ZCZC MIATCDAT2 ALL TTAA00 KNHC DDHHMM Hurricane Jose Discussion Number 51 NWS National Hurricane Center Miami FL AL122017 1100 PM EDT Sun Sep 17 2017 Jose's cloud pattern has transformed from one with a tight inner core to one with a large convective band over the northern semicircle that wraps around the center. This change in structure can be seen in recent microwave imagery and aircraft data that show an expansion of the radius of maximum winds. Data from NOAA and Air Force Reserve Hurricane Hunter aircraft still support an initial wind speed of 80 kt, but the minimum pressure has risen several millibars since this morning. Strong southwesterly shear and gradually decreasing sea surface temperatures along the track of Jose are expected to cause gradual weakening, however Jose is forecast to maintain hurricane intensity through 48 hours. Around that time, Jose is forecast to pass north of the north wall of the Gulf Stream and over much cooler waters, which will likely result in an additional decrease in intensity at 72 h and beyond. The NHC intensity forecast is in good agreement with the SHIPS guidance through 72 h, and closer to the global models at days 4 and 5. Jose is moving northward at about 8 kt around the western portion of a mid-level ridge over the western Atlantic. The track forecast reasoning is the same as the previous advisory. Jose should continue northward during the next day or so, then turn north- northeastward as a broad mid-latitude trough passes north of the hurricane. After the trough passes Jose's longitude in about 72 h, the cyclone will be left within weak steering currents and is expected to drift eastward, then southeastward and southward late in the forecast period. The NHC track forecast through 72 h is virtually on top of the previous advisory. The latest dynamical model guidance takes Jose a little more westward very late in the period, and the new NHC track forecast has been shifted to the left at day 5, close to the latest ECMWF ensemble mean. KEY MESSAGES: 1. While the center of Jose is currently forecast to remain offshore of the U.S. coast, the large cyclone could cause some direct impacts from Delaware northward to New England, and any deviation to the left of the NHC forecast track would increase the likelihood and magnitude of those impacts. A tropical storm watch is now in effect from the Delaware coast to southeastern Massachusetts. Interests elsewhere along the U.S. east coast from North Carolina to New England should monitor the progress of Jose through the next several days. 2. Minor to moderate coastal flooding is possible from Delaware to southern New England during the next several days. Please see products issued by local National Weather Service forecast offices. 3. Swells generated by Jose are affecting Bermuda, the Bahamas, and much of the U.S. east coast. These swells are likely to cause dangerous surf and rip current conditions for the next several days in these areas. 4. Jose will produce heavy rain as it passes near southern New England and the mid-Atlantic on Tuesday and Wednesday. Total accumulations of three to five inches are expected over eastern Long Island, southern Rhode Island, and southeast Massachusetts, including Martha's Vineyard and Nantucket. Based on the current forecast, the risk of flooding will be limited in scope. Any deviation to the left of the forecast track, however, could bring heavier and more widespread rainfall to southern New England, Long Island, New York City, and New Jersey. If this deviation were to occur, the risk of urban flash flooding and some river flooding would increase. FORECAST POSITIONS AND MAX WINDS INIT 18/0300Z 32.2N 71.6W 80 KT 90 MPH 12H 18/1200Z 33.4N 71.6W 75 KT 85 MPH 24H 19/0000Z 34.9N 71.6W 75 KT 85 MPH 36H 19/1200Z 36.6N 71.6W 70 KT 80 MPH 48H 20/0000Z 38.3N 71.0W 65 KT 75 MPH 72H 21/0000Z 40.2N 68.8W 55 KT 65 MPH 96H 22/0000Z 39.5N 68.0W 50 KT 60 MPH 120H 23/0000Z 38.5N 68.0W 45 KT 50 MPH...POST-TROPICAL $$ Forecaster Brown NNNN