SURFACE AND RADIOSONDE DATA
 SHOW A SIGNIFICANTLY DRIER LOW- TO MID-TROPOSPHERIC AIR MASS EXISTS
 JUST TO THE NORTH AND WEST OF THE STORM. GIVEN THESE MARGINALLY
 CONDUCIVE ENVIRONMENTAL FACTORS...ONLY SLOW STRENGTHENING IS
 FORECAST. THE OFFICIAL INTENSITY FORECAST IS VERY SIMILAR TO THE
 LGEM GUIDANCE AND BELOW THE GFDL AND HWRF MODELS.
  
 USING A COMBINATION OF CENTER FIXES FROM GEOSTATIONARY AND MICROWAVE
 IMAGERY YIELDS AN INITIAL MOTION ESTIMATE OF 330/5.  A 500 MB SHORT
 WAVE TROUGH IS CURRENTLY PASSING TO THE NORTH AND WILL SOON BYPASS
 THE TROPICAL CYCLONE.  AFTER THE TROUGH DEPARTS THE AREA...A WEAK
 RIDGE IS FORECAST TO DEVELOP TO THE NORTH OF RINA.  THIS STEERING
 PATTERN SHOULD CAUSE THE CYCLONE TO TURN TOWARD THE WEST...BUT AT A
 VERY SLOW RATE OF FORWARD SPEED...DURING THE NEXT 48 HOURS.  BY THE
 END OF THE FORECAST PERIOD A STRONGER TROUGH MOVES INTO THE EASTERN
 UNITED STATES...WHICH SHOULD INDUCE A NORTHWARD TURN.  THE OFFICIAL
 TRACK FORECAST IS CLOSE TO A CONSENSUS OF THE GLOBAL MODELS...WHICH
 ARE WELL TO THE SOUTH AND WEST OF THE GFDL AND HWRF.  THESE LATTER
 MODELS ARE PREDICTING RINA TO BECOME A STRONG HURRICANE THAT WOULD
 RESPOND TO THE DEEP-LAYER SOUTHWESTERLY FLOW OVER THE EASTERN GULF. 
 GIVEN THE PREDICTED ATMOSPHERIC ENVIRONMENT...SUCH A SCENARIO SEEMS
 UNLIKELY AT THIS TIME.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  24/0900Z 16.7N  82.3W   35 KT  40 MPH
  12H  24/1800Z 17.0N  82.9W   40 KT  45 MPH
  24H  25/0600Z 17.4N  83.6W   45 KT  50 MPH
  36H  25/1800Z 17.5N  84.3W   50 KT  60 MPH
  48H  26/0600Z 17.6N  85.0W   55 KT  65 MPH
  72H  27/0600Z 18.5N  86.5W   60 KT  70 MPH
  96H  28/0600Z 19.5N  87.0W   65 KT  75 MPH
 120H  29/0600Z 20.5N  87.0W   65 KT  75 MPH
  
 $$
 FORECASTER PASCH/LANDSEA