Winter Storm: Feb. 7/8 Update #1

A truly complex situation has resulted in many questions regarding the amounts and placements of snowfall totals across the Plains states.  An initial shortwave that is rounding the northern low pressure system is creating some light snow across parts of the central Plains this morning, with accumulations staying rather light through the day today.  The more important feature will be a shortwave and associated trough that is currently making its' way into the four corners region this morning. This will continue to move eastward through the day and make its' way onto the Plains during the overnight, just ahead of this shortwave we will see a brief ridge develop in response to the digging trough which will allow a good return of moisture northward.  As this trough continues eastward it will begin to interact with the cutoff low pressure system that will be positioned over the northern Plains, and this is where the forecast truly becomes complicated.  These two features will eventually come together as one, with the southern stream shortwave allowing for the low pressure system to finally move eastward sometime on Monday. An interesting note found in the Kansas City NWS discussion shows just how unique this event is, as they were not able to find a good analog event for just such an instance.  In other words, they do not have record of a similar event occurring this far east over the Plains states.  All of this comes together to paint a very messy and snowy picture for the Plains, but a wide range of snowfall forecasts for this winter storm.

The morning models have really had a rough time this morning, with a variance of snowfall accumulations greater than 6 inches in some locations between the NAM and GFS.  Of course the Kansas City Metro is once again along the line of receiving anywhere from 6-9" of snowfall to only 2-5" of snowfall depending upon the track of the southern wave and its' precipitation.  We could also see a fluctuation in snowfall amounts depending upon where the two systems interact and begin to push eastward with a strong cold front.  This has essentially led to a hedging of snowfall amounts for the area, with 4-8" a decent forecast at this point with so many questions remaining still only ~24 hours out.  The hardest hit areas will likely be over southern Kansas and Missouri, and then eastern portions of Iowa/Minnesota ahead of the northern upper level low.  Both of these areas will likely see 8"+ snowfall amounts by Tuesday morning. Other portions of eastern Missouri will likely see a good 4-8" swath of snowfall, while areas of northwest Missouri (W of I35, N of KC Metro), Nebraska, and extreme western Iowa will miss out on the majority of heavy snows and see less than 4" of snowfall.  An additional update late tonight is expected, with any additional refining to snowfall totals based upon the location of the southern stream system.