Hurricane center increases tropical development chances to 60 percent

Update 7:55 p.m.: The chances that a tropical system will develop over the next five days was increased to 60 percent by the National Hurricane Center.

The special tropical update, which was issued at 7:40 p.m., said a newly formed area of low pressure has emerged a few hundred miles northeast of the Bahamas.

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The system is supposed to move slowly west-northwest toward the southeastern U.S. That will put it into warmer waters and weaker wind shear, which could allow it to more fully develop.

Center forecasters also increased the chance of development through 48 hours to 30 percent.

The next tropical outlook will be issued by 9 a.m. Thursday.

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There is no guarantee something will form.

“To get a defined depression we need a little bit better circulation to happen, and that very well could happen as we head into the holiday weekend,” said Dan Kottlowski, a hurricane expert with AccuWeather. “The expectation now is that it will track northwest from the northern Bahamas and be off the coast of Jacksonville Friday or Saturday.”

From there, it could head north, or stall out, spinning for a while before moving out to sea, Kottlowski said.

“There is definitely a chance it could be a tropical storm, but there’s still a lot of uncertainty and the process in this case takes a long time,” he said.

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No forecasters were expecting the system to gain much strength, but it was dubbed Invest 91-L, meaning it has the potential to gain tropical characteristics. The National Hurricane Center numbers areas to “investigate” beginning with 90. The “L” represents the North Atlantic basin. Invest 90-L became Hurricane Alex in January.

Despite the questionable future of 91-L, Florida’s National Weather Service forecasting offices began taking note of the system Wednesday, distributing short forecasts on potential Memorial Day weekend weather.

For South Florida, the system may prove a boon. Depending on its location, Palm Beach, Broward and Miami-Dade counties could end up in the southwest quadrant of the storm where a more westerly flow would mean drier air.

“Sometimes you get dry air that wraps into these things and it may even reduce the storms a little for us,” Ippoliti said. “The north side of the system, if it comes ashore, would bring the heavier rain toward Myrtle Beach and the Outer Banks.”

Previous story: The National Hurricane Center has increased the chances of a tropical system developing in the next five days to 50 percent.

A special tropical weather outlook issued at 8:15  this morning says environmental conditions are expected to become more favorable for a subtropical to tropical system to form by Friday.

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The system would be named Bonnie if it gained tropical storm force, but meteorologists aren’t ready yet to declare that a possibility.

While just a grouping of showers and thunderstorms now, wind shear, which is deadly to tropical storms, is expected to weaken over the next few days. Hurricane Center forecasters believe the system will move west-northwest toward the U.S. southeast coast over the weekend.

Hurricane season doesn’t officially start until June 1.

Why a tropical system could be good for South Florida’s Memorial Day weekend. 

Sea surface temperatures are typically need to be greater than 26 degrees Celsius for tropical cyclone development. Near the coast, this graphic shows them as warm as 28 degrees.
Sea surface temperatures are typically need to be greater than 26 degrees Celsius for tropical cyclone development. Near the coast, this graphic shows them as warm as 28 degrees.

The next tropical weather outlook will be issued by 8 p.m. The chances of something forming within the next two days is low at just 10 percent.

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Mark Sudduth, a geographer and founder of Hurricanetrack.com, said the potential system is the result of a frontal boundary “tangling up with an upper level piece of energy or trough.”

Even if the system develops, Sudduth said he doesn’t think it will be more than a rain maker.

“Water temps in the region are only marginal for development though they do get warmer in the Gulf Stream closer to the coast,” Sudduth wrote in a blog this morning.  “If this were August, I would be more concerned, it’s May so my level of concern is about a 1 out of 10 – mainly due to the potential for heavy rain and possible rough surf conditions along some of the beaches along the Southeast coast.”

While a few days ahead of schedule, early tropical development has some precedents.

Hurricanes have formed in every month but February. Last year, Tropical Storm Ana opened the 2015 hurricane season with a May 9 debut.

Vertical wind shear graphic valid as of Friday shows low shear in area off southeast coast. Wind shear values should be less than 10 meters per second for a tropical cyclone to form.
Vertical wind shear graphic valid as of Friday shows low shear in area off southeast coast. Wind shear values should be less than 10 meters per second for a tropical cyclone to form.

 

This year, Hurricane Alex formed Jan. 14, making it only the second January-born Atlantic hurricane on record.

Other hurricanes refusing to adhere to man’s calendar include Alice, which formed Dec. 31, 1954, but managed to live through the New Year before dissipating Jan. 4. Another tropical storm dubbed Ana formed in 2003 on April 20, while Alberto was named on May 19, 2012. Alberto was followed just days later by Beryl, which formed May 26 of that year.

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First tropical system of season may be brewing

The official start of the 2016 hurricane season is June 1, but the atmosphere is brewing up a little preview that may form into a tropical system by Memorial Day.

Meteorologists are watching forecast models that show an area of low pressure forming near the Bahamas that has the potential to become the season’s first tropical depression with a path toward Florida, Georgia and the Carolinas.

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Andy Mussoline, senior meteorologist with the Pennsylvania-based AccuWeather, said the system is a signal that weather patterns are shifting, making things more favorable in the Atlantic for hurricanes.

Will a tropical cyclone be named after you this year? 

The official start date is June 1.

“We think any development that would occur later this week will be slow with a tropical depression likely the beginning,” Mussoline said. “We have warm water, low wind shear. Something may show up as early as Thursday.”

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While a few days ahead of schedule, early tropical development has some precedents.

Tropical Storm Ana, May 2015. Credits: NASA Goddard MODIS Rapid Response Team
Tropical Storm Ana, May 2015. Credits: NASA Goddard MODIS Rapid Response Team

Hurricanes have formed in every month but February.

Last year, Tropical Storm Ana opened the 2015 hurricane season with a May 9 debut.

This year, Hurricane Alex formed Jan. 14, making it only the second January-born Atlantic hurricane on record.

Other hurricanes refusing to adhere to man’s calendar include Alice, which formed Dec. 31, 1954, but managed to live through the New Year before dissipating Jan. 4. Another tropical storm dubbed Ana formed April 20 in 2003, while Tropical Storm Alberto was named May 19, 2012. Alberto was followed just days later by Tropical Storm Beryl, which formed May 26.

While January’s Hurricane Alex was more of a hold-over from the 2015 storm season, its formation date on the calendar made it a 2016 storm.

That means if the system being watched by forecasters develops, it would be named Bonnie.

But some forecasters aren’t ready to fire up the season just yet.

The National Hurricane Center in Miami has not identified the low pressure system that may develop as one to watch for potential tropical characteristics, and Jeff Masters, co-founder and director of meteorology for Weather Underground, confirmed an area of low pressure is expected to form but said the forecast is more muddled from there.

“The models have widely differing ideas on how much wind shear might be present, so it is too early to say if this system is a legitimate threat to develop into a tropical depression,” Masters said Monday.

Tropical cyclones are unique in that they have warmer temperatures at their centers — so called “warm cores” — that are able to sustain the strength of the storm over long distances.

But they need warm ocean waters and low wind shear to prosper — ingredients AccuWeather forecasters say are there.

Ocean temperatures are about 80 degrees with light winds that are expected to remain that way into next week.

Whether a tropical system forms, showers and thunderstorms are expected to increase from Florida to the Carolinas later this week and through Memorial Day with increasingly dangerous surf conditions.

“We think any development will be slow,” Mussoline said. “But we have warm water, low wind shear and high atmospheric moisture, which, combined, can mean tropical formation.”

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AccuWeather predicts 3 storm landfalls in U.S. this hurricane season

Hurricane experts at the Pennsylvania-based AccuWeather are predicting 14 named storms this hurricane season, with three making U.S. landfalls.

Eight of the storms are forecast to be hurricanes, four of which could be major hurricanes. A major hurricane is considered one that is Category 3 or stronger.

AccuWeather released its 2016 hurricane forecast this morning.

Dan Kottlowski, AccuWeather’s lead hurricane forecaster, said one wildcard in this year’s forecast is a cold area of ocean in the northern Atlantic.

If the cooler water migrates southward across the eastern Atlantic and into the tropical cyclone breeding grounds, it will lower sea surface temperatures, limiting storm development.


“This area of colder water started to show up a few years ago and has become larger and more persistent during the past couple of years,” Kottlowski said. “The big question is whether we will go into a La Niña, which is what we’re anticipating right now.”

La Niña is characterized by less wind shear over the Atlantic, meaning more hurricanes could form.

A strong El Niño during the 2015 hurricane season helped protect the U.S. from storms by cutting them down before they could form.

“It’s possible we could flip flop from one extreme to the other, from below-normal seasons the past three years to an above-normal year in 2016,” Kottlowski said.