Zeta is on track for yet another hit on Louisiana. Of the 27 named storms this hurricane season, 7 times the cone has included New Orleans. Only one of those storms directly affected the city in the end – that was 50-mph Tropical Storm Cristobal in early June. But this one is on a beeline for the metro New Orleans area at or near hurricane strength.
Last night, Zeta’s center tracked just south of Cozumel, the island off the northern end of Mexico’s Yucatán Peninsula. Top winds in the storm were estimated at 80 mph at the time. It also put strong winds across the Cancún resort areas before heading toward the Gulf of Mexico.
The trek over land weakened Zeta a bit, just below hurricane strength, but it is likely to restrengthen quickly over the southern Gulf today. The upper winds are supportive, the storm has a well-developed structure and the Gulf water is still very warm.
A well-defined path is in place between a blocking high-pressure system over Florida and the western Atlantic – the system that’s bringing the peninsula of Florida good weather – and a strong upper-level low-pressure system just west of Texas. Now that the storm has developed and the steering is established, confidence in the track is fairly high.
Zeta’s strength is expected to level off, and perhaps it will weaken at bit, as it speeds toward Louisiana and Mississippi, but not enough to avoid causing big problems. The upper winds will become less supportive of a strong storm tomorrow, and the Gulf water gets colder near the northern Gulf coast. But since the storm is forecast to pick up speed, it is still expected to make landfall at or near hurricane strength late in the day.
It will be moving at a good clip, so Zeta’s direct impacts will come and go quickly along the coast. Still, power outages and other issues related to the wind are likely to the right of where the center comes ashore. And because the storm will be moving so fast, it will take fairly strong winds well inland as well.
Flooding rain will be a significant factor along its track as well, as Zeta combines with a cold front farther north.
In addition, as we have seen over and over again in 2020, this northern-Gulf coastline is very susceptible to storm surge. The forecast is for the Gulf water to be pushed 4 to 6 feet above the normal high tide level in southeastern Louisiana and Mississippi, and 2 to 4 feet as far east as Pensacola, which is still recovering from Hurricane Sally.
The City of New Orleans is not right at the coast, so the winds will likely be at strong tropical-storm force there. And the huge levee system built after Hurricane Katrina to protect the city and some of the suburbs will not be challenged by this storm. Some areas outside the levee and flood-gate system will be subject to flooding, however.
After making landfall late tomorrow, Zeta will fly across the Midwest and into the Northeast. In that transit, it will lose its tropical characteristics and become a northern storm in combination with the big upper-level low pushing it along. It will produce nasty weather in the big cities of the Northeast at the end of the week, and may bring the first significant snow of the year to northern New England.
In South Florida, the developing storm along the Northeast coast will help propel a cold front to the south over the weekend. It won’t be strong, but it’s a step in the right direction. And a stronger front is still possible around Election Day next week.
Long-range computer forecast models continue to indicate that a weather pattern somewhat conducive for tropical development may return to the southern Caribbean next week. But one thing at a time.