Cold Air Coming.

Good day, folks.  Normally I don't do longer term weather predictions.  I generally won't go beyond a week ahead in forecasting except maybe to show something unusual.  There is too much variable in modeling to trust beyond 5 days or so, for storm systems.  However, longer range model runs can be useful in spotting trends.  Longer range is not good for precise storm tracks, but it an tell us that there may be a storm coming in general.

It is in the trends and generalities where I see some issues coming up over the next two weeks, and perhaps longer.   This first model graphic I am going to show you is a temperature model in the 10-14 day range.  This depicts some dangerous and deadly cold working into the area from the western great lakes all the way into the Rockies.  It has Chicago at -18 degrees, -25 into W IA.  And the cold is expansive with temps in the teens and 20s deep into the south.

 

Similarly, the next graphic is a departure from normal graphic that shows the potential for very cold weather.  If your average low were 20, you might see something like -12 for a low.  Remember that these are air temps.   There will be wind chills on top of this.

 

Preceding this cold outbreak will likely be a winter storm from the middle to the end of next week that travels across the country.  While details and locations can be difficult to pinpoint at this time, the trend is there.  Here is one models depiction of the possible snows. Notice that some parts of the upper plains could be measuring snow in feet. 




With these types of extreme conditions being possible, now is the time to prepare.  You need to be ready for being stranded for days without power in subzero temperatures.  The following link is a good list of the things you might need to be properly prepared for the extreme winter weather that can occur.

Winter Preparedness Checklist



The longer term trend that seems to be developing is for these same areas to be colder than normal for the entire month of December.  Where I am, we are going to have our coldest November since 1937.  While I do expect the extremes in the models to modify some, we will still likely be in some pretty extreme weather.  This is one of those forecasts where I hope I am completely wrong.