Jacopo Riboldi
Lecturer in Atmospheric Dynamics at ETH Zurich 🇮🇹🇨🇭
Tackling climate research problems from a weather-centered perspective 🌦🌀🌡
- The strong pressure gradient between a cut-off cyclone over N Africa and a cold anticyclone over eastern Europe will lead in the next few days to very strong SE winds and heavy precipitation over southern Italy and Spain. The whole western Mediterranean will feel it! 🌀⛈️🌬️🌊 Plots: charts.ecmwf.int
- Why is it happening? Upper-level anticyclones have been present between Greeland and Scandinavia in the last few weeks, and as a result the North Atlantic jet stream has been located more south than usual. This means that Atlantic cyclones can enter more easily into the Mediterranean (NAO-).
- The propagation of a Rossby wave train from N America did the rest: as the ridge amplified over the N Atlantic and merged with the anticyclone E of Greenland, the trough originated the deep cut-off low over N Africa. The wave train is expected to continue its eastward propagation to the Pacific 〰️➿
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View full threadThe connection between Rossby waves and extreme weather, as well as their economic and societal impacts, are the main topics of the "2nd Workshop on the Dynamics of Rossby waves, compound extremes and impacts" starting tomorrow at @vuamsterdam.bsky.social, attended by 150+ scientists!! 〰️🇳🇱
- In only 8 days, it is EGU26 submission deadline! 🚨 If your work involves Rossby waves, jet streams and extreme weather/climate events, consider submitting your abstract to the "Atmospheric Rossby Waves and Jet Dynamics" session! 🌬️〰️🌀 Invited speaker this year: Dr. Philipp Breul (University of Köln)
- An interesting new project about the physical and dynamical processes behind extreme windstorms in present and future climate 🌬 at @unirdg-artcol.bsky.social Consider applying if you are interested!
- Interested in revealing how moisture-driven surface cyclones can develop into hazardous windstorms, now and in the future? You could do it at @unirdg-met.bsky.social @ncas-uk.bsky.social, working with @benharvey.bsky.social, @jriboldi.bsky.social, Sue gray and me! jobs.reading.ac.uk/Job/JobDetai...
- "Sycophancy essentially means that the model trusts the user to say correct things,” says Jasper Dekoninck, a data science PhD student at the Swiss Federal Institute of Technology in Zurich".
- AI models are 50% more sycophantic than humans go.nature.com/3L1LwA1
- Reposted by Jacopo RiboldiCette carte est unique au monde. Après plusieurs mois de modélisation, AgroClimat2050 dévoile une 1ère mondiale : la biogéographie future (c’est-à-dire l’aire de répartition) de l’une des 🍎 les + consommées au monde (Golden) grâce à un modèle agroclimatique qui n'a pas d'équivalent en Europe. 1/7
- Storm Boris hit central Europe with extreme precipitation in September 2024: how will this event look like in a warmer climate? 🌧🌡 Many different, but equally correct answers can be given! Discover the nuances in our new work, now in open discussion at egusphere.copernicus.org/preprints/20...
- Reposted by Jacopo RiboldiBref coup de chaud mardi&mercredi associé a une dépression "pompe a chaleur" au large du Portugal #PlumeDeChaleur, puis probable mise en place d'un très puissant #DomeDeChaleur (fort anticyclone) pour la fin du moins de Juin avec persistance de chaleur extrême (Sud 🇫🇷). Effrayant mais pas surprenant!
- Reposted by Jacopo RiboldiUnder pressure from the Trump administration, the National Science Foundation (NSF), a $9 billion agency funding scientific research that has made America great, has canceled over a thousand grants and slowed new funding. That's just the beginning and will get way worse unless Congress intervenes.
- Dear weather and climate dynamics enthusiasts, an exciting session with 24 contributions (orals+posters) awaits you at EGU25 **tomorrow**, Monday 28.05, from 14 to 18 in rooms M1 and X5. Hope to see many of you there at the "Atmospheric Rossby Waves and Jet Dynamics" session! 🌬️〰️🌀
- Reposted by Jacopo RiboldiAn incredible view of a dust storm charging south across Mexico.
- Reposted by Jacopo RiboldiPremière #galerne (coup de vent brutal sur Pays Basque/Sud Landes) ce soir 18 Avril autour de 19h avec rafales locales proches de 100km/h. Renversement/renforcement extrêmement rapide des vents au passage d'un front orageux après belle journée de chauffage (Température ~25°C dans le Sud-Ouest) 1/
- Doppler radars for tornado and severe weather rapid warnings, hurricane hunters' flights for improved track and intensity forecasts, weather and climate models used by many stakeholders... NOAA excellence and contribution to society are under threat. Full support to it and to @ametsoc.org effort!
- The 2026 budget passback plan calls for eliminating NOAA Research, the scientific backbone that keeps weather forecasts, alerts, and warnings accurate and effective. This would have disastrous consequences. Read the AMS statement, in partnership w/ @nwas.org: bit.ly/4cz2RtC
- Reposted by Jacopo RiboldiOne of a meteorologist’s biggest pet peeves is “my app says it’ll be ____”. Weather apps can miss so many details that a meteorologist will know. Let’s use tomorrow in NYC — my app says it’ll be 78 degrees but rainy. But is that the full story? Spoiler alert… no, it’s not!
- Reposted by Jacopo RiboldiFrom life-saving weather warnings and cancer treatments to tech breakthroughs, federally funded science drives progress. In an open letter, the AMS urges strong federal science funding to ensure our future. More: bit.ly/4j6rQGZ
- Reposted by Jacopo Riboldi🧵: I am getting texts on what scientists should do in this perilous and scary moment. My advice: your biggest power is to organize through your professional societies. A few ideas -
- Reposted by Jacopo Riboldi🚨Paper alert 🚨 Do you wonder about how emotions influence climate-friendly outcomes? @kimdoell.bsky.social and I have analyzed how 8 emotions influence climate beliefs, climate policy support, sharing climate messages, and climate behavior across 63 countries. We found that... 1/
- Reposted by Jacopo Riboldi
- Reposted by Jacopo Riboldi129 cm di neve in 12 ore a Obihiro (Hokkaido), nuovo record nazionale. A record-breaking 1.29m of snow fell in Obihiro, Japan, within just 12 hours on February 4, 2025, setting a new national record for 12-hour snowfall and leaving cars stranded in deep snow. 1/2 watchers.news/2025/02/04/j...
- Reposted by Jacopo RiboldiAumento de las frecuencias de bloqueo en simulaciones de modelos climáticos idealizados de muy alta resolución, por @bernat_jimenez igeo.ucm-csic.es/aum... #IGEOinvestiga
- Interesting read! There are many neopositivist and even "messianic" expectations about AGI, I hope we will soon have more realistic expectations about that "bubble", too.
- Reposted by Jacopo RiboldiIt's no exaggeration to say today brought a truly historical weather event to the Gulf Coast - lots of places all the way down to the water got over 6-8 inches of snow, shattering records going as far back as 1895 in some places. Let's review what caused this historic event 🧵
- It is high time to meditate on the effect that North American conditions can have on Europe (and not only from a meteorological viewpoint!) In the current event, I like how it is the same trough now above the southern US that moves over the Atlantic to support the strong Atlantic cyclogenesis 🌀
- As noticed by @simonleewx.com, this event is a nice example of the "pathway" connecting central North America cold spells to windstorms over the British Isles just a few days later -see figure below, taken from doi.org/10.1029/2022... (Anomalous 2m T in blue; magenta: jet stream; orange: sfc wind)
- The risk of windstorms over the North Sea region remains significantly high up to 7-10 days after the cold spell. This is consistent with the zonal flow pattern expected in the next few days over the North Atlantic and "seen" by medium-range models. (3/4) bsky.app/profile/simo...
- This drastic circulation change indicates that the large-scale flow configuration has to be fully reconfigured over the North Atlantic after the cold spell. Does such a pattern shift happen as a result of the cold spell, or is the cold spell a byproduct of it? That's an open question imo. (4/4)
- 📢 Extended abstract submission deadline for the storm tracks workshop! 📢 15 Jan. 2025 -> 20 Jan. 2025 A very focused meeting, bringing together many experts of storm tracks and extratropical dynamics 🌦 I attended the previous one and can only recommend it 🙂
- Very interesting review co-authored by @usyseth.bsky.social profs @manuelaibrunner.bsky.social and A. Prein about the increasing "hydroclimatic volatility", aka sudden transitions from drought to flooding or vice versa. Water cycle gets faster in a warmer climate!🌡🌧🔄 www.nature.com/articles/s43...
- The fires ravaging the outskirts of Los Angeles are driven by anomalously strong easterly winds, locally known as 'Santa Ana winds". Low-level winds speeds over the area exceed 5 standard deviations in anomaly (though wind speed is not gaussian, but ok). But why are they so strong?
- They are driven by a deep, isolated upper-level cyclone over S California, that resulted from a spectacular anticyclonic Rossby wave breaking event over the west coast. Notice the <-3σ anomalies (thanks @aliciambentley.bsky.social for the maps).
- Winds will gradually weaken during Thursday as the cyclone slowly moves eastward. Another impression of the importance of Rossby wave breaking events for different types of impactful extremes!
- In 10 days, it is EGU25 submission deadline! 🚨 If your work involves large-scale dynamics and extreme weather/climate events, then consider submitting your abstract to the "Atmospheric Rossby Waves and Jet Dynamics" session! 🌬️〰️🌀 Invited speakers: Peiqiang Xu (IAP) and Talia Tamarin-Brodsky (MIT)!
- Reposted by Jacopo RiboldiNew evidence that it was the economic vibes, stupid open.substack.com/pub/paulkrug...
- Very interesting! A "red" weather alert might now have a direct effect on the GDP 🚨 An even greater responsibility for @aemet.extwitter.link and civil protection bodies. It will be an occasion to further refine the national warning system, while making Spain more resilient to climate change 🌦
- Reposted by Jacopo RiboldiRedrawing the global warming stripes. In a new paper led by Sebastian Sippel published in Nature today, we show that the early 20th century global ocean surface temperatures and thereby global mean surface temperature were warmer than previously thought. Thread... (1/13)
- The 942hPa "bomb" cyclone roaring tonight off the west coast of N. America features a clear warm seclusion, making it a "warm-core" storm of non-tropical nature. Downward-bending isentropes mark the warm core at the center. Winds around it decrease with height, following the thermal wind law (1/7)
- The cyclone also boasts a vertically aligned PV tower, a typical feature of intense cyclones: low-level potential vorticity generation is usually tied to large latent heat release in clouds close to the cyclone center, corresponding to heavy precipitation. (2/7)
- Even though this is NOT a tropical cyclone, the storm even features a "eye" with some relatively drier air at the center, surrounded by a moist "eyewall" (ok, maybe I am stretching a bit too much here). (3/7)
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View full threadDespite the similarities, this cyclone is not -I repeat- of tropical nature. ❌🌴 But when looking at Hart diagrams without knowing the context, it may look tropical! What a fascinating storm 🌀 As usual, thanks to TropicalTidbits and @aliciambentley.bsky.social for the amazing maps 😀 (7/7)
- 30-sec time lapse of a rain shower in the wake of ex-Kirk, taken from my office in #Zurich
- Reposted by Jacopo RiboldiWV RGB loop of Helene's extratropical transition.
- Reposted by Jacopo RiboldiCheck out our new perspective piece published this week, which dives into an early career view on the importance of supporting and training scientists for interdisciplinary work in the rapidly growing field of extreme weather and climate event research... #OpenAccess Paper: doi.org/10.1002/asl....
- Bluesky now has over 10 million users, and I was #2.247.128! 🦋🦋🦋🦋🦋
- Cyclone Boris is affecting the weather of Eastern Europe for the next few days, bringing exceptional rainfall to Austria, Czech Republic and the neighboring countries. 🌧☔️🌫❄️ A thread with some meteorological aspects of this storm I found fascinating:
- 1a. I find fascinating the complex structure of the flow in which the cyclone is embedded. For example, focus on the cloudy area over CZ, where it is raining a lot. At the surface, strong northerly flow⬇️; at 300hPa, south-easterlies↖️ almost orthogonal to the isobars.
- 1b. The northerly wind is related to the strong pressure gradient between the anticyclone over France ("pushed" over Europe by the cyclone S of Iceland) and storm Boris. It continues since Tuesday and is the responsible of the chilly weather we had during the week over western Europe ❄️
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View full thread2c. The feature I probably like the most are the across-front wind changes in the cross section. Left: northerly wind (coming out of the page) close to the surface in the cold air Right: easterly wind (right-to-left, along cross-sect.) at the warm side. The frontal boundary is visible in wind, too!
- Impressions from the European Met Society meeting #EMS2024 in Barcelona Great venue, interesting talks, amazing colleagues :)
- Reposted by Jacopo Riboldi
A strong upper-level ridge (500 hPa height > 5900 gpm) will bring a sunny and very warm summer weekend to central Europe. By Saturday evening, the 'heat dome' will center over the Alps, with freezing levels exceeding 5000 meters!
