Long Range Forecast – Second Half of February

***Watch WISN 12 News for the latest forecast updates!***

*****Check back Friday evening for a complete update on the weekend forecast.  For now enjoy the blog entry below from Thursday****

The first half of February is almost complete, so in this blog we are going to take a look back and ahead to the February forecast made and posted on this blog January 26. If you are new to the blog I will reintroduce a weather pattern theory that we use and are the ONLY station in Milwaukee to use this theory to provide accurate long range forecasts and trends.

Making long range forecasts is always tricky, but a weather pattern theory known as the LRC allows for accurate long range weather forecasts to be made. LRC stands for 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.

The major winter storm that just passed through Southeast Wisconsin brought anywhere from 4″ well inland over parts of Jefferson and Dodge Counties, to just over 12″ of snow to areas closer to Lake Michigan. Milwaukee’s official snow total from this storm was 8.8″. Remember that the LRC is based on the premise that the weather pattern is cycling, so going back 60-62 days to December 8-9 and then to October 9-10 shows that this storm should come back to the western Great Lakes. Now the question is…did our February long range forecast pick up on this storm? Here is what our forecast called for…

February 8-14

In discussing this period, let’s start with a remember when? Looking back into December, a major winter storm hit southern Wisconsin around Dec. 8-9. Madison, WI had around 18″ of snow, and here in Milwaukee about 3″ and also a good deal of rain.

The February version of this storm should return! This does not mean 18″ of snow will fall or it will be more rain than snow in Milwaukee, but what I’m focused on is that the overall pattern will repeat, producing a storm. It would be hard for this storm to be as intense as the December storm, considering the pressure with that storm was the equivalent of a category 2 hurricane! Back in December the jet stream phased, meaning the northern and southern brances of the jet stream essentially became one, allowing for the abundance of moisture and an intense storm.

Looking back to October 8-9 when the cycle was just forming, this part of the pattern did produce a storm, but only 0.21″ of precipitation occurred, comparing that to early December’s 0.84″, the result of each storm at the surface varied.

For this forecast I do think a storm will form over the Midwest in the Feb. 7-9 timeframe and likely bring snow to many areas. If enough warm air is pulled in, a mix or rain could occur. This will be one of potentially two major storms we see during February, and could be the biggest snow maker of the month for parts of our area. This potentially large storm could impact the region through the 10-11 as a quick shot of arctic air is drawn in on the backside of the storm. Again, it would be very tough for this storm to be as strong as the previous time through the cycle, but it will likely be somewhere between the October and December versions.

By late in this period another clipper system will move through the region producing snow showers. Ahead of this clipper temperatures will likely jump to around average…in the 30s. Behind the clipper another push of cold air will drop temperatures.

 

Not only did our local area see snow from this system, but areas like Washington D.C., Baltimore, Philly, and New York all had significant snow from this same storm system. A lot of times if the general public hears about a long range forecast it is coming from the Climate Prediction Center. The CPC issues 6-10 day outlooks daily. I went back and dug up the archived CPC 6-10 day outlook that was issued on February 2 to see what the CPC thought about the period that we highlighted as bringing potentially the biggest snow of the month to Southeast Wisconsin.

Below is the CPC 6-10 day outlook for February 8-12. This forecast highlighted a high probability of below average precipitation from the upper Midwest through the Great Lakes and into the mid-Atlantic and Northeast.

Now that we have looked back, what is in store for the last half of February? My thoughts really have not changed since the February forecast was made back on January 26. Here is the breakdown for the last half of the month from that forecast back on the 26th.

February 15-21

This period of February will likely bring active weather to parts of the South, East, and Northeast. We’ll watch for a big storm to form and move from the Gulf Coast to the East in the 17-19 timeframe.

Tempeatures should moderate during this period, and by the end, our focus will shift to a storm in the West. There could be light snow by the 21st around Wisconsin.

February 22-28

The last week of February should bring a couple of things to Milwaukee…the wettest storm of the month…and also the warmest high temperature of the month. Let’s compare this back to December first.

The map below is from December 24, two well defined upper lows were stretched across the Plains. This would eventually form into a very impressive storm that brought over 1.50″ of precipitation to Milwaukee…most of that falling as rain. Looking back 60-62 days from December 24 to October…keeping in mind the 60-62 day cycle…another very wet storm produced over 2.20″ of rain in Milwaukee.

This was a long duration storm for our area that came at us in a few pieces, with the main energy around December 24-25. I do expect this to be a wet storm once again, with the greatest impact from February 23-25, but even around the 21-22 some snow or a mix could occur. This storm should once again bring rain to the region, with some mix/snow. This would be the second of 2 big storms for Milwaukee in the month. During this period we will also see our warmest temperatures of the month…likely occurring around 23-25.

Behind this storm the month should end cool.

The last 2 times through the cycle a very large upper low formed over the nation’s mid-section. Here is what the 500mb flow looked like during the previous cycle on Christmas Day.

I do expect another large and very wet storm to develop in the timeframe mentioned above…the question may be…will it be rain, sleet, or snow?

Thank you for taking the time to read this extensive and in depth blog entry! The LRC is not proven or perfect, but it is the best tool that I have found to provide viewers with accurate long range forecasts and trends. If you have questions or thoughts about the long range forecast please post them to the comments section of the blog.

Jeremy Nelson

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11 Responses

  1. Great Post as usual Jeremy

    • Zach,

      A long read…but I think most should enjoy. Thanks for stopping by.

      Jeremy

  2. So what do you think of the 15th – 21st as far as precipitation goes?

    Also, this question is for either Jeremy or Mark. I was wondering why this winter’s temperature pattern is so “middle of the road” compared to most years. Two winters ago we had a day in the sixties in January. Last winter we almost hit sixty in early February. But, both winters also featured numerous nights going below zero. This winter (not counting December 1st) we haven’t been above 43, but we also haven’t recorded a zero or below reading (at the official airport location). It just seems like the arctic surges don’t have much of a punch this year.

    Can’t wait for your March outlook Jeremy. Hopefully the word rain will be mentioned much more often than snow and sun mentioned much more than either of the two.

    • Daniel,

      I don’t expect us to see a major storm during this timeframe. Maybe some snow showers, flurries, or light snow. The last week of February is when I think a much wetter storm could impact our area.

      In regards to the surface temperatures. What happens with the overall pattern directly relates what occurs at the surface. While I firmly believe and use the LRC…there are other factors that play a role too. El Nino could be keeping our temps moderated a bit. But in regards to not being below zero, really every location except Mitchell has been this winter. So it has gotten cold at times. Our warmest temperature occurred with the late January and December storms in the low 40s. And again, I expect a jump in temps with our storm around the 24-25ish.

      Jeremy

  3. Yes, Daniel. The El Nino has certainly made it’s mark. That is why we haven’t seen the dramatic temperature contrasts, and why California and the Deep South have been soaked with rain. The El Nino has also contributed to the Mid-Atlantic being socked with over 50 inches of snow.

    • Robert,

      El Nino is a factor, but not the sole reason for the mid-Atlantic seeing all the snow. If El Nino was the sole player than each El Nino year should produce extremely high snow totals. This is not the case. The increased moisture and stronger southern jet has led to more intense storms in the East, but the overall pattern keeps the mid-Atlantic in the area of heavy precipitation.

      Jeremy

  4. Here is a third party assessment of this year’s El Nino. I agree and assert that the AO pattern is as/more responsible for what is happening along the east coast than El Nino.

    http://news.discovery.com/earth/where-is-el-nio-when-we-need-him.html

    While El Nino may bring a stronger southern jet, that is only half the ingredients needed for what has been an excessive snow season in the Mid Atlantic. The other ingredient needed is cold air, and that has been provided in spades by the strongly negative AO.

    Earlier this year, the Climate Prediction Center updated their December forecast when it was evident the El Nino signal was being overtaken by the power of the negative Arctic Oscillation.

    “THE LONG WAVE UPPER LEVEL CIRCULATION PATTERN PREDICTED BY THE GFS,
    EUROPEAN CENTRE (ECMWF) AND THE CANADIAN MEDIUM RANGE WEATHER FORECAST MODELS
    INDICATE A NEGATIVE ARCTIC OSCILLATION (AO), A NEGATIVE NORTH ATLANTIC
    OSCILLATION (NAO) AND A POSITIVE PACIFIC-NORTH AMERICAN OSCILLATION (PNA)
    PATTERN. THESE FEATURES ARE ASSOCIATED WITH BELOW NORMAL TEMPERATURES
    THROUGHOUT MUCH OF THE CENTRAL AND EASTERN PORTIONS OF THE CONUS. THIS IS
    EXPECTED TO OVERWHELM THE USUAL ENSO TEMPERATURE TELECONNECTION PATTERN FAVORED
    IN THE EARLY PART OF AN EL NINO WINTER, AND THEREFORE THE TEMPERATURE OUTLOOK
    IS SUBSTANTIALLY ALTERED FROM THE OUTLOOK ISSUED IN MID-NOVEMBER. ABOVE NORMAL
    PRECIPITATION AMOUNTS ARE EXPECTED IN THE EARLY PART OF DECEMBER FOR MOST OF
    THE SOUTHEASTERN CONUS, INCREASING THE CONFIDENCE FOR ELEVATED CHANCES OF ABOVE
    MEDIAN PRECIPITATION FROM THE EARLIER OUTLOOK BASED WHICH WAS BASED ONLY ON EL
    NINO TELECONNECTION. ”

    Ultimately, if you look at the pattern closely, October and December both were anything but an El Nino pattern. I think this is more attributed to the recurring cycle of the LRC rather than strictly El Nino or the AO. In concert, it is all having an effect, but think giving only one actor the curtain call is slighting the rest of the cast. 😉

  5. Today the GFS is showing the storm near the end of the month taking a track across the southeast and up the east coast. What’s interesting about this is that about 10-12 days before the Christmas storm, this was the same track being shown on the models up until about six days prior to the event actually taking place. That is when the track shifted dramatically to the west and of course we all know the rest. It will be interesting to see if this storm track shift shows up again on about the 17th or 18th this month.

    • Good observation. The models often push storms that hit us initially too far south. We’ll see if this begins to trend north.

      Jeremy

  6. Interesting approach. I’ve noticed the snow season here seems to be have some repetition of patterns, so it’s comforting to see there’s some theory to confirm the possibility. Your forecast for first weeks of March?

    • Adrian,

      I’ll go over the forecast for March probably on Thursday. Not only will I give the forecast…but my reasoning behind it. Thanks for reading!

      Jeremy

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