Tropical Storm OLIVIA

ZCZC MIATCDEP1 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM OLIVIA DISCUSSION NUMBER   4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP162006
800 AM PDT TUE OCT 10 2006
 
THE CYCLONE HAS BEEN MAINTAINING DEEP CONVECTION OVER AND NORTH OF
THE CIRCULATION CENTER FOR 6 TO 9 HOURS NOW.  A TRMM PASS AT 0721
UTC SUGGESTS THIS CONVECTION HAS SOME BANDING STRUCTURE...AND
DVORAK INTENSITY ESTIMATES FROM THE THREE AGENCIES RANGE FROM 35 TO
45 KT.  ON THIS BASIS...THE DEPRESSION IS UPGRADED TO A 40 KT
TROPICAL STORM.  ONLY A LITTLE MORE DEVELOPMENT IS EXPECTED DUE TO
SOUTHERLY SHEAR...WHICH IS FORECAST TO SHIFT TO SOUTHWESTERLY AND
INCREASE AFTER 24 HOURS.  THIS...COUPLED WITH COOLER WATERS FROM
36-72 HOURS...IS EXPECTED TO RESULT IN DISSIPATION BEFORE THE END
OF THE FORECAST PERIOD.

THE INITIAL MOTION ESTIMATE IS 005/5...BASED IN PART ON THE TRMM
PASS.  OLIVIA IS MOVING AROUND THE PERIPHERY OF A MID-LEVEL
RIDGE...AND SHOULD SOON BE FEELING THE EFFECTS OF A LARGE MID- TO
UPPER-LEVEL TROUGH TO THE NORTHWEST OF THE CYCLONE.  ALL GUIDANCE
TURNS OLIVIA SHARPLY NORTHEASTWARD WITHIN THE NEXT 24 HOURS...BUT
THERE IS A LARGE AMOUNT OF SPREAD IN THE GUIDANCE AFTER THAT.  THE
UKMET AND ECMWF MODELS WEAKEN THE CYCLONE AND TAKE IT SLOWLY
EASTWARD IN THE LOW-LEVEL FLOW...WHILE THE GFDL MAINTAINS A MORE
COHERENT STRUCTURE AND CONSEQUENTLY FOLLOWS A DEEPER FLOW MORE
RAPIDLY TO THE NORTHEAST.  THE GFS APPARENTLY WANTS TO HAVE IT BOTH
WAYS...SPLITTING OLIVIA INTO TWO VORTICITY MAXIMA...ONE OF WHICH
GOES NORTHEASTWARD AND A WEAKER LOBE THAN LINGERS TO THE SOUTH.  I
AM INCLINED TO THINK THAT OLIVIA WILL FOLLOW NORMAN'S LEAD...WHICH
CURRENTLY APPEARS TO BE IN THE PROCESS OF SHEARING OFF AND SLOWING
DOWN.  THE OFFICIAL FORECAST IS A LITTLE SLOWER AND TO THE RIGHT OF
THE PREVIOUS FORECAST...AND FAIRLY CLOSE TO THE CONU CONSENSUS.
  
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      10/1500Z 14.6N 127.5W    40 KT
 12HR VT     11/0000Z 15.3N 126.9W    45 KT
 24HR VT     11/1200Z 16.2N 125.6W    45 KT
 36HR VT     12/0000Z 17.0N 123.7W    40 KT
 48HR VT     12/1200Z 17.7N 121.8W    35 KT
 72HR VT     13/1200Z 19.0N 118.0W    25 KT...REMNANT LOW
 96HR VT     14/1200Z 20.0N 114.5W    20 KT...REMNANT LOW
120HR VT     15/1200Z...DISSIPATED
 
$$
FORECASTER FRANKLIN
 
NNNN