Tropical Storm Cristobal takes aim at U.S. Gulf Coast

The third named system of the very young 2020 hurricane season is forecast to make landfall along the northern Gulf of Mexico coast, likely around Louisiana, this weekend. This is the earliest in the season that a third named system has ever formed in the Atlantic.

Cristobal is churning in the southern Gulf of Mexico, straddling land between Mexico and the Bay of Campeche. The storm strengthened overnight, acquiring winds of 60 mph. However, its proximity and interaction with land will likely weaken it in the short term over the next day or two.

As of Wednesday's late morning advisory, Cristobal had maximum sustained winds of 60 mph. The storm is now moving inland and is expected to weaken to a tropical depression by Thursday, but it will gather strength again once it moves back over the Gulf on Friday.

Because of the storm's very slow forward speed, extreme rainfall is already occurring and is expected to continue. Up to two feet of rain has already fallen and much more is forecast. This is already causing life-threatening flash floods and mudslides.

Two to three feet of rain is forecast in southern Guatemala and El Salvador.

In the Mexican states of Campeche, Chiapas, Quintana Roo, Tabasco and Yucatan, up to 25 inches of total rain is forecast. Belize and Honduras are forecast to receive lesser amounts, about 3 to 6 inches with isolated spots totalling 10 inches.

Even though Cristobal is over land, because of the storm's large circulation and tentacles which extended into the warm waters around the Yucatan, it will not completely dissipate. Instead, deep tropical moisture will continue to feed into the system, allowing it to maintain the integrity of the circulation. Therefore, once it moves north on Friday, it will be able to strengthen once again.

On Friday the storm is forecast to pull back northward into the open Gulf of Mexico waters. At that time it will begin to gain organization and intensity once again. With that said, it's early in the season and water temperatures are not quite warm enough to produce a monster storm. Also there will be increasingly strong winds in the upper atmosphere across the Gulf of Mexico, working to counteract strengthening. As a result, only modest intensification is forecast by the National Hurricane Center. 

While the exact track of the system is still uncertain, the computer model guidance is converging on a path that would take the storm into the northern Gulf Coast area late in the weekend or very early next week. The most likely spot for landfall is Louisiana, but it could be as far west as eastern Texas or as far east as the western Florida Panhandle.

Because we do not expect this to be a major hurricane, wind will not be the greatest threat. But some wind damage could occur, with downed trees and powerlines and power outages possible. In addition, as is the case in almost all landfalling tropical systems, isolated tornadoes are likely.

The biggest impact will be the rainfall. A large and extended rain event will begin on Saturday and continue through Monday. In general, 4 to 6 inches of rain will fall, but some isolated spots could tally over 10 inches. This is likely to cause pockets of flooding, especially east of the track from Louisiana to Mississippi, Alabama and western Florida.

Since Cristobal is not expected to become a particularly intense storm, it  will likely be a test run for what looks to be a very active hurricane season. With state resources stretched thin by the protests and the coronavirus pandemic, officials suggest using this time to get prepared for the season ahead. 

In:
• Gulf Coast of the United States