Gabrielle became a major hurricane at 12:00 UTC today, which means the 2025 Atlantic hurricane season has, to 22nd Sep, seen 2 hurricanes with both becoming major. A rare circumstance, with only four prior occurrences since 1900 (IBTrACS database): 1930, 1935, 1991, & 2009.

By the end of today, the Accumulated Cyclone Energy (ACE) will be ~56% of average for the date. At this point in the season, it would take some long-lived significant hurricanes to bring the ACE back up to average. The season is far from over. bmcnoldy.blogspot.com/2025/09/surg...

On Monday morning, #Gabrielle rapidly intensified to become the season's second major hurricane (Erin was the other). bmcnoldy.blogspot.com/2025/09/surg...

And... Hurricane #Gabrielle is now on the list too, from #Bermuda: bmcnoldy.earth.miami.edu/tropics/radar/

Super Typhoon #Ragasa 's inner core is coming into radar range of Taiwan... long updating loop available at bmcnoldy.earth.miami.edu/tropics/radar/ #NandoPH

The autumn #equinox is coming up on Monday for us in the northern hemisphere! In #Albuquerque, we lose 131.3 seconds of daylight, we have 12.1 hours of daylight, and the maximum solar elevation above the horizon is 54.9°.

Quick shot from the front porch!

The most difficult moment of my 41 year career happened eight years ago today (9/19), warning my compatriots on a livestream that the worst was about to happen.

This 23-hour radar loop shows Category 5 Hurricane Maria approaching Puerto Rico on September 19-20, 2017. It made landfall as a Category 4 hurricane ~6am on the 20th, but right around that time, the winds in the outer eyewall obliterated the radar and the loop ends. Maria devasted the entire island

99 years ago today: the Great Miami Hurricane makes landfall as an upper-end Category 4 hurricane and devastates the Miami area. 5 years ago today: the hyperactive Atlantic crosses into using the Greek alphabet for names as Alpha and Beta form on the same day.

It was an honor to be invited to speak during the opening session of the Southwest Florida Resiliency Summit. It began with influences on tides, then described the forecasts with origins back to 2020 and operational since 2023 thanks to collaboration with the South Florida Water Management District.

On average by this date, the Atlantic has had 9 named storms, 4 hurricanes, and 1 major hurricane. In 2025, we have seen 6 named storms, 1 hurricane, and 1 major hurricane. The Accumulated Cyclone Energy (ACE) is down to just 54% of average. Plenty of time left in the season for trouble though...

Useful terminology tidbit for Atlantic hurricane enthusiasts: The "Main Development Region" (MDR) is a slice of the deep tropical Atlantic where "most major hurricanes begin developing". Importantly, the Caribbean Sea is included in it, and makes up nearly 40% of it! [1/3]

In the western US and the Florida peninsula, astronomical summer is typically hotter than meteorological summer. Zooming in to Miami, that's certainly the case, ESPECIALLY when humidity is factored in. If you define summer to be JJA, you're definitely not centered on the peak:

Twelve days after it formed, Category 2 Hurricane #Ike made its fourth and final landfall near Galveston, TX. at 2 a.m. on September 13, 2008. It generated a 17-20-foot storm surge in Chambers County... very significant for "only" a Category 2 hurricane. [1/2]

I was rummaging through old files and came across this little gem: 7 hours of mostly 1-minute images of Hurricane Daniel on July 25, 2000 (from GOES-L, later GOES-11). Here's the thing... I made these images from raw data collected during the science check-out period; it was not yet operational.

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

The tide gauge in Key West FL has a phenomenal 113-year-long observational record. I created some "heatmap" graphics to illustrate the variations in water levels over the years, which includes influences like hurricane storm surges, the seasonal cycle, supermoons, and sea level rise. [1/4]

24 years ago, on the morning of September 11, 2001, Category 1 Hurricane Erin was located just off the northeast U.S. coast. It was being ushered out to sea by a strong cold front, which brought clear skies and northerly winds to the northeastern states. [1/3]

September 10, 2017: Hurricane #Irma makes landfall in the Florida Keys and then on the southwest coast... strong wind, heavy rain, and storm surge affect all of the Florida peninsula. bmcnoldy.earth.miami.edu/tropics/irma...

If we measure the hurricane season by ACE averaged over the 1991-2020 climate normal, the halfway point of the season is on September 12.

“It’s still hurricane season. We have half the season left, so I have no doubt at all we’ll be watching storms sooner than we want to be.” www.scientificamerican.com/article/atla...

Yesterday, I had the honor of being invited to give a 1-hour seminar at @csuatmossci.bsky.social as part of their INCUS seminar series (incus.colostate.edu). I had an ambitious topic that I admittedly could only scrape the surface of, but I had a great time putting it together and presenting it!

The "peak day" of Atlantic hurricane season depends on which period of record you use and which metric you use! We could look at "named storm days" or "accumulated cyclone energy", and we could look at the climate normal (1991-2020), past 50 years (1974-2024), or the full record (1851-2024)... [1/2]

The 2025 Atlantic hurricane season is strangely quiet for the climatological peak week, but even since 2000, plenty of other years were quieter through September 8: 2001, 2002, 2006, 2009, 2013, 2014, 2015, 2018, and 2022.

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

125 years ago today: the Great Galveston Hurricane of 1900... 4th deadliest natural disaster in US history. A major hurricane landfall in TX that was well-forecast by the Cubans, and ignored by the US Weather Bureau. Not a shining moment in international relations, and with terrible consequences.

U.S. Responds To Rising Sea Levels By Patting East Coast With Towels https://theonion.com/u-s-responds-to-rising-sea-levels-by-patting-east-coas-1847614367/

Not sure how I had the bandwidth to recognize and create this at the time, but it was a moment of amazing coincidence on September 7, 2017. x.com/BMcNoldy/sta...

Category 5 Hurricane #Irma on September 6-7, 2017. bmcnoldy.earth.miami.edu/tropics/irma...

Nighttime is supposed to be a break from the day time heat. But that relief is getting harder to feel. So far this decade the number of days that lows failed to dip below 80 degrees has already doubled compared to the 2000’s. And the decade isn’t even halfway over.

8 years ago today, on the morning of September 5, #Irma intensified to a Category 5 hurricane for the first time as it approached the Leeward Islands. It maintained that status for an incredible 78 hours of terror. A collection of satellite & radar loops: bmcnoldy.earth.miami.edu/tropics/irma...

"Records confirm what runners, bar and restaurant owners and just about anybody who spends time outside in South Florida can sense. Miami nights are hotter than ever." www.miamiherald.com/news/local/e... @weatherkos.bsky.social @miamirosenstiel.bsky.social

Happy 2nd Gotcha Day, Rocco! 🥰🐕 Hard to believe it's been two years now with this smart, snuggly, sassy, and spoiled little cavapoo!

The last week of August into the first week of September is the climatological peak of ocean heat content in the Gulf of Mexico, but the current area-average is at near-record levels, creeping up to 2024's all-time record high. bmcnoldy.earth.miami.edu/tropics/ohc/ [1/2]

With August's data in the mix, the Oceanic Niño Index (ONI) has dropped a bit after a stall during the previous two periods. It's still neutral, but trending ever so gradually toward La Niña again. bmcnoldy.earth.miami.edu/tropics/oni/

Can we actually use animated GIFs on here now?!? 🥳🥰🤯 In my 2 years and 2 weeks on Bluesky, this has been my #1 wishlist item all along. Happy day!

I have a long updating radar loop of Hurricane #Lorena from Cabo San Lucas available at bmcnoldy.earth.miami.edu/tropics/radar/

Today is Fort Lauderdale's 23rd consecutive day with a heat index of 101°F+. That is the 2nd-longest streak in the city's history. The longest streak of 101°F+ heat index days is 26 days and that happened twice (in 2023 and in 2020). bmcnoldy.earth.miami.edu/fll/

September 2, 2019: Here's a radar loop of Category 4-5 Hurricane #Dorian sitting over the Bahamas on September 1, 2, and 3. My blog post from six years ago today: "The unimaginable: Category 5 Hurricane Dorian stationary over Bahamas" bmcnoldy.blogspot.com/2019/09/the-...

Sept 2: Today is the 90th anniversary of the most intense landfalling hurricane in U.S. history: the 1935 Labor Day Hurricane. Peak sustained winds were 185 mph when it tore through the Florida Keys. And like the other U.S. Category 5 landfalls, it was only a tropical storm three days prior. [1/2]

September 1, 2019: An incredibly ominous satellite loop of Hurricane Dorian coming to a standstill over the Bahamas... at Category 5 intensity.

We may not have mangoes anymore, but we have grapes! This is a mini-picking to bring over to a neighbor's house this evening. Most of our grapes are for wine, but there are some amazing red and green table grape vines out there. 🍇🍇🍇🍇🍇🍇🍇🍇 Plenty more for the coyotes and birds too.

Since I recently shared these wind swaths for Katrina and Erin, I figured I'd bring these back up from last October: Helene and Milton.

Decided to crank out a wind swath from my parametric model for Hurricane #Erin... interesting! Storm parameters like the track, intensity, radius of maximum wind, and size/shape of tropical storm force winds all come from the observed preliminary "best-track" data.

"Hurricane forecasts have made huge leaps since #Katrina hit 20 years ago, but that progress is threatened by Trump administration cuts to research." www.scientificamerican.com/article/20-y...

I wrote about how Hurricane Katrina helped spur pretty remarkable improvements in hurricane forecasts since 20 years ago and how current and planned budget cuts by the Trump administration to research could set us back.

This radar loop of Hurricane #Katrina in 2005 spans August 28 at noon (CDT) through the morning of the 29th at 8:54am when communication with the radar was lost.

Here's a wind swath for Hurricane #Katrina generated from a parametric model I coded up. Wind speed reduction over land is a generous 30% (the reduction is usually more, but south Florida and south Louisiana offer exceptions). @miamirosenstiel.bsky.social

This radar loop of Hurricane #Katrina in 2005 spans August 28 at noon (CDT) through the morning of the 29th at 8:54am when communication with the radar was lost.