000 WTNT41 KNHC 291501 TCDAT1 HURRICANE DANIELLE DISCUSSION NUMBER 33 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062010 1100 AM AST SUN AUG 29 2010 DANIELLE HAS BEEN GRADUALLY WEAKENING TODAY AS DEPICTED IN THE GEOSTATIONARY AND POLAR ORBITING SATELLITE IMAGERY. VISIBLE AND MICROWAVE SATELLITE IMAGERY FROM THE 0948Z TRMM AND 0950Z SSMIS SUGGEST THAT THE MID-LEVEL CENTER OF DANIELLE IS DISPLACED SOMEWHAT NORTHEAST OF THE SURFACE CENTER. DVORAK CI NUMBERS ARE AT 4.5 FROM TAFB...OR 77 KT...AND 4.0 FROM SAB...OR 65 KT. A 0830Z AMSU INTENSITY ESTIMATE FROM CIMSS SUGGESTED SOMEWHAT HIGHER WINDS...BASED UPON A WELL-DEFINED MID AND UPPER LEVEL WARM CORE. THE INITIAL INTENSITY IS SET AT 75 KT AS A BLEND OF THESE. DANIELLE IS MOVING A BIT FASTER...23 KT...TOWARD THE NORTHEAST THIS MORNING UNDER THE INFLUENCE OF A VIGOROUS SHORTWAVE TROUGH TO ITS NORTHWEST AND A SUBTROPICAL RIDGE TO ITS SOUTHEAST. THE MODELS ARE IN TIGHT AGREEMENT THROUGH 48 HOURS IN DEPICTING MOTION TOWARD THE NORTHEAST AT A SLIGHTLY SLOWER SPEED. THE FORECAST TRACK IS QUITE SIMILAR TO THE MODEL CONSENSUS AND THE PREVIOUS ADVISORY EXCEPT FOR THE 96 HR POINT. THAT FORECAST POSITION IS WEST OF THE PREVIOUS ADVISORY BUT EAST OF THE MODEL CONSENSUS...WHICH SHOWS DANIELLE MOVING NORTH-NORTHWESTWARD WHILE IN THE PROCESS OF IT BECOMING ABSORBED. DANIELLE IS CURRENTLY EXHIBITING SOME BAROCLINICITY WHICH IS BEING MANIFEST THROUGH THE COLD AIR ADVECTION ON THE NORTH AND WEST SIDE OF THE CYCLONE. HOWEVER...AS THE SYSTEM MOVES NORTHEASTWARD AND A SURFACE HIGH REMAINS NEARLY STATIONARY OVER THE MID-ATLANTIC STATES...THE EXTRATROPICAL TRANSITION SHOULD BE DELAYED. DURING THE NEXT DAY OR SO...DANIELLE SHOULD WEAKEN GRADUALLY DUE TO MODERATE VERTICAL SHEAR AND DECREASING SSTS UNDER ITS TRACK. ALL DYNAMICAL MODELS AGREE THAT A FULL EXTRATROPICAL TRANSITION WILL OCCUR IN ABOUT TWO DAYS...AND ET IS INDICATED HERE AT 48 HOUR. AFTER THIS TRANSITION...THE SYSTEM IS LIKELY TO REINTENSIFY SLIGHTLY AND REMAIN A LARGE AND STRONG EXTRATROPICAL CYCLONE THROUGH 4 DAYS. THE INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY AND A BIT HIGHER THAN THE CONSENSUS OF THE STATISTICAL AND HURRICANE MODEL GUIDANCE...AS BAROCLINIC FORCING SHOULD MAINTAIN AT LEAST A HIGH END TROPICAL STORM AS DEPICTED BY THE GLOBAL MODELS. BY DAY 5...THE CYCLONE SHOULD BE ABSORBED BY ANOTHER EXTRATROPICAL CYCLONE IN THE FAR NORTH ATLANTIC. THE OCEAN PREDICTION CENTER PROVIDED POSITION...INTENSITY...AND SIZE GUIDANCE FOR THE EXTRATROPICAL PORTION OF DANIELLE. FORECAST POSITIONS AND MAX WINDS INITIAL 29/1500Z 35.5N 55.5W 75 KT 12HR VT 30/0000Z 38.0N 53.8W 70 KT 24HR VT 30/1200Z 39.7N 51.9W 65 KT 36HR VT 31/0000Z 40.9N 48.5W 60 KT 48HR VT 31/1200Z 43.1N 42.3W 65 KT...POST-TROP/EXTRATROP 72HR VT 01/1200Z 47.0N 34.0W 65 KT...POST-TROP/EXTRATROP 96HR VT 02/1200Z 57.5N 34.0W 55 KT...POST-TROP/EXTRATROP 120HR VT 03/1200Z...DISSIPATED $$ FORECASTER LANDSEA/BERG