One of the most powerful storms on record to ever hit the mainland United States has grown in size and strength overnight. The risk of massive storm surge, heavy rain, flooding, and strong winds is very high when compared to other hurricanes. If possible, those who are under an order to leave should leave immediately.

It is going to be catastrophic. According to the National Weather Service, it is going to be a life threatening storm.

Less than 20 miles away from Sanibel Island, the center of the storm is located off the coast. According to the most recent public advisory from the National Hurricane Center, the eye of the storm is expected to hit Port Charlotte in the next few hours.

The storm has winds of 155 mph and is 40 miles from the center. About 175 miles from the storm's eye are tropical storm force winds. The winds are not always dangerous.

The worst storm surge south of Ian's center is expected to hit the cities of Cape Coral and Fort Meyer. There is a chance of storm surge from 2 to 12 feet. Surges between 4 and 6 feet are predicted for the bay.

The storm is expected to bring a lot of rain. There will be up to 18 inches of rain in central and northeast Florida. The measurement of rain amounts in feet is not good.

The precipitation totals are being increased by the remnants of a cold front in the north. The front is expected to slow the storm down and make it linger and hammer areas with more water.

Noah Brauer, a researcher at the University of Oklahoma, said that slowing down isn't a good thing. Slower storms cause the same areas to get hit for longer by rain and winds.

Earther spoke to Brauer from Florida while he was in a car. He was surprised by the sharpness of the storm's gradient while he was in the area. We are only seeing tropical storm force winds because we are so far away from the actual eye of the storm. It was raining pretty hard but the winds were only blowing at 30 to 45 mph. He said that there were a number of cars out and about on the highway.

There are 2.5 million people in the state who have been ordered to evacuate.

Why did Hurricane Ian get so strong?

Cuba is home to 11 million people and the entire electrical grid was knocked out when the storm hit. The hurricanes strength increased after Cuba.

It passed over a warm and deep area of the Gulf of Mexico called the loop current, which gave it more energy and water. He said that the sea surface temperature in the Gulf is above average this fall.

Ian is the first major storm to hit the Gulf this year. The warmest water at the surface has not been stirred up by hurricanes in the region. Hurricanes derive their power from ocean and atmospheric heat, so warm sea surface temperature is a particular driver.

According to Jake Carstens, a scientist at Pennsylvania State University, only four hurricanes have ever been stronger when they hit the US. There have been at least six Category 4 or 5 hurricanes to hit the continental US in the last 6 years.

Ian would be the strongest storm on record to hit southwest Florida, and its size is much larger than 2004, which was the most significant storm in that area. Ian was called a "generational storm for southwestern Florida" by him.

Although the link between Hurricane Ian and climate change cannot be established, previous research has found that human-caused climate change is intensifying Atlantic hurricanes.