000
WTPZ42 KNHC 291429
TCDEP2
TROPICAL STORM BORIS DISCUSSION NUMBER  10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP022008
800 AM PDT SUN JUN 29 2008
 
MICROWAVE DATA CONTINUE TO SHOW THAT THE CENTER OF BORIS IS LOCATED
ON THE NORTHERN EDGE OF DEEP CONVECTION DUE TO SHEAR.  THE OUTFLOW
APPEARS TO BE A LITTLE BETTER DEFINED IN ALL QUADRANTS...BUT
CONVECTION REMAINS ASYMMETRIC. T-NUMBERS HAVE NOT CHANGED SO
INITIAL INTENSITY IS KEPT AT 45 KNOTS. MOST OF THE GLOBAL MODELS
INDICATE THAT A LARGER SCALE CYCLONIC CIRCULATION ASSOCIATED WITH A
DISTURBANCE FORECAST TO DEVELOP SOUTH OF MEXICO WILL BE THE
PREVAILING FLOW.  IN FACT...THE GFS ABSORBS BORIS INTO THE NEW
DISTURBANCE. THIS WOULD DISCOURAGE TO FORECAST AN INCREASE IN
INTENSITY. IN ADDITION...SHIPS MODEL GRADUALLY WEAKEN BORIS MAINLY
DUE TO DRY STABLE AIR APPROACHING THE CYCLONE. ONLY THE GFDL AND
HWFR MODELS STRENGTHEN BORIS IN THE NEAR TERM BUT THEN WEAKEN IT
THEREAFTER.  THEREFORE...THE BEST OPTION AT THIS TIME IS TO
GRADUALLY WEAKEN BORIS.
 
THE INITIAL MOTION IS 270 DEGREES AT 8 KNOTS. SINCE THE STEERING
CURRENTS ARE FORECAST TO WEAKEN WITH THE DEVELOPMENT OF THE NEW
DISTURBANCE...THE OFFICIAL FORECAST CALLS FOR A WESTWARD MOTION WITH
A GRADUAL REDUCTION IN FORWARD SPEED.  BY DAY 3...BORIS SHOULD BE A
REMNANT LOW MOVING SLOWLY WESTWARD. THIS IS THE SCENARIO PROVIDED BY
MOST OF THE TRACK GUIDANCE. ALTHOUGH...SOME GLOBAL MODELS ARE
BEGINNING TO FORECAST AN EASTWARD TURN ASSUMING THAT BORIS WILL
BECOME ABSORBED BY THE NEW DISTURBANCE FORECAST TO DEVELOP.
 
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      29/1500Z 15.0N 116.2W    45 KT
 12HR VT     30/0000Z 15.0N 117.5W    40 KT
 24HR VT     30/1200Z 15.0N 119.0W    35 KT
 36HR VT     01/0000Z 15.0N 120.5W    30 KT
 48HR VT     01/1200Z 15.0N 122.0W    25 KT
 72HR VT     02/1200Z 15.0N 124.0W    25 KT...REMNANT LOW
 96HR VT     03/1200Z 15.0N 126.0W    25 KT...REMNANT LOW
120HR VT     04/1200Z 15.0N 128.0W    20 KT...REMNANT LOW
 
$$
FORECASTER AVILA