2017 Atlantic hurricane season (Bob/AGCK/Collin/Sassmaster/Nuno/Odile/Money Hurricane/Steve)

The 2017 Atlantic hurricane season was an extremely active season; surpassing the activity of the 2005 season, thus making it the most active Atlantic hurricane season on record.

Tropical Storm Arlene
On December 29th, models began forecasting an organized low forming to the east of Massachusetts on January 1st with maximum sustained winds of 60 miles per hour; as a cold front to the north of Massachusetts formed by December 30th, disturbed weather trailed behind the front as the system quickly got invested by the National Hurricane Center, giving it a 20% chance within 48 hours and a 40% chance within 5 days. Hoewver, as the system began to lose frontal boundaries by December 31st, the chances were upped to 50% within 48 hours and 70% within 5 days. By January 1st, the cold front began to rapidly decay, which eventually the system lost frontal boundaries by 5AM eastern time on January 2nd, upgrading the system to Subtropical Depression One, showing signs of a subtropical system as it began to rapidly intensify, moving north at the same time as the NHC upgraded the system to Subtropical Storm Arlene later that day on January 2nd about 100 miles southeast the coast of Maine, becoming the northernmost tropical storm to be classified ever in the basin. Arlene then began to slowly intensify, as it began to move southeastern at 12 miles per hour, which the speed gradually lessened by January 4th, which the system remained at 50 miles per hour. The system then unexpectedly turned tropical due to a patch of warm waters and limited vertical shear by January 5th, intensifying to 60 miles per hour by the next advisory as the system began turning back to the north due to a large high pressure system stationed to the north of Bermuda, losing tropical characteristics for two advisories before regaining them by January 6th. The system then rapidly intensified to 65 miles per hour with a minimum pressure of 989 millibars early on January 7th, as the system neared Newfoundland, tropical storm warnings and even hurricane watches were issued for the area; the system then intensified to a peak of 70 miles per hour on January 8th before making landfall in Newfoundland in the afternoon, causing flooding, slick roads and power outages, all causing eight fatalities in the process as the system's structure then broke down and split up into two parts after dissipating; one would regenerate into a depression for a brief day while the other part would be absorbed by a larger extratropical cyclone in Ontario. Overall, Arlene caused $700 million in damages and eight fatalities, and one indirect fatality, therefore Arlene was not retired.

Hurricane Bret
On April 8, an extratropical cyclone developed north of the Bahamas. This cyclone rapidly organized to produce winds in excess of 60 mph. Initial conditions such as strong wind shear, cool sea-surface temperatures and dry air limited development of the extratropical cyclone. While most cyclones move north, a ridge of high pressure to the north pushed the extratropical cyclone eastward, towards the eastern Subtropical Atlantic. Early on April 11, frontal features associated with the cyclone dissipated. Convection began to build around the center of the cyclone, and at 21:00 UTC on April 11, the National Hurricane Center designated the cyclone Subtropical Storm Bret. Initially, Bret was not expected to intensify due to cool sea surface temperatures. However, by early on April 12, Bret began to produce hurricane-force winds, but still had a rather elongated appearance. Due to this, Bret was still considered a subtropical storm. However, an eye feature developed later that day as Bret began to turn more tropical. At 21:00 UTC on April 12, Bret was reclassified as a fully tropical hurricane, becoming the first known April hurricane in the Atlantic basin on record. Bret meandered around in a loop, acquiring a peak intensity with 80 mph winds. Hurricane Warnings were issued for the Azores as Bret maintained intensity as it passed to the east of the islands. Bret became extratropical on April 14 while still producing hurricane-force winds. Bret's remnants made landfall in the United Kingdom, producing strong winds and heavy downpours. Bret's remnants caused 7 deaths, all of which were in Ireland and Britain. Damage was light.

Hurricane Gert
On June 14, the National Hurricane Center began monitoring the Bay of Campeche for tropical development. A low pressure area rapidly developed on June 15. On June 16, a Hurricane Hunters aircraft found a closed circulation and designated the system a tropical depression. Later that day, the depression was upgraded to Tropical Storm Gert. Virtually no wind shear and warm waters of 86 degrees F allowed Gert to rapidly intensify into a category 3 hurricane on June 18. Gert rapidly weakened over land, dissipating by June 20. Gert made landfall in Northern Mexico as it tracked northward, causing 56 deaths and $2.56 billion in damages.