Matt Lanza

First Monday of Atlantic hurricane season brings mostly calm conditions

In brief: No tropical development is expected in the Atlantic this week. Next week looks modestly more interesting, but there are no real serious signs of anything specific to be concerned with. We also talk about a potpourri of notes at the end.

Atlantic update for the week ahead

No tropical development is expected in the first full week of June. At this time, the Atlantic looks mostly under control. We continue to see standalone GFS operational model runs blow up tropical systems in the Gulf. As we noted on Saturday, this is frequent, common May and June bias of the GFS model and typically never verifies, certainly not as shown.

No tropical development is expected this week in the Atlantic. (NOAA NHC)

At least at this point there remains no ensemble agreement from the European model (or the GFS really) and no operational model agreement from the Euro, ICON, or AI modeling. So the GFS operational model, as it so often does this time of year, stands on its own with whatever it’s showing.

Looking ahead

Heading into next week, I do think things will look at least marginally more interesting, however I’m not sure that it’s going to end up on the Atlantic side of Mexico. Modeling seems to be hinting at some sort of gyre-ish pattern (not sure that it’s a true gyre though, so we’ll call it quasi-gyre lite) over Central America. When this happens, as it often does in June, we can start to generate sloppy storms in the Gulf or storms in the Pacific. Which side of the continent these storms form in is always a challenging question, depending on a lot of things.

The best ingredients next week may end up over Central America or in the Pacific rather than in the Caribbean or Gulf. (Tropical Tidbits)

This time around, my gut feeling is that it may be the Pacific that cashes in with activity, just given model signals and where the best upward motion in the atmosphere may locate itself. Of course, as noted, this is always a challenging problem, so it’s not like we’ll just ignore it and call it a day. It will bear some watching, but at this point, no reliable model guidance is latching onto significant, organized development risk in the Atlantic heading into next week. So we have no real concerns at this point.

Other notes

A couple miscellaneous items that I’ll bring to your attention today.

Colleague and friend Michael Lowry wrote a particularly poignant op-ed this weekend in the New York Time about the risk of the rampant cuts to NOAA and the National Weather Service. While the newly released budget from Friday shows a small increase in funding to the NWS proper, don’t be fooled. Parts of the agency that are critically important to grow our understanding, improve forecasting, and increase our knowledge of meteorology are being absolutely gutted in that budget proposal. And to this point, there has been no sign that anyone in this administration wants to seriously do anything to get the NWS staffed back up to adequate levels today. This is not political, it’s common sense.

On a more positive note, I wrote a piece that I may ultimately republish here next year. But it is about which Major League Baseball stadiums see the most frequent postponed games due to weather. A few locations truly stand out, with a couple interesting surprises thrown in.

Finally, Arizona and northern Mexico had quite the soaking yesterday as Alvin’s remnants were shoved northward.

Rain totals across southern Arizona ranged from a few hundredths to an inch or two. (NOAA)

Some of the rain totals were fairly impressive with a few spots seeing north of 1.5 inches. We even had a flash flood warning just northwest of Phoenix this morning. Showers today will expand to the northern part of Arizona, as well as portions of southern Utah and western Colorado. All mostly welcome rain to be sure, but as is always the case in the West, localized flooding can occur with relatively small rain totals.

Long-range forecast scareicane season has arrived for the eastern Gulf

In brief: With the GFS model showing its first real scareicane of the season, we take a look at the facts and discuss the real potential of tropical development in the second week of June. Verdict? You don’t need to get too worked up.

Hurricane season hasn’t even officially opened in the Atlantic yet, and we’ve already got foreboding headlines about the first possible threat. A colleague of mine pointed out a Newsweek article referencing an AccuWeather outlook that suggests tropical development is possible between June 6th and June 13th. Seek it out if you wish, I am not linking to it in here.

We’ve also seen the GFS model show some solutions for tropical development in the Gulf over the next 10-12 days or so. As you can see from the last 10 runs of the GFS model forecast for 00z Tuesday the 10th (evening of Monday the 9th), there is zero consistency on where this goes or how strong it will be.

The last 10 GFS operational model runs for 10 days from now showing some potential tropical development but zero consistency on placement or intensity. (Tropical Tidbits)

In fact, this is very, very normal behavior for the GFS operational model this time of year. Notoriously, the GFS tends to flex in May and early June with numerous threats, not to say it isn’t periodically correct! But in reality, this is what we refer to as a model bias. In other words, the model likes to frequently exaggerate threats this time of year.

So in this case, is there merit to the potential of tropical development in about 8 to 10 days in the northwest Caribbean or southern Gulf? Maybe but not significantly so at this time. The GFS ensemble is showing some support for a possible northwest Caribbean system. The European ensemble has little support for this. The other operational guidance that can see out past 7 days is generally benign, including the ICON (through 180 hours), the European AI model (AIFS), and the European operational model. No signal shows up on any of those for anything organized.

Several things can be simultaneously true:

1.) It is normal for tropical systems to develop in the western Caribbean and southern Gulf in June.
2.) The models do show some semblance of moisture and weak “spin” in the atmosphere in that region in about 6 to 8 days.
3.) The GFS model has been eager about development, but it has historically had a poor track record this time of year in this exact spot and situation.
4.) No other model support really exists for organized development at this time.
5.) You do not need to worry about tropical development at this time.

European model setup next Thursday night shows possible Pacific development but no sign of any real organized Atlantic development. (Tropical Tidbits)

Interestingly, when we deal with these sorts of scenarios, where Pacific development occurs not too far off the coast of southern Mexico, models can sometimes struggle to resolve exactly what or where the system develops. In the GFS’s case, it seems to be wrapping a secondary vorticity maximum (spin) around the east side of the broader circulation in the Pacific, which is what it homes in on to develop in the eastern Gulf. The GFS solution is unlikely to verify as shown. However, the overarching theme does seem to favor more unsettled weather in the Caribbean later next week. I’m not quite ready to say that there is a good chance of tropical development, merely perhaps a slight chance.

I want to remind folks that hurricane season is a six-month slog. It’s not a marathon; it’s an ultra-marathon. News organizations are going to jump on the first iteration of anything they see this season, as they usually do. Even if the reporting is tame and mostly accurate, as it is in this case, there is an implication in the headlines that a serious threat exists, and there is a tendency to bombard people with that. It can get exhausting. One of our goals is to give signal to the noise. Why do we think what we think? Being from Houston, we know firsthand how badly disasters can mess with you mentally when new threats emerge and how important word choice is ahead of storms. This is partially why we want to cover the rest of the Atlantic and U.S. as a source you can trust ahead of hurricanes or extreme weather. Hopefully this does just that for storm-weary Florida folks now.

The 2025 Pacific season opens up, as the Atlantic looks to stay mainly quiet for a bit longer

In brief: In the Pacific, while TD One-E (soon likely to be TS Alvin) isn’t a serious concern, it may bring an influx of moisture to the Desert Southwest this weekend. On the Atlantic side, it looks mostly quiet for the first week or so of the season.

As a meteorologist who is devoted to communication, it’s somewhat important to keep tabs on what is “out there.” In other words, what are people seeing or hearing about that they might want to know more about or understand? I have a bunch of news apps and weather news apps that I get push alerts for because I’m a masochist in order to accomplish this. And let me tell you: They are itching for the Pacific season to open up so they have something to alert the masses about. Of course, they keep the push alerts somewhat vague and general to give you a good scare and force you to open the app to find out what terrors may be lurking in order to cash in on that sweet, sweet engagement revenue.

But enough about them.

Pacific system may bring welcome moisture to the Southwest

Yes, folks, the Pacific hurricane season is underway now. It officially began on May 15th. Our first depression has formed, and while it’s not expected to become a big storm, it will take on the name Alvin, assuming it becomes a tropical storm.

Tropical Depression One-E is expected to become a tropical storm later today. (NOAA NHC)

From a wind and surge perspective, this won’t be a big story. I am somewhat intrigued by the track it takes, which should send it up into Baja because the moisture from this system is likely to push into the Desert Southwest by later this weekend.

Moisture (green and blue) gets flung into the Desert Southwest this weekend into Monday as the remnants of Alvin are funneled north around the east side of an upper-level low pressure system. (Tropical Tidbits)

That will rev up the rain and storm chances across parts of Arizona in particular but also perhaps Utah, portions of southeast California, Nevada, New Mexico, and Colorado.

Info graphic from the NWS Phoenix on the upcoming weather. (NWS Phoenix)

At this point, it does not look like a major rainfall event, but any sort of tropical moisture plume into the desert can end with flash flooding somewhere.

The rainfall forecast through next week shows that isolated pockets of heavy rainfall are possible as tropical moisture pushes into the Southwest. (Pivotal Weather)

Regardless, it will help cool things off. Phoenix sees highs near 105 degrees this Saturday, but the rain chances will nudge high temps back into the mid-90s, a few degrees below normal. Overall, this should hopefully be more beneficial than troublesome.

The Atlantic stays quiet — mostly

On the other side of Central America, the Atlantic looks to open the season Sunday on a calm note. For now, there are no signs of any realistic attempts at development and most reliable model guidance is showing quiet. That being said, by the end of next week we may start to see some semblance of unsettled weather near the Yucatan. That’s a common feature in early June, and it can periodically lead to development (usually sloppy) in the southern Gulf or western Caribbean.

So, at this point, I suspect that the first 10 days of June will be mainly quiet in the Atlantic. But if I were to at least keep track of a place, it would be that Yucatan region starting late next week. More in the days ahead.

Sponsorship

After two summers of The Eyewall and nine summers of covering the tropics for Houston with Space City Weather, we are seeking sponsor(s) for The Eyewall. Please see this post for more details and scroll to the bottom of it to contact. Thanks for your consideration!

Less than a week til the 2025 hurricane season begins, so we take one final look at the situation

We hope everyone has had a safe and pleasant holiday weekend thus far. This time next week, we’ll officially be in hurricane season. So, we figured today was a good opportunity to just run through the situation as it looks today. We’ll discuss NOAA’s seasonal outlook, the overall state of the Atlantic right now, a forecast for the next week to 10 days, and a reminder that intensity doesn’t always equate to impacts.

Seasonal forecast finales

First, the National Oceanic and Atmospheric Administration (NOAA) pushed out their hurricane season forecast on Thursday morning. They are calling for a slightly more active than normal season, with a 60 percent chance of active and 30 percent chance of “average.” They predict 13 to 19 named storms, 6 to 10 hurricanes, and 3 to 5 major hurricanes.

A summary infographic showing hurricane season probability and numbers of named storms predicted, according to NOAA’s 2024 Atlantic Hurricane Season Outlook. (NOAA)

This is right in line with what I think most of us expected, and this is a perfectly reasonable hurricane outlook for this year. The consensus now among most academic and government agencies calls for an average to above average season.

A chart of various named storm predictions from a number of government, academic, and private sector forecasters for the 2025 hurricane season. Virtually all are near to above normal. (Barcelona Supercomputing Center)

Last year, I took a look at how NOAA’s outlooks tended to perform (based on the midpoint of their forecast ranges). To recap:

  • 2024: Forecast 21/11/6 and verified with 18/11/5
  • 2023: Forecast 14/7/3 and verified with 20/7/3
  • 2022: Forecast 18/8/5 and verified with 14/8/2
  • 2021: Forecast 17/8/4 and verified with 21/7/4
  • 2020: Forecast 16/8/5 and verified 30/14/7
  • 2019: Forecast 12/6/3 and verified 18/6/3

Overall, in the last several years, NOAA has tended to do quite well with respect to hurricanes and major hurricanes (2020 excepted) and has had some mixed results with named storms. A reminder than aside from their seasonal outlooks, the National Hurricane Center is coming off their best forecasting year yet in 2024.

State of the Atlantic & Pacific

Water temperatures heading into the season are at slightly warmer than average levels in the Tropical Atlantic as a whole. The main development region, which includes much of the Caribbean is running a slight fever this year but nothing like the extreme one we saw last summer.

Atlantic MDR water temperatures are running slightly above normal but nowhere near levels we saw last year at this time. (University of Arizona/Dr. Kim Wood)

As for the Caribbean and Gulf? Well, the Gulf is in line with 2024’s readings at this time, while the Caribbean is running alongside 2023’s readings. Those, of course are the two warmest readings in the dataset of water temperatures we have for those bodies of water. Over the last 30 days, the Gulf has warmed about 0.8°C, while the Caribbean has warmed north of 16°N latitude and cooled south of there. Basically, the northwest Caribbean and Gulf are as warm as they’ve ever been measured to start the season.

Exceptionally warm water for this early in the season is in place in the Gulf and northwest Caribbean again in 2025. (Cyclonicwx.com)

For the last few months, we’ve been hinting at the idea that there would be minimal signal from the Pacific Ocean this year, as we would see ENSO neutral, or La Nada conditions there. Last year’s forecasts were so dire because in addition to the warm waters, we had the signal for a developing La Niña, colder Equatorial Pacific water which tends to relax wind shear in parts of the Atlantic. We did enter a brief La Niña, but that has since faded and we’re back to neutral conditions now.

On average, model forecasts point to something near neutral this summer and fall, or what we refer to as “La Nada.” (Copernicus, EU Climate Change Service)

At this point, there’s no change in thinking that the Pacific’s state (El Niño or La Niña) should not be a major influence this hurricane season. Other factors will drive the forecast.

With all this put together, a normal to above normal hurricane season seems like the best forecast one could produce right now.

Forecast for the early days

Initially, the Atlantic looks mostly quiet. We don’t see any real signs of anything meaningful at this time. Typically, you’d watch the southwest Caribbean this time of year, particularly if you can get some early season gyre activity around Central America.

Typical storm origin points and tracks in early June. (NOAA NHC)

These systems tend to favor tracks due north or northeast into the eastern Gulf of Mexico or the southwest Atlantic. The Pacific tends to be active in early June, and we have a possible system already there. The first name on the Pacific list is Alvin (Alllllllllllllllviiiiiiin!).

There will likely be some tropical development in the Pacific over the next 7 to 10 days. (NOAA NHC)

In the Atlantic, our first three names are Andrea, Barry, and Chantal.

The unfortunate case of Imelda

One final note today on this year’s storm name list. Imelda will reappear for the first time since this list was used in 2019. For those in parts of southeast Texas, Imelda is a name that may have been worthy of retirement. Imelda killed 7 people, left $5 billion in damage, and flooded people out of homes they had only just recently moved back into after Harvey in parts of Texas. The hardest hit areas were from just northeast of Houston into the Beaumont area, where over 44 inches fell in Fannett, TX.

Rainfall from Tropical Storm Imelda in 2019 was extremely damaging, including for many areas that had not fully recovered from Harvey. (NOAA WPC)

While this will bring back some bad memories for folks, in 2025 it will be a new name for a new system that hopefully goes nowhere near southeast Texas. This also serves as a reminder that storm intensity doesn’t equate to impacts. Imelda, barely a tropical storm by definition was a catastrophic rain-producer in some areas.