The Top 10 Earliest 'First' Atlantic Cyclones

These Storms Formed Long Before the Official June 1 Start

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Subtropical Storm Ana forms off the U.S. East Coast (May 8, 2015). NOAA

May 9, 2015

Have you heard the latest weather news? That's right, the Atlantic has already seen its first storm of the 2015 Hurricane Season -- Tropical Storm Ana. No, you didn't miss the season start. Ana is just early; three weeks early, in fact. (The last time a tropical or subtropical storm formed this early in the Atlantic basin was in 2003 by a storm of the same name (talk about a coincidence!). 

Anytime there's talk about early tropical systems (dubbed "pre-season") it often begs the question: Just how early has the first Atlantic storm of a season spun up? Here's a list of the ten earliest, first tropical cyclones (depressions, storms, and hurricanes) that have formed in the Atlantic basin since hurricane record keeping began back in 1851. (Ana ranks as the the #9 earliest!)

"Earliest" Rank Storm Name Formation Date Season Year
10 Subtropical Storm Andrea May 9 2007
9 Tropical Storm Ana May 8 2015
8 Tropical Storm Arlene May 6 1981
7 Tropical Storm (Unnamed) May 5 1932
6 Subtropical Storm (Unnamed) April 21 1992
5 Tropical Storm Ana April 20 2003
4 Hurricane (Unnamed) March 6 1908
3 Tropical Storm (Unnamed) Feb 2 1952
2 Subtropical Storm (Unnamed) Jan 18 1978
1 Hurricane (Unnamed) Jan 3 1938

Mother Nature Doesn't Care When June 1 Is

The next natural question after is, why do pre-season cyclones form? The atmosphere doesn't care when June 1 is if the oceans are primed for brewing a tropical storm. Warmer-than-normal ocean temperatures When they do, it's because ...why?

While pre-season storms are not unheard of, they are considered fairly rare -- occurring on average every 4-5 years. The last May tropical system was Tropical Storm Alberto which formed on May 19, 2012. (It ranks as the 18th earliest tropical cyclone.) Since 1851, only 26 tropical storms or hurricanes have formed before June's arrival. While pre-season storms are not unheard of, they are considered fairly rare -- occurring on average every 4-5 years. The last May tropical system was Tropical Storm Alberto which formed on May 19, 2012. (It ranks as the 18th earliest tropical cyclone.) Since 1851, only 26 tropical storms or hurricanes have formed before June's arrival.

Sources:

NOAA National Hurricane Center Past Track Seasonal Maps, Atlantic Basin. Accessed May 9, 2015.