000 WTNT42 KNHC 120238 TCDAT2 TROPICAL STORM KATE DISCUSSION NUMBER 13 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122015 1100 PM AST WED NOV 11 2015 Kate continues to undergo extratropical transition. Satellite imagery show that Kate's cloud pattern has become increasingly elongated and asymmetric since the last advisory due to strong westerly shear. The cloud pattern has also taken on a comma-shape appearance, typically a precursor to frontogenesis and a completion of extratropical transition. The initial intensity is lowered to 60 kt, based on a blend of Dvorak CI-numbers from TAFB and SAB. A mid- to upper-level trough is forecast to merge with Kate in about 12 hours or so, which should result in Kate's becoming post-tropical. After this occurs, baroclinic forcing from the trough should allow the post-tropical cyclone to maintain its intensity or perhaps even re-strengthen as indicated in the global models through about 24 hours. Beyond this time, a slow decay is forecast, with the post- tropical cyclone predicted to lose its identity in about 3 days when a new baroclinic development over the far north Atlantic becomes more dominant. The new intensity forecast represents an update of the previous one, with dissipation now shown a day sooner. Kate continues to move rapidly east-northeastward but appears to have slowed down some, and the initial motion estimate is 065/36. As a post-tropical cyclone, Kate's motion is forecast to decrease further during the next during 24 hours while it merges with the extratropical system to the west. A new and potent shortwave trough reaching Atlantic Canada in 2 to 3 days should then cause Kate to accelerate east-northeastward to northeastward until dissipation. The new track forecast is generally slower relative to the previous one, consistent with the multi-model consensus. FORECAST POSITIONS AND MAX WINDS INIT 12/0300Z 40.1N 52.3W 60 KT 70 MPH 12H 12/1200Z 41.2N 50.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 24H 13/0000Z 42.2N 46.8W 55 KT 65 MPH...POST-TROP/EXTRATROP 36H 13/1200Z 43.1N 43.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 48H 14/0000Z 45.3N 37.2W 45 KT 50 MPH...POST-TROP/EXTRATROP 72H 15/0000Z 53.8N 22.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 16/0000Z...DISSIPATED $$ Forecaster Kimberlain