Posted at 6:52 AM on April 13, 2011
by Craig Edwards
Filed under: Winter/spring 2011
Yes indeed, a cold front sliced through central MInnesota overnight. Temperatures will be some fifteen degrees cooler today in many locations. A narrow band of showers is creeping south through the southern third of the state, including the Metro area this morning.
Now we are working to put the puzzle pieces together for the much talked about weather system for Friday and Saturday.
Heres in the output of the NAM model for accumulated liquid precipitation for Friday ending at 7pm. The shaded yelllow is greater than a half inch of moisture.
Spring storms are a tough animal to deal with. Precipitation starting as snow in the middle layers of the atmosphere can change to liquid as it descends to ground level, sometimes in the last few hundred feet overhead. Then there is melting of the snow on the relatively mild ground. Throw in the filtered sunlight of mid April and it is a challenge to predict accumulations.
Here's the best guess at this time from NOAA's Environmental Prediction Center for snow to accumulate greater than four inches on Friday and Friday night.
One more piece you'd like to believe fits the center of the puzzle! Here's a critical layer where snow can sustain itself aloft at about five thousand feet. The blue region, banded over central Minnesota, is zero degrees Celsius; a zone that is favorable for snow production. Seasonally adjusted it would most likely be a mixture of cold rain and wet snow.
Let's get adjusted to today's return to seasonal temperatures. we'll have more on this weather-maker later today.