Tropical Storm Lee forms, expected to become major hurricane. Is East Coast in danger?

Latest updates Wednesday: Hurricane forecasters say Lee is strengthening

Tropical Storm Lee formed in the Atlantic Ocean far east of the United States on Tuesday afternoon and is expected to become a major hurricane, with winds approaching 150 mph by the weekend.

The question is where is it going? And could it impact the U.S.?

"Interests across the Caribbean and along the East Coast from Florida to Maine will need to pay close attention to this feature," AccuWeather meteorologist Brandon Buckingham said. "Depending on the path this system takes, the expected time frame for potential impacts to the United States and Atlantic Canada may be Sept. 13-16."

Lee, with 65 mph winds, is more than 1,200 miles east of the Caribbean islands, the National Hurricane Center said. The hurricane could bring impacts to the Leeward islands by the weekend, but it's too early to determine how close the storm could approach the islands, hurricane specialist Eric Blake, wrote in the center's 5 pm. Tuesday update.

Tropical Storm Lee has formed in the Atlantic and is forecast to become a major hurricane by the weekend, with 145 mph winds by Sunday as it nears the Leeward Islands.

Rapid intensification likely

"It is becoming a question of when and not if rapid intensification occurs with Lee," Blake said. The forecast now predicts Lee will become a Category 4, 140-mph hurricane by Saturday morning east of Puerto Rico and continue strengthening into a 145-mph storm by Sunday.

A reduction in wind shear in its path along with warm ocean water of near 86 degrees will create favorable conditions for Lee to strengthen, Blake wrote, and several models call for higher winds than those in the center's new forecast. Wind shear tears apart developing storms, while warm water acts as fuel to power up storms.

Prediction and timing of winds, as of 5 a.m. Wednesday:

  • 12 hours: 80 mph (Category 1)

  • 24 hours: 90 mph

  • 48 hours: 120 mph (Category 3)

  • 60 hours: 140 mph (Category 4)

  • 72 hours: 150 mph (Category 4)

  • 96 hours: 150 mph

  • 120 hours: 150 mph

Tropical Depression 13, expected to become Tropical Storm Lee, is getting organized in the Atlantic Ocean between Africa and the Windward Islands, in this satellite image provided by the National Oceanic and Atmospheric Administration. .

Track forecast uncertain

Latest indications suggest the storm track could vary across a wide swath spanning from the coast northward to eastern Canada, or even skirt away from the coast entirely, AccuWeather said.

Many of the models forecasters use indicate the hurricane is likely to head northward in the Atlantic, but not all. Any bump westward in the track could be disastrous for the Atlantic Coast anywhere from Florida to Nova Scotia.

While that thought is alarming, weather models show a deep trough of low pressure over the eastern U.S. next week, and that dip in the jet stream "should turn Lee more to the north around this time next week," said Ryan Truchelut, chief meteorologist at Florida-based Weather Tiger.

"Unless something very weird happens, that northward movement should occur well east of Florida, and Lee does not look like a threat to the state," Truchelut said.

According to meteorologist Jonathan Erdman, "a combination of factors will determine where the hurricane eventually goes" as it makes its way across the Atlantic.

T​his includes how strong and expansive the Bermuda-Azores high-pressure area is at the time. "This acts as a steering wheel for tropical waves, storms and hurricanes in the tropics," Erdman said. If the high is weaker, Lee may just recurve out to sea. If it's stronger, then the storm could impact the East Coast of the U.S., he said.

The most likely outcome is that Lee remains offshore, Truchelut said. "But with Lee 10 or more days out, there is sufficient uncertainty in the forecast such that the Eastern Seaboard should keep close tabs on Lee, especially as it will be a strong hurricane."

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Hurricane center's forecast track:

The forecast track shows the most likely path of the center of the storm. It does not illustrate the full width of the storm or its impacts, and the center of the storm is likely to travel outside the cone up to 33% of the time.

Take a look at the spaghetti models

Special note about spaghetti models: Illustrations include an array of forecast tools and models, and not all are created equal. The hurricane center uses only the top four or five highest-performing models to help make its forecasts.

Most spaghetti models keep the storm north of the Caribbean. However, Bermuda could face a major hurricane next week.

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Dangerous impacts possible even if it stays offshore

A National Weather Service forecast office in eastern North Carolina reminded residents Tuesday that "even when tropical systems stay out to sea, there are still distant impacts locally (dangerous rip currents, large breaking waves, etc.)."

In addition, the weather service said that "every system that develops always serves as a reminder to finish general hurricane season preparations if you haven't already."

How is the 2023 Atlantic hurricane season stacking up?

Lee is the 12th named storm to form this season. If it does become a hurricane, it would be the season's fourth hurricane and third major hurricane.

An average hurricane season produces 14 named storms and seven hurricanes. Even before the season started, forecasters said 2023 was likely to be a busier-than-normal season, but in August they bumped up their predictions, calling for 14-21 named storms.

Contributing: Cheryl McCloud, USA TODAY Network

This article originally appeared on USA TODAY: Tropical Storm Lee forms in Atlantic: Is Lee going to hit Florida?