Weather Extremely awkward shut-off pressure is now slowly taking over Finland – this is a difficult phenomenon to predict

For the heat cannot predict the end at this time. The heat mass that arrived over Finland during Midsummer has come to stay for the time being, and it brings with it not only high daytime temperatures, but also tropical nights.

This summer’s heat record was already broken on Sunday, when the mercury readings in Nuuksio, Espoo, were recorded at 31.2 degrees in the afternoon.

Tropical nights also arrived in Finland at Midsummer, as the night before Sunday in Southern Savonia in Rantasalmi broke the border of a tropical night.

On a tropical night, the temperature does not drop below 20 degrees. In Rantasalmi’s Rukkasluoto, the lowest night temperature was 20.6 degrees.

Read more: The summer heat record was broken on Sunday in Nuuksio, Espoo and Kumpula, Helsinki: “There is no end to the heat”

Monday the night before, tropical nights were already observed at a total of seven observation stations in the eastern and southern parts of the country. Meteorologist of the Finnish Meteorological Institute Antti Kokon according to tropical nights were observed especially near hot water-heated waters.

“Currently, the water bodies in southern and central Finland have warmed to more than 20 degrees in many places. This, in turn, heats nearby land and keeps temperatures high at night. ”

In addition to warm inland waters above 20 degrees, night temperatures also remained in the Coastal Region. On the night before Monday, the lowest night temperature in Tulliniemi, Hanko, was 21.4 degrees and at the Helsinki Lighthouse measuring point 21.1 degrees.

“Helle is so strong now, and when the sun is still reindeering and a weak wind doesn’t stir the seawater, the surface water has also gotten warmer at sea,” Kokko says.

“The heat will continue at least next week,” Kokko says.

As Monday is an even hotter day than Sunday, tropical nights are also likely to be experienced the night before Tuesday, especially in the southern, eastern and central parts of the country.

But Why can’t even an experienced meteorologist predict the end of Finland’s heat right now?

The reason is found in a rarer meteorological phenomenon called shut-off high pressure, which currently contains all of Fennoscandia.

Closing high pressure refers to a large and long-lasting high pressure that literally currently closes the Nordic countries to embrace high pressure.

Indeed, the name refers to the ability of high pressure to block the entry of low pressures into a particular area. Meteorologists refer to the phenomenon as “a block from above”.

“In the northern hemisphere, around high pressures the winds go clockwise and around low pressures counterclockwise. This causes the high pressures to form a U-shaped letter, according to which they move in a wavy direction to the east, ”Kokko explains.

However, at the barrier high pressure, the conventional formula in which the high pressures fly as U-shaped waves to the east is broken.

“At shut-off high pressure, your U-shaped high-pressure back closes to the letter O. Such a large area remains under long-lasting high pressure, where low pressures cannot reach. ”

The barrier high pressure center is currently above Belarus and the Baltics.

Shut-off pressures are not the rarest in the world, but not quite every summer weather phenomenon. In rainy and cool summers, they are not necessarily noticeable in Finland.

And how long will the high shut-off pressure and the heat it brings over Finland last? According to Koko, it is impossible to say exactly.

“Such high pressure is long lasting and lasts for at least a week, possibly two. Their eruption is uncertain and difficult to predict. ”

Currently, warnings from the Finnish Meteorological Institute are in force in the southern and eastern parts of the country. Stormy heat is warned in the central parts of the country and in the western parts of Northern Ostrobothnia.