A strong wind can be a serious danger for a light tourist vessel, even if one disregards the waves it causes. For this reason it is best to become acquainted with Baikal's winds and the signs by which one can tell of imminent trouble while still on dry land in calm conditions.
Lake Baikal is surrounded on all sides by mountain ranges that have a significant effect on the climate, and on the formation of air currents in particular. The determining factor is the presence of depressions between the mountains around the lake in which temperatures differ considerably from the temperature of the main basin — the Baikal depression. The biggest difference in temperature, up to 30–40 degrees, occurs in autumn, which leads to considerable changes in pressure and the onset of powerful currents of air.
The impact of winds on Baikal depends on geographical location, time of year and time of day. The best season is actually the one we are most interested in — summer. 80% of June and July is calm or with slight wind (waves rise no more than half a metre). More often than not severe winds occur in autumn, for example, in the region of the Island of Olkhon from October to December, on average there is a strong wind 58 days out of 100.
Over a twenty–four hour period the calmest time is two to three hours after sunrise and approximately the same before sunset. Rarely is there a whole day without wind. One can get an idea of calm weather periods from the diagram below showing the prevailing winds at various places along the coast.
Characteristically, a Baikal wind is stronger near capes. Even in completely calm weather, there can be a small wind opposite a cape, and in windy weather the increase in wind speed can be considerable. This should be born in mind when passing rocky capes with sheer drops into the lake.
The winds of the Lake Baikal basin are divided, according to their origin, into global and local. The first is connected with the passing of atmospheric fronts and air masses over the lake — these are the strongest winds. Local winds arise as a result of differences in air temperature over water and land. A vivid and well–known example is the breeze that blows from the sea to the land in daytime and from land to sea at night. A local wind does not usually present a danger. An exception to this, it would seem, is the «pokatukha» — «the roller» — which we will talk about a little later.
Depending on direction, two kinds of Baikal wind are distinguished — lengthwise and cross winds. The former blow along the lake's rift valley and, thanks to the considerable build–up distance, raise high waves, the latter blow across the basin and are distinguished by their treacherousness and ferocity.
A good description of Baikal's winds can be found in Oleg Gusev's «A Naturalist at Baikal». According to Oleg Gusev, there are some 30 names for Baikal winds, and often one and the same wind will have a few names.
A description of the most notable air streams occurring at Baikal is given below. I should note that it is not for nothing that Baikal is famous for its impetuousness. Even in the calmest season of summer severe storms can blow up. Not infrequently a number of winds will blow together and it is difficult to understand which one we have to contend with. In such situations the wind can abruptly change to the opposite direction.
Wind current directions and prevailing winds for the summer period at Baikal are shown on the map of Baikal winds.
Verkhovik, also known as the Angara (this second name is used more often in the northern part of the lake; in the south this causes confusion as the wind at the source of the river Angara is also called the Angara). Sometimes the names Verkhovka, Sever and Siver are used. The wind is so called because it blows from the valley of the river Verkhnaya Angara (the word «verkhny» in Russian means «upper», tr.), that is, from the upper end of the lake.
The Verkhovik can blow at one and the same time over the whole of Baikal. In summer, this wind rarely reaches the southern end of the lake, limiting itself to Cape Tolsty as a southern boundary (there are six capes with this name at Baikal, but in this case it is the cape situated about 10 kilometres to the east of the settlement of Listvyanka). In north Baikal, the Verkhovik blows from the north, in central and south Baikal, from the north–east.
A particularly ferocious Verkhovik occurs in December before Baikal freezes over. The wind isn't gusty but usually blows evenly. The weather accompanying this wind is dry and clear.
Verkhovik usually starts up in the morning, after sunrise, and frequently fades away towards sunset, however, it can blow long and without let up — up to ten days. Such protracted winds begin in mid August. Thanks to its considerable duration and absence of gusts, it can cause very large waves. This is one of the best known and most significant winds at Baikal.
The herald of Verkhovik is a bright red horizon before sunrise.
Kultuk is also known as Nizovik, or Nizovka. Wind blowing from the lower, southern end of Baikal, from Kultuk bay (more exactly, from the Kultuchnaya valley). This is a south–westerly wind. It blows in the opposite direction to Verkhovik, but also along the length of the lake's basin. Kultuk raises severe storms, rain and overcast skies. Sometimes in the spring and early summer Kultuk can blow in clear weather. This wind can blow over the entire lake basin, but not for such a long time as Verkhovik. Quite frequently Kultuk will spring up unexpectedly, and with the same suddenness can give way to the opposing wind — the Verkhovik. Kultuk causes the most severe storms on Baikal, raising huge gloomy leaden waves.
Kultuk is heralded by sombre storm–clouds that gather in the south–west part of Baikal.
The Barguzine is a strong, even, north–easterly wind. It can also be called the Polunochnik (sometimes the Barguzine blows at night) and by the now unused name of Barguznik. This stream of air bursts out of the Barguzine valley.
Unlike the lengthwise winds — Verkhovik and Kultuk — the Barguzine blows across the lake basin and only in its central part. Though it is thought that in certain conditions the Barguzine can reach southern Baikal. It neither lasts as long, nor is it as strong as the Verkhovik or Kultuk.
Barguzine usually blows for more than a day, most frequently beginning after sunrise and dying down towards sunset. This wind usually brings sunny weather. Wind speed rarely rises above 20 metres per second, though in the Barguzine bay it can reach hurricane force.
A north–westerly wind. This is one of the cross winds. A cold air stream bursts down from the mountains (this is how it got its name — in Russian «gorny» is the adjective «mountain») — from the slopes of the Primorskiy and Baikalskiy ranges and effects only the western shores of Baikal.
This wind is caused by the presence of the ridges of the Primorskiy and Baikalskiy mountain ranges along the northern shores of Baikal. Cold arctic air masses approaching Baikal accumulate in the mountains unable to pass over them at first. But, having built up to a critical mass, the cold air rolls over the ridges and, building up speed, rushes down the steep slopes towards Baikal. In some places along the coast, in mountain river valleys, conditions are perfect for the build–up of air streams. In this way the Sarma, Kharakhaikha and other kinds of mountain gale force winds arise.
Gornaya is the most ferocious and treacherous of Baikal's winds. It blows up all of a sudden and gains speed in gusts. Gornaya can reach a maximum speed of 40–50 m/sec. Gornaya is often called Sarma, though actually Sarma, like Kharakhaikha, Buguldeika, and Angara are all different kinds of Gornaya wind.
There are a number of signs that allow one to predict the onset of Gornaya. In summer, it is often preceded by calm, windless weather and fatiguing heat, when clouds appear above the mountain tops slowly to form a sullen wall of cloud, stretching out over the mountain range. A dramatic fall in atmospheric pressure can also be quite a good sign.
My own observations show that, in summer, Gornaya starts most often at night.
Sarma is a strong squally wind that bursts out from the valley of the river Sarma that opens up into the Maloye Morye. It is one of the Gornaya (mountain) winds. Cold arctic air from the Prilenskiy heights (the high upper reaches of the river Lena — tr.) rolls over the Primorskiy range into the valley of the river Sarma, that narrows towards Baikal like a natural aerodynamic pipe, and forces its way out at up to hurricane force.
Sarma can blow continuously for days and at times the wind is so strong that it can uproot trees, overturn boats, tear the roofs off houses and sweep cattle from the shores into the lake. The roofs of houses in the village of Sarma, situated in the valley of the river with the same name, are tied to the ground by the villagers. This wind is more frequent and fierce in the autumn and winter. On average, the Sarma blows for 10 days in November, and for 13 in December. Sarma usually covers the Maloye Morye and western part of Baikal, but sometimes it can also be felt of the eastern side of the lake. The speed of this wind builds up in leaps and bounds and quickly reaches hurricane force.
Layered cumulus clouds with sharply outlined edges gathering over the heights of the Primorskiy range near the Sarma gorge is a sign of Sarma's imminent onset. Usually, some 2–3 hours pass between the start of cloud build–up and the first gusts of wind. The last warning is the opening of the «gates» — the appearance of an opening between the mountain peaks and the lower edge of the storm clouds. Sometimes shreds of clouds can be seen sweeping down the mountain slopes. Some 15–30 minutes after this the wind springs up.
This is another kind of Gornaya with extremely ferocious squalls that blows out of the valley of the river Goloustnaya. It occurs most often in autumn and winter, when it is at its strongest and most long–lasting. The name comes from the Buryat word "khara" — black.
A strong cross wind that bursts out of the valley of the river Buguldeika. Like all mountain winds it can blow for days without letting up.
This is also one of the mountain winds that blows out of the valley of the river Angara. It can be very powerful and raises ferocious waves at the source of the Angara. It usually blows evenly without squalls. Occurring most often in autumn and winter, it brings cold damp weather to the eastern shores of the lake.
A cold south–easterly cross wind, blowing from the valley of the river Selenga. It can reach the western shore and leads to a swell in the area of the settlement of Buguldeika.
Rolling down from the ridges of the Khamar–Daban range, air masses coming from Mongolia reveal themselves in the form of a warm south–easterly wind. Shelonnik's speed rarely rises above 10 m/sec.
The name was most likely introduced by people from Novgorod — the south–easterly wind on the river Shelon that flows into Lake Ilmen has this same name. Shelonnik occurs most often in spring, autumn and early winter, and covers only the southern part of the lake. It brings warm weather.
A strong, short–lived, local squall. It can be heralded by a long drawn out cloud or strip of mist over the water (according to Valentin Bryansky, this cloud–herald has cylindrical form, rotating around a long axis and forms mid–way up the mountains). After a while the cloud begins to move quickly with an intense squall that capsizes boats and breaks trees, sweeping away everything in its path.
This is how an eye–witness, Lev Perminov, describes the Pokatukha: «A strange cloud caught my attention. The cloud had a smallish diameter and stretched out evenly over the lake along a west–east axis. It appeared as if the cloud remained motionless for a long time, but unexpectedly darted to the east. I thought it sensible to get onto the shore, but just then, I saw a 'devilish spiral' in front of me, whirling along low over the water. Twisting clockwise (if seen from the east), the spiral, at unusually high speed for a cloud skimmed along over the water. There was something mystical about this rotating form. The lake boiled. Dangerous, high waves rolled behind the cloud.»
There is very little information about the Pokatukha. It would appear that this wind occurs only on the eastern coast of Baikal in the section between Vydrino and Boyarsky.
In conclusion, I would like to say that, although much statistical data has been accumulated on Baikal's winds, it is still impossible to answer the question: from which direction will the prevailing wind blow in any part of Baikal, for example, in July. The reason for this is that the main wind streams are from far away, i.e. they are determined by outside conditions, passing through the Baikal basin with atmospheric fronts. And today, even meteorologist find it hard to predict the weather.