Proverbs and Poems in Frost's Descent
Interesting Meteorological Knowledge in Proverbs
First, “Heavy frost brings sunny weather” and “When there is frost, there usually will be a sunny day.”
These two proverbs straightforwardly present the relationship between frost and sunny weather. But in fact, it’s not always like that. The frost mentioned in those proverbs refers to radiation frost, caused by cold high. Under the control of cold high, there are more downward currents of air. There fore, the sky at night is clear and the moon is bright and the next day is sunny.
Second, “Snow falls onto high mountains, while frost falls on low-lying land.”
These two proverbs have shown that there tends to be snow on high mountains and frost on low-lying land. But the question is, why does this happen?
We all know that the higher the place, the lower the temperature. For of this reason, when the temperature near the ground is still above 0℃, the temperature on high mountains is already below 0℃.
Clouds are hundreds or even thousands of meters away from the ground, so the temperature around and in the clouds must be lower than that of the ground. The water content inside the clouds forms into snow due to the low temperature there. Then snow begins to fall downward, it melts gradually and finally melts into raindrops when it reaches the ground. Sometimes the snow hasn’t melted when it reaches high mountains, so there is snow up there.
As for why there is frost on low-lying ground, this also relates closely to temperature. We all know that the lower the temperature, the greater the density. In this case, the coldest and heaviest air always goes to the lowest places. When the air reaches there, it will stay and condense into frost.
Third, “Just one frosty morning can’t ensure a long period of sunny days.”
We have said that frost is controlled by the dreaded cold high, which is common in spring and autumn. No matter what kind of frost it is, the strength of the frost and cold air relate closely.
“Just one frosty morning can’t ensure a long period of sunny days” shows that cold air is not very strong and the temperature is not very low and quick to move away. Therefore, the cold air moves somewhere else, and after bringing one frosty morning, the place will be under the control of low air pressure, and the weather will turn bad.
However, if there are continuous frosty mornings, this shows that the cold high is very strong and stable and moves slowly. In that case, the sunny weather can last for a few days or a week.