#weatherdad 1/16/18

Looks like there is a significant pattern shift pending in upper-Midwest weather, compared to what we have had for most of the past few weeks.  In the next two weeks, the GFS model is showing 3 strong storm systems that could bring significant Gulf of Mexico moisture into our area.  It is too early to say how much of that will be rain, snow or a mix, but there is a potential for a lot heavier precipitation than we have had so far this winter, which has featured mostly Pacific moisture that was largely depleted after it made it over the Rockies.

Before we get to the significant precipitation, it looks like we will have a substantial warm-up through Friday, when temperatures are likely to exceed 40F in the metro area and much of southern MN.  Saturday should be back in the 30s as high clouds build ahead of a late weekend storm system.  The weak wave that is supposed to generate that storm is still up over the Aleutians, so the intensity and track of the storm are still very much up in the air.  But both the 12Z GFS and 12Z European model are showing a significant low pressure developing over SE Colorado early Sunday, dropping over the Oklahoma Panhandle, and then hooking NE into southern Wisconsin by late Monday.

The European model is just slightly north of the GFS on the track, but there is pretty close agreement for a storm this far in the future.  However, agreement does not mean accuracy, as both models could have the same types of biases.

Just for purposes of a heads-up on the potential of this system, below I’m providing the forecast accumulated precipitation graphic from the 12Z GFS model for this storm.  This shows a very sharp cutoff in amounts on the NW side of the storm.  If this graphic was accurate, the far SE metro would get 12 inches or more of snow (rain would stay down over NE Iowa), and the far NW metro would get only a couple inches, with nothing at St. Cloud and points north.

 

My main purpose this far in advance is to make you aware that if you have travel plans from mid-day Sunday through mid-day Monday, you should pay attention to later forecasts.  I’ll plan to send an update or 2 later this week as newer forecasts are available.