According to the professor, Estonia has mostly been under the influence of an anticyclone this summer. Particularly in the western part of the country, convective precipitation and thunderstorms have occurred almost daily, brought by local cumulonimbus clouds. Predicting the exact areas of rainfall is so difficult that people who want to avoid rain should instead monitor real-time radar images throughout the day. These images show the movement of rain cells and thunderstorms.

"On a larger scale, cyclones alternated in Western Europe, while to our east, a powerful anticyclone prevailed over Russia. Under the influence of these two pressure systems, warm air arrived from the south, sometimes drier, sometimes more humid, depending on which pressure system dominated," Post explained.

However, the storm that began on Saturday evening turned out to be a cyclonic storm, which is unusual for Estonia. "The cyclone formed quite close to us, which is already very rare in itself. It moved very slowly and followed an unusual trajectory. When such a cyclone with intense rain clouds moves slowly or even stalls, the areas where it rains can receive record amounts of precipitation," noted the climate scientist.

According to Post, the cyclone has not disappeared yet but has simply moved on from the Baltic countries.

The storm's path has also been unusually significant. "Typically, storms move from west to east, more precisely northeast. In this case, it moved slowly east and then southeast, heading towards Belarus. By now, it has formed a very extensive and high-reaching atmospheric vortex somewhere over southern Russia," said Post.

The professor also noted that the scientists at the Free University of Berlin named the cyclone "Kirsti." Usually, only very strong or widespread storms are given names.

Estonia still affected by the cyclone

The cyclone that broke rainfall records in Latvia and Lithuania over the weekend, and brought heavy precipitation to Southern Estonia, is now far away over Russia. However, according to Post, the storm's tail is long. As a result, it continues to affect Estonia's weather, bringing plenty of thunderstorms and rain.

"Usually, our air comes from the west. The cyclones that direct our region's air circulation are also situated in the west. Currently, however, our weather is influenced by this same powerful cyclone over Russia. The air mass it carries with it, the storm's tail, is thousands of kilometers long," Post said.

"It is quite interesting to observe the direction from which the rainfall areas are moving day by day. Initially, the air came from the west as usual, but then it started coming from the south and southeast, then from the east, northeast, north and now from the northwest," the scientist described the air flow's rotation, which has essentially made a full circle.

According to Post, intense convective thunderstorm cells are reaching Estonia with the long tail of clouds. Southern Estonia has experienced heavy showers and thunderstorms all week. Strong thunderstorms have also occurred elsewhere in Estonia; for example, in the middle of the week, a massive thunderstorm line stretched from Viljandi to Latvia.

"This is all part of one and the same powerful air system that is still affecting us. It is very rare for it to last this long. Summer cyclones are usually short-lived," said the climate scientist.

According to Piia Post, the amount of precipitation has been significant in Latvia, Lithuania and Estonia. During the peak of the storm, more than 200 millimeters of rain fell in 24 hours in Latvia. In Southern Estonia, more than half of the monthly rainfall norm fell in a single day over a very large area. In some places, more rain fell than usually falls in an entire month. For example, in Võru, 66 millimeters fell, which is 87 percent of the July norm.

Estonians do not take weather warnings seriously

Piia Post emphasized that the Environment Agency issued the highest-level red warning for dangerous weather on Sunday due to the storm. However, she believes people do not take these warnings seriously enough. "People seem to think that the weather forecast is always wrong," noted the professor.

Post suspected that people cannot distinguish between the aforementioned hard-to-predict convective precipitation and the well-predictable frontal precipitation.

"In the case of a cyclonic storm, where precipitation accompanies a front, modern weather forecasting is very accurate. This was also true on Sunday and Monday. However, people do not differentiate between the levels of warnings or the types of precipitation," the climate sciences professor pointed out. Intense and widespread precipitation can have very dangerous and costly consequences.

The storm Kristi mostly affected Southern Estonia: it raised the water levels of rivers and lakes, flooding fields and roads. "There are many fields where harvesting or other agricultural work is now hindered because the ground is muddy, and machinery cannot be used. Similarly, in cities, prolonged heavy rain can cause even more trouble," the scientist acknowledged.

"In Viljandi and Võru, streets were also flooded. Videos from several Latvian cities, where high water levels remained on the streets for a long time, serve as a warning example here. The cyclone's path could have been a bit more to the north. In that case, the heavy rain would have impacted Estonia's most densely populated area – Tallinn and its surroundings," Post explained.

One might also ask if Estonian cities are prepared for such intense storms. Although larger Estonian cities like Tallinn and Tartu have increasingly considered storms in their climate plans, there is still room for improvement, according to Post.

"One thing to consider is maintaining tree groves properly, as storms bring strong gusts of wind. For example, in 2019, a storm hit the city of Võru. During the renovation of the city center square, only a few trees from the previous period were left standing. These were pines, which have very deep roots and should be storm-resistant. Almost all of them broke," Post noted.

"If you leave standing a few trees that have not grown alone before, they will break in a storm. The same can be seen with individual seed trees left after forest logging – the storm breaks them like matchsticks," the climate sciences professor explained.

Post also believes that city planning should consider that the burden of rainwater should not fall solely on drainage systems. According to her, these systems can be supported with natural solutions. "There should not only be hard surfaces where water can flow but also surfaces where water can seep in," Post suggested as one solution.

"In general, city governments and their waterworks are aware of the problems. No one designs a stormwater system for an extremely strong storm because such events are so rare. Therefore, incorporating natural solutions is a good idea. Extreme storms just have to be endured," summarized the scientist.

At the same time, Piia Post believes that the issue is not only whether city governments and water companies are ready for strong storms but also whether people are prepared.

"People's awareness is low. They do not distinguish between a 'scattered' and 'localized' weather forecast and a forecast that is essentially certain. Warnings are not taken seriously. As one teaching on happiness says, we must differentiate between the things we can change and those we cannot. We cannot change the weather, but we must consider storms in planning and construction," she said.

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