000 WTNT41 KNHC 232035 TCDAT1 SUBTROPICAL STORM JERRY DISCUSSION NUMBER 3 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL112007 500 PM EDT SUN SEP 23 2007 JERRY IS BEGINNING TO TAKE ON A MORE TROPICAL APPEARANCE ON VISIBLE SATELLITE IMAGES. LOW CLOUD LINES ARE WRAPPING MORE TIGHTLY AROUND THE CENTER AND THERE IS SOME DEEP CONVECTION NOT TOO FAR TO THE NORTHEAST OF THE CENTER. AMSU DATA SUGGEST THAT THE CYCLONE HAS ALREADY ACQUIRED A SHALLOW TO MODERATE DEPTH WARM CORE. SATELLITE CLASSIFICATIONS REMAIN SUBTROPICAL T2.5 AND THE OVERALL AMOUNT OF DEEP CONVECTION IS LIMITED...SO THE CYCLONE WILL STILL BE DESIGNATED AS A 35-KT SUBTROPICAL STORM FOR THIS ADVISORY. JERRY WILL PROBABLY MAKE THE TRANSITION TO A TROPICAL CYCLONE WITHIN THE NEXT 12 HOURS. SOME STRENGTHENING IS EXPECTED...HOWEVER THE INTENSIFICATION PROCESS WILL SOON BE CURTAILED BY COOLING SSTS AND INCREASING SOUTHWESTERLY SHEAR. A LARGE AND POWERFUL EXTRATROPICAL CYCLONE MOVING OFF OF THE CANADIAN MARITIMES IS FORECAST TO ABSORB JERRY IN 36-48 HOURS...IF NOT SOONER. JERRY HAS BEGUN TO MOVE SLOWLY NORTHWARD...360/5. AS THE STEERING FLOW INCREASES IN ASSOCIATION WITH THE MID-TROPOSPHERIC TROUGH DIGGING OFF OF SOUTHEASTERN CANADA...JERRY SHOULD ACCELERATE NORTH- NORTHEASTWARD BEFORE THE LARGER EXTRATROPICAL SYSTEM CATCHES UP TO THE TROPICAL CYCLONE...AND ABSORBS IT. THE OFFICIAL TRACK FORECAST IS SIMILAR TO THE PREVIOUS ONE AND IS IN GOOD AGREEMENT WITH THE CONSENSUS OF THE DYNAMICAL MODELS. FORECAST POSITIONS AND MAX WINDS INITIAL 23/2100Z 36.8N 46.3W 35 KT 12HR VT 24/0600Z 38.5N 45.1W 40 KT...TROPICAL 24HR VT 24/1800Z 41.7N 42.3W 45 KT...TROPICAL 36HR VT 25/0600Z 47.0N 38.5W 45 KT...BECOMING EXTRATROPICAL 48HR VT 25/1800Z...ABSORBED BY LARGER EXTRATROPICAL CYCLONE $$ FORECASTER PASCH