000 WTNT41 KNHC 310232 TCDAT1 Hurricane Oscar Discussion Number 17 NWS National Hurricane Center Miami FL AL162018 1100 PM AST Tue Oct 30 2018 While conventional satellite imagery continues to show an area of deep convection over the center of Oscar, recent microwave data suggest that the inner core has become fragmented and that the circulation is tilted from southwest to northeast. The overall cloud pattern has also expanded northward as Oscar begins to interact with a frontal zone that is approaching the system from the northwest. A blend of the latest Dvorak T- and Current Intensity (CI) numbers yields an initial wind speed of 70 kt for this advisory. Oscar will be moving over decreasing SSTs and into an area of higher vertical wind shear tonight and Wednesday which is likely to cause some additional weakening during that time. The hurricane should complete its extratropical transition in about 24 hours, and the dynamical models indicate that the post-tropical cyclone is likely to maintain 60-65 kt winds for at least another couple of days. Some weakening is expected by 96 hours before the system merges with another low pressure area over the far northeastern Atlantic. Oscar has turned northeastward and continues to accelerate. An additional increase in forward speed is anticipated during the next day or two, as the cyclone becomes embedded within deep-layer southwesterly flow ahead of a mid-latitude trough. Late in the period, the post-tropical low is forecast to slow down over the northeastern Atlantic. The track guidance remains in good agreement, except for some forward speed differences late in the period. The NHC track forecast is once again close to the various consensus aids and very similar to the previous advisory. Large swells from Oscar are expected to continue to affect portions of the coast of Bermuda through Wednesday. Please consult products from your local weather office as these conditions could cause life-threatening surf and rip currents. FORECAST POSITIONS AND MAX WINDS INIT 31/0300Z 32.8N 55.2W 70 KT 80 MPH 12H 31/1200Z 35.6N 52.6W 65 KT 75 MPH 24H 01/0000Z 40.2N 48.9W 65 KT 75 MPH...POST-TROP/EXTRATROP 36H 01/1200Z 44.3N 44.4W 65 KT 75 MPH...POST-TROP/EXTRATROP 48H 02/0000Z 48.2N 38.7W 60 KT 70 MPH...POST-TROP/EXTRATROP 72H 03/0000Z 55.2N 24.3W 60 KT 70 MPH...POST-TROP/EXTRATROP 96H 04/0000Z 61.0N 12.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 120H 05/0000Z...MERGED WITH LARGER EXTRATROPICAL LOW $$ Forecaster Brown