Around September 19, another tropical wave entered the Atlantic. It moved west-northwest for the next few days and displayed some impressive thunderstorm activity, though it lacked a well-defined center. The system acquired enough organized to be classified Tropical Depression Seventeen on September 23, when it was roughly halfway between the African coastline and the Lesser Antilles. At the time of formation, the low-level center was rather west of the deepest convection, having outrun the rest of the system. Most of the mid-level spin was similarly displaced east of the center.
Despite battling wind shear, the system's satellite presentation improved steadily and it strengthened into Tropical Storm Philippe shortly after formation, with gradual intensification occurring thereafter. The center of the storm reformed northeast of its previous position on September 24, bringing the low-level circulation closer to the convective canopy. Over the next few days, wind shear increased some more, exposing the center again and slightly weakening Philippe. Sporadic bursts of thunderstorm activity continued to generate gale-force winds well east or southeast of the center, but the cyclone was very poorly organized as it continued generally westward. It turned northwest on September 27, but this motion was short-lived. In fact, Philippe was barely a tropical storm by the 28th: there appeared to be multiple centers of vorticity stretching east to west and the overall circulation was highly elongated.
Complicating the storm's situation further was newly formed Tropical Storm Rina to the east. The two storms influenced each other and began to orbit cyclonically around a common center due to the Fujiwhara effect. On Philippe's part, it slowed dramatically and took an unusual dip toward the southwest beginning late on the 28th and continuing through September 30. During that time, the center again became better defined and the storm deepened a little as a more solid central dense overcast became established.
The influence of Rina waned on October 1 as the distance between the cyclones increased. A mid-level ridge northeast of the storm became the dominant steering feature of Philippe's relatively shallow vortex, and it moved generally west-northwestward the next couple of days. The convection had become more vigorous, but was still displaced south and east of the center by shear for the most part. During the evening of October 2, the center of the storm made landfall in the island of Barbuda. Due to Philippe's structure, however, heavy rains spread into most of the Leeward Islands in the wake of the center's passing.
For the next day, the storm's center continued northwestward, passing north of the remaining Caribbean islands in its path, but the main area of convection moved almost due west into the northeastern Caribbean. This meant that heavy rainfall continued on the islands, but the cyclone itself lost organization as the separation between center and thunderstorm activity became greater and greater. By that night, the circulation was so ill-defined that Philippe was barely a tropical storm. New convection ultimately developed somewhat nearer the shallow vortex as the system turned north. Some of the activity was the result of the interaction of Philippe with a frontal boundary well north of the center, though. Regardless of its origin, this part of the storm swept over Bermuda by October 5 and brought tropical storm conditions there.
The next morning, Philippe's center was absorbed into the larger frontal system and it became post-tropical. The remnant low interacted with another non-tropical low to its west and the combined system ultimately deepened and swept into the upper northeast U.S. and Atlantic Canada by October 8.
The image above shows Philippe on September 27. The center is nearly exposed at the cloud cover's western edge. The storm struggled with wind shear nearly all of its existence.
Philippe was a meandering, long-lived, and hard-to-predict tropical storm. It has the strange distinction of being the first known Atlantic tropical cyclone to last as long as it did (13 days) without achieving maximum winds of more than 50 mph.
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