WASHINGTON — (CNN) As people make outdoor plans to enjoy the last unofficial week of summer and the Labor Day holiday, several tropical storm systems are threatening the southeastern US and the Hawaiian Islands.

Several could make landfall — or at least brush the coastline — later this week, bringing heavy rains and possible flooding.

With the statistical peak of hurricane season approaching in early September, storms are spinning off the Carolinas and in the Gulf of Mexico.

Currently designated Tropical Depressions Eight and Nine, respectively, both are expected to become tropical storms at any time.

When they do, they’ll get the names “Hermine” and “Ian.” (Whichever system first reaches tropical-storm strength — winds at 39 mph or greater — will become Hermine.)

Here’s a breakdown of the storms and where they are heading.

The closest storm to US soil is Tropical Depression Eight, which was only 75 miles from Cape Hatteras in North Carolina as of Wednesday morning.

Fortunately it has changed direction and is beginning to head back out into the open Atlantic.

Some strengthening is expected as the storm accelerates northeast and it could become a tropical storm, which would earn the system a name.

The major concern from this storm is the rip current threat that extends from North Carolina all the way to Florida and should not be underestimated by swimmers in that area.

This storm, which has now emerged in the Gulf of Mexico, is the bigger threat to the Southeast this week.

Any system that lingers in the Gulf in August or September will draw a long, watchful eye from forecasters and emergency planners, and Tropical Depression Nine is no different.

Water temperatures in the Gulf are plenty warm enough to support hurricane development, and the Gulf Coast is full of vulnerable population centers from Tampa to Texas.

The forecast calls for the weather system to drift toward the north and then move northeast Wednesday and Thursday, while gaining strength and becoming a tropical storm in the process.

Since landfall of this system is expected within 48 hours, the National Hurricane Center has issued a tropical storm warning for portions of Florida’s Gulf Coast.

It is possible that the storm will reach hurricane intensity before landfall, which is why a hurricane watch is also in place.

A watch means that hurricane conditions are possible within 48 hours.

Gov. Rick Scott declared a state of emergency in Florida Wednesday morning in preparation for Tropical Depression Nine.

“By declaring a state of emergency in advance of this storm, we are ensuring that state, regional and local agencies can work together to meet the needs of our communities,” he said.

Fortunately, an advancing trough over the central and southern US will kick the system to the east before it has a chance to strengthen much further, most likely leading to a landfall somewhere in the Florida Panhandle to the Big Bend area.

The longer the storm lingers in the Gulf before it makes the turn to the right, the more it could strengthen, and it may have a higher chance of landfall in the more populated Panhandle.

In addition to the wind and rough seas associated with tropical storms, heavy rainfall could also be a major threat from this system.

Rainfall amounts of 5-10 inches are possible over the Florida peninsula through Friday morning and isolated totals could reach 15 inches, according the the National Hurricane Center.

“These types of rain totals, especially when they fall in just a few hours, could lead to flooding similar to what we saw in Louisiana just a few weeks ago,” CNN Meteorologist Chad Myers warned.

The Central Pacific Hurricane Center in Honolulu is tracking Hurricane Madeline, now located about 200 miles east of the Big Island of Hawaii.

The powerful storm that was a Category 4 is now packing winds of 90 mph, a Category 1, as it makes its close approach to the Big Island.

The official track predicts the center of Madeline will pass just south of Hawaii, although some models still expect a landfall late Wednesday on the Big Island.

Whether the storm makes landfall or not, hurricane-force winds and very heavy rainfall are likely.

Therefore, the Central Pacific Hurricane Center has issued a hurricane warning for the Big Island, and a tropical storm watch for the islands of Maui, Molokai and Lanai.

Given the elevated terrain of the islands, the rainfall — which could total 12 inches — may cause dangerous mudslides and flash flooding.

Hawaii residents cannot let their guard down after Madeline moves through, however, as Hurricane Lester is fast on its heels.

Lester, also a Category 3 storm, is expected to approach the Hawaiian islands this weekend.

The forecast currently calls for Lester to miss the islands directly, pushing just to the north, but the entire island chain is still in the forecast “cone of uncertainty.”

Hawaii frequently has storms approach the islands but rarely deals with hurricane landfalls directly. In fact, only two hurricanes have made landfall in Hawaii since 1950, and none have hit the Big Island.

In 2014, Hurricane Iselle weakened to a tropical storm 12 hours before making landfall on the southern portion of the Big Island.

But recent studies have shown that hurricanes may become more frequent in Hawaii thanks to climate change, a pattern that’s certainly been seen over the past couple of years.

El Niño also has played a role in the recent uptick of storm activity there.