ZCZC MIATCDEP2 ALL TTAA00 KNHC DDHHMM TROPICAL STORM ISIS DISCUSSION NUMBER 19 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2 PM PDT SUN SEP 12 2004 ISIS IS SHOWING SIGNS OF WEAKENING. VISIBLE ANIMATION DEPICTS A POORLY DEFINED PARTIALLY EXPOSED LOW-LEVEL CENTER. OUTFLOW BOUNDARIES APPEAR MORE ABUNDANT THAN LOW CLOUD LINES ASSOCIATED WITH THE CENTER. IMAGERY ALSO REVEALS WIDESPREAD STRATOCUMULUS FORCING IN FROM THE NORTH AND NORTHWEST. WHICH LEADS US TO BELIEVE THAT THIS MAY BE RESTRICTING THE MOISTURE CONTENT IN THE LOW/MID LEVELS. WATER VAPOR ANIMATION INDICATES THAT THE EASTERLY SHEAR PERSISTS. SATELLITE CURRENT INTENSITY ESTIMATES FROM ALL AGENCIES REMAIN AT 45 KT. THE INITIAL INTENSITY REMAINS AT 45 KT JUST IN CASE THE CENTER HAS MOVED OR REDEVELOPED FURTHER BENEATH THE CONVECTION. IF THIS IS NOT THE CASE AND THE CURRENTLY UNFAVORABLE ENVIRONMENT CONTINUES...THE INTENSITY WILL HAVE TO BE DECREASED ON THE NEXT ADVISORY. THE SHIPS MODELS HAS CONSISTENTLY BEEN TOO LOW ON THE STRENGTH OF THE EASTERLY SHEAR. 10 TO 20 KT UPPER EASTERLIES REMAIN OVER THE TROPICAL CYCLONE ACCORDING TO THE CIMSS SHEAR ANALYSIS. THE INTENSITY FORECAST REMAINS UNCHANGED FOR NOW. HOWEVER...THE SLOW INTENSIFICATION TREND TO 55 KT IN 48 HOURS MAY BE TOO GENEROUS GIVEN THE CURRENT STATE OF THE ENVIRONMENT. THE INITIAL MOTION IS WESTWARD OR 270/8...WHICH IS SLIGHTLY SLOWER THAN THE PREVIOUS ADVISORY. THE FORECAST TRACK IS BASICALLY AN UPDATE OF THE PREVIOUS FORECAST...AND AGREES WITH THE MODEL CONSENSUS. FORECASTER ROBERTS/BEVEN FORECAST POSITIONS AND MAX WINDS INITIAL 12/2100Z 17.4N 124.1W 45 KT 12HR VT 13/0600Z 17.4N 125.4W 45 KT 24HR VT 13/1800Z 17.4N 127.5W 50 KT 36HR VT 14/0600Z 17.4N 129.5W 50 KT 48HR VT 14/1800Z 17.4N 131.0W 55 KT 72HR VT 15/1800Z 17.4N 133.0W 55 KT 96HR VT 16/1800Z 17.4N 134.0W 55 KT 120HR VT 17/1800Z 17.4N 134.5W 55 KT $$ NNNN
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Page last modified: Sunday, 12-Sep-2004 20:34:31 UTC