A new tropical wave entered the Atlantic basin right at the end of August and produced disorganized shower activity as it moved westward. Not much organization occurred until September 4, when conditions became more favorable and thunderstorm activity much more concentrated. By early on September 5, the disturbance was producing winds near tropical storm force. Hours later, the center of circulation was organized enough to name the system Tropical Storm Jose. The newly-formed storm was located about halfway between Africa and the Lesser Antilles and was moving west-northwest.
Moist air and low shear allowed Jose to begin strengthening immediately. A predecessor to an eye was already becoming evident during the afternoon of September 6, and the cyclone was a minimal hurricane by the evening. Simultaneously, Irma and Katia were also hurricanes, making 2017 the first Atlantic season to have three hurricanes at once since 2010. Jose's intensification continued well beyond category 1 strength. During the afternoon of September 7, it became another major hurricane as the eye became well-defined on satellite imagery. The next morning, it exploded into strong category 4 intensity. Jose's heading shifted northwest during the day, bringing on a track to just miss the northern Leeward Islands to the northeast. As it approached the islands during the evening, the storm reached its peak intensity of 155 mph winds and a central pressure of 938 mb, just below category 5 strength.
Partially due to the outflow of Irma, upper-level winds became less favorable for Jose overnight, and a weakening trend had begun by the morning of September 9. The hurricane made its closest approach to the northern Leeward Islands before noon. Fortunately for the islands, which had been devastated less than four days prior by Hurricane Irma, the center passed to the northeast, and wind radii were low on the southwest side. Nevertheless, tropical storm conditions did affect some areas for the better part of the day. The system moved northwest away from the Caribbean that evening, and Jose maintained category 4 strength through the morning of September 10. The eye disappeared that day, however, and the system steadily fell through category 3 strength into category 2 overnight. Very deep convection was still present around the center, however. Atmospheric steering currents were also weakening, causing Jose to lose forward speed and veer toward the north into September 11. During the day a developing mid-level ridge began turning the system toward the east, and its heading was due east by early the next morning. Although the hurricane maintained impressive thunderstorm activity during this time, little to no banding could form in the face of strong wind shear. As a result, Jose decayed into a minimal category 1 hurricane by September 12.
At this point, the system stabilized in intensity, and continued its slow clockwise loop over the western Atlantic by moving southeast overnight and into September 13. Warm waters allowed large pulses of deep convection to continue, offsetting the unfavorable upper-level winds and causing some upward fluctuations in intensity. Later that day, Jose turned sharply south and then west as the nearby ridge continued to evolve. The system lost some organization overnight, and weakened a bit on September 14 to a tropical storm. Another factor that inhibited strengthening later that day and early the next is that Jose was completing its loop and crossing over cooler ocean waters left in its wake when it traveled across the region a few days previously. Nevertheless, the storm remained at the brink of hurricane strength into September 15. That day, it recovered some deep convection as it turned northwest, and restrengthened into a hurricane. The storm still struggled some with dry air over the next day, but gradual strengthening occurred. Having reached the western periphery of the steering ridge, Jose also took an overall turn toward the north, although the center wobbled some to the east and west as it did so. On September 17, Jose reached its secondary peak strength of 90 mph winds and a pressure of 967 mb.
By that evening, Jose was beginning to display some characteristics of an extratropical cyclone. As it passed the latitude of North Carolina well offshore, its inner core weakened but its wind field expanded. Nevertheless, it hung on to minimal hurricane strength over the next day as it continued generally northward. Early on September 19, the cyclone's outermost rain bands swept across the mid-Atlantic coast and southern New England. Later in the day, the system turned toward the northeast, away from the coast, though the system was so large that some coastal rains continued. By this time, the center of circulation had moved north of the warm Gulf Stream waters, resulting in weakening. Jose finally lost hurricane status and became a tropical storm. Gradual decay continued into September 20. Meanwhile, the storm turned toward the east and slowed down, coming nearly to a standstill that night southeast of Cape Cod. Rain continued for portions of southern New England through the 21st. Late that evening, however, Jose no longer had enough convection to remain a tropical cyclone, and was classified post-tropical. The circulation continued to spin down offshore as it moved little over the next few days. It finally dissipated on September 25.
The above image shows Jose at peak intensity approaching the Lesser Antilles.
Jose's long track held it offshore of the U.S. east coast for many days, causing prolonged high surf and rip current risks.
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