3 days ago
Hurricane season in the Atlantic tropics: A quiet June with July trending more intense
'June is normally a quiet month,' said Phil Klotzbach, senior research scientist at Colorado State University. 'We've had above-average wind shear, and with cooler sea surface temperatures compared to this time last year.'
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Take a look at sea surface temperatures for the third week of June compared to last year. The main development region was running extremely hot last June compared to late August, which helped spawn Beryl so early. This year is much different.
The reason being? Strong trade winds from a stronger Bermuda high have helped with evaporative cooling of sea surface temperatures, keeping ocean temperatures closer to normal.
Sea surface temperatures are much cooler this year (left) versus the third week of June last year (right) when Hurricane Beryl formed.
Weather Models
Since there's virtually no possibility of another tropical storm forming before Monday, we set our eyes on July, where the season typically begins to awaken.
What does a normal July look like?
July is usually another quiet month across the Atlantic tropics, with about 7 percent of the season activity occurring during this month. Of course, the busiest months of the hurricane season occur between August and October, with the peak date around September 10.
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Over the past 30 years or so, July averages about 1.5 named storms, with .6 becoming hurricanes and .1 strengthening to a major hurricane — meaning we typically get a hurricane every other year, with 1 major hurricane every decade during July.
In addition to the Gulf and Western Atlantic, the Caribbean and the Western edge of the tropical Atlantic, just to the east of the Antilles, become possible formation spots for tropical storms and hurricanes during July as sea surface temperatures generally reach the typical 80-degree minimum to support development.
Tropical activity increases across the East Coast and Western Atlantic during July.
Boston Globe
What will this July look like?
Long-term models suggest that sea surface temperatures will creep up, with wind shear becoming less intense, but it may take a while. July typically only produces one named storm, and I wouldn't be surprised if we cap off the month with just one named storm for this time around.
There is another hurricane stat worth noting about July systems — there is a growing trend with Accumulated Cyclone Energy (ACE). ACE is a metric that measures the intensity of hurricanes. This means that July storms are trending stronger and longer-lasting. Take a look at how storm intensity during July as increased since 1950.
Accumulated Cyclone Energy during the month of July since 1950.
Phil Klotzbach, CSU
And one last stat regarding July activity. 2020 tied the record for the number of named storms with five — Edouard, Fay, Gonzalo, Hanna, and Isaias. The only other year on record with five named storms was in 2005.
New England and July tropical activity
New England hardly sees a direct landfall from tropical storms or hurricanes as it is, let alone during July. However, there have been several remnant storms that have pushed into the region, along with weakened tropical depressions and post-tropical systems, all flooding parts of New England over the years.
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Last July, New England was impacted by the remnants of Hurricane Beryl, dumping flooding rains across parts of New Hampshire and Vermont.
Tropical Storm Fay in July of 2020 made landfall in New Jersey, but most of New England took on the brunt of the storm.
The last direct landfall from a tropical storm or hurricane in New England during July? Tropical Storm Beryl in July of 2006, storm names are recycled until their retired, made landfall on Nantucket.
All in all, it takes one storm to make a world of difference, regardless of the time of year. Take a look at the costliest and strongest hurricanes, in terms of pressure, on record.
A list of the seven costliest hurricanes on record.
Boston Globe
The six strongest hurricanes on record in terms of barometric pressure.
Boston Globe
Ken Mahan can be reached at
