Eric Berger

Headlines

• Invest 97L has reached Cuba, and will near the Florida Keys by Saturday
• Our confidence in its track is increasing, raising the risks to Florida, and lowering them for the northern Gulf of Mexico coast
• All tropical threats are in play, but we’re most concerned about heavy rainfall at this time
• Risks are also rising for the southeastern United States, particularly coastal regions of Georgia and the Carolinas

Status of Invest 97L

The tropical wave we’ve been tracking continues to get better organized, and it now has the designation Invest 97L. The approximate center of the system is now near or over the eastern end of Cuba, and it should move along the island today bringing showers and thunderstorms to Cuba and other Caribbean islands. Interaction with land may limit any attempts to organize today, but by Saturday it should emerge near the Florida Keys and move into the southeastern Gulf of Mexico. At this point the National Hurricane Center gives the system a 90 percent chance of eventually becoming a tropical depression or storm. In this case it would be named Debby.

Forecast clarifies some

If you read our update on Thursday, you’ll recall we were in “watch-and-see” mode with this tropical system. Well, we’ve watched. And now, we’ve seen. All of our major model guidance now predicts that 97L will move into the southeastern Gulf of Mexico, and likely remain near—perhaps just offshore—the coast of Florida on Saturday and Sunday. During this time it could well strengthen into Tropical Storm Debby, but this is not sure thing as I don’t know how disorganized 97L will be when it moves off of Cuba.

At some point this weekend, perhaps on Sunday, or Sunday night, 97L is likely to turn toward the northwest. This could bring the system into Florida anywhere from south of Tampa Bay to the coastal bend of Florida. A stronger storm would likely turn more quickly. In any case, residents of the Florida Keys and the West Coast of Florida should be preparing for tropical weather as early as Saturday.

After 97L crosses the Florida peninsula it may reemerge into the Atlantic Ocean somewhere near Jacksonville, Florida. At that point its center should remain just inland, or perhaps move offshore before moving into South Carolina or North Carolina as a stronger storm. East Coast regions from Jacksonville north to coastal Carolina and possibly even Virginia should be prepared for tropical impacts from Monday through Wednesday of next week.

We mentioned that residents of the northern Gulf of Mexico coast should remain vigilant in yesterday’s post, but at this point all of our guidance suggests the storm’s impacts will occur from the Florida Panhandle and to the east.

97L impacts

So far we’ve mentioned that coastal residents in Florida and up the East Coast should prepare for tropical weather, because all of the impacts associated with a tropical system are in place: strong winds, storm surge, and inland rainfall. The extent of these impacts will depend on how much 97L strengthens before moving into the west coast of Florida, and then whether it has time to restrengthen over the Atlantic Ocean if it spends time offshore of Georgia and the Carolinas. That is impossible to forecast at this time, and probably won’t be until 97L develops a better defined center of circulation.

The one bit of good news is that it now appears that this tropical system will probably miss an area of low steering currents over the northern Gulf of Mexico. This means that its track should be more conventional, first turning north, and then to the northeast as it moves poleward. This should help to limit rainfall totals, but some of our models are still showing very high amounts in coastal areas of Western Florida and coastal Carolina. Again, these totals will depend on the location and forward speed of the storm this weekend and during the first half of next week. Regardless, flooding is a concern.

Elsewhere in the tropics

Beyond 97L, as we get deeper into August, there is likely to be some activity over the next week or 10 days. At this point the area of greatest interest may be the southern Caribbean Sea, where something may spin out of the gyre in that region next week. We shall watch and see what happens.

Headlines

• A tropical wave is moving near Hispaniola, and likely to cross Cuba over the next couple of days
• We have a lot more questions than answers about the strength and intensity of the tropical system after this
• However, it poses a distinct threat to Florida and the northern Gulf of Mexico coast
• Rainfall is a particular concern due to a lack of steering currents next week

Tropical wave getting better organized

The tropical wave we’ve been discussing for much of this week has a better satellite appearance today as it is bringing a large area of showers and thunderstorms to the Caribbean. As of Thursday morning, the center of this activity appears to be situated near Hispaniola, and the system should continue to move steadily to the west-northwest.

Our forecast models have really struggled to get a handle on the evolution and track of this tropical system over the last couple of days, and there has been a decided westward shift in the guidance. Whereas it once appeared that the tropical system—which if it were to develop would be named Debby—would travel to the east of Florida, it now appears as though it will remain south of Florida and move into the eastern Gulf of Mexico.

One reason for this is that it no longer appears as though the tropical wave will become Debby any time soon. A more rapidly strengthening system favored a poleward turn more quickly into the Atlantic. However, most of the model guidance now keeps the system below tropical depression strength for the next several days as it moves over Cuba and into the southeastern Gulf of Mexico this weekend.

What happens in the Gulf of Mexico?

If only what happened in the Gulf stayed in the Gulf. As the outlook from the National Hurricane Center outlook above makes clear, there is broad uncertainty about what happens to the system as it moves off of Cuba. It could conceivably move into Florida, or over any part of the eastern Gulf of Mexico. As of this morning most of the guidance favors a blob moving into the Eastern Gulf.

If the storm remains offshore, it would find more favorable conditions for development this weekend, or early next week. So it’s possible, and perhaps even likely, that we’ll see a tropical storm off the west coast of Florida in three to five days time. At a minimum, this will be a rainmaker. And depending on how strong it gets, there could be wind and storm surge threats as well. However, it is a fool’s errand to try and make such predictions now as there is a ton of uncertainty about a storm that a) has not yet formed, b) must still traverse the spine of Cuba, and c) may then interact with parts of Florida’s landmass. The bottom line is that residents of Cuba, Florida, and southern Mississippi and Alabama (and maybe even Louisiana) should be tracking the storm’s progress over the coming days.

A lack of steering currents

The party doesn’t end early next week, unfortunately. Let’s assume the system moves near the Florida Panhandle by Sunday or Monday. At that point it will run into an atmospheric pattern known as a “col,” not to be confused with the state or military rank. A col, in meteorology, means a place where a trough and ridge intersect. Essentially, due to weak steering currents, this tropical system could spin around and make some wild turns in such an upper air pattern.

For example, the European model brings the center of a very weak tropical system to the Florida Panhandle late next Monday, and then retrogrades the system back over the northern Gulf of Mexico for much of next week. The GFS model brings a strong tropical storm to the coastal bend region of Florida on Sunday, moves it all the way into the Atlantic Ocean off the Carolinas, before bringing it westward all the way back to Destin Florida and then Biloxi, Mississippi, before it finally lifts north on Tuesday, August 13. That’s 12 days from now!

The bottom line is that Florida and the northern Gulf of Mexico coast need to buckle up and be ready for anything over the next week or 10 days. We just don’t know what is going to happen. My biggest concern, for the time being, is the potential for very heavy rainfall along the Florida Panhandle or the west coast of the state. However, as the storm evolves, so will the threats it presents to us.

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.