000 WTPZ42 KNHC 290826 TCDEP2 TROPICAL STORM BORIS DISCUSSION NUMBER 9 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP022008 200 AM PDT SUN JUN 29 2008 BORIS CONTINUES TO STRUGGLE WITHIN A STRONG SHEAR ENVIRONMENT. THE LOW-LEVEL CENTER REMAINS PARTIALLY EXPOSED ON THE NORTH SIDE OF DISORGANIZED CONVECTION YIELDING NO CHANGE IN THE SATELLITE INTENSITY ESTIMATES. THE INITIAL INTENSITY IS THUS UNCHANGED AT 45 KT. VERTICAL SHEAR IS EXPECTED TO CONTINUE OR EVEN INCREASE OVER THE CYCLONE DURING THE NEXT DAY OR SO. ADDITIONALLY...BORIS IS EXPECTED TO MOVE OVER PROGRESSIVELY COOLER WATERS BEYOND 36 HOURS. SUCH AN ENVIRONMENT SHOULD RESULT IN GRADUAL WEAKENING DURING THE NEXT COUPLE OF DAYS WITH BORIS EXPECTED TO BECOME A REMNANT LOW IN 3-4 DAYS. THE OFFICIAL INTENSITY FORECAST IS A LITTLE LOWER THAN BEFORE AND IS IN BEST AGREEMENT WITH THE SHIPS AND LGEM MODELS. BORIS IS EXPECTED TO CONTINUE ON A GENERAL WESTWARD MOTION DURING THE NEXT COUPLE OF DAYS AS A MID/UPPER-LEVEL RIDGE NORTH OF THE CYCLONE BUILDS WESTWARD. SUCH A STRAIGHT FORWARD PATTERN WOULD NORMALLY RESULT IN GOOD AGREEMENT AMONGST THE VARIOUS TRACK MODELS. HOWEVER...SEVERAL OF THE GLOBAL MODELS SUGGEST A NEW CYCLONE COULD FORM EAST OF BORIS IN 2-3 DAYS POSSIBLY AFFECTING THE STEERING. IN FACT...THE GFS...ECMWF...AND GFDL SHOW BORIS OR ITS REMNANTS LOOPING BACK TO THE EAST OR NORTHEAST BEYOND 72 HOURS. CONVERSELY...THE UKMET...HWRF...AND NOGAPS MODELS MAINTAIN A WESTWARD MOTION. THE OFFICIAL FORECAST FOLLOWS THE LATTER OF THESE TWO SCENARIOS AND MAINTAINS A WESTWARD...ALBEIT SLOW...MOTION THROUGH THE ENTIRE FORECAST PERIOD. FORECAST POSITIONS AND MAX WINDS INITIAL 29/0900Z 15.0N 115.4W 45 KT 12HR VT 29/1800Z 15.1N 116.6W 40 KT 24HR VT 30/0600Z 15.2N 118.2W 35 KT 36HR VT 30/1800Z 15.3N 119.8W 35 KT 48HR VT 01/0600Z 15.4N 121.4W 30 KT 72HR VT 02/0600Z 15.5N 124.5W 30 KT 96HR VT 03/0600Z 15.5N 127.0W 25 KT 120HR VT 04/0600Z 15.5N 130.0W 20 KT...REMNANT LOW $$ FORECASTER RHOME