Tropical depression forms in Atlantic, expected to become Tropical Storm Gaston: See track

A tropical depression formed in the Atlantic early Tuesday, and another one could form later this week in the Caribbean, hurricane forecasters said.

The Atlantic depression is forecast to strengthen into Tropical Storm Gaston late Tuesday or early Wednesday.

Forecasters are also tracking powerful Hurricane Fiona, which is strengthening in the Atlantic after causing catastrophic flooding in Puerto Rico and the Dominican Republic.

Hurricane Fiona and the Atlantic depression don't pose a threat to Louisiana. It's too early to accurately say where the Caribbean disturbance could go if it develops.

Related: 60+ nonperishable items to consider for your emergency kit

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

Hurricane Fiona in the Bahamas

Hurricane Fiona was strengthening in the Atlantic as it continued to batter the Turks and Caicos Tuesday morning, forecasters said.

The storm, now a Category 3 hurricane, has caused catastrophic flooding in Puerto Rico and the Dominican Republic and has claimed a life in the French territory of Guadeloupe.

As of 10 a.m., Fiona was about 40 miles northwest of Grand Turk Island and was moving northwest at 9 mph.

It has winds of 115 mph and strengthening is expected over the next few days. Fiona is forecast to have peak winds of 140 mph, which would make it a powerful Category 4 storm.

Flooding continues across Puerto Rico, where forecasters said 35 inches of rain could fall, leading to life-threatening flooding, mudslides and landslides. President Joe Biden has declared a state of emergency.

See the full advisory with current watches and warnings.

Disturbance heads toward Caribbean

Forecasters also are tracking a tropical wave that's several hundred miles east of the Windward Islands. It has become better organized Tuesday morning, they said, and a tropical depression is likely to form in the next few days.

It's moving west at 15 to 20 mph and is expected to reach the Caribbean Sea, forecasters said.

It has a 70% chance of developing into at least a tropical depression within five days.

The disturbance is expected to bring heavy rainfall and gusty winds to parts of the Windward Islands, regardless of development.

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. If the system in the Atlantic becomes Gaston as expected, the next available name is Hermine.

Read the full outlook.

Depression in the Atlantic

A tropical depression formed in the Atlantic early Tuesday, becoming the 8th depression of the season, forecasters said.

No watches or warnings are in effect, but forecasters said residents in the Azores should monitor the storm.

It has winds of 35 mph, and it's expected to strengthen into Tropical Storm Gaston later Tuesday or early Wednesday.

As of 10 a.m., the depression was about 1,110 miles southwest of the Azores and was moving north at 10 mph over the open waters of the Atlantic, forecasters said.

The current 5-day forecast does not have it strengthening into a hurricane.

Read the full advisory.

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 six named storms this season - Alex, Bonnie, Colin, Danielle, Earl and Fiona. The next available name is Gaston.

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.

The Associated Press contributed to this story.

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Editor's note: This story has been updated with the 10 a.m. advisories from the National Hurricane Center.