Tropical Discussion 2025

[tireman4]

Tropical discussion

[Pas_Bon]

Gulf of Mexico hasn’t been too kind to us. Let’s see if the Gulf of America does any better.

[tireman4]

Michael Ferragamo

[tireman4]

2025’s hurricane outlook season begins, but what is actually known at this point?

February 26, 2025 at 8:02 am by Matt Lanza

It’s a very quiet week nationally, weather-wise, so let’s discuss hurricane season. It’s the time of year where some outlets in the infantile battle of “who called it first” begin releasing seasonal hurricane outlooks. I say that somewhat derisively, but sometimes it does seem like a never-ending battle we fight in this field: First and loudest vs. most prudent.

Did the sizzle fizzle?
Anyway, the pre-hurricane season season is here now. WeatherBELL, the outlet that said last season would be a “season from hell” is back for 2025, though striking a less foreboding tone. They call for about 15 to 19 named storms, 7 to 9 hurricanes, and 2 to 3 majors. Their idea of a less hostile season is rooted in the cooling of sea surface temperatures in the Atlantic. And indeed, if you compare the most recent available data from February 23rd to the same time in 2024 (with a few additional days added on either side), you can see things have cooled rather considerably between Africa and the islands, or the Main Development Region (MDR).


The MDR has cooled by anywhere from 1 to 2 degrees Celsius versus this same time last year, however the Gulf and the western Atlantic are notably warmer.
While we may say “Oh, that’s good, 2025 is way cooler in the MDR!” the reality is that those water temperatures would still be at record levels had we not had 2024 and 2023 happen.


While sea surface temperatures across the MDR are running about 0.75-1°C cooler on average versus last year, they’re still at the 3rd highest level on record, trailing only 2024 and 2023.
Has the Atlantic’s fever broken? It’s probably too early to speculate a whole lot on that, as what caused it to happen in the first place is still a little bit debatable. So I would refrain from making any grand proclamations about what’s happening out there. Those of us that follow sea-surface temperatures in the tropics closely in the run up to hurricane season know how quickly things can change.

The Gulf and Caribbean are still at or near records, however, which gives anyone living on the Gulf Coast or in the Southeast a little bit of pause. I certainly don’t want to undersell what’s happening there, but it’s only February 26th. A warm Gulf in spring has not been uncommon in recent years. In fact, if you compare the March through May sea-surface temperatures in the Gulf of Mexico over the last 10 years (2015-2024) versus the 10 years prior (2005-2014) to that, you can see a notable warming.


Sea-surface temperatures in the Gulf and just off the Southeast U.S. coast have been much warmer in recent years than earlier in this century.
Some of this is likely related to climate change, some of it related to whatever is happening presently with respect to warm global water temperatures, and some of it could be internal variability. The Gulf is slowly warming overall, but no season sees this trend happening more substantially than spring. Most other seasons are averaging about 0.25 to 0.5°C warmer, whereas spring is clearly 0.75° or warmer. My point here: While this is troubling, it’s also not guaranteed to continue at this record amplitude into the meat and potatoes of hurricane season.

So, our Atlantic SSTs are cooler in the MDR, warmer in the Gulf and Caribbean, and much warmer in the northern Atlantic versus 2024.

What of La Niña?
We are currently in a low-end weak La Niña event. Historically, this will end up near the bottom (or “least cold”) of the list of La Niña events since 1950.


An extremely weak La Niña event may be about to peak with a fluctuation back to neutral, or La Nada conditions later this spring.
Will we end up seeing a flip to El Niño this summer? Well, your guess is as good as mine. When we look at the EU’s Copernicus program chart of multi-ensemble forecasts for El Niño, we see the several hundred members skew toward an average near zero, which would keep us generally close to ENSO neutral (La Nada) conditions heading into spring. If you want to squint, you may be able to see a 55/45 split toward El Niño over La Niña but that may be presumptive.


The forecast heading into spring and summer shows most models congregating near ENSO neutral/La Nada conditions in tropical Pacific.
Remember, La Niña was expected last summer, and those cooling events in the tropical Pacific are extremely highly correlated to active Atlantic hurricane seasons. That, combined with the raging warm water temperatures led to the catastrophic forecasts last season. This year we are unlikely to have La Niña during hurricane season, though we may end up with limited signal from the tropical Pacific overall. We will still have very warm water temperatures, but they won’t be as doomsday looking as last year.

So putting those points together: Cooler Atlantic SSTs, a weakening already weak La Niña trending to neutral, and I think you have a recipe for what should be above average hurricane season outlooks from anyone issuing them in the coming weeks. However, they will not be anywhere near last year’s numbers. Is that good? Bad? I don’t know; this meteorologist tends to think seasonal hurricane outlooks are not particularly valuable. But the appetite for them is insatiable. Last year’s hurricane forecasts mostly just snuck into the lower end of the verified ranges and the worst-case seasonal forecast outcomes were not even close to being realized. But it ended up being the third costliest hurricane season on record in the Atlantic. So were the forecasts wrong? Or were they right because it did end up being such a bad year even though the numbers weren’t realized? Does it even matter?

Whatever the seasonal forecasters say in the weeks ahead, our messaging here remains consistent: You should prepare for every hurricane season the same way, as if that will be the year the storm comes to you. And as we’ve learned on more than one occasion in recent years, even “weaker” storms can cause dramatic damage. Prepare for the worst, and hope for the best. Much more to come in the weeks ahead on the upcoming season.

[tireman4]

Austerity measures threaten to stall absolutely amazing, cost-saving hurricane forecast progress
February 27, 2025 at 7:56 am by Matt Lanza
Hurricane forecasting has never been better. We say that a lot, but the statistics bear that out, and last hurricane season was literally the best one yet.


National Hurricane Center track forecast errors have been steadily improving over the last 30 years, and 2024 set a new benchmark.
This week, the National Hurricane Center released a preview of their annual verification report. They rigorously verify their forecasts each year and compare them to the key tools that they utilize to assist in forecasting. And this year was a doozy in a good way. Put one way: The track forecast 5 days out in 2024 was equivalent to the error of a 2-day track forecast as recently as 2000-2005. Think about that for a second. They have improved track forecast errors by a whopping 3 days on average in 20 years. A 3-day track forecast today performs better than a 1-day track forecast did on average in the late 90s and early 2000s as well. The amount of improved lead time you have on storms today compared to less than 20 years ago is incredible.

Intensity forecasting is another matter. While it too has improved over the last 20 to 30 years, the rate of improvement is not quite to the level of track error. That said, a lot of research has been coming out in recent years with respect to rapid intensification, and one would expect to see these forecasts pick up further improvement in the years ahead. This statement will likely put off some folks, but sometimes the truth can do that: It is likely that climate change plays some role in the idea of chasing a moving target. This is especially true in recent years with extremely warm water temperatures in the Atlantic basin. How has this changed the behavior of rapid intensification? That in and of itself makes things difficult. So while the long-term average continues to go in the right direction, we need to continually invest in research and understanding of the mechanics of hurricanes to improve both lead time and forecast accuracy even more.


Intensity forecast errors have been improving at a slower rate and with more year-to-year noise than track forecasts, however the trends are very positive.
Within the report, the probability of detecting a rapidly intensifying hurricane in 2024 sat at around 70 percent. I don’t know what that was 20 years ago, but it was nowhere near that level. Per the report, “although RI remains one of the biggest challenges at NHC, it is worth noting that advancements in hurricane modeling and understanding of the science are making a difference in improving forecasts for even the most challenging cases.” Investment in research is literally paying dividends. As Jeff Masters noted in his discussion on this topic, these research improvements likely saved billions of dollars in 2024 itself, let alone over the last 10 years or so.

Some of the work that’s gotten us here has happened organically through research to improve forecasts and models, often funded by federal programs, but the bulk of this specific for hurricanes is likely attributable to the Hurricane Forecast Improvement Project (HFIP). HFIP was established within NOAA back in 2007 after the very bad 2004 and 2005 hurricane seasons. HFIP goals are to improve hurricane forecasts, extend lead time, extend forecast confidence, and more. It’s interesting to read comments from Bill Read in 2008 about the HFIP and then to see the results we have in the 15+ years since. Our Houston audience should know Bill Read who is about as legendary as a meteorologist can be in a community. He was also the director of the National Hurricane Center from 2008 through 2012 as HFIP began being implemented.


A 2008 interview with Bill Read for the Tampa Tribune discussing the state of hurricane forecasting.
The problem is always funding. HFIP got a nice boost back in the first Trump administration when the Weather Research and Forecasting Innovation Act was passed by Congress. Millions of dollars were allocated to weather research with that law. HFIP was specifically cited in the bill as an area to focus on. And indeed all this money and hard work to improve these forecasts is now bearing fruit.

But we sit in a perilous moment. At the risk of getting too political here, the current “slash and burn” philosophy of cutting government spending risks halting the progress that has been made. Meteorology is sitting at a crossroads right now as it is: Physics-based modeling and AI-based modeling are now both entering operational phases together, and the work being done to marry the best parts of these different technologies is just beginning. The potential results are tantalizing. Forecasts will never be perfect. But if we can continue to reduce errors and improve forecast lead time, we can save lives, save property, and reduce the economic impact from storms. If the couple billion that was put into this effort led to the economy saving tens of billions of dollars from hurricane impacts in recent years, then how does cutting a few hundred million or a billion help improve efficiency, as is the stated goal of Department of Government Efficiency? It’s a simple math problem, and the math doesn’t check out, no matter how much of a deficit hawk you may be. If these programs added no value and cost more than they saved or added to the economy, that would be another thing entirely.

Bill Proenza was director of the NHC back in 2007. He had an interesting tenure, leading the NHC through a tumultuous 6 months. He was known for being a bit brash and for publicly criticizing his bosses, the combination of which led him to be let go from that job. That style may work in some sectors, but in the NHC, the best leaders usually cause fewer distractions. Regardless of that, he made a very good point back in 2011 during talk of budget cuts in that Congress He told the Miami Herald at the time that the short-term savings of cutting hurricane research flights (allocating $17 million in funding to the program it was under versus the $29 million it had been funded at) would come with higher long-term costs. This is exactly the problem. Your political ideology may color how you feel about cutting spending, but the simple reality is that when people without expertise in matters begin to cut programs without understanding them, they’re accepting higher long-term costs in exchange for the short-term gratification of “hey, we did something.” If one is truly concerned about budgets and deficits, they would look at this problem through nuanced lens. Could efficiency be improved in certain areas of programs or research and development? Absolutely. I’m sure it could be. Does the possibility of taking an axe to a program through significant personnel losses or funding cuts put us all at risk of poorer long-term outcomes both physically and fiscally? Yes. Is the prudent way slower? Yes. Is the slower way smarter? Also, yes.

The forecast improvements in recent years have produced amazing outcomes, saved lives, and saved the economy billions of dollars. If we pull the rug out from under this program right when it’s literally at its best, we risk halting that progress, increasing costs and burdens on federal, state, and local governments, not to mention people and small businesses in the path of increasingly complex and dangerous storms. It’s simply not the fiscally prudent thing to do. Many folks in hurricane alley share the priorities of the current administration, which is fine but it’s important to understand the potential ramifications and impacts to us all in certain instances and to make sure your elected officials understand that. Given what we’ve witnessed between Texas and Florida since 2017 or so, it’s in our best interest to continue to work to improve hurricane forecasts as much as possible.

[tireman4]

Max Velocity


en Español

000
ABNT20 KNHC 171617
TWOAT

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1220 PM EDT Mon Mar 17 2025

For the North Atlantic...Caribbean Sea and the Gulf of America:

Central Subtropical Atlantic:
A non-tropical area of low pressure located about 700 miles
northeast of the northern Leeward Islands is producing gale-force
winds and a large area of disorganized showers and thunderstorms.
Additional development of this low is not expected as it moves
northward to northwestward into an environment of strong
upper-level winds and dry air tonight and Tuesday. Additional
information on this system can be found in High Seas Forecasts
issued by the National Weather Service.

No additional Special Tropical Weather Outlooks are scheduled for
this system unless conditions warrant. Regularly scheduled Tropical
Weather Outlooks will resume on May 15, 2025, and Special
Tropical Weather Outlooks will be issued as necessary during the
remainder of the off-season.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...low...10 percent.

&&
High Seas Forecasts issued by the National Weather Service can be
found under AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and
online at ocean.weather.gov/shtml/NFDHSFAT1.php

$$
Forecaster Cangialosi/Pasch

[tireman4]

Hurricane Names Retired from 2024

[tireman4]

The National Tropical Weather Conference. It is live on Facebook

https://www.facebook.com/NTWCLive

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Michael Faragamo

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The Eyewall
Could the 2025 Atlantic hurricane season have some tricks up its sleeve? Breaking down the CSU Outlook
By Matt Lanza on April 9, 2025

Late last week, the team at Colorado State University issued their always hotly anticipated seasonal hurricane outlook for the Atlantic Basin. To clear this up at the beginning, their forecast calls for:

17 named storms (normal 14)
9 hurricanes (normal 7)
4 major hurricanes (normal 3)
Accumulated cyclone energy: 155 (normal 123)
Nothing about this forecast on the surface is especially notable or alarming or fascinating. It's simply a slightly above average forecast.

But what is somewhat notable about their forecast is some of the under the hood items they address. First, we are likely to be coming out of a La Niña event, something we discussed last back in February. But as the CSU team notes, we don't know for sure if we're headed for El Niño or ENSO neutral (La Nada) conditions. ENSO neutral summers combined with warm water temperatures "typically provides a more conducive dynamic and thermodynamic environment for hurricane formation and intensification." In other words, hurricanes like those background conditions.

We do not yet have a "plume" from the C3S suite for April, but the March plume skewed slightly toward El Niño development.


Multi-system ensemble of various forecast models predicting a trend toward positive sea-surface temperature anomalies this summer, possibly giving a slight edge to a developing El Niño event. (Copernicus)
If we get to El Niño conditions by late summer or fall, that does not guarantee that conditions will shift to become more hostile to hurricane development. But that may take the edge off a bit. However, if we "hang" near the neutral line or even in weak La Niña territory, any hostile conditions may be apt to stay away, ensuring a busier season than usual.

In addition to the forecast for named storms and such, the CSU team also does try to convert that seasonal outlook to a prediction of U.S. landfall risk. Indeed, with a more active season expected, the odds of a U.S. landfall are also higher. They have a 51 percent chance of a major hurricane landfall on the U.S. coast, compared to a historical average of 43 percent. The odds on the East Coast are 26 percent, compared to 21 percent typically. And in the Gulf of Mexico, the landfall odds between the Florida Panhandle and Brownsville are 33 percent versus a 27 percent average.

According to the CSU team, all model guidance is pointing to an above-normal season. Water temperatures remain well above long-term averages across the Atlantic. As we noted earlier this year, however, this is not last year's Atlantic sea-surface temperature profile. But it's still quite warm.


March 2025 minus March 2024 sea-surface temperatures, showing year over year warming in the Caribbean, Gulf, and mid-latitudes, but not in the tropical Atlantic. (NOAA PSL)
From the map above, you'll notice that the eastern Atlantic has cooled markedly since last year, however the Gulf, Caribbean, and northern Atlantic Ocean are all warmer. The fire that was burning all last summer in the eastern Atlantic is still smoldering, but it has been somewhat extinguished. The Gulf and Caribbean are another matter. The Gulf is warmer than 2024 by a good bit but still lags 2023. While the Caribbean was warmer than 2024 in March, it has since cooled some in April, taking it back under 2024 levels. Water temperature conditions can change quickly, but the bottom line is that the Atlantic, with the exception of the eastern basin are in the upper echelon of warm years at this point. The warmer overall waters in March in the eastern North Atlantic (north of the tropics), along with the warm Caribbean do correlate to active hurricane seasons.

The bottom line is that the underlying data support the idea of an active hurricane season -- but not to the levels feared last year. But there aren't very many red flags at this time arguing against that outcome. At least last year, we had the expectation of a developing La Niña to help grease the wheels a bit, and a slow development could have slowed the hurricane season a bit. This year? There's no real glaring red flag that says the season will bust. But hurricane seasons always have surprises. Hopefully this year's involves calm.

Colorado State's seasonal hurricane forecast is just that, a seasonal forecast. Should you plan your life based on this? No. But they generally have good skill. And their skill in the last 10 years or so has been great. You still have a few weeks, but it's time to start thinking about, refreshing, and planning for the season ahead. There's a lot of uncertainty this year in terms of FEMA and federal response to storms, so it probably behooves you to plan that kit even a bit more than usual. We have tips on our preparedness page, which we will go through and adjust any broken links when we have some time in the coming weeks.

[tireman4]

Andy Hazelton