Active Weather Pattern Ahead

***Watch WISN 12 News today at 5, 6, & 10pm for the most accurate forecast!***

Thank you for stopping by the Weather Watch 12 blog.  Today we are going to look ahead to the timeframe of February 21 to around March 3.  This 11 day stretch should bring a very active weather pattern to the central U.S., and in turn bring above average precipitation to Southeast Wisconsin during this week and a half stretch.

Back on January 26 I made a long range forecast for the entire month of February.  Highlighted within that forecast I said the biggest snow of the month would occur on February 8-9.  On those two days Milwaukee picked up 8.8″ of snow, with some spots topping out at a foot of snow!

In that same forecast I highlighted the last week of February as one that should bring another active period of weather to the region.  Several storm systems will form during this timeframe and likely continue into the early part of March.  I don’t think our immediate area will take a direct hit each time the storms pass by, but one of the potentially 3 storms should bring a heavier amount of precipitation.

If you are curious how the long range forecast for February was made that is a great question.  I use a long range weather pattern theory called the LRC…Lezak’s Recurring Cycle.

I have been very excited to introduce this theory to viewers here in Southeast Wisconsin. I first learned about the theory 4 years ago while working in Kansas City. Here is what the theory states:

  • A unique weather pattern sets up every year between October 1st and November 10th
  • The weather pattern cycles, repeats, and continues through winter, spring and into summer. Identifying the cycle length helps tremendously when making long range weather predictions.
  • Long term long-wave troughs and ridges become established and also repeat at regular times within the cycle. These dominant repeating features are a clue to where storm systems will reach peak strength, and where they will be their weakest.
  • The LRC is a winter-long pattern! There is a pattern! It isn’t just one long-wave trough, storm system, or ridge. It is a sequence of troughs and ridges that are cycling across the Northern Hemisphere.

To put this in very simple terms, the weather pattern that occurs in October and November repeats thru the Winter, Spring, and into the Summer. The cycle length will vary each year. Determining the cycle length each Fall really holds the key in using the LRC to forecast into the future. A very good idea of the cycle length is usually determined anywhere from late November thru December. Once the pattern goes thru its second cycle a period of days can be placed on the cycle length. As I have mentioned in previous blog entries, the cycle length this year is about 60-62 days.

Here is why I am confident in the forecast based on the theory above.  Below is a 500mb archived map from December 22, 2009.  I labeled the features that stand out 1-5.  The upper level low labeled #5 dropped into the Southwest back in December and eventually curved northeast and brought our area a very wet period for about 2 days.  Will this same weather pattern repeat? 

Let’s jump ahead roughly 60-62 days to the forecast for February 22-23.  Below is a 500mb FORECAST map from the 12 GFS.  This map again is labeled 1-5 highlighting the larger features.  If you compare the map above to the forecast map below…our main features are in virtually identical spots!

To me this adds to my confidence of a storm developing during the last week of February.  The last 2 times through the cycle this storm brought a quick push of mild air followed by cooler temperatures.  It will be interesting to see the setup this time around, but anything from rain to sleet to snow is possible. 

On the heels of this storm…March will likely begin with more active weather and another storm in the nation’s mid-section.  I’ll talk more about this potential storm in the coming days, but overall the timeframe from February 21 to March 3 should be very active and could bring Southeast Wisconsin many chances for precipitation.  Also, the first week to 10 days of March overall should have below average tempeatures…especially in the northern Plains and upper Midwest.  Remember those areas saw a brutally cold start to January.

If you have thoughts or questions about the weathern pattern please leave them in the comments section of this blog.  Have a great day and thank you for stoping by the Weather Watch 12 blog and watching WISN 12 News! 

Jeremy Nelson

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7 Responses

  1. Great blog Jeremy! I love how you added the numbers. This made it much easier for novice map readers (like me :P) to read and understand.

    • Pat,

      I think most people that stop by the blog aren’t die hard weather nuts:) So the numbers make things easy to pick out. Have a great day and thanks for stopping by.

      Jeremy

  2. Hello Jeremy-Great blog as always. I promise I have been reading them, just not much time to post a response. I wish I had more time to analyze the data myself but this forum keeps me updated.

    I think WISN is very lucky to have brought you on board–I see many new changes that raise the bar of forecasting in the Milwaukee area. This blog gives credibility to what mets do on a daily basis–not simply regurgitating model data or copying the NWS forecast, but truly evaluating the data, knowing the science behind the weather, looking at patterns, and using experience to forecast the most likely events to occur. I have asked all my friends, family, and co-workers to follow the blog so they understand why you are forecasting what you do—and understand why the forecast may be off a bit (so far that hasn’t happened). I also think you’ve done a great job explaining the LRC and applying it to a different location. I look forward to watching this theory in practice in the months to come…I may be a believer (no matter what Ted says).

    Your passion for the weather is clear and it’s fun to see how you’ve grown since college. Anyways, kudos to you and the WISN staff–Milwaukee is lucky to have you!

    Andrea

    • Andrea,

      Thanks for reading the blog and sharing it with your friends and family. I was a huge skeptic of the LRC when I firsted learned about it. But seeing it happen over 3 years made me a firm believer. As more people around the country are introduced to the LRC and see its value, I think it will catch on. There is some research ongoing, but it would be nice to have people all over the country looking at this theory too.

      Take care and drop me an email sometime!

      Jeremy

  3. Maybe we should just give up on the models and stick with the LRC because it is performing a lot better. I’ve seen everything for the 23rd – 25th period suggested over the past few days… from 20s and sunny, to 30s and snow, to even near 50 and rain.

    On the other hand, in my opinion at least, I don’t think the LRC does much for predicting temperature patterns. If so, January would have been warm all month like November was and we’d be in for a warm March as well. An even better example is that mid-January 2009 day when the high was 0 and the low was -10, the next day the low was -12. The next time through the cycle which would be mid March… well we had that record high on St Patrick’s Day of 75.

    • Daniel,

      A few points here. The LRC picks up on long term long wave ridges and troughs. It is best used when looking at the overall pattern. Since what happens at the 500mb level obviously effects the surface…we try to use our knowledge of the pattern and make fairly precise forecasts for the surface. It does pick up on temperature trends but there are many variables at the surface that impact temperatures.

      Keep in mind in November there was no snow on the ground in the Plains or upper Midwest. In January there was a huge snowpack and that directly impacted temperatures. I even mentioned this when I made the January forecast back on December 28. Trying to look at surface temps is tricky though.

      In regards to January 2009 and March 2009 the cycle length varies each year. Some years the cycle length is 40 days, others 60 days, etc. I can try to find out what the cycle length was last year, but I’m guessing those two dates don’t correspond to one another. If you have other questions just let me know.

      Jeremy

      • Actually I have hundreds of questions I could ask as there’s so much to learn about the various aspects of weather forecasting, but I’ll save a few of those for future days.

        Thanks again for all you contribute to the blog and also for your detailed responses you’ve given me over the past few weeks.

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