Five things to know about soon-to-be Hurricane Erin

Boston Globe

a day ago

Erin is the fifth named storm of the season
The fifth named storm of the Atlantic hurricane season typically forms on Aug. 22, but Tropical Storm Erin arrived over a week earlier than average, and this tropical system was the farthest-forming storm in the current season, which runs from June 1 to Nov. 30.
Erin formed near the Cabo Verde Islands on Aug. 11, one day before last year's fifth-named storm, Ernesto, and nine days earlier than 2023's fifth storm, Emily. In fact, Erin is the earliest fifth-named storm since Hurricane Elsa formed on June 30, 2021.
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Over the past six years, there has been only one time, in 2022, when the fifth-named storm formed after Aug. 22.
Heavy rain from storms that eventually became Tropical Storm Erin earlier this week led to at least a half-dozen deaths in the Cabo Verde Islands. The storm has since remained out to sea, with possible impacts to the Leeward Islands and Puerto Rico expected within days.
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Erin had to overcome hostile conditions
You may have already noticed this, but Erin wasn't really doing a whole lot of strengthening over the last couple of days. This is because the storm was engulfed in a swath of dry Saharan dust that played an atmospheric tug-of-war with the tropical storm.
Hurricanes depend on drawing moisture from the hot Atlantic Ocean to sustain and form thunderstorms, but the dry air in the mid and upper levels of the atmosphere had been choking the storm, wicking out moisture as the system tried to regenerate.
Erin ultimately won the match, and most of the dry Saharan dust dissipated or was displaced, allowing Erin to 'breathe' easier, setting the stage for the storm to strengthen to a likely major hurricane by the end of the weekend.
The takeaway: This is a sign that we're entering peak hurricane season, when sea-surface temperatures are at their warmest and can help storms overcome challenges high in the sky.
Erin has overcome a plume of dry Saharan dust that will allow it to strengthen into a bona fide hurricane.
Boston Globe
What track is Erin likely to take?
A well-timed trough, an area of low pressure, over the Eastern U.S. should help bump Erin away from the coast and out to sea.
Hurricanes are steered by several factors, and these factors change depending on where they emerge. For example, a storm forming in the Gulf will have different influences directing the track versus a storm forming in the Eastern Atlantic.
For storms like Erin, which formed in the Eastern Atlantic, the most common influences are the strength of the Bermuda High, which lives and meanders across the Northern Atlantic, and the presence of a surface trough across the Eastern US when a hurricane nears. A surface trough indicates an area of low pressure. But above this surface low lives a pocket of high pressure that holds steering winds.
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I mentioned in a previous post that it's like atmospheric bumper cars. Pockets of high pressure and their wind direction can push and pull storms. An area of low pressure may tug at storms. A lot is going on above our heads.
That said, Erin is forecast to grow into a major hurricane, which makes me want to look at the mid-layer to see how Erin will be influenced by the time it tracks north, up the Atlantic. In other words, the storm will be big enough to be influenced by larger weather patterns.
The clockwise direction from the Bermuda High will be pulling Erin to turn to the northeast as it approaches the Carolinas and moves up the East Coast. Separately, a trough will be expanding over the Northeast, which also means higher-level winds will provide an easterly shove to Erin. And as of now, it looks like the steering winds in the mid- to upper layers of the atmosphere will be strong enough over the Northeast to ensure Erin doesn't impact New England.
Take a look at the winds below, helping push Erin away from the region as it nears.
The upper-level winds should be strong over New England, pushing east against Erin and steering the storm away.
Pivotal Weather
Erin is paving the way for more tropical storms
Erin may very well have trailblazed a path for future storms for the rest of the month. Tropical systems pack an extreme amount of energy regardless of whether they're a tropical storm or a Category 5 monster.
Hurricanes draw energy from the sea and disperse the heat and moisture in their wake. By ingesting a large pocket of dry air, Erin, in a way, helped set the stage for future development across the Main Development Region — and the forecast shows that sea-surface temperatures will stay elevated with light trade winds. Remember, the lighter the winds, the lower the evaporation rate, and temperatures stay warmer.
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Hurricanes love an environment with low wind shear on top of very warm seas. Take a look at the rest of August, with increased chances for storms to form across the region where Erin was born and later traversed.
In the next couple of weeks, we have a good chance for more tropical storms and hurricane formation across the Main Development Region, shaded red and white.
CPC
How does this tropical storm compare to previous storms named Erin?
The storm name 'Erin' was first introduced in 1989, and the current storm is the seventh time the name has been used for the Atlantic.
The strongest Erin was back in 2001 when the September hurricane intensified into a major Category 3 storm with top wind speeds of 120 miles per hour.
Also, there have been two U.S. landfalling storms named Erin, in 1995 and 2007. The 1995 Category 2 storm made two landfalls in Florida, on the east side and then on the panhandle. In 2007, Erin formed in the Gulf and pushed into Texas as a tropical storm.
The tracks of all tropical storms and hurricanes named Erin since 1989.
NHC
Ken Mahan can be reached at