Within the context of the cooperation between EUMETSAT and ESSL on user preparation for the MTG data, an experimental visualization of Lightning Imager (LI) data was introduced to the ESSL Weather Displayer. Its preliminary name is “Geometry and density” and it connects all the detected LI groups (connected pixel detections at one acquisition frame of 1 ms) within one single LI flash (collected LI groups that are correlated in space and time within 330 ms) and can be taken as a proxy for the geometry of the flash as seen from space. Each flash is given a different colour. Such a flash geometry can cover large areas, something that has earlier been discovered by using the ISS-LIS and GOES-GLM instruments. In the ESSL Weather Displayer, the visualization combines this information with data on highly active convective cells. Those active cores are made visible via plotting the LI group density if surpassing 1 LI groups per km² within a 5 minute time frame (colour shading from black via magenta, red, orange and yellow to white). Possible applications of such a product may range from public outreach activities via identification of new active updrafts all the way to lightning safety at airports.

LI group density is also visualized in gridded form. In addition, the area size of flashes is plotted for each single flash (the size of red or yellow circles related to the flash area). This allows a forecaster to identify physical processes that are ongoing within a convective complex. Large flash areas are typical for flashes in the stratiform regions while a high number of small flashes can be indicative for a very intense updraft, as it is often seen with supercells in early LI data.

You can read the full newsletter here.

Figures: Screenshots from ESSL Weather Displayer for a geographic area of Albania and surroundings on 4 October 2024 at 09:00 UTC. Left: LI Group Area (red circles). Middle: LI Group Density. Right: LI Geometry and Density (geometry approximation of LI flashes and LI group density above 1 for identification of active convective cores). Data source: EUMETSAT. Visualization: ESSL.

Wiener Neustadt, Austria, 15.07.2024

Europe needs Twisters campaign

Researchers from all over Europe are organising high-density measurements of severe storms. Similar to the new film Twisters, the plan is for mobile storm chasing teams to collect essential weather data directly from storms.

This is planned to be ground-breaking. Severe weather researchers from 14 European countries want to work together to get to the bottom of severe thunderstorms so that they can provide better warnings in future. To this aim, they are currently planning the largest European measurement campaign on severe thunderstorms to date. “We want to use the latest technologies, such as weather drones. To do this, it is extremely important that mobile measurement teams get very close to the storms. This is the only way to gather the crucial information,” says Alois Holzer, initiator of the European “TIM” measurement campaign to start in 2026.

As can be seen in the new movie Twisters, the European research teams will also be tackling the storms with the newest generation of weather sensors. “In contrast to some scenes in the entertainment film Twisters, however, the highest safety standards apply in our research campaign, and we have also made a joint commitment to responsible behaviour with regard to the environment and the local population,” emphasises Alois Holzer, Director of Operations of the European Severe Storms Laboratory ESSL in Wiener Neustadt.

While the basic scientific structure is to be financed through traditional research funding, the project is still looking for major donors for the individual mobile measurement teams. Alois Holzer says with a twinkle in his eye: “We hope that the kind of support from major donors possible in North America can also be achieved in Europe. We are also in dialogue with various public authorities.”

The urgency of being able to better understand and predict severe weather, and thus to strengthen civil defence, is certainly given, as the frequent severe weather events show. The measurement campaign will focus on hailstorms, flash flood events, dangerous squalls and tornadoes. In the past year alone, severe thunderstorms have caused 524 fatalities in Europe, as reported by the ESSL.

The ESSL is an independent, non-profit research institute based in Wiener Neustadt in Lower Austria. It also operates the European Severe Weather Database (ESWD) and is a European leader in the training of meteorologists in the field of severe weather warnings. A year ago, the ESSL established the International Fujita Scale (IF-Scale) as a new standard for categorising tornado damage.

This press release is under embargo for re-publishing until: Wednesday, 17 July 2024, 00:00 UTC

LINKS:

European Severe Storms Laboratory (ESSL):         www.essl.org
TIM Field Campaign:                                                  www.tim-campaign.eu

LIVE EXPERT TALK:

The TWISTERS expert talk will take place on Tuesday, 16 July 2024:

Attendance:

ESSL was asked by the City of Wiener Neustadt to support a major civil defense exercise for the city and surrounding districts. On July 5th, shortly before the start of the exercise, ESSL Director of Operations Alois Holzer gave a lecture on tornado basics as a prelude for the management team of around 40 officials. The tornado scenario of the exercise concerns urban areas.

Already 10 years ago, ESSL provided the tornado scenario for a similar civil defense exercise. The recent talk gave the participating entities insight into the impacts of violent tornadoes. Part of the presentation was the case of 24 June 2021 over Czechia, when 6 persons died and hundreds were injured in an F4 tornado. Even more people were killed in the historical tornado event of the year 1916, when 34 persons died in another F4 tornado that struck the northern neighborhoods of Wiener Neustadt.

ESSL and collaborators drafted a document on the “International Fujita Scale” (IF-Scale). It defines a new method to rate tornado and wind damage and was presented at the European Conference on Severe Storms in Bucharest, Romania, earlier this month.

The document is open for commenting until 31 May 2023. ESSL plans to implement the new scale in the European Severe Weather Database by 1 July 2023.

More information on the IF-Scale draft you can find here.

The workshop is scheduled for autumn, from 16 to 18 October 2023, and takes the very broad view. Target audience are forecasters (“warners”) and heads of forecasters, researchers and practicioners related to warnings, civil protection authorities, and end users of warnings (especially from critical infrastructure).

The following topics will be covered:

1. The broad multidisciplinary view: risk ethics (philosophy, moral reasoning), human behaviour (psychology) and legal frameworks (just) in the context of the warning process
2. Limitations and new prospects for ingredients-based warning approaches: How should the risk matrix be defined? Can more life be brought to forecasting impacts beyond the marketing term?
3. Communication – dealing with uncertainty: Why is there so little progress in communicating the warning uncertainty, and how can this be improved?
4. Action advice and public education: from understanding to response and action. We are seeking for good practice examples.
5. General and tailored warnings: What are the necessary differences? And how can the gaps between warners, emergency managements and end users be best bridged?
6. From physical ingredients to impact warnings: Are impacts in high-end meteorological events easier to predict and stronger tied to the physical magnitude than in more frequent and modest events?
7. A critical moment in the meteorological sphere: transition from forecasting to nowcasting and the resulting potential sudden jump in probability of extremely rare events. Should there be a stronger focus on the warning means in the “last hour”? When in time and at which probability and intensity threshold should sirens and other “strongly interrupting and potentially also frightening” means of warning be used?
8. Cross-institutional and cross-border communication: What is needed to ensure the flow of relevant information in extremely time-critical and high workload situations?

A detailled invitation can be downloaded here (PDF).

The registration for the 11th European Conference on Severe Storms is open and normal registration fees apply until 7 April. Starting 8 April, late registration fees do apply.

Please register here for on-site participation or online streaming (remote presentations are not foreseen).

General information on the ECSS including the scientific and social programme can be found here.

Online webinar: 20 April 2023, 12:00 to 14:30 UTC
Free of cost. Targeted to forecasters in nowcasting and warning operations.

We present and discuss MTG-related news relevant to forecasters: 

• The current status of the MTG commissioning (Stephan Bojinski, EUMETSAT)
• The ESSL Testbed 2022 in retrospect and lessons learned from expert workshops (Alois Holzer, ESSL)
• Testimonial from a forecaster who participated in the ESSL Testbed 2022
• Interesting cases from 2022 revisited (Tomas Pucik, ESSL) 

Please register for the webinar here:

https://events.teams.microsoft.com/event/517ea179-3349-405b-92ac-1a7cb04faa93@df7e8a07-a3fd-42a8-b745-17aa52648828

This webinar features key 2022 results from the joint ESSL-EUMETSAT activity introducing MTG data to operational weather forecasters in Europe. ESSL trainers describe highlights of severe convective weather cases that were analysed by forecasters during the testbeds in Wiener Neutstadt. Forecasters provide testimonials on their testbed experience and the importance of satellite products in the forecasting process. In addition, the ESSL expert workshops put the spotlight on novel MTG products such as the 0.9um FCI channel to detect low-level moisture, or the Lightning imager. The audience will learn about key take-aways from these workshops, for later use in training on MTG for all users.