2017 Atlantic hurricane season (Bob's active scenario)

The 2017 Atlantic hurricane season was a very active season that resulted in the formation of 18 tropical cyclones, 17 named storms, 11 hurricanes and 6 major hurricanes. This season had the most major hurricanes since the hyperactive 2005 season. The above-normal activity in this season was caused by warm sea surface temperatures in the Atlantic and a lack of El Nino in the Pacific.

Tropical Storm Arlene
A cut-off low pressure area developed in mid-April along a cold front in the North Atlantic. It slowly lost its frontal characteristics and developed into Subtropical Depression One by 18:00 UTC on 18:00 UTC on April 18. Little strengthening occurred over the next day. However, the depression strengthened to Subtropical Storm Arlene at 06:00 UTC on April 20. This made Arlene the second April named storm in the Atlantic on record. 12 hours later, Arlene reached its peak intensity with maximum sustained winds of 60 mph as an eye-like feature appeared on satellite. Convection began to diminish later that night, and Arlene began to weaken slightly. However, winds remained near 50 mph until the cyclone transitioned into an extratropical low by 12:00 UTC on April 21. Arlene did not affect any land areas.