Four years ago, a disaster planning project called "Hurricane Phoenix" imagined what the worst-case scenario would be for a hurricane hitting Tampa. The result looks a lot like some of the forecasts for the region as Hurricane Milton approaches.

The 2020 project war-gamed a major hurricane, including realistic, frightening videos. The fictional "catastrophic, historic" Hurricane Phoenix made landfall in mid-October with winds of 160 miles per hour with gusts up to 200 mph. The storm surge completely inundates downtown Tampa, cutting off all bridges.

The training exercise simulation was intended to help emergency responders, business owners and others think through what a major hurricane making landfall around the city would mean for them and how they could prepare.

Right now, the forecast for Milton isn't quite as dire as what the Hurricane Phoenix scenario foretold. But current forecasts contain warnings echoing the seriousness of the scenario.

What happens to Tampa during the fictional Hurricane Phoenix?

In the invented storm, the surge reaches the second floor of the Tampa General Hospital, which is unable to take new patients. St. Petersburg becomes an island. Significant wind damage tracks well inland.

In the aftermath of the fabricated hurricane, the damage is "unimaginable" with beaches "essentially gone." The Howard Franklin Bridge, the central bridge spanning Old Tampa Bay from St. Petersburg to Tampa, is completely destroyed. Businesses are in ruins, the entire region devastated.

Major structural damage hits many buildings with roofs being especially vulnerable to wind-borne debris. Most windows are blown out of high-rise structures.

Citrus, Hernando, Hillsborough, Manatee, Pasco and Pinellas counties all experience life-threatening rain, wind and storm surge. Communications, television and most radio stations are knocked out. Debris blocks critical roadways, delaying emergency response.

When the tide comes in, it is 9 to 12 feet above normal. Storm surges overtop barrier islands and push a massive volume of water into Tampa Bay, at least 20 feet above normal at St. Petersburg and 26 feet above the normal tide level near downtown Tampa. Areas far inland are flooded along rivers and canals.

Between 27 and 43% of area fire stations, hospitals, police stations and schools are damaged. Many are declared non-functional.

There is some speculation that MacDill Air Force Base may permanently close. Port Tampa Bay, the fourth-largest in Florida, may take three years to again become fully operational.

With a focus on small businesses, the report suggests that immediately after the hurricane 40% of small businesses would be closed and one year later one-quarter of them would still be shuttered. Within two years, 90% of impacted small businesses would fail.

What's the forecast for Hurricane Milton?

A major hurricane in October with Tampa Bay in the crosshairs — that's both the fictional scenario from Hurricane Phoenix and the current situation as Milton advances toward Florida.

But while the landfall location, strength and aftermath of Hurricane Milton is still unknown, forecasters say there are some dire scenarios still on the table.

"Milton has the potential to be one of the most destructive hurricanes on record for west-central Florida," John Cangialosi, a specialist with the National Hurricane Center, warned in an update Tuesday. Damaging winds, life-threatening storm surge and heavy rainfall will extend well outside the forecast cone, he said.

Milton underwent rapid intensification on Monday, with sustained winds of up to 180 mph. As of Tuesday it was still a Category 4 storm but fluctuations are anticipated as it comes closer to the coastline. The monster storm is anticipated to likely make landfall late Wednesday as a Category 3 storm, but nothing can be ruled out.

Rainfall of between 5 and 12 inches, with localized areas of up to 18 inches are expected across central and northern portions of the Florida Peninsula through Thursday.

Storm surge happens as a tropical storm or hurricane pushes water toward the coast, triggering catastrophic flooding along the shore, and in bays and inlets. 

The National Hurricane Center said "life-threatening" flooding is possible. Peak storm surge forecasts run as high as 10 to 15 feet in the entire Tampa Bay area.

Other disaster scenarios predicted tragedy

Some planning scenarios have mimicked actual events that happen later. Meteorologists and hydrologists can predict where storms can come and what they could do – exactly the kind of information local officials and emergency planners can use to better prepare for storms, sometimes years in advance.

For example, one year before Katrina made landfall, state and parish officials participated in a disaster simulation exercise in which a fictional Category 3 hurricane named "Pam" hit the New Orleans area.

The Hurricane Pam scenario foretold disaster. The fictional storm brought sustained winds of 120 mph, upto 20 inches of rain in parts of Southeast Louisiana. Storm surges topped the levees and flooded the New Orleans area. It assumed that as many was 300,000 people would not evacuate in advance; 500,000 to 600,000 buildings would be destroyed, phone and sewer services would be knocked out and chemical plants would be flooded.

In 2005, Hurricane Katrina devastated New Orleans. Winds reached up to 125 mph.

Levees failed, flooding parts of the city and trapping thousands of people on rooftops and in attics. As much as 80% of the city was covered in water that went as high as 20 feet, destroying much of the city's transportation and communication infrastructure.

Despite mandatory evacuation orders, tens of thousands of people did not evacuate and as many as 20,000 took refuge in the Superdome, the city's "refuge of last resort."

As many as 1,400 people died during Katrina and its aftermath.

Contributing: Dinah Pulver