In our recent blog post about very large hail events of 2018, we mentioned that hail produces large damage. However, it is rarely deadly, in contrast to flash floods. Based on the data from  the European Severe Weather Database, by 12 December, flash floods have killed 152 people across Europe, parts of northern Africa and the Middle-East.

While most of the heavy rainfall events were reported in central Europe, the most deadly flash floods occurred in the Mediterranean area, including the 5 events with the highest number of fatalities, ranging from 12 to 21.

Heavy rain and deadly flash flood reports across Europe in 2018. 5 events with the highest number of fatalities are indicated.

Who was at most risk during the flash floods? Out of 35 events with more than 1 fatality we identified 16 that involved vehicles being swept away by the floods. Because not all reports include detailed description of the fatality circumstances, the ratio of events including fatalities in cars is likely even higher. The deadliest flash flood also involved a vehicle. In a tragic event on 25 October, a flash flood swept away a bus in Jordan, killing 21 persons onboard.

Besides vehicles, several events involved a group of hikers being swept away by flash floods in the narrow canyons. The first such event occurred in Israel, on 5 May and resulted in 10 fatalities. On  1 August, 5 hikers were killed on Corsica and 10 hikers drowned in the Pollino national park in Italy on 20 August.

This shows that data from the ESWD can be used not only to identify the areas with the highest severe weather incidence, but also to compare the impacts of severe weather phenomena or to find out which groups of people are at most risk in a given severe weather type.

Based on feedback from ESWD users collected at meetings in November 2017 and the ESWD User Forum in March 2018, the European Severe Weather Database has been updated to Version 4.4.

A number of changes have been made, particularly to the submission form. The most important changes are:

1. Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan were added, so it is possible to enter reports for these countries. ESSL aims to learn more about storms in Central Asia!

2. The submission form has been simplified substantially.

3. Place and time accuracy have become required fields.

An updated version of the submission form. Time and place accuracy (in red boxes) are now required fields. Drop-down menu can be accessed by clicking at “More Details”

4. Funnel clouds can not be submitted into ESWD anymore.

5. The country can now be changed in the submission form.

6. Impacts of the event can now be indicated by ticking checkboxes. Each type of severe weather has a different set of impacts that can be selected. This step streamlines the reporting of impacts into the ESWD, and makes it easier to compile statistics of severe weather impacts of the storms across Europe.

An example of impact choices for large hail event type.

You can try out the new version by accessign the ESWD website. We welcome your feedback at eswd@essl.org!

Severe hailstorms can cause extensive economic damage to both crops and properties. Report by Munich RE shows that damage of individual events can exceed billions of dollars as the risk has increased in the past decades. Hail damage to properties, such as cars, roofs and windows, becomes substantial when the diameter of hailstones approaches and exceeds 5 cm. Each year there are a number of such events when hail of this size occurs across Europe and this year, 2018, was no exception.

By looking at the ESWD dataset, we found 26 days, when hail exceeded 5 cm and caused significant damage to the properties. The spatial distributions of these major hail events and associated hail sizes can be found in in Fig. 1. The largest hail size was observed on 8 June 2018, when the town of Črnomelj, Slovenia was hit by giant hail up to 12 cm in diameter, destroying hundreds of roofs and cars. The hail swath on that day (40 km) was much shorter compared to long-lived hailstorms of 1 May in Poland (220 km) or the hailstorm of 30 June in southern Russia (200 km).

Fig. 1. Severe hail reports associated with 26 damaging hailstorm events over Europe in 2018. Size and colour of the symbol represent the observed hail size.

These damaging hailstorms occurred in an environment of moderate to high CAPE and bulk 0–6 km wind shear exceeding 15 m/s, conditions which favour strong updrafts and well-organized convection, including supercells. Our research shows that such conditions may become more frequent in the future. As we compare with the sounding database developed by Pucik et al (2015), most of these events occurred in typical conditions for damaging hailstorms (Fig. 2). Several of these events formed in rather weak vertical wind shear (i.e., bulk 0-6 km shear ranging from 10 to 15 m/s) but these cases were confined to the proximity of complex orography, where shear could be strongly enhanced locally.

Fig. 2. Environments of damaging hailstorms over Europe in 2018 (dots) compared to the relative frequency of hail > 5 cm (colour bar) as a function of CAPE and 0-6 km bulk shear based on Pucik et al (2015). Colour of dots represents the maximum observed hail diameter with each event.

Description of individual events

01.05.2018 (Poland). An isolated supercell cut a 220 km long hailswath across the regions of Mazowieckie and Podlaskie in northeastern Poland with hail up to 5 cm in diameter.

02.05.2018 (Slovenia). Very large hail was recorded in the districts of Lendava, Murska Sobota, Gornja Radgona and Ljutomer in northeastern Slovenia, with hailstones up to 6 cm in diameter. Hail damaged cars and roofs.

15.05.2018 (Bulgaria). Very large hail hit several villages and towns within a 120 km long path tracking through the districts of Vraza and Pleven in northwestern Bulgaria with hailstones up to 7 cm in diameter. Extensive damage to cars and trees was reported from the town of Pleven.

24.05.2018 (Spain). Hailstorm hit the town of Garciaz in Extremadura province, southwestern Spain, with hailstones up to 7 cm in diameter. Cars, roofs and fruit plantations were damaged by the storm.

26.05.2018 (France and Italy). Violent thunderstorms hit the regions of Aquitaine and Poitou-Charentes in southwestern France with a 100 km long hailswath originating near Bordeaux and devastating vineyards in the area. Hail up to 6 cm in diameter was reported. On the same day, very large hail, up to 7 cm in diameter was also reported from Piemonte province, northwestern Italy.  

27.05.2018 (Turkey). Severe hailstorms hit Samsun province, northern Turkey. Six people were injured in Muratbeyli village as 6 cm large hailstones smashed car rear windows and roof tiles.

04.06.2018 (Italy). A right-moving supercell brought violent hailstorm to the town of Noceto in Emilia-Romagna province, northern Italy. Very large hail up to 8 cm in diameter damaged cars.

08.06.2018 (Slovenia and Croatia). Two very severe hailstorms occurred in Slovenia and Croatia. The town of Črnomelj in southern Slovenia was particularly hit as supercell produced hail up to 12 cm in diameter. Hundreds of cars, roofs and solar panels were seriously damaged. Another supercell hit the districts of Karlovačka, Zagrebačka and Krapinsko-Zagorska in central and northern Croatia. Hail up to 10 cm in diameter hit Grabovec town, damaging cars.

11.6.2018 (Germany and Czech Republic). Violent, wind-driven hailstorm from supercell damaged roofs, facades and windows in  Furth im Wald town in Bayern state, southeastern Germany, and along the Czech-German border. Hail up to 6 cm in diameter was observed.

12.6.2018 (Ukraine). Supercells produced very large hail over Uzhhorod town and Irshava district in Zakarpatska province, southwestern Ukraine. Car rear windows and roof tiles were smashed by hailstones up to 6cm in diameter. On the same day, a violent hailstorm hit villages in the northern parts of Bihor County in western Romania. Hodoš village was worst hit by hailstones up to 6cm in diameter, destroying roof tiles.

13.6.2018 (Serbia). Supercell produced wind-driven hail with diameter up to 6 cm over central and east Serbia. Extensive damage to crops, windows, roofs, cars and facades of houses was observed.

26.06.2018 (Turkey). Violent hailstorm with hail up to 6 cm in diameter caused damage in Düzce province, northwestern Turkey.

28.06.2018 (Ukraine). A violent hailstorm hit areas in Mykolayivska province, southern Ukraine. Hailstones up to 6 cm in diameter caused extensive damage in Yuzhnoukrainsk town.

30.6.2018 (Russia). An isolated, long-lived supercell produced more than 200 km long hail swath with hail up to 8 cm in diameter in the districts of Krasnoarmeyskiy, Timashevsk, Bryukhovetskaya and Pavlovskaya in Krasnodar Region, southern Russia. Novokorsunskaya town was worst hit by very large hail which caused extensive damage to crops, cars, car windshields, roofs and windows. Additionally, very large hail up to 6 cm in diameter also caused extensive damage to cars and houses in Pavlo-Ochakovo area, Rostov province.

01.07.2018 (Russia). A violent hailstorm hit Stavropol region, southern Russia. Hail up to 7 cm in diameter hit the local areas of Bekeshevskaya town.

04.07.2018 (France). Several hailstorms produced very large hail up to 8 cm in diameter over France. 11 people were injured in the Poitou-Charentes region village of Saint-Sornin, where 7 cm hail produced extensive damage to roofs. Houses in villages south of La Rochefoucauld town were badly damaged and rendered uninhabitable by water damage following the very large hail. In Aquitaine region, southwestern France, very large hail up to 6 cm in diameter caused significant damage in some places east of Pau city.

14.07.2018 (Italy). A severe hailstorm hit Piemonte province, northwestern Italy. The town of Chivasso was hit by giant hail up to 10 cm in diameter. Cars and roofs were damaged during the hailstorm.

16.07.2018 (Italy). Several instances of very large hail, up to 8 cm, were reported from Marche province, eastern Italy. Hail caused extensive damage to cars in the town of Pesaro and surrounding villages.

21.07.2018 (Bosnia and Herzegovina). Very large hail up to 8 cm reported from Srpska territory, northern Bosnia and Herzegovina. 1 person was injured by 6 cm large hail in Prijakovci village, north of the city of Banja Luka. Roofs and cars were damaged by the storms in several villages.

24.07.2018 (Turkey). A strong hailstorm hit parts of Kastamonu province in northern Turkey causing extensive damage to cars and houses in Kuzyaka and Seyh villages by hailstones of at least 5 cm in diameter.

05.08.2018 (Czech Republic). Very large hail up to 6 cm was reported from villages in Zlín and Olomouc regions, eastern Czech Republic. Cars and roofs damaged by the hail.

07.08.2018 (France). Very large hail up to 6 cm (weighing 150 g) was reported in Basse-Normandie region, northern France. Roofs, cars and vegetation were damaged.

09.08.2018 (France). Very large hail up to 7 cm fell over Marseille city and Aubagne town, southern France.

28.08.2018 (Spain). Very large hail up to 7 cm in diameter was observed in Euskadi region, northern Spain.

02.09.2018 (Italy). Very large hail up to 8 cm was reported from Abruzzo province, eastern Italy with extensive damage to cars and roofs.

05.09.2018 (Spain). A severe hailstorm hit Albalate del Arzobispo town in Aragón province, northeastern Spain with giant hail up to 11 cm in diameter causing damage to roofs and cars.

13.09.2018 (Turkey). Severe hailstorm with hail up to 6 cm in diameter hit Kastamonu city in northern Turkey. Extensive damage was inflicted to cars and houses.

At the recent General Assembly the ESSL Members elected a new Executive Board (EB) to take office on 1 January 2019. While Director Pieter Groenemeijer, Treasurer Alois Holzer and Deputy-Directors Kathrin Riemann-Campe and Bogdan Antonescu were re-elected for another period of 3 years, Michou Baart de la Faille was elected as a new Deputy Director.

New ESSL Deputy Director Michou Baart de la Faille

Baart de la Faille is from Utrecht in the Netherlands and 32 years old. She is a general aviation forecaster and KNMI chair of general aviation position. She contributes to the KNMI project for the improvement of its weather warning system and also participates in the ARISTOTLE project with the goal of delivering global hazardous weather information to the European Commission’s Emergency Response Coordination Center.

At ESSL she already worked for the ESSL Testbed in 2018. Her main role within the ESSL EB will be to strengthen ties to the National Hydro-Meteorological Services in Europe.

Recently, our trainer Tomáš Púčik has participated on the World Bank project “Strengthening Early Warning of Mountain Hazards in Central Asia” by giving a course on forecasting severe convection in Bishkek, Kyrgyzstan. Forecasters from Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan participated in the course.

Púčik says that it was a very interesting experience and he enjoyed interacting with the forecasters from this part of the world.

On a related note, ESSL is planning to add Kyrgyzstan, Tajikistan, Turkeminstan and Uzbekistan in the future update of ESWD. We are looking forward to start collecting more data from this region and also we hope we will be able to welcome some of the Central Asia forecasters at our Testbed activites in the future.

Trainees and their trainers in Bishkek, Kyrgyzstan in late October 2018.  Photo (c) World Bank

In its latest EMS Message the European Meteorological Society introduced the ESSL to their readers. ESSL’s Director Pieter Groenemeijer provides an overview about the research as well as training and testbed activities, and he also describes the latest developments and finances.

ESSL and EMS are connected via a Memorandum of Understanding since about 10 years already. A main goal is to advertise and co-sponsor the conferences of the partner’s institution – the reason why ESSL lists the EMS Annual Meetings in its calendar of activities.

Read more here.

One of the topics of this edition is an overview of the ESWD entries for the period April to July 2018. Read the full newsletter here.

Registration for most ESSL events in 2019 including the ESSL Testbed is now open. You can find an overview of our activities here.

Brandnew training courses include a specialized seminar for convective windstorms/tornadoes and specialized seminars for aviation forecasters.

As a new service we offer a pretest in the form of an online quiz for people who are unsure which seminar to attend.

Only the ECSS registration is not yet open. Conference registration will open in late autumn 2018.

Tornado (and also very large hail) close to Vienna International Airport on 10 July 2017. Photo (c) Robert Gallina. The new seminar for aviation forecasters will concentrate on probabilistic forecasting and decision making for the aviation sector applications.

On our ESSL Testbed Blog, the presentations schedule for this week has been updated. Everyone can join these presentations remotely.

Presenters will be Helge Tuschy and Ulrich Blahak (both DWD, Germany), and Thomas August (EUMETSAT).

The latest ESSL Newsletter contains the following topics:

• ESWD summary of 2017. As an example, over 16,000 reports of severe wind gusts were entered to the database last year.
• Five new peer-reviewed publications related to ESSL research have been published recently.
• New training events have been fixed in the past few days, including tailored events for aviation meteorology.

You can download the full newsletter here.