A "reasonable worst case scenario" forecast shows half of Key West underwater due to storm surge, according to a Weather Channel meteorologist.

Hurricane Irma, a Category 3 storm as of 4 p.m., is predicted to turn away from Cuba and make landfall in the Sunshine State by Sunday morning. Forecasters say the eye is expected to make landfall in Key West. Officials and forecasters have warned of the dangers of "life-threatening" storm surge associated with the storm.

"A reasonable worst case scenario has over half of Key West underwater due to storm surge," said Weather Channel meteorologist and weather producer Greg Diamond in a tweet that was retweeted by the National Weather Service Key West. "This is why @NWSKeyWest is saying to get out #irma."

The graphic he shares shows large swaths of Key West under 1 to 3 feet of water. Key West sits at the end of a string of islands, or "Keys," extending from the southern tip of the Florida peninsula. The National Weather Service predicts up to 5 to 10 feet of storm surge in the low-lying Florida Keys.

The outer bands of the storm are already lashing out at the Keys, and as of 4 p.m. Saturday, tropical storm force winds were detected in the Florida Keys.

Even before the eye was predicted to be making heading towards the area – the most dangerous part of the storm is near the eye, where the most intense winds are usually found – the National Weather Service issued a stern message Friday afternoon to Key West residents that with the coming of Hurricane Irma they need to evacuate because "this is as real as it gets."

"Nowhere in the Florida Keys will be safe," the NWS Key West account said in a tweet in all caps. "You still have time to evacuate."

With more than 20 people killed in connection to the storm in the Caribbean, Florida Gov. Rick Scott warned residents not to take a risk if they have been ordered to evacuate.

"If you've been ordered to evacuate, you need to leave now," Scott said in a press conference Saturday morning. "Do not wait. Evacuate. Not tonight. Not in an hour. You need to go right now."

He also cautioned of the often underestimated threat of storm surge, which could reach 6 to 12 feet in some places.

"You will not survive all of the storm surge," he said. "This is a life-threatening situation."