Parade of storms could bring Minnesota a very wet week

- A train of storms is beginning to appear across parts of North America and the Pacific Ocean that look like they will bring a weeks’ worth of wet weather to much of the Upper Midwest.  A large trough is diving into the West Coast as the “parent” low so to speak, sits and spins in the Gulf of Alaska.  This sends a parade of storms into the West Coast because they have nowhere else to go since they are being driving by and around the low near Alaska.

So how much rain are we talkin?  Well, it’s WAY too early to tell specifics.  It’s even too early to tell whether all 3 of these storms will affect Minnesota in the coming days, but with the trough in the west and the transition zone is the center of the country, there is a high probability of rain in Minnesota.  Let me show you a different way to “see” these storms…

The following images show vorticity in the atmosphere across the US.  Vorticity is just a fancy shmancy word for spin.  Well, we know low pressure areas spin, and these low pressures are responsible for our rains.  So the areas that show vorticity are likely where a low pressure resides and the rain that typically comes with it…

On Sunday, our vorticity is just to the west of Minnesota and approaching, which means we are getting positive vorticity advection… or the spin (vorticity) is increasing (positive) in Minnesota which means a low pressure is moving through and is likely providing rain.

By Tuesday, our first vorticity blob (low pressure) is gone and replaced by a new one that is working into the upper Midwest yet again…

A similar look at what’s happening in the west coast on Thursday with the third system pushing into the country and heading east…