679 
 WTNT41 KNHC 271447
 TCDAT1
 TROPICAL STORM BETA DISCUSSION NUMBER   3
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 11 AM EDT THU OCT 27 2005
  
 MORNING SATELLITE IMAGERY SHOWS BETA AS A SMALL BUT WELL ORGANIZED
 TROPICAL STORM.  VISIBLE IMAGERY SHOWS A CENTRAL DENSE OVERCAST
 WITH SOME OUTER BANDING IN BOTH THE EAST AND WEST QUADRANTS...WITH
 INFRARED IMAGERY INDICATING CLOUD TOPS TO -80C.  A RECENT SSM/I
 OVERPASS SHOWS AN SMALL EYEWALL FORMING UNDER THE CDO.  SATELLITE
 INTENSITY ESTIMATES ARE 45 KT FROM TAFB AND SAB...AND THAT IS THE
 INITIAL INTENSITY.
 
 THE CENTER OF BETA IS SOMEWHAT TO THE EAST OF THE PREVIOUS
 ADVISORY...AND THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 350/2. 
 BETA IS DRIFTING TOWARD A WEAKNESS IN THE SUBTROPICAL RIDGE CAUSED
 BY A LARGE DEEP-LAYER TROUGH OVER THE EASTERN UNITED STATES. 
 LARGE-SCALE MODELS SUGGESTS THAT AFTER A SERIES OF SHORTWAVES PASS
 THROUGH THE SOUTHERN END OF THE TROUGH IN THE NEXT 24-36 HR...THE
 TROUGH SHOULD LIFT A LITTLE NORTHWARD AND ALLOW WEAK RIDGING TO
 BUILD ACROSS THE NORTHWESTERN CARIBBEAN.  THIS EVOLUTION SHOULD
 CAUSE BETA TO DRIFT SLOWLY NORTHWARD OR NORTH-NORTHWESTWARD FOR THE
 NEXT 24-36 HR...FOLLOWED BY A WESTWARD MOTION.  ALL THE DYNAMICAL
 MODELS EXCEPT THE CANADIAN...WHICH HAS HAD A NORTHWARD BIAS IN
 SIMILAR SITUATIONS...FOLLOW THIS SCENARIO.  THE NEW FORECAST TRACK
 IS SHIFTED TO THE NORTH AND EAST OF THE PREVIOUS TRACK BASED ON THE
 INITIAL POSITION AND MOTION.  THE FORECAST TRACK NOW CALLS FOR
 LANDFALL IN NORTHEASTERN NICARAGUA IN 72 TO 96 HR.
 
 WITH THE SMALL EYEWALL AND GOOD OUTFLOW IN THE WESTERN SEMICIRCLE...
 BETA APPEARS SET UP FOR RAPID INTENSIFICATION.  INDEED...THE RAPID
 INTENSIFICATION INDEX ATTACHED TO THE SHIPS MODEL SHOWS A 56
 PERCENT CHANCE OF 25 KT OR GREATER STRENGTHENING DURING THE NEXT 24
 HOURS.  THE NEW INTENSITY FORECAST WILL NOT INCREASE QUITE THAT
 MUCH...BUT DOES SHOW SIGNIFICANT STRENGTHENING DURING THE NEXT 72
 HR SIMILAR TO THAT OF THE GFDL.  THE INTENSITY FORECAST MAY NEED TO
 BE REVISED SIGNIFICANTLY UPWARD IN THE NEXT ADVISORY IF CURRENT
 TRENDS CONTINUE.  ONE POSSIBLE RESTRAINING FACTOR IS THAT THE WARM
 WATER OF THE SOUTHWESTERN CARIBBEAN IS RELATIVELY SHALLOW...AND THE
 SLOW MOTION OF BETA WILL LIKELY RESULT IN SOME UPWELLING OF COLD
 WATER.  HOWEVER...THE EFFECTS OF THIS MAY NOT BE FELT FOR 24 HR OR
 MORE.
  
 FORECASTER BEVEN
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      27/1500Z 11.5N  81.3W    45 KT
  12HR VT     28/0000Z 11.9N  81.3W    55 KT
  24HR VT     28/1200Z 12.4N  81.4W    65 KT
  36HR VT     29/0000Z 12.9N  81.7W    75 KT
  48HR VT     29/1200Z 13.3N  82.1W    80 KT
  72HR VT     30/1200Z 13.5N  83.0W    85 KT
  96HR VT     31/1200Z 13.5N  84.5W    40 KT...INLAND
 120HR VT     01/1200Z 13.0N  86.5W    25 KT...DISSIPATING
  
  
 $$