000 WTNT44 KNHC 220834 TCDAT4 TROPICAL STORM NICHOLAS DISCUSSION NUMBER 35 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 4 AM EST WED OCT 22 2003 INCREASING WEST-NORTHWESTERLY VERTICAL SHEAR IS TAKING A TOLL ON NICHOLAS. THE LOW-LEVEL CENTER IS NOW EXPOSED WELL TO THE WEST OF THE DEEP CONVECTION...WHICH HAS DECREASED CONSIDERABLY IN COVERAGE AND INTENSITY OVER THE PAST FEW HOURS. SATELLITE INTENSITY ESTIMATES ARE 35 KT FROM ALL AGENCIES...SO THAT IS THE INITIAL INTENSITY. THE EXPOSED CENTER IS EASY TO FIND EVEN IN THE DARK...AND NICHOLAS IS A BIT SOUTH OF THE PREVIOUS ADVISORY. THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 260/8. DESPITE THIS SWERVE TO THE LEFT...THERE IS LITTLE CHANGE IN THE OVERALL FORECAST PHILOSOPHY. SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE THAT A LARGE AND POWERFUL BAROCLINIC LOW AND ASSOCIATED DEEP-LAYER TROUGH ARE MOVING EASTWARD FROM THE U. S. EAST COAST. THIS SYSTEM SHOULD TURN NICHOLAS NORTHWESTWARD IN 12-24 HR AND NORTHWARD THEREAFTER AS SHOWN IN THE FORECAST TRACK. GUIDANCE IS NOT UNANIMOUS ON THIS...AS BAMM... BAMS...AND LBAR FORECAST A NORTHWESTWARD TRACK WITH NO TURN TO THE NORTH. RIGHT NOW THAT APPEARS UNLIKELY GIVEN THE STRENGTH AND SCOPE OF THE APPROACHING BAROCLINIC SYSTEM. THE VERTICAL SHEAR HAS INCREASED SIGNIFICANTLY OVER THE PAST FEW HOURS AS A SHORT-WAVE TROUGH THAT WAS PARTLY SHIELDING NICHOLAS HAS EITHER DISSIPATED OR PUSHED EAST OF THE STORM. LARGE-SCALE MODELS FORECAST THE SHEAR SHOULD REMAIN STRONG...SO NICHOLAS SHOULD AT LEAST GRADUALLY WEAKEN UNTIL IT IS ABSORBED INTO THE BAROCLINIC SYSTEM IN 72-96 HR. IT SHOULD BE NOTED THAT THE NOGAPS DOES NOT FORECAST THAT ABSORBING...KEEPING NICHOLAS A SEPARATE SYSTEM THROUGH 120 HR. FORECASTER BEVEN FORECAST POSITIONS AND MAX WINDS INITIAL 22/0900Z 18.4N 53.9W 35 KT 12HR VT 22/1800Z 18.8N 55.0W 35 KT 24HR VT 23/0600Z 20.3N 55.7W 30 KT 36HR VT 23/1800Z 22.3N 56.0W 30 KT 48HR VT 24/0600Z 25.5N 56.0W 30 KT 72HR VT 25/0600Z 32.0N 56.0W 30 KT 96HR VT 26/0600Z...ABSORBED BY EXTRATROPICAL LOW