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| #875060 (Received by flhurricane at: 10:43 AM 16.Sep.2016) TCDAT1 TROPICAL STORM JULIA DISCUSSION NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL AL112016 1100 AM EDT FRI SEP 16 2016 Julia continues to feel the impact of 25 to 35 kt of westerly vertical wind shear, as the main deep convection remains about 40 to 60 n mi east of the low-level center. Various subjective and objective satellite intensity estimates are near 35 kt, and that remains the initial intensity. It is noted that buoy 41002 located about 55 n mi northeast of the center is reporting winds of less than 30 kt, so it is possible that initial intensity is a little generous. There is decreasing confidence in the intensity forecast. While Julia is expected to stay in a strong shear environment for the next 60 hours or so, the dynamical models suggest that the upper-level winds over the cyclone may be less than forecast yesterday. After 60 hours, all guidance suggests that the shear should decrease, and at that time the Canadian and UKMET models show re-intensification. On the other hand, the GFS and ECMWF forecast Julia to continue to weaken even in the more favorable upper-level winds. The new intensity forecast stays with the scenario of the previous forecast in calling for the shear to cause the cyclone`s demise. However, this forecast is on the low edge of the intensity guidance, and the chances that Julia will survive and re-intensify are higher than they were 24 hours ago. Julia continues to move erratically east-southeastward with an initial motion of 105/6. The cyclone is expected to meander for the next 2 days or so in weak steering flow. In 3-4 days, a mid- to upper-level trough moving into the northeastern United States should steer the cyclone or its remnants northeastward. There remains a considerable amount of uncertainty in the track forecast due somewhat to the uncertainties in the intensity. A weaker Julia should be slower to move northeastward as shown by the GFS and ECMWF, while a stronger Julia will move somewhat more quickly toward the northeast as shown by the Canadian. Overall, the new forecast track goes with the slower scenario and and is an update of the previous track. FORECAST POSITIONS AND MAX WINDS INIT 16/1500Z 31.1N 75.6W 35 KT 40 MPH 12H 17/0000Z 30.9N 75.4W 35 KT 40 MPH 24H 17/1200Z 30.8N 75.5W 30 KT 35 MPH 36H 18/0000Z 30.9N 75.9W 30 KT 35 MPH 48H 18/1200Z 31.2N 76.1W 30 KT 35 MPH 72H 19/1200Z 32.5N 76.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 20/1200Z 33.0N 74.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 21/1200Z...DISSIPATED $$ Forecaster Beven |
