It’s going to get cold, but will it get stormy?

Good Morning everyone!

I figure I issue a free preview of what I normally do for Premium Members in terms of the Long Range.

Today I want to discuss when I think we’ll start to see storms again.  We all know at this point that the pattern is turning colder, much colder.  However, thus far the models are showing a dry and cold pattern.  There is a reason for this and the cause can be found in the Pacific.

I have one tried and true measure of predicting an up tick in Sub Tropical jet stream activity, which is the jet stream typically seen around Texas and the Gulf Coast.  Basically when convection, that’s thunderstorms, are focused around the date line which is 180 degrees longitude, we are to see an increase in activity in the Sub Tropical jet stream.  This increase leads to a pattern development with a trough in the Southeast in the Sub Tropical jet steam leading to a higher potential for phasing of the Polar/Arctic jet stream with the Sub Tropical jet stream and thus the potential for winter storms.


Click to enlarge! MJO Forecast!!

The way to best determine the location and development of the location of convection is using the Madden Julian Oscillation or MJO.  As you can see here the MJO has been in phases 4 through 5 over the past two weeks, thus leading to a lack of convection around the date line and a very week Sub Tropical jet stream.  These phases are typically seen with La Nina environments and supports a pattern with a strong Southeast ridge.  Sounds familiar, right?

But look at where the MJO is going!  The MJO is heading towards and looks to be stalling in phase 6 and 7, which supports the development of convection around the date line.  This development of convection around the date line strongly supports the potential for a shift of the Southeast ridge off the coast towards the Bahamas, an increased activity of the Sub Tropical jet stream, and a higher potential for East coast storms.

I’m using the ECMWF Ensemble guidance as an example, but I also have similar forecasts from other guidance like the GEFS, GFS, UKMET, and other models.  Even more interesting the ECWMF Weeklies issued on January 8, 2013 suggest a sustained MJO 7 phase through early February!

So given this data and the way the pattern as a whole is setting up with what appears to be a negative EPO, negative AO, and negative NAO pattern configuration; the preliminary data for January 20th on through February 15th suggest a cold and stormy weather pattern for much of the eastern United States.  Does this support snow?  Well, in a broad sense yes the potential for snow will increase exponentially for all of the Eastern United States.  However, I need to stress that each storm will have it’s own characteristics and there is no guarantee that your back yard will have snow.  I can promise that everyone in the Philadelphia and New York City metropolitan areas will have a shot at some fun and I will continue my exponential hair loss with these models and weather patterns.