Eric Berger

Headlines

• Beryl has intensified into a major hurricane and will move into the Windward Islands tonight
• This hurricane will likely cause significant damage to these small islands, including Grenada and Barbados
• Beryl will then approach Jamaica by Wednesday, where it is likely (although not certainly) to remain a major hurricane
• By late this week the hurricane should near the Yucatan Peninsula
• It remains an open question as to where Beryl goes beyond that, although a northwesterly turn into the Gulf of Mexico is a slight possibility
• Invest 96L could bring more misery to areas already impacted by Beryl

State of the Tropics on Sunday

As of late morning on Sunday, the tropical Atlantic remains very active for the end of June. In addition to Beryl, there are a couple of systems the National Hurricane Center is monitoring for potential development. We’ll comment on those at the end of this post, but our primary focus today is the rapidly developing Beryl, which as of 11:35 am ET is a dangerous Category 4 hurricane.

Hurricane Beryl this week

Thanks to warm seas, the system has intensified during the last 24 hours from a 50-mph tropical storm into a powerful 130-mph hurricane as it nears the Windward Islands. It should then cross these islands on Monday and move into the Caribbean Sea. The storm will likely remain sufficiently south of Puerto Rico and Hispaniola to preclude serious damage there, but it could threaten Jamaica on Wednesday and Central America and the Yucatan Peninsula toward the end of the week. After that? Movement into the Gulf of Mexico is possible, but after this point our confidence starts to decrease.

In terms of intensity, additional strengthening of Beryl is likely over the next 24 hours or so as Beryl traverses very warm seas and is encountering relatively little wind shear. The National Hurricane Center forecasts a peak strength of 140 mph sustained winds by Monday morning, when the storm passes near islands including Grenada, Barbados, St. Lucia, and Martinique. These locations should prepare for the most intense wind and surge impacts beginning after midnight tonight, and lasting through at least Monday morning. Localized rain totals of 6 to 12 inches are possible. This is a very serious situation, and residents should prepare accordingly.

As it moves into the Caribbean Sea on Monday and Tuesday, Beryl should encounter moderately stronger wind shear, and this probably will cause some weakening. But the jury is very much out on how much weakening will occur before Beryl approaches Jamaica on Wednesday. The National Hurricane Center forecasts the system having sustained winds of 120 mph at that time, but this is just a reasonable guess. By Thursday night or Friday, as the center approaches Belize and the Yucatan Peninsula of Mexico, it’s likely that Beryl will weaken a little bit further. It will still likely bring hurricane-force winds to these locations sometime between late Thursday night and Friday night, in addition to heavy rainfall.

Hurricane Beryl this weekend

Our certainty about Beryl’s track begins to fade by the weekend. From now until then, a fairly strong high pressure system should continue to push the storm westward. Over the weekend and into early next week, it is possible this ridge continues to steer Beryl westward into the Bay of Campeche. (It is not clear how much interaction with the Yucatan would disrupt Beryl’s circulation, but some weakening is virtually certain). In this scenario, Beryl is likely to move across the southern Gulf of Mexico and plow into the east coast of the Mexican mainland, similar to Tropical Storm Alberto about 10 days ago.

However, there is also the possibility that this ridge weakens, somewhat. At this point, this remains a lesser likelihood when we look at the global models. Still, there is a non-zero chance that Beryl turns northwestward after encountering the Yucatan Peninsula. In such a scenario a tropical system—be it a tropical storm or hurricane—could come to the Texas or even Louisiana coast late next weekend. I understand that everyone would like to have absolute answers about whether this will happen, but we just don’t have that kind of certainty right now.

Bottom line: It’s within the realm of probability, but the odds are fairly low. We can see this distribution of possibilities when we look at the “super ensemble” track of forecasts for Beryl, which favors the ridge holding strong. We should know more about this part of Beryl’s forecast by Monday or Tuesday, and of course we’ll remain on top of that at The Eyewall.

Invest 94L

There is still a short window for this tropical disturbance over the southern Gulf of Mexico to develop on Sunday before it likely moves inland into Mexico on Monday. The primary threat from Invest 94L is heavy rains in southern Mexico and Central America, which saw similar impacts from Alberto just 10 days ago. Regardless of whether this system develops further or not, the effects will be the same.

Invest 96L

The third area of tropical interest is trailing Hurricane Beryl by a few days as it traverses the open Atlantic Ocean. The National Hurricane Center gives this system a 70 percent chance of becoming a tropical depression or storm during the next week, and at this point it seems likely to impact the Windwards Islands in a similar location. This could happen as soon as Wednesday, and could deliver an awful second whammy.

However, I have some questions about how much Beryl will perturb the ocean and atmosphere, and this could help to mitigate the strengthening of this tropical disturbance as it nears the Caribbean Sea in a couple of days. We will be keeping a close eye on the system, in any case.

One-sentence summary

We are going to talk about Otis today because of the hurricane’s dramatic intensification on Tuesday, and overnight landfall along the Southern Pacific coast of Mexico.

Rapid intensification

Otis made landfall on Tuesday night, near Acapulco, with maximum sustained winds of 165 mph. This was a worst-case scenario for this region. Why? Because no storms had been recorded in this area, this strong, before. On top of that, local residents and business owners had less than a day to prepare for the worst hurricane of their lives. So not only was this storm unexpected, there was no institutional memory about what to expect from a major hurricane.

With this startling burst in intensity, Otis has nearly set a record for rapid intensification within 24 hours. The system strengthened from a 50 mph tropical storm at 1 am CT on Tuesday to 165 mph just 23 hours later. That is 115 mph in 24 hours. It is second only to Hurricane Patricia, a Pacific storm in 2015 that saw its maximum sustained winds increase by 120 mph during a similar period.

This morning, as it moves inland, Otis is weakening. As of 7 am CT the storm had 110 mph winds, and will continue to lose intensity as it interacts with mountainous terrain. Nevertheless, Otis will continue to bring damaging winds into Southern Mexico today, along with dangerous storm surge. Heavy rains will remain a problem later this week, through Thursday, for much of Southern Mexico. They are likely to produce significant flooding and mudslides.

Completely blind-sided

Let’s wind things back to Monday night, and have a look at the model forecasts for the intensity of Hurricane Otis. At the time this was a tropical storm, and largely expected to remain so before its landfall into Mexico. None of our ‘best’ models for predicting tropical system intensity anticipated Otis growing beyond tropical storm-strength. In two decades of forecasting I do not recall a whiff like this one.

As a meteorologist, these kind of moments are humbling. Otis will be studied in the coming months and years to understand why it blew up so quickly, and so powerfully, in such a short period of time. In moments like these, forecasters utterly failed the people of Southern Mexico. We must do better.

Hurricane Tammy

Over in the Atlantic Ocean, Hurricane Tammy continues to dance around the Atlantic Ocean. This storm would be a curiosity given its meandering track, but for its potential to come near Bermuda this weekend. As of Wednesday morning, Tammy has sustained winds of 100 mph, and there is a chance for some slight strengthening today.

However, after today it is likely to interact with a cold front, and begin a transition to a non-tropical storm. There is a fair amount of uncertainty in track and intensity. But for now it looks like Tammy will remain far enough south, and just weak enough, to not bring anything more than garden-variety like storminess to Bermuda this weekend.

Beyond Tammy, happily, the Atlantic tropics look quiet.

One-sentence summary

We’re nearing the end of the Atlantic hurricane season, but we need to continue tracking Invest 94L as it is likely to track across or near the northern end of the Lesser Antilles this weekend, including the islands Antigua and Barbuda.

Happening now: Invest 94L

There is precisely one system we need concern ourselves with in the Atlantic, and that is an area of low pressure that is approaching the Caribbean Sea. It continues to lack a center of rotation, but the system is starting to get its act together. The National Hurricane Center projects that it has an 80 percent chance of becoming a tropical depression or storm over the next week. Even if it does not the tropical system will bring heavy rains to parts of the Lesser Antilles this weekend.

By the way, what do we mean when we say the Lesser Antilles? It can be a little confusing, both for readers and forecasters. So let’s spend a moment walking through it. We’ll start with the Greater Antilles, which are the larger Caribbean islands—Cuba, Hispaniola, Jamaica and Puerto Rico—that mark the northern boundary of the Caribbean Sea. As this arc of islands extends further eastward and to the south, the islands get smaller, places like Antigua and Barbuda, Barbados, and Saint Kitts and Nevis.

These islands stretch almost all the way south to South America, and form the eastern boundary of the Caribbean Sea. These are the “Lesser” Antilles since they’re smaller islands. To make things even more confusing, the islands of the Lesser Antilles are divided into three groups: the Windward Islands in the south, the Leeward Islands in the north, and the Leeward Antilles in the west. So Invest 94L is threatening the Leeward Islands, which are part of the Lesser Antilles. Still with me? Good. There will be a quiz at the end.

The good news for the Leeward Islands is that if 94L organizes into a stronger system it is likely to turn to the northwest before reaching land. If it remains weaker, then it could follow a more westerly track into the islands, bringing some winds, high seas, and rains, but nothing too crazy. We’ll fine tune the forecast in a day or two.

What else is out there?

Not much in the Atlantic Ocean.

After 94L does whatever it does, the only other watch area over the next 10 days or so will be in the southern or southeastern Caribbean Sea, where we may see a home-grown storm develop. But that is only a vague threat at this point. And as we approach the end of October, we can generally expect to see the Atlantic tropics winding down for the year.

Here’s the quiz: Anyone got any problems with that?

One-sentence summary

Tropical Storm Lidia dissipated this morning over Mexico, but will bring rainfall and mudslides to part of the country; and its remains will merge with other moisture in the Gulf to bring rains later this week in the southern United States.

Tropics now: Goodbye Lidia, and hello Sean

After rapidly intensifying on Tuesday and slamming into the Pacific Coast of Mexico, Lidia has been shredded by the mountainous terrain of Central Mexico. The big concern with Lidia, accordingly, is now rainfall. The remnants of the system could cause urban flooding and mudslides in Western Mexico today.

After today, those remnants will be drawn into the Gulf of Mexico along with the remains of another Pacific storm, Max, as well as a warm front lifting north. This mess will eventually move to the northeast, toward Florida. We have zero expectations for these lows to congeal into something threatening from a tropical storm standpoint, but it should heighten rain chances for areas from Louisiana through Florida.

Overall rainfall totals look fine, with 1 to 3 inches from Southern Louisiana along the Gulf coast all the way to the Tampa area of Florida. Some locations may see higher amounts, but this system will be pushed out of the region by Friday and Saturday as a broad front brings drier air into the southern United States. So, not a huge concern.

Hi Sean, Goodbye Sean

Tropical Storm Sean has formed in the Atlantic tropics, about halfway between Africa and the Caribbean Sea. This system is expected to piddle along for a few days before it gets swamped by wind shear this weekend most likely. It will not threaten land. That’s probably about all we need to say about Sean.

Tropics later

Beyond Sean there are some mildly interesting features that we are watching.

The first of these is a tropical wave that just moved off of Africa, and should continue to move due westward through the weekend. The atmosphere isn’t overly favorable for development, so the National Hurricane System only gives this system a 30 percent chance of becoming a tropical storm over the next week. But eventually, and we’re talking at least a week to 10 days from now, this system might be something that eventually approaches the Leeward Islands. It’s not something I am really concerned about at all right now, but we will continue to watch it for you.

Beyond this, we probably need to be wary of some late-season development in the Caribbean Sea. Waters remain very warm in those sun-bathed seas, and there are some hints of potential storminess during the last 10 days of October. There’s not much of a threat to point to, just the potential for something to eventually spin up.