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Jonathan Lee

@lee-cyclone.bsky.social
36 followers 101 following 34 posts

Atmospheric science PhD student at NYU | Cornell ‘25

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Jonathan Lee @lee-cyclone.bsky.social · 19/07/2026
🧵Compound extremes are probably increasing faster than individual extremes in a warming world: a thread
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Jonathan Lee @lee-cyclone.bsky.social · 07/07/2026
🧵(1/5) Just ~15 miles southeast of midtown Manhattan, it rained about 8” in the past 24 hours. It would have been a vastly different story had storms were just a few miles north …
Map of past 24 h rainfall in NYC and Long Island area. Many areas got 2” of rain with a spot just offshore getting up to 8”.
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Reposted by Jonathan Lee
Andrew Dessler @andrewdessler.com · 30/06/2026
On The Climate Brink, I explain how we connect extreme weather to climate change. Yes, it's another draft chapter from my forthcoming climate risk textbook. www.theclimatebrink.com/p/how-climat...
theclimatebrink.com
How climate change influences extreme weather
How science shows us how warming makes heat waves, floods, hurricanes, and wildfires more likely or more severe — and why this science is becoming a major public-policy battleground.
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Reposted by Jonathan Lee
Katharine Hayhoe @katharinehayhoe.com · 28/05/2026
RCP and SSP scenarios are not emission scenarios. I repeat: they are not emission scenarios. They are radiative forcing scenarios. Forcing = human emissions + the response of the climate system to those emissions You can only back out emissions by making assumptions about climate sensitivity.
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Jonathan Lee @lee-cyclone.bsky.social · 02/04/2026
Early April temperatures in New York State: yesterday vs today. Some remarkable temperature gradients!
Apr 1: temperatures in mid 30s to mid 40s in northern half of the state, and mostly 60s and 70s downstate (lower Hudson Valley and NYC)
 Temperatures in the mid 30s to mid 40s now covering the eastern half of NYS (including NYC and Hudson Valley, which were in the 70s). But extreme western part of NY is in the 60s and low 70s, with a sharp gradient.
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Daniel Swain @weatherwest.bsky.social · 24/03/2026
Given recent discussion regarding indirect role of anomalous precip (& associated upstream diabatic heating) in amplifying record-breaking heatwaves, even thousands of miles away (inc. Mar 2026 event), I wanted to share this excellent paper from 2025:
nature.com
Blocking diversity causes distinct roles of diabatic heating in the Northern Hemisphere
Nature Communications - Atmospheric blocking patterns are often categorized into several types and diabatic heating is thought to primarily contribute positively to blocks. Here, the authors show...
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Reposted by Jonathan Lee
Pam Kan-Rice @ucanrpam.bsky.social · 19/03/2026
Phone weather apps are inaccurate. Those apps are fully automated and use algorithms that aren’t “sufficiently dynamic,” @weatherwest.bsky.social @ucanr.edu said — and in a nutshell, they’re lacking human expertise and customization behind the scenes.
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Tomer Burg @burgwx.bsky.social · 12/03/2026
One of the wildest 24-hour loops you'll see in the Mid Atlantic - from mid-upper 80s and tornado warnings to 33F and heavy snow
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Jonathan Lee @lee-cyclone.bsky.social · 26/02/2026
AI/ML algorithms can sometimes generate unphysical forecasts: a case in point
A forecast from Apple Weather showing snow next Thursday to Saturday, despite mild temperatures (37/46, 42/51, 43/61 F).
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Jonathan Lee @lee-cyclone.bsky.social · 02/02/2026
Over the past decade, Phil has only been accurate 30% of the time in subseasonal forecasts of spring temperature anomalies in the US. More details in the attached abstract (and graphical abstract, courtesy of NOAA).
Phil saw his shadow 108 times (“more winter”), no shadow 21 times (“early spring”, and no record was made 10 times (since 1887). But he has only been right 30% of the time in the past 10 years. 17.1 - Evaluation of a Simple Terrestrial-Based Predictor for Subseasonal Prediction of Early-Spring Onset 
Phil, P. 

February 2, 2026, 7:30am-7:45am
Gobbler’s Knob (Punxsutawney, PA)

Research in and demand for subseasonal-to-seasonal forecasts have been surging in recent years. Of particular interest is the phenomenon of early-spring onset and whether it can be predicted on subseasonal scales. We present a simple terrestrial, marmot-based prognostication model which only depends on the presence of the shadow of a particular M. monax as it emerges from its burrow, where the absence of a shadow is hypothesized to bring about an early-spring onset. Forecasts are initialized on February 2 of each year between 7:00 and 8:00am Eastern Time (around 12-13 UTC), with an observational record dating back to 1887. Preliminary analyses reveal that the model outputs a shadow and thus favors no early-spring onset in most years, and that forecasts in the past decade have yielded roughly a 30% accuracy. It is concluded that a groundhog’s shadow does not provide meaningful skill to predictions of early-spring onset on subseasonal time scales relative to climatology.  

140th Special Session on Groundhog Meteorology
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Simon Lee @simonleewx.com · 23/01/2026
The extreme cold across eastern N America is due to the Alaskan Ridge regime, which on average brings the coldest winter weather to this region. Is this happening more often? No. During the modern warming era, there has been no observed trend in the occurrence of this regime at this time of year.
A time series of the January–February frequency (in days) of the AKR regime from 1979 to 2025 using ERA5 data, based on the year-round classification of Lee et al. 2023 (J. Climate) updated through 2025.
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Jonathan Lee @lee-cyclone.bsky.social · 24/12/2025
🧵How might snowfall change in a warming world? I set up a very simple “toy” statistical model to explore this question. Isn't it obvious that snowfall decreases as temperatures get warmer? Yes, but …
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Jonathan Lee @lee-cyclone.bsky.social · 24/12/2025
🧵How might snowfall change in a warming world? I set up a very simple “toy” statistical model to explore this question. Isn't it obvious that snowfall decreases as temperatures get warmer? Yes, but …
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Jonathan Lee @lee-cyclone.bsky.social · 18/12/2025
#NCAR is a beautiful place and a national treasure. I had the chance to visit the NCAR Mesa Lab last summer, and their exhibits (free and public) are the coolest and most informative ones I’ve seen on atmospheric and climate science. (1/3)
The front entrance of the sandstone colored NCAR building, with the words “National Center for Atmospheric Research / Sponsored by the National Science Foundation”.
An exhibit titled “Change Over Time”. Climate has changed over time, not only in regions, but also for Earth as a whole. Global temperature has risen and fallen many times, often in response to changes in how the Earth tilts on its axis and orbits the Sun. Large volcanoes and meteors produce temporary global and regional cooling.
Earth's temperature has risen more than 1.3°F (0.7°C) in the last century and most dramatically since the 1970s. The burning of fossil fuels has increased the amount of greenhouse gases in Earth's atmosphere each year since measurements began in the 1950s.
Carbon dioxide and other greenhouse gases absorb heat energy from Earth, allowing less to escape to space. Increasing the amount of these gases makes Earth warmer. Our planet is expected to warm even more if fossil fuel use continues.
Climate models project that many parts of the world, including North America, will experience changes this century. These include more frequent and severe heat waves and more intense bursts of rain and snow with longer dry periods in between. Some of these trends are already being observed.
Humans have always been able to adapt to weather and to changes in climate. Now we are beginning to face the challenge of adapting to a rapidly changing climate with conditions very different than in the past.“A history of understanding” exhibit, with portraits of five individuals (Fourier, Foote, Tyndall, Arrhenius, Callendar). For thousands of years, Indigenous cultures around the globe have viewed the land, sea, and sky as interconnected. Scientists have also known for about two hundred years that carbon dioxide and other greenhouse gases in the sky are formed with elements from the land and sea and affect Earth's temperature. In the 1820s, French scientist Joseph Fourier proposed that the atmosphere might be insulating our planet - the first inkling of what we call the greenhouse effect. In 1856, American scientist Eunice Newton Foote discovered that carbon dioxide and water vapor absorb heat in sunlight. She suggested that changes in the amounts of these gases could change the climate. Three years later, British scientist John Tyndall tested many gases and found that some were able to absorb and emit heat, confirming the greenhouse effect.
In 1896, Svante Arrhenius calculated how increasing carbon dioxide from burning fossil fuels could warm our planet. He speculated that climate warming might be a good thing if it could help farms produce more food, stave off the next Ice Age, and improve the climate of places like his native Sweden. In the 1930s, British steam engineer G.S. Callendar demonstrated that burning fossil fuels was warming the planet. We now know that rapid warming is leading to many problems and uncertainties across the world.An artwork (painting?) of the NCAR Mesa Lab building with mountains and (presumably) cumulonimbus clouds in the background.
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