739 
 WTNT41 KNHC 020228
 TCDAT1
 TROPICAL STORM OTTO DISCUSSION NUMBER   6
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 10 PM EST WED DEC 01 2004
  
 WHILE THE CONVECTIVE PATTERN IS NOT VERY IMPRESSIVE...A 01/2158Z
 QUIKSCAT OVERPASS INDICATED THAT OTTO HAS MAINTAINED A WELL-DEFINED
 LOW-LEVEL WIND FIELD CONTAINING SEVERAL 30-35 KT UN-FLAGGED WINDS.
 DRIFTING BUOY 44623 JUST SOUTH OF THE CENTER REPORTED A PRESSURE OF
 997.5 MB AT 00Z. THE INITIAL INTENSITY IS MAINTAINED AT 35 KT FOR
 THIS ADVISORY BASED ON A DVORAK T-NUMBER OF T2.5...OR 35 KT...FROM
 TAFB AND THE 35-KT QUIKSCAT WINDS. HOWEVER...THE LOWER CENTRAL
 PRESSURE SUGGESTS THAT THE INTENSITY COULD BE A LITTLE STRONGER.
  
 INITIAL MOTION OVER THE PAST 12 HOURS HAS BEEN 150/06.  THE LATEST
 NHC MODEL SUITE IS QUITE DIVERGENT. THE UKMET IS THE LEFTMOST MODEL
 AND TAKES OTTO DUE EAST WHILE THE NOGAPS MODEL IS THE RIGHTMOST OF
 ALL THE MODELS AND TAKES THE CYCLONE ALMOST DUE SOUTH. HOWEVER...
 ALL THE MODELS AGREE ON A SLOW FORWARD SPEED. AS THE MID-LATITUDE
 WESTERLIES BECOME INCREASINGLY MORE ZONAL OVER THE FORECAST PERIOD
 ...WEAK 500 MB RIDGING IS EXPECTED TO OCCUR NORTH OF OTTO. THIS
 SHOULD GRADUALLY NUDGE THE CYCLONE IN A GENERAL SOUTHEAST TO
 SOUTHERLY DIRECTION. THIS IS ALSO CONSISTENT WITH THE FORECAST
 NORTHWESTERLY COMPONENT OF THE VERTICAL SHEAR VECTOR...WHICH SHOULD
 HELP KEEP THE CONVECTION DISPLACED TO THE SOUTHEAST OF THE CENTER
 AND HELP TO DRAG IT IN A GENERAL SOUTHEASTWARD DIRECTION. THE
 OFFICIAL TRACK IS A LITTLE TO THE RIGHT OF THE PREVIOUS FORECAST
 TRACK AND CLOSE TO THE CONU CONSENSUS MODEL.
 
 THE SHIPS MODEL GRADUALLY INCREASES THE 850-200 MB SHEAR TO 35 KT BY
 36H AND DISSIPATES OTTO BY 48-60H. HOWEVER...GIVEN THAT OTTO
 ORIGINATED FROM A COLD-CORE LOW AND LIKELY DOES NOT EXTEND TO THE
 200 MB LEVEL...THE SHIPS SHEAR VALUES MAY BE EXCESSIVE..GIVEN THAT
 THE 300 MB WIND ACROSS OTTO IS EXPECTED TO BE ABOUT 10 KT LESS THAN
 AT THE 200 MB LEVEL. SINCE OTTO IS ALSO FORECAST TO MOVE OVER
 GRADUALLY WARMER WATER...THE INTENSITY WAS HELD HIGHER THAN THE
 SHIPS MODEL AND SIMILAR TO THE PREVIOUS INTENSITY FORECAST.
  
 FORECASTER STEWART
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      02/0300Z 30.2N  49.7W    35 KT
  12HR VT     02/1200Z 29.6N  49.4W    35 KT
  24HR VT     03/0000Z 28.8N  48.7W    30 KT
  36HR VT     03/1200Z 27.8N  47.8W    30 KT
  48HR VT     04/0000Z 27.0N  47.0W    25 KT...DISSIPATING
  72HR VT     05/0000Z 25.5N  46.0W    25 KT...DISSIPATING
  96HR VT     06/0000Z 24.0N  46.0W    20 KT...REMNANT LOW
 120HR VT     07/0000Z...DISSIPATED
  
  
 $$