Time To Panic
Snow and cold weather fans, I have very bad news. A few days ago, it looked very promising for a reversal in the pattern to deliver cold air and possible moisture. I'm amazed how the guidance has flipped so quickly and strongly the other direction. I want to make one thing very clear, it can still get cold! We're going to have the coldest air so far this winter this week. However, the cold is nothing unusual and it sure won't stick around long.
Just as fast as the models turned warm, they can swing the other way too and you know I'll keep watching. Each time it looks like the cold is coming this winter, the models turn around and show more of the same.
I want to emphasize, it can still get cold and it can still snow, but it's very difficult under these conditions.
We must have the Alaskan trough go away. It's incredibly cold up there! A ridge needs to develop and dislodge the cold. The models hinted at this and now the trough is back. That's a barrier to the cold coming south.
I know many love to look at the North Atlantic Oscillation and the Arctic Oscillation for cold air signals. I like the Eastern Pacific Oscillation (EPO). IMO, it all begins there. If the EPO is positive, that's the Alaskan trough. If it goes negative, that's the ridge building and the cold air coming south. We look for a negative AO and NAO for cold air, but both are very positive for the foreseeable future. Could all this change quickly? Yes, but given what has happened so far this winter, I have doubts.
One other element is a Sudden Stratospheric Warming (SSW) event. I won't get into the mechanics of it all, but there are signs in the long range of very warm air developing in the highest portions of the atmosphere. That's the beginning sign of coming cold. However, there's a delayed response to it IF it even happens. SSW events have a way of disrupting the cold pools of air near the pole. It starts to break it apart and sends it south. If it were to happen, it would be weeks later and that puts us well into February or the beginning of March. Also, the question comes up, where does the cold air get directed? It may not even be into the south.
In summary, I don't like what I see, but I hold out hope for all you cold and snow fans. Remember, it can still get cold and it can still snow. However, it's hard to do in a pattern like this. Also, it only takes 1 storm to make people happy. Be positive and be optimistic. I am... for now.
The following maps are northern hemispheric views. A birds eye view on the north pole. I have marked an "X" over Alaska. That's the trough that needs to go away!!! If a ridge builds, the cold comes south. Look at the blues which show up in northern Mexico into the southeast U.S. That's an active storm track! This could make temps near average or a little below, but arctic air is mostly cut off in this pattern.
All these maps are for the first of February.