This is the February 20-23 Winter Storm Analysis.
A winter storm is projected to occur throughout the Plains, Midwest and Great Lakes. There are many key differences in forecasts of what the exact track should be and what type of precipitation will occur in these areas.
So let's start out with where the storm currently is. Below, we have a current image of the energy over the Pacific Ocean off the coast of California.
That big swirl of energy and moisture over Alaska and the Pacific Ocean is our expected storm. I do expect all that moisture to move over into California, strengthen as it begins to move along east, then trek into the Midwest and Great Lakes.
While the Computer Models haven't been handling this storm too well, the GFS ensembles have an image below of the 72 hour precipitation as per the 0z model run.
We definitely see heavy areas of precipitation over the Plains back through the Midwest and Great Lakes. Below are a couple images of the latest run of the GFS model depicting this storm.
Below is the first image. We see the strong low pressure creating heavy precipitation over the Great Lakes, with moderate precipitation dominant over the Plains. The hole to the west-southwest of the low pressure is the dry slot. Keep an eye on that.
About 6 hours later, the low pressure has moved northward, dragging the dry slot eastward. The precipitation is now moderate in the Great Lakes, Plains and Ohio Valley. The blue line right above the low pressure is the rain/snow line. Anyone above the first blue line gets snow. Anyone below it gets rain, typically.
Six more hours later, the low pressure is moving east. Moderate precipitation has turned light across the Upper Plains, with moderate-heavy precipitation ending as well in the Upper Midwest. Attention then turns to the Ohio Valley, where heavy precipitation is dominant.
Snow is the last thing people want across the North after this warm-up. But, to get a feel for how much snow areas may get, below is current snow cover.
All that snow from the Blizzard of 2011 is gone over the Chicago area, with small snow cover in left from the storm that collapsed the Metrodome. Now, compare this current snow cover with the projected snow cover from the 12z run after this storm.
Here, we see a big change as large snowfall totals are evident in the Wisconsin, Minnesota and Upper Plains areas. This is expected to be a big storm.
The Weather Centre will not have SnowCASTs or IceCASTs available for the next couple of days until the models settle out.