Monday, December 21, 2015

Monday Morning Weather Discussion: The Evolution Has Started, Pattern Change Coming

Good morning everyone. The million dollar question going into January was and is will winter ever arrive? I talked about how per my Winter Outlook I expected a slow start in December with warmer than normal conditions, but not this warm! In my posts last week I discussed the stratosphere and how we needed to see the polar vortex break down in order to allow cold air to funnel into the United States. The 1st two weeks of January will tell the tale on winter.Now is the time to see are these models finally starting to move towards the pattern I expect. 

Lets remember based on the current ocean temperature set up, and many other factors I was expecting a jet stream configuration like this for the winter..


So far this has not been the pattern. We have currently had a pattern similar to whats below with all the cold air out west..


If my winter forecast is correct we need to start to evolve to a pattern like this below in January..

So what to the models say? Well I have been following the trends closely last few days and they are very consistent in showing this projected pattern below develop by the time we get to say around New Years..


This would be huge  guys. Notice the red over the west coast and blue on the east. This represents a western ridge of high pressure and an eastern trough of low pressure the exact OPPOSITE of our current pattern. This set up is very similar to my January forecast. The more red or high pressure you get that builds on the West Coast up into Canada, the more cold air that is allowed to funnel into the East. Think of the jet stream like a barrier between air masses. Also, notice the blue or trough of low pressure developing south of the Aleutian Islands of Alaska. Another huge factor we need to see!

Bottom line is this: The seasonal response of the jet stream based on all the factors I used to make my winter outlook is finally starting to show on the long term models. If this continues and verifies for January and especially February this winter is just getting started!


Before we get there, we have a very mild week ahead with rain on tap. Temperatures are going to rise into the high 60s by Christmas Eve! Expect rain to develop tomorrow and also Wednesday night into Christmas Eve morning. Christmas day looks to be clear with highs in the high 50's to low 60's. We do not start to see this pattern change until we get closer to New Years weekend. 

Thanks for checking in, more to come. 



2 comments:

  1. Willie, wake me up when we've got a sudden stratosphere warming event going. Sorry to be grouchy, perhaps I'm in a "bah humbug" mood today. But I've read 4 or so other weather blogs like this over the weekend, everyone wants to be the prophet of change. You've got various synoptic models showing big changes happening at 336 or 384 hours. But those models generally seem to forecast big changes and big events a bit more often than they actually occur. Some of those runs are also showing ridging over the southeastern US, which could give us shots of warmer air between the cold spells as we progress thru January -- the usual January Thaw. Yes, El Nino is going to decline after the new year starts, and there certainly will be times when the AO, NAO, PNA and EPO are going to gang up and give us cold and snow. But the overall northern hemisphere snow anomaly for November wasn't any worse than last year (when the vortex generally held together and AO stayed +), and solar activity has been and is forecast to stay low into January, possibly moderating the stratospheric warming trend and avoiding "SSW-tipping point" events. Seems to me that every reason to anticipate a big permanent phase shift into a cold and snowy pattern in the eastern US has a counter-reason to anticipate continued moderation. If I had to put out a half-assed guess, I'd say that once we get into January, we're going to get into a yo-yo winter, going back and forth between cold/stormy and average-to-moderate (40 degree afternoon) periods. My rough guess would also be that spring will start late, March will be colder than usual -- I believe that has happened before with winters that start off on the mild side. But hey, 14 + day forecasts are a fool's errand, and I've just shown that I am also a fool. Join the club, I guess. Fooling around with weather trends can be fun, so I wanted to get in on it, as to cheer me up !! Happy Holidays, Jim G

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    1. Hey Jim,

      I feel your pain trust me. I actually agree with a lot of what your saying. This winter will NOT be like last winter, especially w the cold. The yo yo terminology is a good way to put it. AS I mentioned in my bullet points from my winter outlook, winter will back off at times providing mild breaks compared to last winter. The issue now is we havent had a winter yet lol. I did anticipate a warm December but not this warm so it caught me off guard. However, the reason I like what the long run models are showing is because 1, they are all showing the same thing with the mean ridge developing in the west and 2, I am looking at the ensembles not the operational weather model. I have noticed that over last 5 days they have not backed off on this flip by end of December. In fact, they have gotten stronger in the means. If you look at the ocean temps and actually where the thunderstorm activity is occurring it is def more west which is key. The seasonal response should be to develop a trough just off the west coast. That is why I am buying what the models are saying, the ocean temps support it. I know there are other arguments out there using very advanced weather terminology like AAM and NAM and mountain torque but honestly I really think the oceans tell the tale. I will know by 2nd week of Jan if my forecast busts or not. IF this upcoming flip is just short term and by say jan 10th we get the mean trough back in the west projected long term I will throw in the towel. Its not over yet Jim hang in there.

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