There were more than a hundred people taking part with 54 agencies.
Meteorologist Jeff Lindner with the Harris County Flood Control District, helped to create the scenario of Polly, a category 4 hurricane that made landfall near Freeport and moved north through the Houston area.
"The players don't necessarily know what's coming, but we designed it to: 'Okay, I didn't expect this. How are we going to deal with it?' If you can go through it and think about it now, and we do go through it in a real event, we'll be much better prepared to handle it."
Harris County Judge Ed Emmett is the director of Homeland Security and Emergency Management when a hurricane strikes. He says you have to consider three P's: partners, people and the press in relaying accurate information.
"There've been some wrong messages put out. We've seen it time after time, but the reason for having these joint exercises is to make sure the various partners involved, and the public, get the right information."
It was the largest hurricane exercise in the region in more than 5 years. It tested how officials dispense timely, accurate and actionable information during large scale emergencies.
The Coast Guard's Captain Bryan Penoyer says the strength of the relationship of the participating agencies was put to the test.
"We think the plans that we developed, particularly following Hurricane Ike, are incredibly strong. But you'll never know that until you actually put load on the circuits sort of speak, and actually test them."
After the exercise was completed, participants discussed areas that needed improvement as they looked for better ways to be prepared when a hurricane hits.
Inside Joint Information Center at TranStar with Tropical Storm Dorian on the screen