Michael Wehner
michaelfwehner.bsky.social
Michael Wehner
@michaelfwehner.bsky.social

Climate scientist

Environmental science 52%
Geography 18%
Pinned
Special issue on Artificial intelligence and machine learning in climate & weather science in Advances in Statistical Climatology Meteorology & Oceanography. ML/AI in atmosphere, ocean & hydrological sciences welcomed. www.advances-statistical-climatology-meteorology-oceanography.net/articles/sch...
ASCMO - Scheduled SIs
www.advances-statistical-climatology-meteorology-oceanography.net

The 3 am warning woke me up and kept me up thinking about the leak in the basement...

Not being an actual meteorologist, I have a question about the NCEP Stage IV radar precipitation dataset. The attached picture is a snapshot of the current SoCal radar. The concentric circles at Hanford and Santa Maria are clearly artifacts. Does NCEP correct for this?

I am sure this is true but not what I want to know. What I need to know is how the risk changes for fires while parked. I would presume that parked gas cars don't ignite but parked e-cars might when charging. We sleep over our car, so fear of house fire keeps me from buying one.

In our recent analysis we find the influence of ENSO on seasonal mean and extreme precipitation is far less than previous estimates with about 10% of the variance explained by natural forcings. link.springer.com/article/10.1... In a companion paper, we examine the anthropogenic role. It is larger.
link.springer.com

Indeed. Thanks for highlighting this fact. I explained some of the nuance behind this at the 2017 AGU session on the 4th US Climate Assessment at around 4:30 in this video www.youtube.com/watch?v=pwVI...
Detection & Attribution of the human influence on climate: 4th US National Climate Assessment Report
YouTube video by Michael Wehner
www.youtube.com
It's happening! Canada launched two programs to recruit international researchers.

Canada Impact+ Research Chairs (1 million/yr for 8 yrs +)
Canada Impact+ Emerging Leaders.

I will do my best to facilitate the process for those interested. Hit me up.

www.canada.ca/en/impact-pl...
The Government of Canada introduces new programs for international researchers - Canada.ca
www.canada.ca

Physics in scream is already GPU. ERF is probably more efficient but not ready for prime time

But no climate model calculations to assess whether it actually works or what the unintended consequences are.

"while econometric methods remain valuable for identifying current sensitivities to climate variability, they may be less reliable for long-term projection." But they provide insight, and can guide policy, even if not market investments. Wish I could be there...

7. "SRM could exacerbate rather than ameliorate some regional changes in climate..." Seems like an understatement to me. All schemes that I examined produced seasonal drought somewhere, especially in the south. And bulk tropical cyclone metrics are highly uncertain. link.springer.com/article/10.1...
Assessing the performance of solar radiation management geoengineering simulations - Frontiers of Earth Science
Offsetting the global warming caused by anthropogenic increases in atmospheric greenhouse gases by deliberate injection of aerosols into the stratosphere is the most studied of solar radiation managem...
link.springer.com

We discussed this a bit in our original article. Most would recognize that the SS scale is a poor warning system as it is only wind based and most deaths are due to either fresh or salt water. NHC maps/summaries are infinitely better warnings. See our last paragraph. www.pnas.org/doi/abs/10.1...
The growing inadequacy of an open-ended Saffir–Simpson hurricane wind scale in a warming world | PNAS
Global warming increases available sensible and latent heat energy, increasing the thermodynamic potential wind intensity of tropical cyclones (TCs...
www.pnas.org

2of2 But just a discussion of cat6 raises awareness that storms are now worse than ever because of AGW. Which was the intent of our article. And for that it has served our purpose. www.pnas.org/doi/abs/10.1...
The growing inadequacy of an open-ended Saffir–Simpson hurricane wind scale in a warming world | PNAS
Global warming increases available sensible and latent heat energy, increasing the thermodynamic potential wind intensity of tropical cyclones (TCs...
www.pnas.org

1of2 My thinking hasn't changed much since Jim Kossin & wrote the PNAS article. The SS scale is very inadequate for communicating imminent danger. But it is not (probably never) going away. A single number can't convey this & we encourage folks to use NHC maps instead or listen to local TV weather.

I have been to both many times. Some rooms at EGU can be a lot smaller, so if there is a session you really want to go to, I advise going early to get a seat.

The attack on @frediotto.bsky.social was seeded years ago by Roger Pielke Jr, who started arguing that this table from a recent @ipcc.bsky.social report proved that climate science cannot attribute extreme weather to climate change.

But Roger is of course lying. And we know this for 2 reasons.

🧵
📣 PRESS RELEASE

Registration for experts interested in serving as Expert Reviewers and providing scientific comments on the First Order Draft of the Special Report on Climate Change and Cities is now open!

Registration closes 30 Nov 2025.

Read more 🔗 www.ipcc.ch/2025/09/17/p...

It would be interesting to calculate the partitioning of cooling by upwelling compared to energy converted to storm energy.

Thanks. And btw, in our cat 6 paper, we do not see substantial risk in the open Atlantic.

Does eyewall replacement cause the expansion in size? Or is it some other physical mechanism like available energy?

Jeff, what is the mechanism causing this expansion in physical size?

I am an executive editor for a journal. I would ask now. It may be that they are having trouble finding a suitable AE. Or it may have slipped between the cracks. In any event, the editor should let you know.

And to consider the change in risk of near shore intense storms agupubs.onlinelibrary.wiley.com/doi/10.1029/...
agupubs.onlinelibrary.wiley.com

You may not want to assume that the risk of landfall remains constant at 11% www.science.org/doi/10.1126/...
Increased U.S. coastal hurricane risk under climate change
Future ocean warming in eastern tropical Pacific will enhance US hurricane risk through changes in steering flow and wind shear. 
www.science.org