Our ESWD team extracted the 10 most deadly flash flood events from the European Severe Weather Database for Spain. Here is the overview:
Rank
Number of fatalities
Date
Place or region
1
5000 *
13 OCT 1403
Mallorca island
2
777 likely >1000 including Orihuela
14+15 OCT 1879
Murcia (region)
3
815
25 SEP 1962
Vallés Occidental (region, Catalunya)
4
>200 **
29 OCT 2024
Valencia urban area (Valencia)
5
87
07 AUG 1996
Biescas (Aragon)
6
85
09 OCT 1787
Tortosa (Catalunya)
7
84
19 OCT 1973
Puerto Lumbreras (Murcia)
8
81
14 OCT 1957
Valencia urban area (Valencia)
9
50
18+19 OCT 1973
Albuñol Valley (Andalucia)
10
33
06 OCT 1863
Llobregales (Valencia)
* The number of fatalities of this medieval event comes with a large uncertainty.
** Number of fatalities as of 2 November 2024. The official numbers are not final yet and likely to change.
The fact that nearly all events occurred in the month of October is striking. The flood event of 29 October 2024 is the deadliest in Spain in more than 60 years and the deadliest so far this year in the whole of Europe and the Mediterranean, i.e. in all regions covered by the ESWD.
We plan to post an in-depth meteorological analysis of the event early next week.
Note: This article was originally posted on 31 October 2024 at 18 UTC and updated at 20 UTC. The “1962 Vallés floods” event was added with the update. The 1962 event ranks on the third position now. We are thankful for a hint to include this important event. Another update on 2 November 2024 at 20 UTC corrected fatality numbers for events on 25 September 1962, 14+15 October 1879, 18+19 October 1973, and 29 October 2024.
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.
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.
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
Online: 12 March 2024, 13:00 – 15:00 UTC
Participation free of cost. Pre-registration required.
We present MTG-related information relevant to forecasters:
• The status of the MTG commissioning (Stephan Bojinski, EUMETSAT)
• The Forecaster Testbed 2023 in retrospect and lessons learned from expert workshops (Alois Holzer, ESSL)
• Testimonial from forecasters who participated in the Forecaster Testbed 2023
• Information on how to register for the Forecaster Testbed 2025 (Natasa Strelec Mahovic, EUMETSAT)
• Interesting cases from 2023 revisited (Tomas Pucik, ESSL)
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.
Kick-off presentation at civil defense exercise for City of Wiener Neustadt and surroundings on 5 July 2023
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.
From left to right: Markus Biffl (Head of City Administration Wiener Neustadt), Alois M. Holzer (ESSL Director of Operations), Doris Hailzl (Head civil protection department and main organizer of exercise). Background: situation room for civil defense emergencies.
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:
The broad
multidisciplinary view: risk ethics (philosophy, moral reasoning), human
behaviour (psychology) and legal frameworks (just) in the context of the
warning process
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?
Communication
– dealing with uncertainty: Why is there so little progress in communicating
the warning uncertainty, and how can this be improved?
Action
advice and public education: from understanding to response and action. We are
seeking for good practice examples.
General
and tailored warnings: What are the necessary differences? And how can the gaps
between warners, emergency managements and end users be best bridged?
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?
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?
Cross-institutional
and cross-border communication: What is needed to ensure the flow of relevant
information in extremely time-critical and high workload situations?
Warners at work at the EUMETSAT-ESSL Testbed 2022
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.
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.
The Nikolai
Dotzek Award goes to three meteorologists with focus on satellite studies. The most prestigious award in the
global severe weather research community is presented every second year in the
memory of ESSL’s founding father, Dr. Nikolai Dotzek, for an outstanding
contribution to the science of severe storms.
As the new generation of satellites in Europe, the United States, and Japan have been launched, their increased capabilities in terms of available channels and resolution will allow for better nowcasting of severe convective storms. It is a good time to acknowledge those who have contributed significantly to our understanding of the processes that occur on top of the convective storms, how they relate to storm severity, and how they can be operationally detected. ESSL presents the 2023 Nikolai Dotzek Award to three scientists who have strongly pushed satellite meteorology forward.
Pao Wang
The first awardee
is Prof. Pao-Kuan Wang, who has used very high-resolution cloud models to
simulate the processes at the top of convective storms. Simulations showed that
overshooting tops act as obstacles to the anvil-relative wind. Thus, most of
the storm top features that we observe from a satellite, such as cold rings,
cold-Us, above-anvil cirrus plumes, storm-top gravity waves or ship wave
patterns result from the interaction between overshooting tops and the ambient
flow. Wang has also shown that some of these features result from internal
gravity wave breaking processes, consequently contributing to lower
stratospheric moistening. Wang was, until recently, director of the Research
Center for Environmental Changes of the Academia Sinica and formerly professor
at the University of Wisconsin in Madison.
Numerical simulation of a supercell showing the development of above-anvil cirrus plume as an example work of Pao Wang.
Martin Setvák
The second awardee is Dr. Martin Setvák, who in the late 1980’s described various forms of increased 3.7 micron cloud top reflectivity of convective storms and discussed its possible link to storm severity and updraft strength. Later he elaborated this concept with Dr. Charles A. Doswell. Together with Dr. Vincenzo Levizanni, Setvák formulated a concept of above-anvil cirrus plumes above convective storms on satellite imagery. He also contributed to the categorization of various storm-top phenomena, such as cold rings, closely collaborating on these topics with Prof. Pao K. Wang. Setvák is the father of the so-called “sandwich imagery”, a combination of infrared and visible channels, which is now in widespread use across the world. Martin Setvák has formally retired but still works part-time at the Czech Hydrometeorological Institute (CHMI).
NOAA-9 AVHRR imagery of an extremely severe hailstorm on 18 August 1986 over central Czechia clearly shows an above-anvil cirrus plume. This was one of the first storms of which the presence of the plume was noted by Martin Setvák.
Kris Bedka
The third awardee is Kristopher Bedka, who together with his team made significant strides toward the automation of the detection of both overshooting tops and above-anvil cirrus plumes. Using large records of these phenomena and their properties, Bedka investigated their statistical relationships with severe weather beneath them. His recent work concentrated on the automatic detection of high ice water content in deep convective storms, adversely impacting aircraft engine and air probe performance. He demonstrated the utility of 1-min super rapid scanning for analysis of satellite-observed cloud properties. His ongoing work expands towards wind profiling with an airborne doppler aerosol lidar – to only mention one of several fields of activity – and offers great promises for nowcasting and improving severe storms climatologies. Kris Bedka is affiliated with the NASA Langley Research Center.
An example from Kris Bedka’s work: Above-anvil cirrus plumes at the top of severe convective storms over Argentina on 8 February 2018. The northern one produced hail exceeding 18 cm.
The Nikolai Dotzek
Award trophy represents a massive hailstone. The prize money is 1000 EUR
together with an invitation to the European Conference on Severe Storms (ECSS).
The award was instigated by the European Severe Storms Laboratory (ESSL) in
2011. The handing over of the award trophy usually crowns the dinner of the
ECSS conference and will take place this year in Bucharest, Romania, on the
10th of May.
Nikolai Dotzek Award trophy
The ESSL aims to contribute to the preparedness of European society for the impacts of severe storms by advancing scientific understanding, building human capacity, and fostering cooperation within Europe in this field.
ESSL provides training to forecasters, scientists, and policymakers on topics related to convective weather. ESSL participates in research projects and organizes the European Conference on Severe Storms to improve and stimulate the exchange of knowledge on severe convection. ESSL aims to establish and maintain close relationships with national weather services and research institutes to strengthen pan-European collaborations. ESSL maintains the European Severe Weather Database, to support research based on observations of severe convective weather or any related impact.
You can download a PDF document of this content here.
More information on the Nikolai Dotzek Award can be found here.
