Finally, wet weather

 The Arctic is still warm and brewing up some cold.  All of North America is just swirling around.

At first, it looks like we get some Pacific air, but a huge Arctic spill is coming out over Alaska.

This spill isn't going anywhere, the Bering Straight is too narrow for a major flow.

All summer, Toronto got massive rain from the Gulf air toddling over some residual cold air.  This looks exactly the same as before.  

The big high-velocity Arctic spills have never brought rain.  That's because they undercut the warm air like a snow plow on the highway.  When the Gulf air just toddles in like now, there is a cylindrical mixing with lots of rain.  It's all in the mechanism.