Tropical storm warnings are already up in Mexico from Campeche to Puerto de Veracruz as the system continues to organize, while there is concern closer to home for possible impacts by the weekend, depending on the storm’s track and intensity.
The system was declared a “tropical depression” on Monday evening and upgraded to a tropical storm at 12:30 p.m. Eastern. This is the earliest third-named storm to form in the Atlantic basin, with the previous record being Tropical Storm Colin, which formed on June 5, 2016.
The jury is out as to how exactly the storm will evolve. In fact, there’s even an outside chance that two named storms brew in the Gulf.
Where Cristobal is now
For the time being, serious inland flooding from heavy rainfall is likely along the Yucatán Peninsula in Mexico and west into the states of Tabasco and Campeche, where a widespread 8 to 16 inches is likely. A few localized totals of 20 to 30 inches are possible.
“Some of these Pacific locations received 20 inches of rain over the weekend, and storm total amounts of 35 inches are possible,” wrote the National Hurricane Center. “Rainfall in all of these areas may produce life-threatening flash floods and mudslides.”
Heavy rains continue to fall in Central America from the storm, which is living its second life. The system originated from a short-lived tropical storm in the eastern Pacific and was briefly named Tropical Storm Amanda. That storm affected Guatemala, Honduras, El Salvador, and Belize.
The storm already has a history of deadly flooding in El Salvador, where at least 16 were killed in flooding and mudslides. Another seven remained missing Tuesday morning. Nearly 25,000 families were affected, according to the Government of El Salvador, with roughly 7,000 people in shelter.
A national red alert remains in effect, the “critical level of danger” spurring the government to recommend residents remain at home.
A tricky forecast
There are multiple wild cards with the track and intensity forecast for Cristobal, leading to below average confidence in the system’s ultimate strength, track and impacts. Among the greatest uncertainties at this point is whether the developing storm will remain over water or spend some time over land in the Mexican state of Tabasco or along the shores of the Bay of Campeche.
At the mid- to upper-levels of the atmosphere, there is a pattern characterized by broad counterclockwise flow — known as the Central American Gyre — over the western Gulf. The system has been embedded within the gyre’s circulation and subsequently has been steered around its periphery. That’s why the system first traveled east, then curved north, and then northwest and west.
It’s as though the system is driving around a traffic circle, but we’re not sure yet what exit it takes. Does it end up being thrust ashore in Mexico, where it could weaken? Or does the system linger over the warm waters of the Campeche Bay for several days? Eventually, the gyre and the tropical storm will contract and merge into one.
That will also have a bearing on how tight the system’s circulation is and therefore the storm’s intensity.
Models split on the storm’s path forward
The European model, historically among the best-performing models, suggests the system will spin for several days over the Bay of Campeche and not travel inland enough to significantly weaken the circulation. The model concentrates the system’s mid-level spin into a tighter circulation, as well, eventually showing a stronger tropical cyclone sweeping north and eventually impacting the United States.
The American GFS model, however, suggests the system may move inland along the Bay of Campeche as early as Tuesday night or Wednesday. That would likely greatly diminish the intensity of the system after its core reemerges over the Gulf of Mexico on Thursday or Friday.
If the American model’s simulation comes to fruition, a weaker tropical cyclone would impact the United States.
That scenario would could lead to another tropical cyclone being named, as the upper-level circulation associated with the gyre and the remnants of the first cyclone we’re tracking would lead to additional storm formation in the Gulf. If that were to occur, it would be the earliest fourth Atlantic named storm in a season on record.
Right now, it’s unclear which of the scenarios will pan out, with the National Hurricane Center writing “[our] forecast track … brings the center close to the coast of Mexico on days 2 and 3.”
Potential for U.S. impacts growing this weekend
By this weekend, there is an increasing risk of a tropical cyclone affecting the United States. Where it does, heavy rain and flooding is likely. A number of the most impactful tropical cyclones to have affected the Gulf Coast in recent years — including Barry, Imelda, and Harvey — will be remembered for their flooding.
The time frame to watch would be beginning later on Saturday and continuing into the start of next week.
A multifaceted event, including potential wind storm surge, inland flooding or tornado risks, cannot be ruled out. But confidence this far in advance remains very low.
Right now, it’s impossible to provide a specific location in the United States more favored to see potential impacts down the line. Instead, anyone from the Texas Coast to the Florida Panhandle should be vigilant and stay aware of the latest forecast developments.
The ongoing coronavirus pandemic is likely to complicate storm preparation and response efforts, which may require people to think about and get ready for storm impacts earlier than they may have in past years.