Hawaii is on alert for Tropical Storm Hone while extreme heat is expected to expand from the South to the Midwest, leaving 25 million Americans under heat alerts this weekend.

A Tropical Storm Warning is in place for the Big Island of Hawaii as Tropical Storm Hone passes south of the islands.

Though it won’t make a direct landfall, the storm is still close enough to potentially bring significant impacts.

The primary threat is heavy rainfall, which could lead to flash flooding and landslides, particularly on the eastern side of the Big Island, where rainfall accumulations of 5 to 10 inches are possible. The smaller islands might experience scattered rainfall of 2 to 4 inches this weekend from Hone’s outer bands.

Tropical storm-force winds are expected to start this evening and continue through the night into Sunday morning. Wind gusts are generally forecast to range from 25 to 40 mph, but some gusts could exceed 50 mph in higher elevations on the Big Island.

Swells generated by Hone will also cause elevated surf and hazardous rip currents for all the islands. These conditions will begin in the Big Island on Saturday and move westward to the rest of the islands over the weekend.

Hone could briefly strengthen into a hurricane as it passes south of Hawaii, but it's projected to remain over open water and eventually weaken back to a Tropical Storm.

Heat alerts for 25 million Americans

Scorching temperatures will continue across much of the southern plains this weekend, but Texas will see some relief as the weekend progresses.

The extreme heat will shift northward over the next few days, moving through the central plains and into the upper Midwest.

An excessive heat warning is in effect for parts of Minnesota and Wisconsin, including Minneapolis on Sunday and Monday.

The heat index could reach near 110 degrees for several cities in the plains and Midwest on Sunday and Monday.

The extreme heat will slide eastward early to mid next week, reaching the Great Lakes and the south by Tuesday and Wednesday.

Metropolitan areas such as Chicago , Louisville, and Atlanta might experience record-breaking high temperatures, reaching up to 95 to 100 degrees Fahrenheit in the middle of next week.