Wednesday, November 4, 2015

Some rain coming... where is the cold air?

View above Squaw Valley, CA - recently covered in several inches of snow
Just 4 days into November and the weather has just been so weird with 70 and 80 degree temperatures. We know as meteorologists that no matter what is forecast in the weather, not everyone will be happy. Some of you are ready for snow and others wish we could just skip the winter season. 

We will see a little rain late tonight and early Thursday, but look how little it will be. Amounts will be well under 0.25" as the main moisture gets shoved east into Missouri

One of the pieces of figuring out our winter forecast is studying the Arctic Oscillation. I know I've mentioned it on the blog before, but this is a little more detailed look at what is happening. Where is all of the colder air that we are supposed to have in November? When the Arctic Oscillation (AO) is positive, much of the cold air remains trapped up around the Arctic. You can still have a stormy weather pattern, but those big cold air masses tend to stay locked up north. Take a look at the recent index and it has been strongly positive. The end result for much of the country is warmer than normal temperatures.

When the AO drops into the negative, there is a MUCH better chance to see cold outbreaks with the possibility of snow. There is a tendency for it to be slightly warmer than normal around the Arctic Circle while Arctic outbreaks dip south. 

The trend moving into the middle of the month is for the AO to move back closer to neutral (maybe go slightly negative) and some much colder air could arrive in the middle of next week (right after Veteran's Day) 

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