Photo: Paula Čurkste / LETA
On Thursday, in many places in Latvia, the sun will appear between the clouds and in many places it will rain briefly, weather forecasters predict.
Heavy rain and thunderstorms are possible locally. The thermometer bar will rise to +14 .. + 19 degrees.
A slow to moderate north, northeast wind will blow, but in the morning wind gusts of up to 19 meters per second are expected on the coast of North Kurzeme.
There will be mostly cloudy weather in Riga, possibly short-term rain. The windless will be replaced by a moderate north, northeast wind, the air will warm up to +17 .. + 18 degrees.
The weather is determined by the cyclone. Atmospheric pressure 749-751 millimeters of mercury at sea level.
Meteorological autumn is gradually entering Latvia
Meteorological autumn has started in Latvia since August 25, according to preliminary data from the Latvian Environment, Geology and Meteorology Center and weather forecast.
Meteorological autumn begins when the daily average air temperature drops steadily below +15 degrees. At several observation stations – including Alūksne, Bauska and Zosēni – the average air temperature has been below +15 degrees since August 25, and current forecasts suggest that at least in some countries this temperature regime will be maintained for a long time.
Observations obtained over many years show that in Alūksne and Vidzeme highlands meteorological autumn usually begins around August 20, but at the latest – in the first days of September – autumn usually occurs on the open sea coast.
It has already been reported that the first and second decades of August in Latvia were 0.9 degrees warmer than normal, July was one degree cooler than usual, while the average air temperature in June rose 3.3 degrees above normal, becoming the second warmest June in the history of national meteorological observations. from last year’s record alone.
Long-term forecasts suggest that both September and autumn and winter are expected to be slightly warmer than normal.
The meteorological autumn of 2019 in many parts of the country continued until February 2020, when the arrival of spring was announced. Due to the anomalous warm winter, weather forecasters had to introduce an additional criterion for determining the beginning of the meteorological spring, after which the boundary between autumn and spring should be drawn if there is no meteorological winter.
Elsewhere in the world, meteorological seasons are often referred to as thermal seasons, while in the United States, the United Kingdom and several other countries, meteorological seasons correspond to calendar seasons, including autumn beginning on September 1 and ending on November 30.
In contrast, the beginning of astronomical autumn is the equinox – during this time both hemispheres of the Earth receive the same amount of sunlight and heat. This year, the astronomical autumn in the northern hemisphere of the Earth will occur on September 22 at 16.31.
The seasons can be divided in other ways. Phenological autumn is marked by the flight of migratory birds, the coloring of leaves and other developments in nature. Climatic autumn boundaries are the average dates of the beginning and end of the previous three decades of meteorological autumn.
Solar seasons are divided according to the length of the day or the duration of sunshine. Solar autumn in Latvia starts every year on August 6 and ends on November 5, thus the beginning of astronomical autumn is the middle of solar autumn.
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