Vikki Thompson

My workplace for the past few years: KNMI radar tower and offices

This week marks my last few days working at KNMI, after a fantastic few years exploring new methods with amazing colleagues and collaborators it's time for the next challenge. First, a holiday ☀️⛰️🚴‍♂️

Mechelen overstroming

Nieuw onderzoek laat zien dat de overstromingen in Limburg in 2021 nog veel ernstiger hadden kunnen zijn. Als het weer nét iets anders was verlopen, hadden de buien langer kunnen duren of op een andere plek kunnen vallen, met mogelijk grotere impact. 🔗 www.knmi.nl/over-het-knm...

With coauthors @hancloke.bsky.social @erichfischer.bsky.social Dim Coumou, Urs Beyerle, & Joy Ommer

@knmi.nl

Showing the rainfall of 14th July 2021 (upper left) and 5 alternative scenarios derived from a climate model, conditioned to the atmospheric circulation patterns of the observed event. Similar to fig.6 of https://www.nature.com/articles/s43247-025-02386-y

📣 New paper:
💧💧💧 In July 2021 record breaking rainfall hit western Europe, we use ensemble boosting to explore different plausible storylines. These show it could have rained for longer, or over a larger area, or in a different place. Are we prepared?

doi.org/10.1038/s432...

Last night, for the second night running, temperatures didn't drop below 20°C in Utrecht 🇳🇱.

🥵🌃🌡️

Due to human activity the chances of such heat are increasing, taking us ever closer to the story told in: www.unseenheat.com

@stichtingcas.bsky.social @timokelder.bsky.social

Map of European daily maximum temperatures for (1st July 2025) tomorrow's weather in (left) a present day climate and (right) a 1.5K warmer climate.

🌡️☀️ It is hot in Europe this week – but how much hotter would it be in the future? Using a weather model we can simulate tomorrow’s weather in a warmer climate. Tomorrow Paris is forecast to reach 37°C, in a world 1.5°C warmer the same weather patterns could lead to temperatures over 40°C.

A selfie at parkrun wearing a climate striped tshirt

#ShowYourStripes day on a #parkrun day made it easy to pick out a shirt.

Climate change impacts sports. Extreme heat, happening increasingly often, forces events to adjust or cancel with little notice. Climate change impacts everyone.

🌧️🌍💧 Our new paper, led by Geert Lenderink, shows recent European extreme rainfall events have localised climate change responses beyond the expected Clausius-Clapeyron rate – potentially enhancing flash floods in a warmer climate.

Read it here: doi.org/10.1016/j.wa... @hayleyjfowler.bsky.social

After a fantastic set of oral presentations the posters sessions in hall X3 now, perfect way to end your #EGU25!

Coming up soon at #EGU25, come along to chat about event attribution at lunchtime in room 2.43

Science poster, available online: https://vikki-thompson.github.io/images/EGU25_poster_thompson.pdf Photo also features a 5 year old.

Today we present an online tool for identifying circulation analogues, now available on Climate Explorer. I'll be at my #EGU25 poster, at X5.171, from 1615 (or after 1800 with my small assistant).

climexp.knmi.nl/analoguesfor...

At #EGU25 this morning, hear me talk about ensemble boosting of extreme rainfall using only the thousand most common English words - PICO spot 3 at 11.08

I'm at #EGU25 this week, and today at 1400 I'll be discussing the western European July 2021 extreme rain in this session:

Leaflet of the EGU25 splinter meeting. Title: Networking session: comparing methods for extreme event attribution. Illustrations: plots from various attribution methods. Time and location: Friday 02.05, 12h45-13h45, room 2.43.

If you are attending #EGU25 and interested in the attribution of #climate extremes: consider joining our networking session on Friday noon!

We will exchange on existing methods, their strengths, and how to compare them:
meetingorganizer.copernicus.org/EGU25/sessio...

W/ @vikkithompson.bsky.social

Poster, text: Networking Session: Comparing methods for extreme event attribution. Conveners: Vikki Thompson, Shirin Ermis, and Marylou Athanase. EGU General Assembly 2025. Friday 12.45-13.45 in room 2.43. Three images of extreme event attribution techniques. QR code links to https://meetingorganizer.copernicus.org/EGU25/session/55165

Are you interested in extreme event attribution and attending #EGU25? Come along to our networking session to discuss the strengths and challenges of different methods.

meetingorganizer.copernicus.org/EGU25/sessio...

@marylouathanase.bsky.social

Super excited to be presenting our ensemble boosting work, 'Imagine rain falling in a different place', in this session:

Photo of me and my daughter outside the EGU General Assembly in 2022

Once again, I am taking my daughter to #EGU25. She has been busy making extreme weather posters 'just like mama'. Any other (ideally english/dutch speaking) ~5 yr olds booked into the childcare, who might fancy some lunchtime picnics?

Poster, text: Networking Session: Comparing methods for extreme event attribution. Conveners: Vikki Thompson, Shirin Ermis, and Marylou Athanase. EGU General Assembly 2025. Friday 12.45-13.45 in room 2.43. Three images of extreme event attribution techniques. QR code links to https://meetingorganizer.copernicus.org/EGU25/session/55165

Planning your #EGU25 travel? If you're interested in extreme event attribution, make sure to stay until Friday to come along to our networking session to discuss the value of multiple methods. @marylouathanase.bsky.social

Enjoyed being involved in this new perspective led by @timokelder.bsky.social, where we show the value of using multiple lines of evidence to assess plausible yet unprecedented extreme events that we need to be preparing for 🌍🌧️🌀🌡️

How to stop being surprised by unprecedented weather Nature Communications - Unprecedented weather events are increasingly impacting societies worldwide. This Perspective explores methods to anticipate such hazards, and it highlights the role of...

How to stop being surprised by unprecedented weather

Kelder et al. discusses a multitude of ways that we could anticipate unprecedented weather events that might otherwise be a surprise

rdcu.be/ecWQF

Perhaps a clue to understanding possible changes in Santa Ana winds that helped drive this January's Californian wildfires:

Hi Nat, the report does identify an increasing trend in frequency and intensity of the observed pattern - work to understand why and model assessment to attribute that trend is now ongoing. Would love to hear further ideas of what could be done!

Ooh, that looks very useful! We haven't looked for a 'why' yet but this looks like it'll be at least part of the answer. Have you checked it out in models too?

The most similar events show a more intense cut-off low, which strengthens the Santa Ana winds. Whether this trend is attributable to climate change needs further research, but other evidence in the report shows climate change has increased extreme fire weather conditions.

Figures taken from https://www.worldweatherattribution.org/climate-change-increased-the-likelihood-of-wildfire-disaster-in-highly-exposed-los-angeles-area/ showing the ERA5 Z500 field of Jan 8 2025 over California, and the closest analogues from a past and present period. Below, a timeseries of the change in frequency of similar events through time - showing an increase between 1950 and 2024.

In @wwattribution.bsky.social report on the LA wildfires this January we show the frequency and intensity of the atmospheric circulation of the event has increased in winter, raising the risk of weather conditions that drive the spread of wildfire.
www.worldweatherattribution.org/climate-chan...

This week at school Fritha is learning about polar animals... 'Mama and Dada have seen penguins in the wild, but only Dada has seen polar bears'. Perhaps not what her teacher expected!

Congratulations to @raedhamed.bsky.social for successfully defending his PhD! He carried out important research on the impacts of compound weather events on crop yields, looking forward to seeing the next stages of his research 🌽☀️🫘🌧️

Thanks to coauthors @climatedann.bsky.social @hcbloomfield19.bsky.social @nathanaelmelia.bsky.social Nick Dunstone and Gillian Kay.

@cabot-institute.bsky.social @knmi.bsky.social @metoffice.bsky.social

Buildings on fire in London during the July 2022 heatwave

We show fire weather – that is the meteorological conditions conducive to wildfires spreading – is increasing in the SE England. With climate projections showing rising temperatures and decreasing rainfall in summer, this trend is likely to continue.

Detecting Rising Wildfire Risks for South East England In July 2022 southeast England experienced a record breaking heatwave and unprecedented wildfires in urban areas. We investigate fire weather trends since 1960 in southeast England using a large ense....

Wildfires aren’t a problem in the UK, right? Wrong. Not on the same scale as we are seeing in LA, but there are thousands of wildfires every year in the UK. In the heatwave of July 2022 wildfires broke out in London.

Our new paper explores the risks: doi.org/10.1002/cli2...