Heavy rain possible Sun-Mon… snow an after thought

- Most of the time, it is snow that is headlining the middle of December.  But as we transition into the last full workweek before Christmas, it’s rain, rain, and more rain.  A large amount of moisture is surging into the Upper Midwest from both the Pacific Ocean and the Gulf of Mexico to combine for one large 48 hour rain event in several states.  It’s severe weather and thunderstorms to our south, with snow in the Rockies and parts of the central Plains.  Around here though, with the exception of parts of the far north and west, snow chances are near zero until Monday.  That’s when this strengthening storm system will pass by to our east, placing us in a more favorable environment for the atmosphere to cool enough for the rain to change over to snow.  The million dollar question is, how fast can we switch over to snow (if at all) before the precipitation comes to an end?  The answer to that question will determine how much accumulation is possible, if any at all.  So here’s the evolution to the storm in the type of precipitation that is expected through Monday…

Parts of the far north and west may initially start as a light wintry mix Saturday night, but then all of us will be warm enough to see rain for Sunday and much of Sunday night.  But by the overnight hours Sunday, atmospheric cooling might be able to change rain over to snow from southwest to northeast as the band of precipitation pulls away.  Right now, accumulation looks minimal at best across the metro and much of the state.  Far northern Minnesota has a much better chance to see at least a couple inches of the white stuff before the storm is over Monday afternoon…