1:10 PM

I can bet there will be some out there screaming that winter is over and January is a warm month after the end of this up coming week.  A large ridge is going to build over the eastern third of the nation while an upper low digs into Alaska shutting down the northwesterly flow over much of North America that has brought cold air south into the United States.

However, this is a relaxation not an end.  The SST and stratospheric conditions continue to support a perdominant negative EPO pattern.  Patterns always go through weakening and restructuring stages, and this one will be no different.  So here is how I see the weather pattern going into January for the Pacific.

The last week of December through the last weekend of December will be very warm for the eastern third of the nation as the ridge over the Southeast will force the storm track from the southern Plains to the Great Lakes.  Sorry, no white Christmas this year for I-95ers.  Meanwhile, an upper low will develop over Alaska and drive south towards the Pacific Northwest, further enhancing the ridge over the eastern third of the nation.  

Heading towards New Year’s day though, the Pacific will amplify once again.  A trough will develop over eastern Asia, which will once again force a ridge to build towards Alaska.  The first week of January, expect a split pattern in the works.  The pattern will develop very similar to the pattern that is currently about to break down.  The southern branch will dig into the Pacific Northwest as the upper low that was over Alaska continues to dig south, but also begin to weaken.  Meanwhile the northern branch of the jet stream will dive from western Canada and into the Plains.  Expect a slow and steady “cold press” over the northern third of the nation.  We may be looking at another round of snow and ice events over the Mid Atlantic once again, but with a colder air mass.  

The second week of January I think will feature a strong negative EPO feature.  The thinking here is that the upper low off the Northwest coast will pump up the ridge over Alaska.  Meanwhile, a ridge along the interior West will begin to build north as well.  If the negative EPO ridge and the PNA ridge connect, watch out for a very cold middle of January.  I’m not convince that will happen as all the cards will have to come into play, but the potential is there, so I thought I should mention it.  The point is that the negative EPO pattern supports a cold pattern for the forecast area, not a warm one.  

As for “big storms”, a lot will depend on the potential for a negative NAO actually developing.  Model guidance and the trends in the stratosphere once again supports the potential for a negative NAO to develop in roughly 8 to 10 days and possibly remained sustained.  However, we’ve all seen this before.  Based on the data alone, I would say that a negative NAO should develop by the end of this year and have a major role in the pattern for January.  However, I’m in a wait and see position until it actually happens.