An Extreme Weather Event Likely Near Lake Tahoe

/An Extreme Weather Event Likely Near Lake Tahoe

An Extreme Weather Event Likely Near Lake Tahoe

Good Morning Weather2020 Bloggers,

A rather fascinating weather pattern is evolving right before our eyes. A blocking pattern is strengthening, and once it forms over the weekend it will be exciting to see what happens next as the models will not be able to handle the breakdown of the block very well at all.  I will try to cover this in my video, and I am also posting the maps below. It’s FRIDAY!

Todays Video Explanation: The Blocking Pattern & What It Means

A Blocking Patter & Lake Tahoe Basin Braces For An Extreme Weather Event from Weather2020 on Vimeo.

Again, please watch the video. I did it in one take so I hope it makes sense.  In the video I am discussing these following graphics as this weather pattern sets up:


The map above shows the 500 mb flow (around 18,000 feet above us) valid tonight, and the map below shows how the block strengthens by the end of the weekend:


If you just look at the flow over the United States and didn’t know about the block, the northern branch that comes over the top of this block and the very cold air mass that is in place, then you would think it is a rather warm weather pattern.  This is not the case, however, and this is just a fascinating pattern evolving before our eyes. There is a big warm-up likely, as a result of what is happening in that southern branch around that big eastern Pacific low that is forming. The question is what will happen next?  And, the even bigger question is how will the “atmospheric river” set up over the Sierra Nevada mountains in this next seven day stretch. There is a good chance of an extreme weather event. These are hard to predict. Will this produce an extreme rain event of 5 to 10 inches liquid, or could it be 20 inches or more and really become extreme? And, what will the snow levels be? Will they be as high as 9,000 feet, or at times will it drop to 6,000 feet. Lake Tahoe is around 6,240 feet above sea level with the mountains approaching 11,000 feet around the Tahoe Basin.


Here is another way of looking at the high over low block:


Now, what happens next is extremely important for next weekend. The computer models are all over the place and for a good reason. The models are error ridden anyway. Using the LRC I know that a storm system should be approaching Kansas City around the 16th or 17th. But, the LRC is not perfect and it could be off a day, two, or three. We have made some excellent and specific forecasts over the past years using this great new method of weather forecasting. When we are wrong in our forecast it is almost always forecast error and not the LRC itself.  This next map shows a forecast of the complete breakdown of that block and the storm I am expecting to show up on the 16th or 17th in the plains. This is the day 10 European model.


My biggest point is… aware of the models while this block is established and begins to break down.  The models are almost always wrong anyway from five days out and beyond.  We will know a lot more in the coming days.

The AO and NAO indexes have been forecast to dip negative, but it just has not been happening.  If these do dip deeper negative, and I am still expecting and forecasting it to happen in February, then our weather could get a jolt of bigger excitement.



Have a great day and thank you for sharing in this LRC Weather Experience. Let me know if you have any questions.


2017-01-07T10:57:36+00:00 January 6th, 2017|General|54 Comments


  1. Michael Casteel January 6, 2017 at 7:59 am - Reply

    I looked back at my recordings and noticed the last arctic blast we got was twenty days ago with a morning temp of -11. I recorded -9 this morning. So is the cycle length 20 days? I am confused on this years LRC cycle length. Thanks and stay warm today bloggers!

    • Gary January 6, 2017 at 9:15 am - Reply

      Michael, there are what we cal harmonics to the cycle. So, if the cycle were around 60 days, then 20 days would be a 1/3rd harmonic. This part of the pattern is likely on that 1/3rd harmonic of the cycle. The big Arctic Blast is more likely to happen around the second week of February. The pattern will certainly be setting up for it to happen. That part of the pattern did not produce an Arctic air mass on our side of the hemisphere in October, so if you just look at the two cycles, then you would say there is a 50% chance of an Arctic Blast equal to that December one at that time, if that makes sense.


      • Michael Casteel January 6, 2017 at 10:53 am - Reply

        Thanks sir!

  2. Richard January 6, 2017 at 8:31 am - Reply

    Whats it looking like now for the Chiefs game ? Yesterday you said Saturday could be the warm day then cold on Sunday. Any models coming into agreement on that yet ?

    • Gary January 6, 2017 at 9:15 am - Reply

      No, the models are not helping at all.


  3. Urbanity January 6, 2017 at 8:35 am - Reply

    Thinking about being bullish on commodities this year, no weather makers in the LRC, all the pieces have to come together to create the perfect storm and that may happen only once or twice this year. Is it just me or does this year look to be very very hot and dry during the summer months. I did notice the most recent Jamstec had a cooler than average late summer, it’s a pretty good model so I am trying to figure that out.

    • Gary January 6, 2017 at 9:16 am - Reply

      Those global climate models are even worse than the ones we are looking at for the next ten days.


  4. Gerry January 6, 2017 at 9:09 am - Reply

    Your sports takes Gary…ouch

  5. Kathy January 6, 2017 at 9:26 am - Reply

    Thinking of my friends in Sacramento and LA and the storm you talk about today….could this help significantly in squelching the ongoing drought out there or if not, since this is the rainy season out there, could this be a more normal winter for them this year? Surely it will help add to the reservoirs.

  6. MMike January 6, 2017 at 11:09 am - Reply

    Latest GFS and GEM model has it pretty cold late next week into Sunday, the Chiefs big day. The GEM has been pretty consistent with this late week cold snap. As far as a storm goes, both models are close to a storm for the same time period, but currently showing the storm not getting it’s act together. Both models do show a warm up into the 50’s Tuesday, and the GFS shoots us into the 50’s Thursday also. The GEM has -2 next Sunday morning. As always, we’ll see how this trends, but for now, it looks cold for the game.

    I recorded 2.7 inches of snow and bottomed out at -8 this morning just west of Liberty.

    • Richard January 6, 2017 at 12:10 pm - Reply

      -2 for the Chiefs game ? Ouch
      Hope not

      • Richard January 6, 2017 at 12:12 pm - Reply

        Ouch because I heard they are opening the gates at 6 a.m.

        • Gary January 6, 2017 at 12:39 pm - Reply

          Are we looking at the models again? Hang on! Remember, they are so bad. That system will likely be a bit faster, and this would allow it to be much warmer. Monday is much warmer, so we need it to speed up. I think it will, this is why you don’t change the forecast based on the flawed model.


          • MMike January 6, 2017 at 12:55 pm - Reply

            Last week the GFS showed this impressive cold snap and snow… it was right from 8-9 days out. They’re not always flawed. I posted it right here on the blog. The GEM was the only major model to predict below 0 temps for this morning from days out…even as late as the 18z run yesterday, none of the major players had below zero temps last night. Only Canadian people did..

            • Gary January 6, 2017 at 1:02 pm - Reply

              The new European Model has an ice storm on the day before the Chiefs game. Again, a flawed model, but of course I am paying attention. This blocking pattern could create one LRC twist. I still say the chance is low.


      • MMike January 6, 2017 at 1:06 pm - Reply


        Clearly that is not set in stone, longs ways out. I’m just posting long range model updates each day to see how the trends predicted now do and what actually happens in 6-10 days. The data has ranged from 64 for a high to 25 for a high.(the last few days of data that is) The trend today is for a cold Chiefs game.

        • MMike January 6, 2017 at 1:10 pm - Reply


          The storm predicted by the EURO is flawed? You have a storm predicted near that time frame. So, you’re not confident in a storm? I know you mentioned the 16th or 17th is more likely, but, I always look for time frames when you predict storms. So, if you say the 16th, I always know that it could be a few days before or a few days later then that date. You’re usually pretty accurate on a general period of time that a storm would hit.

          Was the EURO cold later next week and into next weekend?

        • Gary January 6, 2017 at 1:10 pm - Reply

          The new Euro has a major two day ice storm. Again, I am just telling you what it has. I don’t buy it at all. Again, I am still going to pay attention to it. This blocking pattern could help produce a twist. The big ice storm in 2002-2003 winter, I think it was, I may be off a year, but that winter had almost nothing, then a huge ice storm. So, we have to monitor this closely. It would be a nightmare for the Chiefs game. AGAIN, I am not buying it, just saying!

  7. Bill in Lawrence January 6, 2017 at 11:22 am - Reply

    Good cold January morning to you sir. I bottomed out at around 2 below this morning; we dropped another degree when the clouds thinned out. It would have been interesting to see how low we would have actually gone if we did not have that bit of breeze and the clouds. I was at 4 degrees at 9:00 last night before the cloud deck really moved in; we may have come close to December 18th.

    A couple of random thoughts this morning:

    I wonder if this will be our last below 0 morning for the season. It will have to be the December part of the pattern coming back through to do it as I really doubt this part of the pattern can produce this type cold in early March so it will have to be mid-February. We can get below 0 readings in mid-February so there is for sure a chance but it is not as common as late December and early January. I would put the chance at maybe 30%??

    I have to say, that I am pretty impressed with this Halloween/New Year’s part of the pattern. While it will not have the lasting power of the early-mid December part, it for sure has packed a pretty good punch. I honestly figures we would just have your run of the mill 3-4 day cold spell with highs in the upper 20’s and lows in the mid-teens with very little if any snow; that to me really fir what happened in cycle 1 and looking at guidance as late as Sunday night that is what it showed. Getting 2 inches of snow and a below 0 night was to me pretty impressive. It makes me wonder if this little window may not produce in cycle 3 as well even though that will be early March. If you take the bit of energy from Wednesday and the energy to the south of us last night and today, there may be some players to watch in cycle 3. If you had asked me Sunday I would have said maybe a 10% chance for cycle 3, now maybe a 30% chance? Something for sure to watch.

    Finally, I just want to reiterate something I said yesterday. It is about to really warm up and this week will be a distant memory by next Friday but when I was out early this morning it was 2 below 0 with 2 inches of snow on the ground and I said to myself it does not get any more wintery than this in Lawrence, Kansas. Of course I want cycle 3 to produce more snow and would truly like a 4 plus inch snow event but if it does not happen, I will be content with this winter. This an overall very warm LRC but the two cold set ups to me have delivered quite well; better than any of the events of the past 2 winters. No, this LRC will not go down in the annals of great eastern Kansas and western Missouri winters, but considering the overall set up of this LRC it has not been too shabby at all.

    Oops one last little point. While I agree we are going to have some very hot and dry periods this summer even more so than a normal summer provides and we will make some runs at a 100, I think we avoid a 2012 or 1980 repeat.

    Just some random thoughts on this cold January day.

    Bill in Washington Creek Valley in Lawrence

  8. MMike January 6, 2017 at 11:28 am - Reply

    Hey Bill,

    I think it is actually more common in KC to drop to below zero in Feb. then it is in Dec. I’m not for sure, but I think so.

    • Three7s January 6, 2017 at 11:49 am - Reply

      It is much colder on average in February than it is in December.

      • Bill in Lawrence January 6, 2017 at 2:31 pm - Reply

        MMike and Three7’s:

        Happy Friday!!

        Looking at averages, both December and February average 3 nights below 10 degrees and January averages 5 nights below 10. However, if you look at below 20, February averages 7, January 11 and December 9. If you look at below freezing nights, February averages 19, January 26 and December 22. February is also a degree warmer on average at night than December with January of course the coldest of all 3. The February average temperature is 45 and December is 42 but both average a low of 26. These are for 1981-2010 from NOAA.

        There is obviously is not a huge difference between February and December but the later you go into February, the harder it gets to hit that below 0 reading on average and of course the opposite is true for December.

        I mention this only because the blocking that should develop is in the middle of February so we are quickly loosing the best time on average for KC to go below 0. Can it happen-absolutely and I can remember some from the 1980’s and the 2000’s. The question is can this LRC produce that kind of cold later in the winter season. As I said above, I was surprised at the cold this blocking part was able to produce not just for here but for the lower 48 as a whole so this LRC can deliver the cold; however, I would personally place the chances at around 30% for February. That is just my very humble opinion and I could very well wind up eating some serious crow; see my thoughts about this week in earlier posts LOL

        Gary said something above that I found very important and one that I have missed. The warm ups we will be talking about in the next 2-3 weeks are the January version and will not look like November. Can we make runs at 60 of course and we probably will once or twice, but the cold fronts are going to be stronger and the warm ups afterwards will take a bit longer to get going since it is January; in other words, we are not going to have several days of 60’s and 70’s as we did in November. I said yesterday that I put the chance at a winter event at 8-12% during this warmer period especially if the AO goes as negative as some of the ensembles show and I will stick to that but I did not truly account for was the fact that it is January and some these fronts are going to look different.

        Have a great afternoon everyone

        Bill in Washington Creek Valley in Lawrence

  9. f00dl3 January 6, 2017 at 11:54 am - Reply

    LRC would suggest a warmer solution next weekend than what the models are showing. With all that tropical moisture hitting the Sierra, that’s gotta give us a warm-up. You would think.

  10. MMike January 6, 2017 at 1:01 pm - Reply


    Yes it will, but for earlier in the week into mid week. There’s a cold high in place in the northern plains mid week, how and where does that track and how quick can SW flow/zonal return will be the key to next weekend. Plus, will there be a storm around Friday/Saturday/Sunday.

    Be fun to track, LRC says warm and models say cold(right now) 8-9 days out.

    • Gary January 6, 2017 at 1:07 pm - Reply


      LRC doesn’t say warm or cold. LRC says there is a storm, and it’s January. So, it warms up ahead of these systems, and then the January version blasts us with cold after these systems. So, don’t put words in the LRC mouth, LOL.

      These ups and downs will be impressive the rest of the month. The LRC does say that eventually the warm air wins out later this month, but then we know what is likely in February! The December part of the pattern returns, which also features ups and downs.

      • MMike January 6, 2017 at 1:21 pm - Reply


        What do you mean it doesn’t predict warm or cold, it does it all the time, this period will be warm, this period will be cold..etc….you’re 12 week forecast says a huge warm-up by the weekend.

        • Richard January 6, 2017 at 1:55 pm - Reply

          Bingo Mike
          I cannot look at the models like most bloggers here, but Gary and 2020 informs us about trends with the LRC, right ?
          Warmups, cold snaps, stormy, calm, etc.

          • f00dl3 January 6, 2017 at 2:19 pm - Reply

            The LRC should in practice be able to predict when ridges and storms form. While it doesn’t necessary predict hot or cold weather, ridges drive cold air down while storms pull warm air up just in nature due to how circulations and anticyclones work. You should be able to use the LRC to predict hot or cold spells. If during one part of the cycle storms always track to your north, your always going to be in the warm sector part of the storms because air flows into the cyclone and just get a weak cold front after it passes you by. On the other hand, if storms are always tracking to your south, your going to get blasted with cold air as the air is sucked into the storm from the north. If the storms are coming in riding the mountains like they have this winter, they are always going to be Alberta clippers that give you a shot of snow and a shallow Arctic air mass afterwards for 2-3 days before warm air takes over again.

            • Gary January 6, 2017 at 3:46 pm - Reply


              Good analysis of what the LRC can and can’t do. Overall, we will be writing this up at some point in this next year as you opened my eyes to what we should explain to our clients and to anyone else using our forecasting method or technique. The LRC can get very specific like forecasting the big warm up for that East Rutherford outdoor Super Bowl. We made an incredible forecast and almost got “unlucky” as it did snow the next day. A further example of that type of forecast is the one for next weekends Chiefs game. An analysis of the LRC would indicate a storm around that date, most likely that Monday or Tuesday. There are little systems ahead of that bigger storm as well. I have been trying to be specific so I went 48 degrees and a 20% chance of rain or snow that day. I would like to see how it finally sets up next week before I change that forecast. This is the beauty of the LRC, if you don’t change it, it may very well verify. If you succumb to the models, then you would do what these apps do and get a different forecast every single day. Now, as we get a bit closer if that storm does appear to be coming together a day or two earlier and it looks impacting, then I can change the forecast. This happened on the big “BUST” from last year when I forecasted the big storm for snow in KC. What’s amazing about that big “BUST”, is that it didn’t really bust. It just was a perception that it did because I highly advertised KC getting snow from it. The storm HAPPENED just as it was predicted to happen, but it took that farther north track and Kansas City only got rain from it. My point, however, is that FIVE days before it hit I realized my error and I made the right forecast. Again FIVE full days ahead of it, but it still was perceived to be wrong by Kansas City people. In Omaha, NE it was perceived to be an incredibly accurate forecast. So, again we can get that specific and most of the times we are hitting these long range forecasts for big events.

              On hot and cold periods the LRC will be a huge advantage and great forecast model. We will likely be ready to roll out these forecasts for seasons ahead of us by January of next year. It just is in development. For now, I am pretty sure when we will have heat waves and when they will break. We are working on all of this now.


          • Richard January 6, 2017 at 2:37 pm - Reply

            Trying to reply to yours but the word reply is missing
            Anyway thanks for that explanation.

            • Gary January 6, 2017 at 3:49 pm - Reply

              Can you tell I have the day off from KSHB? I get to interact with you a bit more. Have a great weekend. Snowstorms can where you out when you are the team leader at work. I am relaxing and having a great day.


  11. Hunter January 6, 2017 at 1:21 pm - Reply

    I look forward to seeing how Modelitis Mike’s forecast pans out. Lol

  12. Snow Miser January 6, 2017 at 1:34 pm - Reply

    They’re expecting up to a foot of snow in Raleigh, NC. I wonder when was the last time Raleigh ended up the year with more snow than KC?

  13. Elaine Watson January 6, 2017 at 1:41 pm - Reply

    Gary, Once again thank you for sharing all of your knowledge with us weather enthusiasts. I have been thinking about the LRC and wonder if I am looking at it the correct way. I believe the LRC is a weather cycle that you have discovered and studied. So when you have the cycle for the year pinned down it continues until next fall. There are factors that will affect the way the cycle produces or affects a certain area but the cycle itself remains consistent. Is this correct or am I looking at it backwards and the cycle affects the other players in the weather outcome?

    • Gary January 6, 2017 at 3:48 pm - Reply


      Yes, you are figuring it out. There is much more to it, but you are getting the gist of it.


  14. MMike January 6, 2017 at 2:43 pm - Reply


    There’s no forecast from me nor do I say anyone forecast from a model is right or wrong. I simply post it so we can discuss. I know you’re here to troll, but, at least get the facts straight and don’t make up stuff. Plus, the model data from last week for this week did pretty darn good in the long range.

    • Joe K January 6, 2017 at 10:12 pm - Reply


      Don’t even waste your time responding to the troll. We both know who he is. It amazes me that somebody would be so desperate for attention that they would actually pay to troll a weather blog. Pretty pathetic in my book

  15. someweatherdude January 6, 2017 at 4:57 pm - Reply

    GFS trying to put together a storm for next weekend. Not saying it will happen. Just giving the info.

    • Richard January 6, 2017 at 5:33 pm - Reply

      Is that 8-9 inches of snow for KC on Sunday ?

  16. f00dl3 January 6, 2017 at 8:35 pm - Reply

    Crashing out there. Will we hit -5 in the AM?

  17. Bill in Lawrence January 6, 2017 at 10:12 pm - Reply

    Good evening everyone

    I’m at minus 2 right now. Looking at the current surface charts though we are already in the beginning of the return flow so I would bet we don’t drop much more or we hold steady here if not begin to slowly rise.

    Two back to back nights off below 0 readings; it has been a while since we’ve had back to back nights below 0. This particular blocking part of the pattern has surprised me for sure. I did not think we would rival the first blocking part of this LRC but this has given the December part a pretty good run for its money. Maybe it can throw something together for early March.

    It will be interesting to see if we can catch lightening in a bottle during the warmer part of the pattern. Like I said above, I give it an 8-12% chance and am sticking with that but it is the January/cycle 2 so maybe we can catch lightening in a bottle.

    Have a great evening everyone

    Bill in Washington Creek Valley in Lawrence

  18. Alex Pickman January 7, 2017 at 12:36 am - Reply

    f00dl3, I hit -9 up here in Stewartsville yesterday morning. I suspect its similar again this morning. -2 in Stj right now. I usually have a 5 to 8 degree difference between Stj and Stewartsville.

  19. someweatherdude January 7, 2017 at 8:53 am - Reply

    The new Euro model is showing a massive ice storm in Oklahoma and a massive snow storm in KS, IA and WI next weekend. I can’t post maps (don’t know how), but we’re talking 15 inches of snow in Western KS, 9 around KC and 6-7 in IA.. Then 3 inches of ice in Eastern OK!! That would be a disaster for them. As much as I want snow for KC, I don’t want to see that ice storm to hit anyone.

    Ironically, the Canadian model was the first model to pick up on this storm (if it happens). The GFS and Euro are now showing variations of it. Still a long ways out, but some good eye candy for now.

    • RickMcKC January 7, 2017 at 10:17 am - Reply

      That 00Z Euro is impressive for next Sat-Sun. Showing big ice all the way down into DFW area. Looks like .75 of precip in KC area falling as snow with temps near 20.

      It will be very interesting to see if Bill-in-Lawrence’s hypothesis bears out – that it’s highly unlikely to see that much precip generated in this part of the cycle. It does seem very unusual to see 3″ of rain (freezing or non) in OK at this time of year, regardless of the cycle.

      Maybe this is part of (or a result of) that “atmospheric river” that is currently pounding the west coast. In any case, it would be awesome to have a big snow event during the game next Sunday. Go Chiefs!

  20. Austin Braddock January 7, 2017 at 9:03 am - Reply

    I don’t normally put faith in long term computer models. However anytime the phrase major ice storm, it needs to be paid attention to.

  21. Bill in Lawrence January 7, 2017 at 9:25 am - Reply


    Good beautiful winter’s morning to your sir.

    I have said this a couple of times I know, but I would place our chances of any winter event in the next 2 weeks at around 8-12%. This next part of the pattern is just not conducive to a strong chance of a winter event in this area. That said, it is January and if the AO forecasts are correct, it may dip strongly negative in the next 2 weeks so there are some wild cards to keep an eye one.

    Two considerations with the current model outputs are will there actually be cold air next weekend and the other alarm from these runs is that we have yet to see any storm with that much moisture in the fall and winter versions of this LRC. I think the spring and summer will produce some mositure, but we have yet to see Oklahoma, Kansas, or western Missouri get enough mositure from any event in thew winter and fall versions to give 3 inches of ice or 10 inches of snow. If any event can do that, one would have to argue it would better fit in one of the two blocking parts of this LRC.

    All that siad, I would still place an 8-12% chance of winter event in this next two weeks as looking back to cycle 1, there are some players, there is the AO wild card and it is January not November but I would not go above those percentages.

    Just my humble hobbyist opinion!!!! 🙂

    Have a great Saturday everyone

    Bill in Washington Creek Valley in Lawrence

    • Richard January 7, 2017 at 9:35 am - Reply

      The voice of reason
      Thanks Bill

  22. john marr January 7, 2017 at 9:48 am - Reply

    i very much enjoy reading bills comment thanks bill

  23. Richard January 7, 2017 at 9:48 am - Reply

    If the cycle length is 59-60 days, concerning next weekend was there a storm here 60 days before ? A storm around November 15th ? Memory does not serve me

  24. blue flash January 7, 2017 at 10:14 am - Reply

    We had absolutely no measurable precip between Nov. 7 and Nov. 22.

    • Richard January 7, 2017 at 10:17 am - Reply

      Thanks blue flash

      • blue flash January 7, 2017 at 10:29 am - Reply

        There was a blizzard raging across South Dakota and Minnesota on November 17. Could this possibly translate south in this cycle?

  25. Staci January 7, 2017 at 10:22 am - Reply

    This has probably been discussed on the blog before, but I just looked at Accuweather’s website, trying to plot out possible weather for a March vacation based on the basic premise of the LRC. After checking the weather for the location back in November, I started looking at the site and saw that they are forecasting all the way into April. After some research, I see they use trends to make these long range forecasts, but is this comparable to the LRC?

  26. Richard January 7, 2017 at 10:54 am - Reply

    Other local forecasts this morning were saying it could be dicey next weekend.
    Are you having any clearer thoughts on it yet ?
    And as blue flash just pointed out about the blizzard north of us on Nov 17. Seems to fit the cycle length. Will the cold air be here ?

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