While winter may have been delayed by a few weeks with a large portion of December being rather mild, there is no doubt that we have a lot of winter coming into the US that will break the back of this warmth. System 1 of 3 is hitting now and right around Christmas system 2 will bring yet more snow. Towards New Year a 3rd system will hit, all these systems sliding underneath a cold air mass which will build and build south out of Canada, helped significantly by a favourable blocking high up over Hudson Bay. This is the setup which I envisioned would happen earlier in the month but better late that never right? It’s the perfect setup to push a national snowpack towards 60-70% by New Year.

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Of course we currently have a major winter storm barrelling through the Plains which is deepening as it heads for the Lower Great Lakes. This system will break the snow drought throughout the Lower Midwest in style and may cause big problems for Chicago later Thursday as the low slides east and just SOUTH OF Chicago. More rain than snow and I recon a good 3-6 inches is likely for the city while the north and west suburbs or at least within 30 miles of the Loop, should see a foot to 6 inches.

If your in central Iowa and south-central Wisconsin, you will have an all out blizzard to contend with.

As you can see from the above pressure chart for early Friday morning, there is a deep, 983 mb low positioned over southern Lake Michigan that will drive 50-60 mph biting NW winds straight into Chicago. Temps will be in the low teens with wind chills below zero by this stage and by Saturday AM, the air temperature may be at 10 degrees. Check out that COLD 1024mb high sitting right on the border.

Also expect significantly lake-effect snows over northern Indiana, Lower Michigan and eventually downwind Lakes Erie and Ontario.

By Saturday that low scoots on out and towards the Maritimes, big lake effect snows will result and also cold northwest flow right across the Northeast. May have a struggle to reach the upper 30s in the Big Cities by Saturday with wind chills stuck near or below freezing.

The below chart for Christmas morning shows a powerful 1034mb arctic high centered over Lake Winnipeg which has pressures of 1028 down to SD and 1022 all the way to Missouri, if this shows up folks, that’s a heck of a cold Christmas morning all the way to Texas and a very cold morning across the Midwest and Northeast, Mid-Atlantic too. Christmas morning will certainly make you wish you didn’t right off winter (if you had done).

Later on Christmas Day a storm system starts to get it’s act together and looks to develop and track towards the interior Northeast bringing more heavy Midwest snows (perhaps another blizzard) around the 27th.

Here’s the GFS 2M min temps for next 8 days

Days 8-16, Much colder than front 8 days. See what happens when you lay down that snowpack, it encourages the arctic air south, especially when you’ve a nice blocking high over Hudson Bay!

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