Eric Berger

In brief: Today’s post discusses our increasing confidence in the track for Tropical Storm Erin, and takes a look at some of the near- and long-term risks from this system, which should become a hurricane by this weekend. We also discuss a new Blobby McBlobface in the Gulf.

Status of Erin

As of Wednesday morning the Atlantic season’s fifth named storm retains a fairly ragged appearance on satellite, with the National Hurricane Center (a bit generously, maybe?) holding Erin’s intensity at 45 mph. The system continues to encounter somewhat dry air, and sea surface temperatures that aren’t exactly sizzling. So Erin is just kind of slogging westward across the Atlantic. But it is making progress, having moved about halfway between Africa and the Leeward Islands; and Erin continues moving with purpose, at about 20 mph. On this path the storm should find more favorable conditions in the coming days.

Those conditions include warmer water and, crucially, rising air that should support further intensification. Accordingly, the National Hurricane Center expects Erin to become a hurricane by Friday, and potentially a major hurricane by this weekend. This is well supported by a suite of models we look at, and seems like a reasonable best guess. Bottom line, Erin is still very likely to become this season’s strongest storm to date, by far.

OK, so where is Erin going?

After several days of uncertainty, our confidence in Erin’s track is increasing. Although it is moving west now, it should slowly turn west-northwest by Friday or Saturday, and then northwest on Sunday as it finds a weakness in the high pressure system to its north. By early next week the storm’s center should lie somewhere to the north of Puerto Rico or Hispaniola, and be turning further north.

If we look at the overnight guidance there is a lot of support for this track, and it helps build our increasing confidence. Along this track the center of the storm should approach Bermuda by Wednesday (give or take a day) next week. We’re not saying the track of Erin is a done deal here, as there remains a broad range of outcomes beyond day four or five of the forecast. And we’re going to discuss other risks below. But at this time our land mass of biggest concern is the island of Bermuda. Residents there should be keeping very close tabs on the system.

Other concerns with Erin?

Yes, we have some. Depending on how quickly Erin strengthens (i.e. a slower-to-organize storm would remain further south) we would advise people living in the northeastern rim of Caribbean islands, including Antigua and Barbuda, the Virgin Islands, and Puerto Rico to remain vigilant. These islands are unlikely to see a direct hit from Erin, but they are at risk of higher waves and heavy rainfall beginning late Friday and running through the weekend.

Areas of the US East Coast, such as the Carolinas and Virginias, should also keep an eye on Erin. The risk of a landfall there is very low, but it remains non-zero. More importantly, like the Caribbean islands discussed above, there could be impacts to seas along with heavy rainfall. Overall our concern level for the mainland United States is fairly low, but at a week out we cannot say anything definitive about impacts there.

What about the Gulf?

What about it? I like living there. Good people. Great seafood. This week even the waters near Galveston have even been blue-ish. Oh, you mean the new tropical blob there highlighted by the National Hurricane Center this morning.

Well, I don’t have much to say about this this morning. On one hand, yes, the calendar says it is August. So anything tropical in the Gulf at this time of year raises one’s eyebrows. But I’m having a hard time getting too worked up about a tropical low that will find only marginal conditions for development. If we dig into the ensembles there does not even appear to be too much of rainfall threat. For example, based on the European model, the probability of rainfall amounts of 4 inches or greater is near zero for all but a few isolated areas of Mexico. So yes, we’re going to watch this thing. But no, we’re not going to get too excited about it.

What else?

Overall it’s fairly quiet out there today. We’re watching for some flood concerns in southern Kentucky and Tennessee, including the Great Smoky Mountains area. A flash flood watch is in effect for much of this area, where there could be some training rainfall and higher wind gusts. The threat of heavy rainfall should pass this evening or tonight.

Beyond that, it’s mostly just hot out there in the United States, which is to be expected in August.

In brief: A tropical disturbance will move into the northeastern Gulf a little less than two days from now. Thereafter it should track westward. The most probable outcome is a moderate disturbance moving into Louisiana later this week, with the potential for heavy rainfall. But we will continue to watch things closely to see how the system evolves.

This weekend brought more flooding across parts of the United States. On Saturday evening the Davenport, Iowa area dealt with several inches of rain that flooded some homes and submerged vehicles. By Sunday the flood risk returned to Texas, where a large part of the Texas Hill Country saw a second round of heavy storms, including the previously hard hit Kerrville area. This produced flash flood warnings along and east of Interstate 35, but the strongest of the storms have now moved off to the southwest. Also this weekend there was a devastating fire on the North Rim of the Grand Canyon, which destroyed the historic Grand Canyon Lodge. So all in all, not ideal.

Gulf disturbance

After all of this, we are turning our attention to the tropics this morning. We have been mentioning the possibility of a tropical system developing this week in the Northern Gulf of Mexico for several days, and the National Hurricane Center has now begun highlighting the possibility. As of 8 am ET on Monday, forecasters there give the system a 30 percent chance of becoming a tropical depression or storm this week.

The remnants of a front, currently in the Atlantic Ocean off the coast of Georgia, should move across Florida over the next day or two, and into the northeastern Gulf. Once there, conditions could support the development of this area of low pressure into a depression or tropical storm that would continue moving generally to the west.

As to what happens after this, there is not great clarity in the model guidance. The background conditions, including sea surface temperatures and wind shear, are somewhat favorable for organization and intensification. But this is not an ideal situation, and the system is likely to remain fairly close to land. So we don’t expect this to explode over the deep and warm waters of the Gulf. Eventually it should move toward Louisiana.

One outlier model that appears to be most bullish on the system is the Germany based ICON, which brings a moderate tropical storm toward southern Louisiana by Thursday morning (shown below). Some people may remember that the ICON model is one of the outliers that correctly predicted Hurricane Beryl would impact Texas about a year ago, so we are not completely dismissing it. However, most of our other guidance does not develop a tropical storm, but rather keeps this at a disturbance or a depression level.

So in terms of intensification what we can say right now is that we don’t anticipate a significant wind storm. We cannot rule it out, but high winds and storm surge are not the main talking point. Rather, rainfall potential is.

Precipitation outlook

As this system tracks across the northern Gulf of Mexico, it is likely to bring increased rainfall chances to the Florida Panhandle, southern Alabama and Mississippi, and especially southern Louisiana. For now, NOAA’s Weather Prediction Center has that area, including New Orleans, under a “slight risk” of excessive rainfall next Thursday (shown below) and Friday.

That’s a good starting point, but depending on the evolution of this system that estimate may need to be bumped up in a day or two. The bottom line is that the second half of this week could bring a significant amount of rainfall into Louisiana. Right now we can only monitor the risk, rather than provide a definitive forecast. Hopefully that changes in a day or two.

As for areas further west, including Texas, we cannot rule out impacts at this time. However, none of our reliable guidance shows this system (or its heavy rainfall) tracking far enough to the west to bring heavy rains or winds to Texas. But it is something we will continue to watch.

In brief: Today’s update provides an overview of the dusty tropics and a look at a new seasonal forecast from Colorado State University. We also dig a little deeper into storms today in the Midwest, and the potential for excessive heat in the West.

Hi everyone, Eric Berger here. As you probably know Matt does the majority of forecasting on The Eyewall but I’m here to back him up, and so I pinch hit occasionally. This is the first time I’ve written for the site since we have moved our newsletter over to Substack, and I just wanted to thank everyone who has signed up. The response so far has been tremendous, and we are already making plans to improve The Eyewall as a result. But for now we are going to focus on hurricane season, heavy rains, and heat in today’s outlook.

The tropics

Let’s start in the tropics where, happily, everything is quiet all the way from the Central Pacific Ocean to the Eastern Atlantic. This is not all that abnormal for the first half of July, but it is nonetheless welcome. Looking ahead, due to a variety of factors including a new and fairly large plume of dust moving off the Sahara into the Atlantic, we think things will remain fairly quiet for at least a few more days—and hopefully more!

In this interim period of quiescence I wanted to take a peek at the updated seasonal hurricane forecast from Phil Klotzbach and his team at Colorado State University. As you can see in the chart below, the team has slightly lowered their outlook in terms of named storms and hurricanes, and reduced the overall forecast for Accumulated Cyclone Energy by 10 percent. This is only a slight modification, and given the inherent error within seasonal forecasts such a change does not mean a whole lot. But in the main, you’d rather be trending downward in seasonal activity than upward, no?

As for why the Klotzbach team made the change, here’s what they wrote in their abstract: “We have decreased our forecast slightly and now call for a slightly above-normal 2025 Atlantic basin hurricane season. The primary reason for the slight decrease in the outlook is both observed and predicted high levels of Caribbean shear. High levels of Caribbean shear in June/July are typically associated with less active hurricane seasons.”

Midwest rains

Areas of the upper Midwest, including parts of Iowa, Missouri, Wisconsin, and Illinois will be subject to heavy rainfall on Friday and Friday night. In the big picture we see a large trough over the Central Plains that will be supportive of storms. Such complexes of thunderstorms, known as mesoscale convective systems, will be possible from late morning through the early evening hours. Most likely we will see a line of storms develop over Iowa and Wisconsin before moving southward into Missouri and Illinois.

From an impact standpoint I don’t believe these will be too serious. However, given the setup, some modest flooding is possible later today where the stronger storms set up. This forecast from the Weather Prediction Center provides an idea of where the greatest risk of heavy rainfall will come later today. By late evening the flood risk should be diminishing for the Midwest.

Sizzling in the west

Much of the Western United States will see high temperatures this weekend above 100 degrees. For some areas in Arizona and Southern California, this is nothing new. But the highs for a broad swath of northern California, Oregon, Washington state, and elsewhere in the west will be 5 to 15 degrees above normal. This heat is due to a building dome of high pressure that will affect much of the West through Sunday. The heat should break by Monday for much of the region.

However, the forecast for the Northwest turns even more extreme next week. Areas near Portland and Seattle could see highs in the mid- to upper-90s on Tuesday and Wednesday as high pressure rebounds. There is still some uncertainty in the upper-level pattern that may moderate temperatures slightly. But for these areas this is very high heat, and an Extreme Heat Watch is in place for Tuesday afternoon through Wednesday evening.

That’s all for us today. We hope everyone has a great weekend.