Calculate snow level

One of the important factors when it comes to weather forecasting is knowing the height at which the snow will appear. This is known as calculate snow level. The appearance of solid phase water during rainfall not only affects economic activities and vulnerable environments, but also any type of daily activity.

In this article we are going to teach you how to calculate the snow level and how important it is.

Calculate snow level

calculate snow level

When precipitation occurs in a solid form, it affects a large number of human activities. There are more vulnerable environments such as is road and air traffic, outdoor activities and mountain hiking activities. Almost any daily activity and life in big cities can be affected by snow. A difference in snow level of 200 meters can mean the difference between a rainy day and the complete collapse of a city due to snow. You should get used to cities where snow is more frequent when preparing for this phenomenon and the risks it entails.

We know that temperature plays a fundamental role when it comes to different types of precipitation. Snow most likely occurs when an air mass has temperatures slightly below 0 degrees or close. Keep in mind that this range of temperatures must exist on the surface of the place where we are. When we take a look at the temperature of the air mass, we get an approximation that, in many cases, may not be sufficient. It is quickly when we realize that there are other factors that can lead to errors when calculating the snow level and problems come. Problems derived from making a weather forecast.

Altitude and temperature

snowy town

Altitude and temperature are the first fields that are usually conserved in order to calculate the snow level. It is one of the first factors that gives us a clue about how high the snow level can be. The 0 degree isotherm is the line on which this temperature is kept at the same height. That is, the height from which the temperature is negative under normal conditions. Usually, Thermal inversions do not occur in higher layers, but it can also occur. Snow generally begins to melt below this level. It is usual that the first snowflakes that we find are a few hundred meters below the isotherm. In these places we have a temperature with slightly positive values ​​above 0 degrees.

Another parameter that is usually observed is the temperature at a pressure of 850 hPa. It's about a atmospheric pressure value in which it is usually found around 1450 meters of altitude. The advantage of using this reference system to observe the temperature of an air mass is that it is much more representative of the temperature that exists at lower levels. Another advantage of this type of reference system is that it is separated enough from the ground so that variations in the terrain, solar radiation and the cycles of day and night do not interfere with the temperature. Thanks to these parameters it is possible to calculate the snow level much easier.

Temperature to calculate snow level

calculate snow level

Without a doubt, temperature is the most important environmental variable for calculating the snow level. Analyzing only the temperatures at the lowest levels, it can be seen if we continue to have the snow level correctly calculated. For the same temperature at lower levels, the snow level can vary. The cause of this variation is due to the temperature values ​​found in higher layers. The most normal thing is that all the sketches and guide tables to calculate the snow level usually include temperatures to 500 hPa of atmospheric pressure. In this type of pressure we find ourselves at heights of about 5500 meters above sea level.

If we find a fairly cold atmosphere in the middle and upper layers, there are rises and falls of air that can cause temperature drops. If we find frequent rainfall in these areas, there will be a sharp drop in the snow level. This abrupt descent usually means a few hundred meters lower than expected. The most extreme case that is usually found is when the air is cold enough and unstable in height and can cause deep convection and storms. It is in these extreme cases when the snow level can drop to more than 500 meters. Here it tends to interfere with showers and will lead to more intense and unexpected snowfall.

These cases usually occur in small seasons in winter and in places where it does not snow frequently, but it does snow annually. The pressures of 850 and 500 hPa are by no means set values. In places with high pressures and high geopotentials we can find snow above. On the other hand, they can also be found in depression is that it is very cold and deep since it occurs in various subsidence of the troposphere who have very low geopotentials. It is here where we can find pressure values ​​of 850 hPa in just 1000 meters of altitude.

For snow to exist in these places there must be an environmental temperature of 0 degrees with this atmospheric pressure and as geopotentials of 1000 meters.

Humidity, dew point and mountains

These 3 points are factors that will condition us when calculating the snow level. The humidity is quite conditioning. In environments with high humidity, snowflakes melt faster and just 200 meters below the 0 degree isotherm. Therefore, in these areas the precipitations are usually rain. When a layer of dry air appears in an area closer to the surface, the snowflakes can maintain their structure with hardly any melting for longer. If the humidity is very low and the temperature is positive, a film of water will surely begin to form on the surface of the snowflakes. If the humidity is very low, the water begins to be made, absorbing the energy from the body itself and from the surrounding air.

I hope that with this information you can learn more about the aspects that must be taken into account to calculate the snow level.

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