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| #901970 (Received by flhurricane at: 11:02 AM 08.Sep.2017) TCDAT2 Hurricane Jose Discussion Number 13 NWS National Hurricane Center Miami FL AL122017 1100 AM AST Fri Sep 08 2017 An Air Force Hurricane Hunter plane, the first so far into Jose, found the hurricane was much stronger than previously estimated. A standard 90 percent reduction of the 146-kt peak flight-level wind at 700 mb yields an intensity estimate of about 130 kt, which is the basis for the initial intensity. In the short term, Jose is in a fairly favorable environment. Although the SHIPS-diagnosed shear is near 20 kt, the hurricane is small enough that it has thus far remained sheltered from the upper-level outflow of Hurricane Irma to the west. Internal dynamics will therefore most likely be the driving factor of Jose`s intensity for the next day or so. After that time, all of the intensity guidance forecasts weakening, perhaps assuming that eventually the shear will begin to affect the hurricane. Due to the very high initial intensity of Jose, the intensity forecast is quite a bit higher than the model consensus, even after adjusting for the initial intensity. However, the NHC forecast still follows the model trend of steady weakening beyond 24 hours. The aircraft data also indicated that the center of Jose is a little farther south than previously estimated. Because of that, the NHC track forecast has been shifted slightly south and west of the previous one. Otherwise, there is no significant change to the track forecast, and Jose is still expected to turn northwest before reaching the Leeward Islands on Saturday, as the subtropical ridge begins to retreat eastward. There is fairly good agreement between the global models for the first 48 h. After that, it is still unclear if Jose will begin to move east with an approaching mid-latitude mid-level trough, or if it will remain trapped in light steering flow. As a course of least regret, my forecast splits the difference between these scenarios and shows a slow northeastward motion at day 5. FORECAST POSITIONS AND MAX WINDS INIT 08/1500Z 16.3N 57.1W 130 KT 150 MPH 12H 09/0000Z 16.8N 59.0W 130 KT 150 MPH 24H 09/1200Z 17.7N 61.0W 125 KT 145 MPH 36H 10/0000Z 19.0N 62.9W 120 KT 140 MPH 48H 10/1200Z 20.6N 65.0W 110 KT 125 MPH 72H 11/1200Z 24.2N 68.3W 95 KT 110 MPH 96H 12/1200Z 26.4N 68.6W 85 KT 100 MPH 120H 13/1200Z 28.0N 67.5W 85 KT 100 MPH $$ Forecaster Zelinsky |
