The Evolving 2017-2018 Weather Pattern

Good morning bloggers,

Kansas City Weather Time-Line:

  • Today: Nearly Perfect. Sunny with light winds and a high of 71°
  • Tonight:  Clear and refreshing. Low:  49°
  • Tuesday:  Mostly sunny and nearly perfect again. High:  73°

The weather pattern is cycling and regularly, but at this time of the year something incredible is happening right before our eyes. The weather pattern that we experienced last year got wiped out by the end of the first week of October and we have now been experiencing the very beginning of the 2017-2018 pattern since around October 6th or 7th.  The new LRC is just now setting up and it continues to evolve for another few weeks. We must continue to be patient before we make too many conclusions. Last year we had a 56 to 61 day cycle centered on 58.5 days. The year before that it was 47 – 52 days, centered on 49.5 days. The cycle length is just one of the three main aspects of the LRC.  The other two are that a unique weather pattern sets up between October 1st and November 30th, and long-term long wave troughs and ridges become established. These features are where storm systems reach their peak strength and where storm systems reach their weakest strength most often.  These features are just beginning to show up and I do not know where they are yet, no one can tell this early if we use the centerpiece of the big atmospheric puzzle, the LRC.  How many of you have jumped to conclusions by looking at the error ridden computer models?

1This first map shows the 500 mb flow, around 18,000 feet up. The 500 mb level just happens to be around half way up through the atmosphere in weight. The top of the atmosphere is 0 mb because there is no weight above that level. The surface pressure is closer to 1,000 mb, with the average surface pressure being 1013.25 mb (29.92″).  So, 500 mb is literally half way through the atmosphere in weight, and this happens to be located close to 18,000 feet above us or in the troposphere where the weather we experience here on earth happens.

This map shows the pattern developing right now.  The flow is fairly flat. Where the flow buckles next is rather important. But, also keep in mind we are already ten days into this pattern and in this very early stage we already have experienced some bucking near Missouri. Look at what is forecast to happen next:


By 7 PM Sunday, or 00z Sunday, a trough is again forecast to intensify as it approaches the Missouri River Valley.  This will make it 15 full days of the pattern where this is where the flow intensified. This is an important factor. Hopefully you are still with me here.  Take a look at what happens next:


The strongest storm of this early season is forecast to form over the Great Lakes at the 500 mb level by around one week from now.  This buckling of the flow is once again on the models. Let’s see what happens before we jump to any conclusions.  A big ridge forms out west.

The first huge difference from last year:

Last year on this date California was getting blasted by a very wet series of storm systems. This year it is completely dry out there so far, and this next storm will just provide a glancing blow to the far northern part of California leaving the fire devastated areas dry again. This is not a good development for California.


The first trough swinging by this weekend produces this surface set up for Saturday night. And, then look:


The big buckling of the flow finally produced this over the east. It is still odd, in some respects as this model doesn’t show a major storm there, which could be a factor, but I just won’t be able to put my LRC finger on it until we get into next week.

So, I recommend patience, patience, patience. Once we know the pattern, we will be able to know when the computer models are right, and when they are likely wrong.  Right now we are just finding out. There are other factors to consider and we will go over these tomorrow.

Have a great day and thank you for sharing and participating in this weather experience featuring Weather2020 and the cycling pattern.




Share and Enjoy:
  • Print
  • Digg
  • StumbleUpon
  • del.icio.us
  • Facebook
  • Yahoo! Buzz
  • Twitter
  • Google Bookmarks

1 comment to The Evolving 2017-2018 Weather Pattern

  • anshad

    Hi Gary,

    Always fascinating to see this pattern set up each year. (I have been crossing my fingers for a few years now for a wet and cold pattern so we can get some decent snow)

    I wanted to get your thoughts on Saturday, as NASCAR will be in town. Friday and Sunday look good as of now (Sunday being the main event), but do you think Saturday will be a washout, or will the 2pm Xfinity Series race be okay?

    Thanks as always for your insight into all of our crazy weather!