Subtropical Depression TWENTY-TWO

ZCZC MIATCDAT2 ALL
TTAA00 KNHC DDHHMM
SUBTROPICAL DEPRESSION TWENTY-TWO DISCUSSION NUMBER   2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT SAT OCT 08 2005
 
CONVECTION ASSOCIATED WITH SUBTROPICAL DEPRESSION TWENTY-TWO HAS
DECREASED SOMEWHAT DURING THE DAY...WITH THE OUTER BAND SEEN
EARLIER DISSIPATING AND THE LOW-LEVEL CENTER BECOMING FULLY EXPOSED
FOR A TIME.  DURING THE PAST COUPLE OF HOURS...A NEW BURST HAS
FORMED JUST WEST-NORTHWEST OF THE CENTER.  SATELLITE INTENSITY
ESTIMATES ARE SUBTROPICAL 35-40 KT FROM SAB...SUBTROPICAL 25-30 KT
FROM TAFB...AND TROPICAL 25 KT FROM AFWA.  THE INITIAL INTENSITY
WILL REMAIN 30 KT BASED ON A BLEND OF THESE ESTIMATES AND THE
OVERALL ORGANIZATION BEING SIMILAR TO THAT OF 6 HR AGO.

THE INITIAL MOTION IS NOW 300/17.  OTHER THAN THAT...THERE IS LITTLE
CHANGE IN THE FORECAST PHILOSOPHY FROM THE PREVIOUS PACKAGE. BEFORE
36 HR...THE CYCLONE SHOULD MOVES GENERALLY WEST-NORTHWESTWARD WITH
SOME DECELERATION BETWEEN A LARGE DEEP-LAYER RIDGE TO THE NORTH AND
A LARGE MID/ UPPER-LEVEL LOW TO THE SOUTH.  AFTER 36-48 HR...THE
TRACK FORECAST BECOMES LOW CONFIDENCE AS A SIGNIFICANT SPREAD
APPEARS IN THE GUIDANCE.  IF THE LARGE-SCALE MODELS ARE RIGHT...A
SECOND LOW PRESSURE AREA WILL FORM SOUTH AND SOUTHEAST OF THE
SUBTROPICAL DEPRESSION...WHICH COULD STEER THE SYSTEM MORE
WESTWARD.  ON THE OTHER HAND...IF THE NEW LOW IS SLOWER TO FORM OR
TROUGHING CONTINUES ALONG THE EAST COAST OF THE UNITED STATES AS
SUGGESTED BY THE LARGE-SCALE MODELS...THE CYCLONE COULD TURN MORE
TOWARD THE NORTH.  THE TRACK FORECAST AFTER 48 HR CONTINUES TO CALL
FOR A GRADUAL NORTHWARD TURN AT A DECREASING FORWARD SPEED ON THE
PREMISE THAT THE U. S. MID/UPPER-LEVEL TROUGH WILL BE THE DOMINANT
STEERING MECHANISM.
 
THE DEPRESSION REMAINS IN DEEP-LAYER EASTERLY FLOW NORTH OF THE
MID/UPPER-LEVEL LOW WITH ABOUT 15 KT OF SHEAR.  THE SHIPS MODEL
SUGGESTS THAT THE SYSTEM WILL UNDERGO PULSES OF SHEAR DURING THE
NEXT THREE DAYS...AND THEN UNDERGO SIGNIFICANT SHEAR AFTER THREE
DAYS.  THE GFDL AND THE LARGE-SCALE MODELS ALL LOSE THE SYSTEM IN
36-72 HR.  ALL OF THIS...COMBINED WITH SEA SURFACE TEMPERATURES OF
26C-27C ALONG THE FORECAST TRACK...SUGGEST THE CYCLONE COULD
STRUGGLE TO INTENSIFY.  THE INTENSITY FORECAST CALLS FOR MODEST
STRENGTHENING A LITTLE ABOVE THAT OF THE SHIPS MODEL... WITH A PEAK
INTENSITY OF 50 KT IN 48 KT.  THE NEW INTENSITY FORECAST CALLS FOR
A FASTER WEAKENING AFTER 72 HR THAN THE PREVIOUS PACKAGE.  IF THE
LARGE-SCALE MODELS ARE CORRECT ON THE FORMATION OF THE SECOND
LOW...OR IF THE SHIPS MODEL IS RIGHT ABOUT THE SHEAR... THE CYCLONE
COULD WEAKEN EVEN FASTER.  THERE IS STILL A CHANCE THE SYSTEM COULD
FULLY TRANSITION TO A TROPICAL CYCLONE DURING THE NEXT 36-48 HR.
 
FORECASTER BEVEN
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      08/2100Z 29.1N  60.8W    30 KT
 12HR VT     09/0600Z 30.1N  62.8W    35 KT
 24HR VT     09/1800Z 31.1N  65.5W    40 KT
 36HR VT     10/0600Z 31.9N  67.9W    45 KT
 48HR VT     10/1800Z 33.0N  69.8W    50 KT
 72HR VT     11/1800Z 34.5N  72.0W    50 KT
 96HR VT     12/1800Z 36.0N  72.5W    40 KT
120HR VT     13/1800Z 37.5N  72.5W    30 KT
 
 
$$
NNNN