HURRICANE ETA TO HAVE CATASTROPHIC IMPACTS IN CENTRAL AMERICA – THEN WE HAVE TO WATCH THE REMNANTS
Stunningly strong Hurricane Eta is pounding the Caribbean coast of Nicaragua. A devastating impact on coastal communities is likely. Eta’s vicious winds will destroy all but the strongest structures, and the Caribbean water is forecast to rise 14 to 21 feet above normal tide levels at the Nicaraguan coast.
Hurricane Eta is one of the strongest storms ever recorded in November – the strongest being a tremendously destructive Category 5 that hit central and eastern Cuba in 1932. That storm peaked in intensity in the Caribbean not far from where Eta was located yesterday.
There is a lot of deep warm water in the central and western Caribbean, even in November. If the atmospheric environment is super-supportive, like it is now, there is nothing to limit the strength of hurricanes there.
Eta’s top winds are weakening as it makes landfall, but it won’t change the outcome.
By later today, Eta’s winds will be winding down significantly as the system tracks over Nicaragua and toward Honduras. Over the next few days, the center of the storm should be over the mountainous terrain, which will likely disrupt or destroy the circulation at ground level and the top winds will rapidly diminish.
Once Eta is over the land, however, the extreme threat comes from torrential rain falling over the mountains. More rain will fall at higher elevations – 2 to 3 feet of rain is forecast – and that water has to come downhill. Gullies and creeks will become unsurvivable torrents. Rivers will swell, sweeping away structures along their banks.
Thousands of people have died from this type of scenario in the past – 1998’s Hurricane Mitch and 1974’s Hurricane Fifi are both estimated to have killed 8,000 to 10,000 people or more in Honduras and Nicaragua. It’s a frightening situation.
The strong winds over Florida are caused by the high contrast in pressure between the high-pressure system to the north, which pushed the cold front through the state, and the extreme low pressure of Hurricane Eta to the south. Breeziness will continue through the week, but it won't be quite as strong as Eta’s pressure rises as the storm weakens, and the high to the north moves away.
By the end of the week, the remnants of Eta are forecast to move back over the Caribbean. Whether Eta’s circulation is part of those remnants, or whether it’s just a broad upper-level system that incorporates some of Eta’s spin, is an open question.
If the National Hurricane Center can track the surface circulation through the mountains, and a new storm develops once it gets over the water, it will be called Eta once again. If, however, Eta’s circulation is ripped up by the high terrain, and a new circulation forms with winds eventually reaching 40 mph or higher, it will be called Tropical Storm Theta.
Whatever the new system is named, assuming it organizes and strengthens, its eventual track is highly uncertain. A strong dip in the jet stream is forecast to move across the Gulf over the weekend. To what extent that will scoop up the new system – assuming it exists – and pull it north is unclear. The system’s location and strength will affect how ex-Eta and the dip interact.
It’s also unclear whether the jet-stream dip will create a supportive or hostile environment for the system to strengthen.
The consensus of the computer forecast models is that Eta/Theta, or whatever the system is at the time, will be in the vicinity of Cuba at some point over the weekend, and moving slowly. If this is approximately correct, tropical moisture will be spreading over South Florida, and substantial rain would be likely.
For now, speculation is useless. There is a long history of hurricane becoming disheveled over mountains and never recovering. As we’ve learned during this relentless hurricane season, slow-moving systems that are in the organizational stages are impossible to forecast well. And in this case, we’re talking about developments a week from now.
We have to see what happens late in the week after Eta, or whatever’s left of it, emerges or reforms over the Caribbean.
Between now and then, the people of Nicaragua and Honduras are going to be impacted by another historic storm. It’s hard to imagine how a catastrophe can be averted with an extreme hurricane like Eta bearing down.