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 water in solid form during precipitation not only affects economic activities and vulnerable environments, but also every type of daily activity. You can also learn more about how and when snow will fall to be better prepared by consulting keys and tips to detect it.
In this article we are going to teach you how to calculate the snow level and how important it is.
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 are coming. Problems arising from making a weather forecast. You can also review how storms affect the weather to better understand these phenomena, as mentioned in Storm Éowyn.
Altitude and temperature
Altitude and temperature are the first fields usually kept in mind when calculating the snow level. This is one of the first factors that gives us an idea of the height at which the snow level can be located. The 0-degree isotherm is the line where this temperature is maintained at the same height. That is, the height above which the temperature becomes negative under normal conditions. Normally, Thermal inversions do not occur in higher layers, but it can also occur. Snow typically begins to melt below this level. The first snowflakes we encounter are usually a few hundred meters below the isotherm. In these places, temperatures range slightly above freezing.
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
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 pressure and high geopotentials, we can find snow above. On the other hand, they can also be found in very cold and deep depressions, since they occur in various depressions in the troposphere with very low geopotentials. This is where we can find pressure values of 850 hPa at just 1000 meters above sea level.
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, precipitation in these areas is usually rain. When a layer of dry air appears closer to the surface, snowflakes can maintain their structure for longer periods of time, barely melting. If the humidity is very low and the temperature remains positive, a film of water will likely begin to form on the surface of the snowflakes. If the humidity is very low, they begin to process water, absorbing energy from their own bodies and the surrounding air.