The May holidays are less than a month away and many are already starting to make plans for the big weekend. Plans for May are often associated with out-of-town vacations and trips to the country, which are just as often spoiled or interrupted by bad weather. We decided to find out in advance what meteorologists expect from the weather in May this year.
Meteorologists say they can give a fairly accurate forecast for seven days, but they also make longer-term forecasts – even for six months. Such predictions become probable: that is, experts estimate the probability that the weather will be cold or hot. For example, a temperature rating “below normal” is predicted if the probability is at least 60%.
– You will not see here how much is below the rule, it is beyond knowledge. At the same time, “the temperature is above normal” is the most likely scenario, this probability is 60%. But the probability that the temperature will be around the norm is 25%, and 15% is the probability that the situation will be the opposite, says meteorologist Roman Vilfand. “It’s difficult for people to get used to the idea, but it’s true: in the long run, only average features can be described. That is, it can be the average monthly, average seasonal temperature. It is virtually impossible to describe the dynamics of the weather in a month or a season. This is out of theory.
Roman Vilfand is a Russian meteorologist, scientific director of the Hydrometeorological Center of Russia, a member of the board of Roshydromet and the scientific and technical board of Roshydromet.
In May, the average monthly temperature in most of Russia is expected to be close to normal. It will be warmer than usual in the east-northwest and north of the Volga Federal District, as well as in most of the Urals Federal District. Temperatures below average monthly values for the entire history of the observation are not expected anywhere yet, however, in some areas it will be colder from May 2021. Such weather is expected in the southern Urals region, in Taimyr, north of Yakutia.
At the same time, you need to understand that if they generally promise us a hot month, it does not necessarily mean that it will be evenly hot. It may turn out to be cool, but with several unusually hot days, or it may even consist of constant changes in heat and cold – the average monthly temperature will be the same.
With the rains, a similar story: meteorologists do not say how they will be distributed in a month – it will be a downpour or two weeks of rain. It is also impossible to predict how much rainfall will be, just “above” or “below” the rule.
Meteorologists expect below-normal rainfall in the south of the Central and North Caucasus Federal Regions, in the southernmost part of the Volga Federal District, in Buryatia, in the Trans-Baikal and Primorsky Territories. Most of the normal rainfall is likely to fall in the northeastern part of the Urals, in the northern part of the Siberian Federal District, in the northern and central regions of Yakutia.
At the same time, forecasting rainfall is even less accurate than predicting temperature – the maximum probability set by meteorologists is 50%. No, this does not mean that it will rain or not – there are three options: rainfall is close to normal, below the norm or above.
“The atmosphere is a complex chaotic system, it has noises that can never be predicted and it contributes – about a third – to average performance. “This uncertainty is embedded in the forecast,” explains Roman Vilfand. Everything in life has a probabilistic background. Man knows exactly what he will do today, tomorrow, the day after tomorrow. At least every self-sufficient adult has such a plan.
But what will he do in a month? For example, he plans to go on vacation, but he plans it based on the information available today. But he does not know what his state of health will be, maybe the conditions at work will change, an epidemic will start, the political situation will change. There are unknown factors. passes some time, the information is identified and becomes more detailed. The information we have just described will be more detailed, it will be adapted.
A particular difficulty in determining the forecast within a month is that there are more and more weather anomalies in recent years. As climatologist Andrey Kiselev said earlier, the number of dangerous hydrometeorological phenomena has almost doubled compared to the end of the last century.
“Weather depends on what happens in the climate system itself, and the anthropogenic factor, that is, the effect of human activity, prevails,” says Kiselev. – It is believed that internal variability is responsible for each individual phenomenon. However, the increase in the frequency of these phenomena is a result of the influence of the anthropogenic factor. If it is very simple to explain: the temperature is rising. This means that the energy of the whole system is increasing, and it must find some production.
Andrey Kiselyov, Candidate of Natural and Mathematical Sciences, Main Geophysical Observatory named AI Voeikova, author of the book “Climate Paradoxes”.
We will see a more accurate forecast for May at the end of April: the forecast for the month is published on the last day of the previous month. And even that will not be exhaustive and can change.
“Details are corrected within a month with ten-day, five-day and detailed forecasts,” says Roman Vilfand. – There are procedures that are well thought out and allow you to extend the long-term forecast by up to nine days. For example, weighting an anticyclone. Such procedures are rare, but they do happen. The fact that you can now trust the 7-day forecast is already a huge achievement.
Designs sometimes need to change more than just that due to weather, but also for other reasons, so you can find many options in advance. To properly plan your weekend, we have prepared a reminder: see how we will work in May. By the way, if the weekend is not enough for you, you can still have time to take a vacation. Just check first how profitable it will be for you to go on vacation in May.