The snow to liquid equivalent is the amount of liquid that is produced after melting snow. The temperature profile at both the surface and aloft are important factors that determine this value. The "average" snow to liquid ratio is 10:1. This is saying that if 10 inches of snow fell and that snow was melted it would produce 1 inch of liquid in the rain gauge.
WET SNOW WITH ABOVE FREEZING GROUND: Wet snow is snow that has a high liquid content as it reaches the surface. It gets this liquid content by partially melting before it hits the ground. The wetness of the snowflakes makes it easier for snowflakes to stick together as they fall, thus a wet snow will often have large snowflakes and a lower number of snowflakes. If the ground temperature is above freezing the snowflakes will continue melting. In these situations a snow event can occur but snow won't accumulate on the ground.
WET SNOW WITH AT OR BELOW FREEZING GROUND- It this situation the snow will accumulate on the ground. This is the best situation for producing snow where the making of snowballs is the easiest. The snow is sticky due to its high partial liquid content. The ratio for wet snow will be less than 10:1. For example, a 5:1 ratio may occur in which it takes 5 inches of snow to produce 1 inch of liquid equivalent.
DRY SNOW- A dry snow has little to no liquid water content thus this snow will be less dense than average. Less dense meaning there will be a lot of air pockets between the snow crystals. Dry snow is not sticky and thus it is difficult to make snowballs with it and the wind blows it around substantially. The ratio for dry snow will be greater than 10:1. In extreme cases it can be 30:1 or greater. Dry snow occurs when the temperatures aloft are well below freezing and the surface temperature is below freezing. Since dry snowflakes are less sticky they are less inclined to stick together as they fall, thus a dry snow will often be composed of a large number of small snowflakes.
|Record||63°F February 19, 1997||0°F February 19, 1936|