We’re about to flip the calendar to June, which marks the start of meteorological summer. It also marks the start of Hurricane season in the Atlantic Basin (North Atlantic Ocean, Caribbean Sea, and Gulf of Mexico).
Hurricane season in the Atlantic runs from June 1 through November 30, but it got off to an extraordinarily early start again in 2017 when Tropical Storm Arlene formed back in April. Alex became the second tropical storm on record during the month of April in the Atlantic when it strengthened on April 20. Arlene stayed out in the open Atlantic without affecting any land areas, before merging with a larger extratropical storm on April 23. The next storm that forms will be given the name Bret.
In a normal season, the Atlantic Basin sees 12 named storms, of which 6 become hurricanes and 3 become major hurricanes (Category 3 or higher on the Saffir-Simpson Scale). While there are plenty of hurricane forecasts out there, these were pioneered by Dr. William Gray. His research team at Colorado State University continues his work, and for this season is calling for 11 named storms, of which 4 could become hurricanes, and 2 major hurricanes. They are scheduled to release an updated forecast on Thursday.
Of course, an active season doesn’t guarantee that a storm will make landfall in the United States though. In 2010, there were 19 named storms, 12 hurricanes, and 5 major hurricanes. Only 1 storm, Tropical Storm Bonnie, made landfall in the United States. On the flip side, 1992 was a quiet season, with just 7 named storms, 4 hurricanes, and 1 major hurricane, with the first named storm not forming until August 16. Of course, that first storm was Andrew, which slammed into South Florida on August 24 as a Category 5 hurricane, one of just 3 Category 5 storms to ever make landfall in the United States.
The peak of the season usually occurs from mid-August through late September, but an early start isn’t unusual. On average, the first named storm of the season occurs on July 9, with the first hurricane forming around August 10. In 2015, there were two tropical storms during May and June (Ana and Bill), while 2012 saw 4 named systems (Alberto, Beryl, Chris, and Debby) with 1 hurricane (Chris) forming before the end of June. Last year, 2 storms formed before the end of May (Hurricane Alex in January, Tropical Storm Bonnie in late May), then 2 more tropical storms in June (Colin and Danielle)
Here in New England, we should always pay attention when a storm is nearing the Bahamas, as those are the ones that have the potential to impact us. Using data back to 1851, a tropical storm makes landfall in Southern New England or Long Island once every 4 years, while a hurricane makes landfall once every 8 years. The last tropical storm to make landfall was Irene, which passed right over New York City in 2011, so we’re about due for another one. As for hurricanes, while we’ve been threatened several times in the past few years, the last one to make landfall was Hurricane Bob in 1991. That 26-year gap is the 2nd longest on record, second only to the 28 year gap between 1896 and 1924. In other words, we are very overdue.
The Atlantic remains fairly quiet right now, and we’re not expecting anything for form in the next few days. Even if something were to form soon and head this way, the waters off of New England are too cold to sustain a tropical system, so we’d see something more like a typical nor’easter. Only two tropical storms have ever made landfall in the Northeast before the end of June. The first was an unnamed minimal tropical storm that crossed Long Island and went into southern Connecticut on May 30, 1908. The other was Tropical Storm Agnes, which made landfall near New York City on June 22, 1972, then caused devastating flooding across parts of the Mid-Atlantic states. In terms of hurricanes, the earliest one to ever make landfall up this way was Hurricane Belle, which slammed into Long Island with 90 mph winds on August 9, 1976. We did have Hurricane Arthur pass just offshore of Nantucket on July 4 in 2014. While it did not make landfall, it made for a rather wet and cool holiday, especially across Cape Cod and southeastern Massachusetts. Statistically, the most likely time for a hurricane to hit New England is between the middle of August and late September. Of the 23 hurricanes that made landfall in New England or Long Island since 1851, 20 of them have done so between August 19 and September 27.
Some of the statistics in this post were supplied by Gary Gray and David Vallee. David is probably the local expert in Southern New England on tropical systems and their impacts on the region. He’s written several papers on them including a nice review of 20th Century storms.