More Snow in the Northern United States

The north and south central plains are experiencing below freezing temperatures which will lie in the low 30s and low 40s tomorrow. Temperatures above the surface will lie in the low 30s and low 40s as those near the surface. Dewpoint values will range in between the low 20s to upper 30s which is slightly less than the actual temperatures. Low temperatures and lower dewpoints will lead to cold dry weather conditions. But, an upper level trough will sink downward from the north. bringing an area of low pressure with it. This is called the polar vortex. Down in the deeper south near the gulf of mexico and the North Atlantic Basin, warmer and moister airmass may collide with this very cold air dome. This may lead to possible snowy, but mixed conditions due to marginal temperatures present at upper levels of the atmosphere. Freezing rain will also become possible due to cold air damming across mountainous areas. Temperatures in these areas will be below freezing. Possible ice may form along the surface if the temperatures remain long enough below freezing. 

Chance of precipitation near the Great Lakes will be effected with mixed, light/moderate snow, which will become lake effect snow. This precipitation will become mesoscale, which is also known as a beta weather system.

Also, the north plains may experience light/moderate rain, mixed rain and snow, and possible freezing rain.

Adding on to this forecast, the upper Mississipii Valley, Northern Plains, and the Northwest is expected to get over two or less inches of snow on Tuesday all the way till Thursday. Temperatures will be below freezing at all layers of the atmosphere, which will allow snowflakes to stay frozen as they will make their way to the surface. Dewpoints will range between the upper 30s to the upper single digits. Some of this precipitation may remain light for a while. Relative humidity may be moist enough for this type of precipitation, including some light rain as well, but in the beginning. Some snow may be heavy at most due to very strong winds at low and upper levels of the atmosphere, resulting from steep pressure gradients. 

Unfortanately, very little to no convective available potential energy will be present in this atmosphere. But, the good news is that a strong possible cold front from the north will allow for elevated snow showers to occur along it. Without the help from CAPE, frontal boundaries can also play a huge role in lift and active weather. A large mid level trough of low pressure will form across the nation.

-- Kendall Smith