January Weather Pattern

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Last week we began talking extensively about the warm-up for this week. It began today with low 30s at Mitchell Airport in Milwaukee, and will continue for the rest of this week. Wednesday and Thursday still look like the warmest days this week with highs well into the 30s.

Since the forecast is quiet this week, let’s take a look at the January weather pattern. Back on December 29th I made a forecast for the entire month of January based on the LRC.

The LRC is a theory that says the weather pattern sets up from October 1 to November 10 each year, and then begins to cycle. The LRC uses the large scale weather pattern, determining the locations of the long term long wave ridges and troughs across the northern hemisphere. The best way to study the pattern is at 500mb, or the middle of the atmosphere. The pattern can be translated down to the surface, but a seasonal shift of the jet stream, moisture content, snow pack, etc. all need to be considered when looking ahead. By December when the weather pattern generally repeats for the first time, the cycle length can be determined, thus allowing for fairly accurate long range forecast to be made. For this LRC season(winter, spring, summer) the cycle length is roughly 60 days.

Before we look ahead…let’s look back to where we have been. Again, anything that references the January forecast that I made was done on December 29.

Here is what I was forecasting for January 8-15:

January 8-15

The second week of January will look a lot like the first week in terms of precipitation to start. A clipper should arrive somewhere around the 7-9th window bringing light snow or flurries and a push of cold air. This should be a pretty quick hit of cold, before a warm-up ahead of the next potential storm. The end of this period around the 15th give or a take a day should bring a bigger change to the region.

The big question for this time around in the cycle is how will this storm move. Back in November this storm never really ejected or lifted north into the upper Midwest. It became cut-off and traveled east. This is one storm that could bring us a good snow, but if the cold air wins and it stays south then little or no snow. For this forecast I will lean in the direction of this not being a major storm for us, but one that we should watch.

I identified the clipper and brief cold snap that followed, but did not recognize the lake effect snow that resulted in heavier snow totals. Again, the theory that I use is not able to predict lake effect snow weeks out, just like in the summer it would not be able to forecast a single thunderstorm over a given location for hours producing inches of rain. It is the general pattern that I focus on. So, now that the warm-up is in sight as mentioned above, where is the storm around the 15-17?

Let’s first look back to November 17 at the 500mb chart. This is exactly how things looked on the 17th. A well defined upper low near the Missouri and Arkansas border, a split flow in the jet stream, and a trough near the Pacific Northwest.

Let’s now fast forward and look at that same storm roughly 60 days later, or the cycle length of the pattern this LRC year. The map below is from the 12Z GFS and is valid for January 16…roughly 60 days after the map above on November 17.

Looking at the map below for January 17 the upper low is shifted more to the south, which is expected due to the seasonal shift of the jet stream. There is also a trough present over the Pacific Northwest. Due to the split flow that will be present, the storm will stay to our south, and temperatures will remain average to a little above average.

Overall, this part of the forecast has worked out pretty well, and if you look back to the entire January forecast that I made, I also included the map comparison of this upcoming storm that will miss us to the south.

So the big question is, will another major storm hit us this month. Right now I will continue my thinking from back on December 29 and say yes. Here is what I said then.

January 24-31

The last week of January looks to be the most exciting and wettest of the month for our area. If we are going to see a major winter storm during January, I think this would be the storm and timeframe for our area. Again, the question will be where does it move, but unlike the storm around the middle of the month, this one should lift north into our region. This storm could be rain, sleet, snow, or all of the above. This storm should be followed by a push of arctic air that likely will end the month cold.

One of our long range models that we use forecasts out 384 hours. To be honest, with most models once you get past about 3-5 days their accuracy is not very good. But since we know the pattern and that a storm should be around the region roughly 60 days from November 24, we can expect something fairly large to be around Milwaukee somewhere around January 24.

The model that forecasts out long range is now locking onto a pretty impressive storm on the 24th! This is not how the storm will look on the 24th, but this certainly supports my thinking! I do think when this part of the pattern repeats we could see rain, sleet, or snow. So get ready, the most exciting part of January may still be ahead!

So what are your thoughts on the rest of January? Do you think we will see a storm around the 24th?

Thank you for stopping by the Weather Watch 12 blog and make sure to stop back often. Tomorrow we will discuss the warmer days ahead, and our potential for clouds, fog, and freezing drizzle in the coming days.  Don’t forget to join our Facebook Fan Page: WeatherWatch 12

Jeremy Nelson

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6 Responses

  1. Jeremy, I hope you are right, not only about the longer warm temps but also the storms at the end of the month. I think Mark is starting to buy into the LRC and will start to use it more extensively after the next couple predictions are right:) Dan

    • I encourage anyone trying to learn more about it to follow it for a year. The bigger features of this year’s weather pattern are easy to pick out and really help people new to the theory learn what it is all about. A recent discussion from the Climate Prediction Center closed with this line…

      IN SOME RESPECTS…THIS IS SIMILAR
      TO THE FLOW PATTERN AROUND NOVEMBER 8-9 2009…BUT WITH STRONGER
      DYNAMICS ALOFT AND NO TROPICAL CYCLONE INVOLVED.

      Jeremy

  2. Jeremy – here is some text from a NWS Area Forecast Discussion that I found in early December…

    THIS IS A VERY COLD
    MID LEVEL AIRMASS THAT WILL BE DISPLACED RATHER FAR TO THE SOUTH
    EVEN FOR THE FIRST FEW DAYS OF DECEMBER. (USUALLY IF WE SEE A MID
    LEVEL COLD/LOW HEIGHT ANOMALY LIKE THIS IT HAPPENS LATER IN
    DECEMBER OR IN JANUARY DURING THE HEART OF THE COLD SEASON). THIS
    PATTERN ACTUALLY HAS SOME SIMILARITIES TO THE 10 OCTOBER EVENT
    LAST MONTH.

    • More people are beginning to realize how identifying the pattern can be very useful in picking out the features that are to come. I’m sure as more people begin their own analysis of this theory it will expand even more.

      Jeremy

  3. Hey Jeremy!

    I am very excited that the theory is getting out there! I live in Omaha, NE, and followed you, along with the rest of the weather team at your station in Kansas City.. After following the LRC for 2-3 years now, I definitely believe in it.. It is great that you are taking the theory and expanding it to those in Wisconsin! I am trying my best to let those in Omaha know about it.. Hopefully it begins to catch on here as well.. Who knows, it might just take over the entire world soon! Anyway, I was wondering if you had an opinion about this storm set to come in around Jan 25th (using a 62 day cycle) for Omaha, NE.. There are some question marks about whether it will be rain, snow, or fz rain.. With extensive snow pack here (about 20-24″), I would think perhaps fz rain with shallow cold layer near the sfc? Just wondering what your opinions would be on this.. Thanks, and keep up the good work!

    Ross

    • Ross,

      The fine details of that storm for the Midwest won’t be known until likely with most storms 1-3 days out. I’m confident we will have a storm around, but the temperature profile, moisture content, rain/snow/sleet are all features that are somewhat mesoscale and can’t be determined by the LRC. Just think…a difference of only about 2 degrees could mean all snow or all rain for some areas. It will be fun to track this in the next two weeks! Thank you for stopping by our blog!

      Jeremy

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