KMSP - The 2016 Atlantic hurricane season is officially over now that we have entered December, and it was the first time in a while we could call it “busy”. The overall activity was the highest since 2010 and likely the deadliest since 2005 with perhaps 1700 or more fatalities. (The exact number of fatalities is still unknown because Haiti isn’t exactly sure how many were killed when Matthew passed by). The season ended with 15 named storms, which is 3 more than normal; 7 hurricanes, which is 1 more than normal; and 3 major hurricanes, which is right about average.
The key number though is the Accumulated Cyclone Energy or ACE as it’s called, was 30% above average. The ACE takes into account overall strength of each storm. The stronger the storm, the more ACE it racks up. For example, you could have 15 hurricanes one year, but actually have a smaller ACE number than a year with 4 hurricanes. This could happen because maybe the majority of those 15 hurricanes were weak and only lasted for a few hours, or a day… while those 4 hurricanes were strong and lasted for a week… or maybe even 2. In 2016’s case, hurricane Matthew had a VERY large ACE as it stayed at major hurricane status for over a week, one of longest lived major hurricanes of the last 50 years.
It was mostly hurricane Matthew that increased the ACE so much this season and was one of the strongest storms to ever hit Haiti. It was the first category 5 hurricane in the Atlantic Basin since 2007 and the southernmost Category 5 on record. At peak strength, it packed winds of nearly 200 mph, but thankfully weakened slightly before making a devastating run into Haiti where at least 1500 were killed. It then moved onto Cuba and the US coast, hovering precariously offshore of Florida & Georgia, before making landfall in the Carolinas and bringing devastating rains to the area. 49 people were killed in those 4 states, mostly from flooding and storm surge.
But Matthew wasn’t the only storm of note in 2016. The year was actually bookended by very unusual storms as well. The year started with Alex in January, the first January hurricane since 1938. It formed on Jan. 13 in the northeast Atlantic, a very unusual place in itself, and then passed through the Azores as a Category 1 hurricane and tropical storm, and lost its tropical characteristics on Jan. 15.
Then there’s Otto at the end of the season. Otto formed in the southwest Caribbean in late November, passed just north of Panama, then intensified to a Category 2 hurricane as it made landfall in southern Nicaragua — the southernmost hurricane landfall in Central America. It was the latest hurricane formation in the Caribbean, and the first storm to cross from the Atlantic over to the east Pacific as an intact tropical cyclone since 1996.
While we are “officially” done with the Atlantic hurricane season, it doesn’t mean we can’t see more storms. But as you might imagine, storms forming anytime between December & April are exceedingly rare and to get 2 in back to back years would be unprecedented. But one other unprecedented streak continues; it has now been 11 years since a landfalling major hurricane in the U.S.... The longest such drought in history BY FAR. The graph above shows the amount of days between landfalling major hurricanes.