‘Intense’ Hurricane Sam rages over open Atlantic

By Mary Gilbert, AccuWeather meteorologist Published Sep. 26, 2021 9:15 AM MDT | Updated Sep. 26, 2021 5:46 PM MDT

AccuWeather forecasters say confidence is growing that the United States will miss out on a direct hit from Hurricane Sam, but the monster storm will still be able to make some waves.

As of Sunday evening, Hurricane Sam was located about 880 miles to the east-southeast of the Leeward Islands and was tracking to the northwest at 7 mph. Hurricane-force winds extend outward up to 30 miles from the center of Sam and tropical-storm-force winds extend outward up to 90 miles.

Sam remained a Category 4 major hurricane on the Saffir-Simpson Hurricane Wind Scale with maximum sustained winds of 150 mph. A major hurricane is any storm classified as a Category 3 hurricane or greater.

With its increase in wind speed through Sunday afternoon, Sam is less than 10 mph shy of becoming the 2021 Atlantic hurricane season’s first Category 5 hurricane. Its wind speeds already match those of Hurricane Ida’s, which also topped out at 150 mph before barrelling into Louisiana in August.

AccuWeather forecasters say Sam’s journey to attain its current strength was impressive, to say the least. Sam was the fifth storm this season to undergo rapid intensification, following in the footsteps of Elsa, Grace, Ida and Larry.

Meteorologists define rapid intensification as an increase in a storm’s maximum sustained winds of 35 mph or more within 24 hours, and Sam surpassed that benchmark. Sam first earned its name on Thursday morning when it became the 18th named storm of the season. Less than 24 hours later, Sam had strengthened further into a hurricane, the seventh of the season.

Sam is seen less than 1,000 miles from the Leeward Islands on Sunday, Sept. 26, 2021. (Photo/AccuWeather RealVue™ satellite)

“Low wind shear and high water temperatures will continue to fuel the intense hurricane,” AccuWeather Senior Meteorologist Alan Reppert said.

While Sam is a monster of a hurricane, it will remain in the best place possible for a dangerous storm at the start of the week–largely out over the open ocean, away from any landmasses. However, as the week continues, the impressive storm may take a swipe at parts of the Caribbean.

Sam began to adopt more of a northward component to its motion this weekend and the hurricane will continue to gradually turn more to the north as the week progresses. Precisely how quickly Sam makes its northward turn will be critical in determining exactly how much impact the strengthening cyclone will have on the Caribbean’s Leeward Islands.

The sooner Sam begins to track to the north, the more likely the hurricane’s dangerous eyewall, with its destructive winds, will avoid the islands into midweek. AccuWeather forecasters say an earlier turn to the north is the most likely scenario at this time, likely preventing a direct strike on the Leeward Islands.

Even without a direct strike, parts of the Caribbean can still feel some impacts from Sam.

“Even though Sam is forecast to pass to the north and northeast of the northern Leeward Islands, rough surf, high waves and rip currents will impact the shores of the islands over the next several days,” AccuWeather Senior Meteorologist Dan Pydynowski said.

The risk for rip currents will extend to shorelines well beyond the Leeward Islands as the powerful Sam continues to track generally north over the open Atlantic.

As Sam remains a formidable hurricane, it will continue to produce progressively larger swells that propagate outward from the center. These swells will generate building seas ahead of the storm and usher in large waves and rough surf, even for areas hundreds of miles away.

“Rough surf and rip currents are likely to reach much of the eastern coast of the U.S. later this week,” Pydynowski cautioned.

Almost the entirety of the Atlantic coast from central Florida to Maine will encounter building surf and increasing rip currents beginning as early as midweek.

About 100 deaths per year in the U.S. occur as a result of rip currents, according to the U.S. Lifesaving Association. So far this year, there have been at least 19 rip current deaths along the Atlantic coast, according to data from the National Weather Service.

“In the longer range, as Sam tracks nearly due north, the hurricane may threaten Bermuda later in the week or by the upcoming weekend,” Pydynowski said.

Beyond Bermuda, AccuWeather forecasters urge people living as far north as Atlantic Canada to monitor Sam for potential impacts during early October.

As Sam spins over the open Atlantic, it follows in the tradition of some powerful, even infamous, “S” storms. While Sam is not forecast to strike the U.S. directly, other S storms, less powerful than Sam, have had a major impact on U.S. soil.

One of the most destructive storms in recent memory to carry an “S” name was Superstorm Sandy, which plowed into New Jersey in October of 2012 with ultimately devastating consequences. Damages from Sandy in the U.S. ultimately amounted to $65 billion, according to a National Hurricane Center report.

The most recent “S” storm to actually strike the U.S. occurred during 2020’s record-breaking hurricane season. Hurricane Sally strengthened into a Category 2 hurricane over the northern Gulf of Mexico and made landfall on the Alabama Panhandle on Sept. 16, 2020.

As Sam spins over the open Atlantic, it follows in the tradition of some powerful, even infamous, “S” storms. While Sam is not forecast to strike the U.S. directly, other S storms, less powerful than Sam, have had a major impact on U.S. soil.

One of the most destructive storms in recent memory to carry an “S” name was Superstorm Sandy, which plowed into New Jersey in October of 2012 with ultimately devastating consequences. Damages from Sandy in the U.S. ultimately amounted to $65 billion, according to a National Hurricane Center report.

The most recent “S” storm to actually strike the U.S. occurred during 2020’s record-breaking hurricane season. Hurricane Sally strengthened into a Category 2 hurricane over the northern Gulf of Mexico and made landfall on the Alabama Panhandle on Sept. 16, 2020.

With the recent formations of Sam and short-lived Subtropical Storm Teresa, the prolific 2021 Atlantic hurricane season continues to outdo itself. Only two names remain on the predetermined list of tropical names for the 2021 season

Sam is the 18th named storm of the 2021 season, which is on pace for AccuWeather’s forecast of 20-25 named storms prior to the end of the year. If the remaining designated names for 2021, Victor and Wanda, are exhausted, additional storms will be named using a supplemental list prepared by the World Meteorological Organization.

Adria, Braylen and Caridad are the first three names on the list, which is being used for the first time after the Greek alphabet was retired earlier this year. The Greek alphabet had been used to name storms during only two Atlantic seasons: the hyperactive 2020 and 2005 hurricane seasons. By late September in 2020, the National Hurricane Center had already started using the Greek alphabet to name storms, with Alpha forming on Sept. 17.

In addition to 20-25 total named systems predicted this year, AccuWeather is projecting up to 10 hurricanes and five to seven major hurricanes. Including Sam, there have been four major hurricanes thus far with maximum sustained winds of 111 mph or greater. There have been eight landfalls in the U.S., and there may yet be another direct impact or two on the U.S. before the end of this season.

Atlantic tropical tracks as of Sept. 26, 2021.

With the recent formations of Sam and short-lived Subtropical Storm Teresa, the prolific 2021 Atlantic hurricane season continues to outdo itself. Only two names remain on the predetermined list of tropical names for the 2021 season

Sam is the 18th named storm of the 2021 season, which is on pace for AccuWeather’s forecast of 20-25 named storms prior to the end of the year. If the remaining designated names for 2021, Victor and Wanda, are exhausted, additional storms will be named using a supplemental list prepared by the World Meteorological Organization.

Adria, Braylen and Caridad are the first three names on the list, which is being used for the first time after the Greek alphabet was retired earlier this year. The Greek alphabet had been used to name storms during only two Atlantic seasons: the hyperactive 2020 and 2005 hurricane seasons. By late September in 2020, the National Hurricane Center had already started using the Greek alphabet to name storms, with Alpha forming on Sept. 17.

In addition to 20-25 total named systems predicted this year, AccuWeather is projecting up to 10 hurricanes and five to seven major hurricanes. Including Sam, there have been four major hurricanes thus far with maximum sustained winds of 111 mph or greater. There have been eight landfalls in the U.S., and there may yet be another direct impact or two on the U.S. before the end of this season.

Atlantic tropical tracks as of Sept. 26, 2021. (Click to Source)

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