Hurricane forecasters tracking 4 systems in Atlantic, including Earl and Danielle

Hurricane forecasters on Thursday morning were tracking four systems in the Atlantic, including Hurricane Earl, Tropical Storm Danielle and two more disturbances.

A tropical depression or storm could form within 24 hours from one of the disturbances, they said in a 7 a.m. outlook.

The named storms do not pose a threat to Louisiana. It's too early to say where the other two disturbances could go if they develop.

Earl is the second hurricane of the Atlantic season. Hurricane Danielle formed last week after a two-month lull in the tropics. No named storms formed in August, which is only the third time that's happened since 1950.

The Caribbean Sea and the Gulf of Mexico are expected to stay quiet for the next 48 hours, forecasters said.

Here's what to know about the tropics as of 11 a.m. Thursday from the National Hurricane Center.

Hurricane Earl strengthens

Hurricane Earl has strengthened and is now a Category 2 hurricane, forecasters said. A hurricane watch is in effect for Bermuda.

As of 10 a.m., Earl was about 230 miles south of Bermuda and was moving north at 13 mph.

On the forecast track, the center of Earl is expected to pass to the southeast of Bermuda late Thursday. Tropical storm conditions are expected to begin in the day in Bermuda, along with life-threatening surf and rip current conditions.

Earl has winds of 105 mph and strengthening is expected for the next couple of days. Peak winds of 130 mph are forecast, which would make it a powerful Category 4 hurricane. Cat 4 storms have winds of at least 130 mph.

Read the full advisory.

Danielle heads for Portugal, Spain

Tropical Storm Danielle, which was a hurricane at one point, has been downgraded to post-tropical cyclone, forecasters said Thursday morning. It's in the open Atlantic and is expected to turn and could reach Portugal and Spain as a tropical depression, according to the National Hurricane Center.

As of 10 a.m., Danielle was about 715 miles northwest of the Azores.

Winds have decreased to 65 mph. Danielle is forecast to remain a large post-tropical cycle over the north Atlantic for the next several days, even as its peak winds decrease, meteorologists said.

No coastal watches or warnings were in effect Thursday.

Read the full advisory.

Disturbance by Cabo Verde

A short-lived tropical depression or storm could form later Thursday in the Atlantic, hurricane forecasters said.

The disturbance currently is about 1,000 miles northwest of the Cabo Verde Islands, forecasters said in their 7 a.m. Thursday outlook.

The disturbance is expected to move west to northwest at 15 to 20 mph. It has a 70% chance of developing into a tropical depression within five days.

The shaded area on the graphic is where a storm could develop and is not a track. The National Hurricane Center releases a track when a tropical depression forms or is about to form.

The categories, in order of increasing strength, are tropical depression, tropical storm and hurricane (categories 1 through 5). Systems are named when they develop into a tropical storm. The next available name is Fiona.

Tropical wave by Africa

Hurricane forecasters are tracking a tropical wave emerged over the west coast of Africa and is over the Atlantic.

Environmental conditions appear generally conducive for some gradual development, meteorologists said, as it moves northwest over the Atlantic.

It has a 30% chance of developing into at least a tropical depression within five days.

Read the full outlook.

Busiest time of the season

This is historically the busiest time of the Atlantic hurricane season.

In the last 100 years, the tropics have been the most active in August, September and October, with Sept. 10 being the peak of the season, according to federal forecasters. About 80% of the systems that have hit the Gulf Coast formed during this time, according to the National Weather Service in Slidell.

So far, there have been five named storms this season - Alex, Bonnie, Colin, Danielle and Earl. The next available name is Fiona.

Hurricane season ends Nov. 30, but storms can form any time.

Storm categories

On the Saffir-Simpson Hurricane Wind Scale, the wind categories are:

Tropical depression: up to 38 mphTropical storm: 39 to 73 mphCategory 1 hurricane: 74 to 95 mphCategory 2 hurricane: 96 to 110 mphCategory 3 hurricane (major hurricane): 111 to 129 mphCategory 4 hurricane: 130-156 mphCategory 5 hurricane: 157 mph and higher

What to do now

Now is the time to review hurricane plans and make sure your property is ready for hurricane season.

Here are some tips from the National Weather Service for how to prepare for the season:

Put together an emergency kit. Here are 60+ nonperishable items to consider including.Check emergency equipment, such as flashlights, generators and storm shutters.Make a plan with your family or close friends and decide how you will get in touch and where you will go if there's an emergency. Here's how to decide if you should evacuate.Plan your evacuation route and have an alternate route. Here are 15 things to do before evacuating.Make a plan for your pets. Here are some tips.If you have a generator, check it and see if any maintenance needs to be done. Don't forget these important generator safety tips.Do any maintenance you've been putting off on your vehicle.Review your insurance policies.Keep your trees around your home trimmed to prevent damage from broken branches. Here's advice from gardening expert Dan Gill.Have materials in advance to board windows to protect them from flying debris.

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