Editor's Note: (A version of this article originally appeared in the weekly weather newsletter, the CNN Weather Brief, which is released every Monday. You can sign up here to receive them every week and during significant storms. )
(CNN) If you went to bed hoping Ian would go away, your dreams didn't come true.
It's big, strong, and will move northeast and soon slow down -- all recipes for a worst-case scenario for the western coast of Florida.
For residents in the Tampa Bay area, "it's time to stop looking on the internet and hoping that it'll go away. It's time to start acting," Jamie Rhome, the National Hurricane Center acting director, told CNN meteorologist Jennifer Gray on Monday.
Ian made landfall in western Cuba early Tuesday as a Category 3 hurricane with 125 mph winds. "Significant wind and storm surge impacts (are) occurring over western Cuba," the hurricane center said.
Ian's path takes it off the coast of Cuba and into the Gulf of Mexico.
The storm intensified rapidly Monday and is expected to strengthen even more rapidly as it moves into the warmer waters of the Gulf.
Read: Climate change is causing hurricanes to intensify faster than ever
The crazy thing about this is that the hurricane center forecast this rapid intensification. It has been difficult to predict in the past, but confidence in this storm's intensity is high.
"The NHC forecast for Ian has shown an unprecedented rate of strengthening from a tropical storm to a powerful hurricane (winds increasing faster than in any previous forecast produced for any other tropical storm) -- showing the confidence forecasters have in the potential for explosive growth)," CNN meteorologist Brandon Miller said.
That confidence is only increasing now that the storm is moving where they expected and at the intensity they expected.
Yet, even though we have a better idea of where this storm is going to go -- looking at you, Florida -- there is still some slight uncertainty about the exact landfall location.
Don't focus on that middle line shown in the forecast cone here:
Anyone inside the cone is at risk of a landfalling major hurricane, one of last night's big updates. The hurricane center now says Ian will maintain major hurricane intensity when it hits Florida.
Hurricane-force winds extend outward up to 35 miles and tropical storm-force winds extend outward up to 115 miles from the center of Ian. This means that more than 15 million people will likely experience tropical storm-force winds, including all of Tampa metro and other cities such as Orlando, Tallahassee and Jacksonville.
These are the most likely arrival of tropical storm-force winds:
The exact location of the hurricane's landfall will make a dramatic difference in the location of the surge.
"Landfall in the southern part of the cone will take Tampa Bay out of the extreme surge and put Charlotte Harbor in the center of the worst conditions," CNN meteorologist Chad Myers says. "Landfall to the north of Tampa puts the massive surge right into Tampa Bay."
Why coastal communities should fear storm surge
Literally, 50 miles one way or the other changes everything.
If it makes landfall north of Tampa, this will push water levels to a height not seen in over 50 years of tide level records in Tampa Bay.
"This is a near worst-case approach angle coming in from the south and west and stalling," Rhome said.
That slowing forward momentum will allow for another extreme event to unfold. There are damaging winds in the eyewall and the surge. There is also the potential for flooding rainfalls, said Myers.
There is "the potential for rainfall totals of 20 to 25 inches as the storm appears to temporarily stall after landfall creating massive rainfall flash flooding," said Myers.
The average September brings about 6 inches of rain to the Tampa region.
This means "Ian is expected to dump at least 2 to 3 months' worth of rain by Friday," Miller said.
The Weather Prediction Center has issued a level 3 of 4 risks for excessive rainfall for much of Florida for the next three days because of Ian. Heavy rainfall starts in southern Florida today and slowly moves up the peninsula through Friday.