Tropical Storm NICHOLAS
ZCZC MIATCDAT4 ALL TTAA00 KNHC DDHHMM TROPICAL STORM NICHOLAS DISCUSSION NUMBER 25 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 5 PM EDT SUN OCT 19 2003 AFTER A SLIGHT RE-INTENSIFICATION EARLIER TODAY...NICHOLAS IS AGAIN ON A WEAKENING TREND...AS WESTERLY VERTICAL SHEAR RE-ASSERTS ITS INFLUENCE. THE LOW-LEVEL CIRCULATION CENTER BECAME VISIBLE THROUGH THE CIRRUS OVERCAST...EXPOSED TO THE WEST OF THE DENSE CONVECTIVE CLOUD SHIELD. THE INTENSITY ESTIMATE IS REDUCED TO 45 KT FOR THIS ADVISORY. DYNAMICAL GUIDANCE CONTINUES TO SHOW STRONG...AND INCREASING...SHEAR IN STORE FOR NICHOLAS. THUS WEAKENING IS FORECAST...AND THE ENVIRONMENT MAY BECOME SO HOSTILE THAT THE SYSTEM COULD DISSIPATE BEFORE THE END OF THE PERIOD. STEERING CURRENTS REMAIN WEAK...AND THERE HAS BEEN LITTLE APPARENT MOTION OVER THE PAST FEW HOURS. GLOBAL MODELS AND THE GFDL HURRICANE MODEL SHOW A MOTION BETWEEN NORTHWEST AND NORTH OVER THE FORECAST PERIOD WITH VARIATIONS IN FORWARD SPEED. NICHOLAS IS EXPECTED TO SLOWLY WORK ITS WAY THROUGH THE SUBTROPICAL RIDGE AND BECOME INFLUENCED BY A MORE NORTHWARD STEERING FLOW TO THE EAST OF A LARGE MID-LEVEL TROUGH OVER THE EXTREME WESTERN ATLANTIC. THIS ADVISORY'S FORECAST TRACK IS ABOUT THE SAME AS ITS PREDECESSOR. IT IS ALSO SIMILAR TO THE GUNA CONSENSUS AND THE LATEST FSU SUPERENSEMBLE MODEL OUTPUT. FORECASTER PASCH FORECAST POSITIONS AND MAX WINDS INITIAL 19/2100Z 17.7N 47.5W 45 KT 12HR VT 20/0600Z 18.3N 47.9W 45 KT 24HR VT 20/1800Z 18.8N 48.5W 40 KT 36HR VT 21/0600Z 19.4N 49.2W 40 KT 48HR VT 21/1800Z 20.2N 50.0W 35 KT 72HR VT 22/1800Z 22.5N 52.0W 30 KT 96HR VT 23/1800Z 25.5N 52.0W 30 KT 120HR VT 24/1800Z 29.0N 52.0W 25 KT NNNN