Remarkable to see what hurricanes can do when they traverse exceptionally warm water. Gabrielle rapidly strengthening to a Category 4 hurricane today right as it passed over record warm sea surface temperatures for the time of year.

Pretty neat radar evolution w/ #Gabrielle which rapidly intensified into a Cat 4 #hurricane today. An eyewall replacement cycle occurred, but instead of the typical cycle of the inner replacing the outer eyewall, it appears the two eyewalls merged & did not interrupt continued intensification.

Hurricane Gabrielle becomes a major storm. This morning's view shows a few bursts of intense convection within Gabrielle's inner core.

Apparently when we get hurricanes in the Atlantic this year, we get majors. Gabrielle rapidly strengthening to a major Category 3 on its way to Cat 4 while two other systems wait in queue. Busy Atlantic this week with plenty to discuss. My latest ⬇️

NHC Atlantic Outlook update for Mon, 22 Sep 2025 11:47:23 UTC Additional Details Here.

Photographs of Super Typhoon #Ragasa shared by JAXA astronaut YUI Kamiya aboard the ISS. Original post: xcancel.com/Astro_Kimiya... #NandoPH #台風18号

2.5-minute rapid scan #Himawari9 Visible images provided a phenomenal view of low-altitude mesovortices within the eye of Category 5 Super Typhoon #Ragasa, as the storm center approached islands within the Luzon Strait (between Taiwan and the Philippines).

Credit to the AI models for catching the signal first on the leading tropical wave that we discussed Friday (yellow outline added at 2 PM ET Sunday). Guidance has shifted east since. We'll see what comes of it, but a big jet stream dip next weekend favors a turn near the Bahamas.

We haven't gone this deep into the hurricane season with only one hurricane since 1994. Gabrielle should get us another hurricane before the weekend is out, but odds favor a pass east of Bermuda. I also discuss what AI models are sniffing out longer term ⬇️

In a not-so-hard-to-imagine alternate timeline, Gabrielle's still struggling to become the next Atlantic tropical cyclone. Even so, Gabrielle's formation yesterday ended a 20-day active storm drought, the likes of which we haven't seen in at least 86 years. ⬇️

Whatever dry air/stability issues have been plaguing the deeper Atlantic, from a South Florida standpoint I'm just glad nothing's snuck into the southwest Atlantic or northwestern Caribbean so far. Waters impressively warm in the lanes storms often take into South Florida.

"We are entering an era where the challenge of anticipating the unprecedented is becoming part of daily operations." —statement from @nwas.org & @iaem-org.bsky.social urging sustained investment in tools, partnerships, personnel, and policies in an increasingly dangerous era nwas.org/nwa-iaem-joi...

We're setting the kind of records we like seeing this hurricane season! The latest from @bhensonweather.bsky.social and I on newly-formed Tropical Storm #Gabrielle: yaleclimateconnections.org/2025/09/the-...

A new tropical depression formed early Wednesday, breaking the Atlantic’s unprecedented 20-day dry spell at the peak of the hurricane season. It may be Gabrielle soon, but a series of upper-low speed bumps will act to slow its strengthening this week. ⬇️

I’m proud to say that @noaa.gov and NCEI has released a 1 year retrospective on #Helene using ESRI Story Maps. arcg.is/aqCD4 Here is a brief thread of how this came to be and how NOAA can still do good things (even while wearing pajamas).

One advantage of a late African wave train is a weaker subtropical high. This should help turn 92L and the one behind it safely before reaching the U.S. Bermuda, on the other hand, will want to monitor 92L, which could become Gabrielle in short order. ⬇️

NHC Atlantic Outlook update for Mon, 15 Sep 2025 23:09:43 UTC Additional Details Here.

It's been 18 days since we've had an active tropical system in the Atlantic. The last time the Atlantic was shut out from August 28th through September 15th was 1939 (never in the modern satellite era). The unprecedented dry spell could end this week ⬇️

Wrapping up this post from a week ago: Here is event verification as of 12 UTC Friday 12 Sep 2025. All quiet in the N Leeward Islands today. A tropical wave is nearing the islands, but it's not the same system as ex #91L which dissipated long ago. Be careful when choosing your weather info source.

NHC Atlantic Outlook update for Fri, 12 Sep 2025 17:32:24 UTC Additional Details Here.

Today's that day: the climatological peak of hurricane season, and the halfway point of the season in terms of historical activity.

Activity will slowly pick up over the next week or two in the Atlantic, starting with the disturbance tagged by NHC this morning. For now at least development will be gradual with no foreseeable threats to land. Details in this morning's newsletter ⬇️

Interesting to see how much stronger and farther south and west the Azores (subtropical) high has been over the past two weeks compared to the 30-year climatology and the same period in other recent seasons

Want to come work for the National Hurricane Center, #NHC? There are two new job postings that were just announced yesterday. The 1st opportunity is a position within the #Hurricane Specialist Unit, #HSU: GS-13 Hurricane Specialist Position -- www.usajobs.gov/job/845559000

Today I discuss not only the new system we'll be tracking next week but all the changes afoot across the tropics for the back part of September. The soggy South Florida weather might wane, but at the expense of a more conducive Atlantic. My latest ⬇️

NHC Atlantic Outlook update for Wed, 10 Sep 2025 18:01:43 UTC Additional Details Here.

Today is the first time since 2016 and only the 4th time this century without an active tropical system in the Atlantic basin at the climatological peak of the hurricane season. If models are right, the dry spell ends next week. My very latest ⬇️

While unlikely the primary culprit for our anemic September start, a pumped up Azores high the past few weeks is likely helping to sweep much drier air from higher latitudes into the deep tropics and Caribbean. This has also led to some anomalous cooling of the eastern MDR.

Only two hurricane seasons in the modern record – 1992 and 1968 – went the two weeks leading up to the traditional hurricane season peak without an active named storm. Now we'll add 2025 to the list. My thoughts on the unusually quiet start to September ⬇️

The ocean heat content averaged over the Gulf of Mexico is now the highest on record -- surpassing even the crazy-high values we saw just last year. bmcnoldy.earth.miami.edu/tropics/ohc/ @miamirosenstiel.bsky.social

Invest 91L definitely goes in the forecast hall of shame. Bob Ross might call it a happy accident. I call it a colossal whiff. Kudos to Google's newest machine learning-based DeepMind model for catching the trends first. My 91L post-mortem in today's newsletter ⬇️

Boy, that deescalated quickly. #Invest91L

Forecast models downtrended noticeably overnight in developing and strengthening Invest 91L next week. Is it a fluke or is it a trend? Regardless, the Lesser Antilles should monitor closely this weekend. I discuss the big shift in today's newsletter. ⬇️

Wind shear anomalies across the bellwether Caribbean tumbled into August compared to the start of hurricane season when it was at near-record levels. This below average wind shear is consistent with a budding La Niña and indicative of a healthy Atlantic headed into its peak.

Newly designated Invest 91L is becoming better organized, but until it has a defined circulation, models will struggle with its future. Regardless, it's taking that quintessential Cabo Verde track so we'll need to monitor its progress next week. My latest ⬇️

If you're hoping for certainty in the forecast for the Atlantic tropical wave, you're not going to get it just yet. Models are jumpy on this one, but there are some general trends we'll be watching that I discuss in today's newsletter. ⬇️

INBOX: National Weather Service employees organization files federal lawsuit against President Donald Trump's executive order to ban some federal unions.

NWS is hiring! Lead Meteorologist (Job Series - 1340) openings are now on USAJobs.gov. Use your science, technical, and communication skills to lead shifts, issue critical forecasts and warnings, and help protect lives and property. Apply today!

This is AI2ES, my AI institute. No way around it other than to say this is really awful. We are doing so many amazing things! We want to keep doing amazing things but without this level of funding, we will not be able to do so.

6-year anniversary of Hurricane Dorian stalling over the Bahamas. The result was category 1+ winds for over a day and a half, and category 3+ winds for 12 hours straight! The product attached here was derived from recon observations, and one of the first collaborations with @burgwx.bsky.social

The only game in town this week and probably next is a disturbance now with a high chance of development west of Africa. Models are all over the map with this one, so today I take a closer look at the differences and what we can expect. ⬇️

September 1, 2019: Hurricane Dorian makes landfall on the Abaco Islands, Bahamas. Dorian was the last Cat 5 Atlantic landfall and the strongest landfalling Atlantic hurricane in the modern era, tied with the 1935 Labor Day hurricane. Imagery: UW/CIMSS

As jaw-dropping today as it was then

As the MJO emerges towards the Maritime Continent and restrengthens, you can see it couple with the base state. Quick change from muddled to a well-defined wavenumber 1 pattern!

Only about once a decade on average do we get a stormless Atlantic basin on Labor Day weekend. We're lucky to get two years of it in a row. Today's newsletter takes a closer look at historic Labor Day weekend hurricanes and what's next in the Atlantic. ⬇️

The only College GameDay host who picked Florida State? That would be Lee Corso, the former FSU player. "Florida State is my school, how would I pick against them? Florida State upsets Alabama."

The government's colossal failure to respond after Hurricane Katrina led to major reforms at the nation's top disaster agency. Now, the Trump administration has reversed some of those changes.

This is a really nice piece by Scientific American's Andrea Thompson on the progress we've made improving hurricane forecasting. It's hard to understand why something that's had bipartisan support for decades, and is demonstratively cost-effective, is about to be thrown under the bus.

A somewhat different post today. On the 20th anniversary of Katrina, we ask the question, “Have we learned enough?” The uncomfortable reality is that we probably have not. More here or at theeyewall.com. open.substack.com/pub/theeyewa...

For the 20th anniversary of Katrina's landfall, I did a special article: my personal recollections as NWS meteorologist-in-charge in Jackson, MS from the days leading up to and through landfall. Behind the scenes for an emotional journey through a historic event: https://tinyurl.com/4h2a23sf