Powerful Jet Stream…….Rain & Snow

/Powerful Jet Stream…….Rain & Snow

Powerful Jet Stream…….Rain & Snow

Good morning Weather2020 bloggers,

A strong storm system is blasting into the west coast this morning.  The Lake Tahoe area is a target this morning with 125 mph wind gusts forecast to occur today over the higher ridges.  Can you imagine that? Take a look at this forecast alert:

Lake Tahoe Area Forecast:

 

  • Timing:  Snow and rain will spread quickly across the Sierra and Lake Tahoe basin this morning and become heavy. Snow will decrease briefly this afternoon…with bands of snow and snow showers developing again tonight through early Friday morning
  • Total snow accumulations through Friday morning: Above 7,000 feet….1 to 2 feet with locally up to 3 feet near the Sierra crest. Below 7000 feet…7 to 14 inches with 18 inches possible west of Highway 89
  • Winds: Southwest 30 to 45 mph with gusts up to 65 mph. Ridge gusts up to 125 mph. The strongest winds are expected through 8 AM this morning. Damage to trees is possible
  • Snow levels will start out high near 8,500 feet early this morning, then falling quickly to below 5,500 feet by midday. Lake level is 6,200 feet

The weather pattern is about to buckle. What I mean is it is about to go from zonal flow, west to east, to more wavy and meridional flow, north and south.  A powerful jet stream is now heading towards the west coast. Take a look:

Powerful Jet Coming In

As this jet stream blasts in the morning, the Lake Tahoe area and the higher ridges are in the right position to have these high winds reach the surface. Look at what happens to the flow aloft by noon Friday:

1

This storm will move into the southwestern part of the nation by Friday.

2This next map shows what the weather pattern is forecast to look like by Sunday morning, December 13th. This storm is moving through one of the LRC long term long-wave trough positions. It is actually taking a great track to bring Kansas City snow, but guess what….it’s likely going to be too warm.  We forecasted this storm, and this developing series of storm systems to arrive during the next ten days to two weeks. Take a look at the last cycle, or 50 days ago:

LRC Cycle 1 October 23

The weather pattern sets up every fall between around October 1st and November 10th, cycles, and then repeats. We have identified the likely cycle length and if you go back 50 days you can see a similar storm system on October 23rd. The December version is a bit stronger and farther south, but even the shape of the storm is the same.  Look at the dip in the flow over Nebraska and the Dakota’s. A similar dip is approaching the plains states this weekend.

I don’t know how to say this any other way, “the lightbulb” went off!  In the past seven to ten days the LRC finally came into focus. It is really one of the more incredible moments every year and it’s hard to describe. And, those of you who have been following the LRC with us for the past decade will likely understand the best. This is the first example of the year. You can not make these comparisons before, roughly the end of November. The old pattern fell apart in September and early October and we now have a pattern cycling that has never happened before.  This is just one snap shot in time. It isn’t just this one day, but the entire pattern that is cycling.

This storm is likely taking a great track for heavy precipitation in the KC metro area and surrounding areas. It is also taking a track that would usually produce heavy snow, but it appears it will be just a bit too warm. We will continue to monitor this closely.

Here is a rainfall forecast from the 06z (midnight) run of the GFS model:

Screen Shot 2015-12-10 at 7.25.31 AM

Let’s see how the models look today. The models will narrow in on a more consistent solution after this energy blasts over the west coast today.  Most of the energy has been located over data sparse regions across the eastern Pacific Ocean.

Take a look at what is happening and forecast to happen with the Arctic Oscillation:

AO December10

The AO has been staying, “living”, mostly in positive territory this season. It did dip into negative territory one time around the second week of October, and it is forecast to do about the same type of dip in the next week. Let’s continue to monitor this closely. When the AO and NAO dip into negative territory there is an increased chance of blocking and the potential for the Arctic air to build and blast south. So, we must pay close attention to these developments. Some of the models have it getting pretty cold in ten days or so.

Have a great day and thank you for participating in the LRC Forecast Experience Blog. Let us know if you have any questions or comments.

Gary

2015-12-10T07:05:32+00:00December 10th, 2015|General|0 Comments

No Comments

  1. Bill in Lawrence December 10, 2015 at 7:29 am - Reply

    Gary:
    Good Morning to you sir!!!

    A couple of random observations/thoughts….I’m sure the limb will break!! 

    It appears ( I think??) that the 0Z GFS Operational model finally caught on to the possibility of the AO going negative around the 16th of December. There is some weak blocking beginning to show up in the Eastern Pacific around that time and the surface temps/solutions began to show that on this run. We look to stay below for freezing for around 3-5 days beginning next Thursday before we would warm to just above for about 12 hours until what I believe is the first true arctic front blasts in around the 23rd. That 3-5 days also looks to throw out one heck of an ice storm from Possum Kingdom Lake Texas through Oklahoma City into Tulsa late next week.

    The question would be does this run have any chance of verifying in any way shape or form. I would argue that at least for the period out to around 220 hours it has modeled the LRC pretty well. Will there be changes….absolutely…I have not looked at the 6Z ( I usually don’t look at the “off” runs) but I would imagine it has a totally different solution than the 0Z. However, the solution of the 0Z to me lines up very well with what happened around mid-October when we were early into cycle one. We had a week where we were below normal for about a week but dry…very similar to the 0Z’s rendition of mid to late next week. Also, the AO forecast looks very similar to what it did in Mid-October. Oklahoma also had the bulk of the moisture in that time frame in October just as this particular run shows. As far as the arctic looking front of the 23rd we did have one more strong cold front in mid to late October as the AO began to rise back to positive…I would guess that that is what this model run has picked up on but in the December version which could make it an arctic front.

    The question will be –is the cold air really strong enough to oppress the whole moisture stream mid week next week or will it shift north in future model runs? Can the cold air we get in place next week hold out until the next shot blasts in around the 23rd to where that storm on the GFS around that time would be more wintery??

    Whatever the case, and keeping in mind all of the model flipping back and forth we will see over the next 7 days (4 runs a day of the GFS…I would not be surprised if we see several solutions where we stay in the 60’s for the next 7 days) I would argue that the LRC is showing the way for our best shot at winter weather beginning around the 16th and lasting until around Christmas or just a bit beyond. At which point the AO will be extremely positive again and we will begin watching for 1-2 day periods where we can catch lightening in the bottle and get lucky. We have the 1-2 storms that created the blizzards out west and of course the Thanksgiving event-all of which occurred when the AO dipped to negative/neutral for 1-2 days. Then of course…in late January Cycle 3 will start and all of us winter weather folks can get our hopes up for the next long stretch of possibilities.

    Okay…I promise I will step away from the key board for a while as I am really not sure if this makes one iota of sense or if the limb is still there!!! 

    Have a great day everybody….enjoy this beautiful day of weather…breezy though it may be!!!

    Bill in Lawrence

    • Gary December 10, 2015 at 7:55 am - Reply

      Great job as usual Bill. Thank you so much. We appreciate your input immensely. I just posted the latest AO index chart. We must watch this closely. And, look at the LRC comparison I posted today. Here we go, let the ride begin. This first storm would usually produce snow here, and still may. We have a series of storm systems lining up.

      Gary

  2. Rickmckc December 10, 2015 at 8:33 am - Reply

    It really is astounding to see a system so perfectly located for a major snow storm in Kansas City produce rain in mid December.

  3. Anonymous December 10, 2015 at 8:36 am - Reply

    Bill, you mentioned Possum Kingdom Lake, Texas. I have been going to that lake my whole life and have a cabin their. Small world !!!

  4. LS Mike December 10, 2015 at 8:38 am - Reply

    Bill, you mentioned Possum Kingdom Lake, Texas. I’ve been going their my whole life, and have a cabin their. Small world!

    • Bill in Lawrence December 10, 2015 at 9:22 am - Reply

      LS Mike:

      Small world indeed!!! 🙂

      My fiancee’s family has had a place there for years as well. Beautiful area for sure!!!

      We were just down in October-nice to finally see the lake filled back up!!!

      • Anonymous December 10, 2015 at 9:46 am - Reply

        Bill, my place is around the bend from Hell’s Gate have to go by boat to get to it. I told my peeps down there D/FW area to not worry the lake(S) will stay full all year. Of course they said I doubt it and mentioned back into a drought, this was right after October first of November. I told them that the pattern has changed and your in a good spot for lots of rain. Of course I was using the LRC and look what happened on Thanksgiving…. They got a ton of rain again.

      • LS Mike December 10, 2015 at 9:49 am - Reply

        Bill, my place is by boat access only around the corner from Hell’s Gate, beautiful lake. So thankful it has filled back up. Told my family that it will stay full this year with the new pattern, lots of rain down there.

  5. Getmbuck December 10, 2015 at 9:03 am - Reply

    Gary any idea at this point on the timing of the weekend precip? Mainly looking for approx start time, peak hours and projected end time. You did a good job on predicting the timing for the thanksgiving deluge so wanted to see if you are at that point yet for this one

  6. Craig December 10, 2015 at 9:13 am - Reply

    If this is Dec 12, one can only imagine how interesting this might be 100 or 150 days from now. Be sure to scroll down to the part about Eastern KS and MO.

    http://www.spc.noaa.gov/products/outlook/day3otlk.html

  7. Rockdoc December 10, 2015 at 9:37 am - Reply

    06z run of GFS showing what could be a white Christmas? If the surface low shifts just a wee bit south then there could be even more snow. Most of the snow is to the north and into Iowa right now, but nonetheless temps are in the teens starting around the 24th to be supportive of snow⛄ Something to keep our eyes on.

  8. MMike December 10, 2015 at 10:41 am - Reply

    Got all the sandbags ready for the flooding rains this weekend….what a waste of a great storm.

    IT should SNOW this time of year!!!!

    • Gary H December 10, 2015 at 11:27 am - Reply

      I completely agree. So frustrating! But I’m enjoying the nice weather too. Very odd to still be doing yard work this time of year.

  9. Alice December 10, 2015 at 11:18 am - Reply

    Here are some interesting stats put out by the NWS Kansas City…
    Late first snow events followed by the total inches those same winters…

    First snow Total for the year
    Jan 21, 1980……..23.5 inches
    Jan 18, 1955……..20.2
    Jan 7, 1934……….7.2
    Jan 2, 2002……….8.6
    Jan 2, 1897……….28.9

    (Were any of these years El Nino years ? )

  10. Gary H December 10, 2015 at 11:39 am - Reply

    Last couple of runs of the GFS has some very interesting winter weather near or over KC on Christmas Eve day. Looks like something to definitely watch. Canadian (GEM) is a bit different bringing the storm in a few days earlier (but still snowy). Euro (00Z) is nowhere close to either, but let’s see what 12Z says. Any ideas whether the recent GFS solutions fall in line with the LRC?

  11. Hunter December 10, 2015 at 11:41 am - Reply

    Are any of the storms that fit the LRC for this cycle expected to be complex, Gary? I know last year that word was thrown around a lot as we were just not in the right spot.

    Why is it always complex when the air is cold enough to produce snow (which I have noticed storms are notorious for missing us when it’s freezing or below)? But when it’s warm for just rain, the storm track is just so perfect we get a good bout of it…

    • Gary December 10, 2015 at 12:20 pm - Reply

      Hunter,

      The storm is just as “complex”. But, last year we were not in the right spot and this year, although we may not be in the perfect spot, we are more in the right spot to have fully functional storm systems. This one coming our way now has many challenges. The NAM model had it just cold enough for a changeover to snow in KC, but the other models thus far have it just a bit too warm.

  12. MMike December 10, 2015 at 11:55 am - Reply

    Gary H,

    All rain this winter….at least we’re getting moisture. It was 58 degrees this morning when I woke up………………….WHAT?????

    I wonder if we can some how figure out how to get it to snow at 60 degrees.

    I was reviewing the last few runs of the GFS and GEM models…the weirdest thing happen when I I would play each run…a screen popped up and it said….”No snow for KC…sell your shovels….way too warm this winter” Must be a new feature they have…messaging.

    • terry mercer December 10, 2015 at 12:02 pm - Reply

      Yeah right very funny. You Must have already had too much eggnog before Christmas lol.

    • Dale December 10, 2015 at 12:04 pm - Reply

      At least we are getting some storms in KC. I am glad to see exciting weather, even though it’s not snow. Let it rain, let it rain, let it rain!

  13. stl78 December 10, 2015 at 12:14 pm - Reply

    It’s not just warm in kc. I’m in Minneapolis right now where it is in the 40s and raining. Hard to believe its raining in dec in minn!

  14. Morgan December 10, 2015 at 12:20 pm - Reply

    So much for that cold signal around Christmas. Not a good look on the 12z GFS. More GLC rain storms. Sucks to waste all of this moisture on rain this time of year.

    • CRW December 10, 2015 at 1:42 pm - Reply

      Like someone said a while back, the cold is always 10-14 days away.

    • HEAT MISER December 10, 2015 at 1:55 pm - Reply

      It sure is a good thing that the GFS is meaningless two week out huh? Nobody would much stock in that…oh wait…..

      • Dale December 10, 2015 at 2:24 pm - Reply

        Kinda like you do when it’s showing a snowstorm? Thanks CRW.

        • Heat Miser December 10, 2015 at 3:22 pm - Reply

          Naw…I recognize it’s totally unreliable…just hope it happens

          • CRW December 10, 2015 at 3:55 pm - Reply

            We will probably know for sure a day or two before the snow actually happens.

  15. terry mercer December 10, 2015 at 12:30 pm - Reply

    Gary are any of the models showing when the Arctic cold or cold air coming in middle of next week?

  16. Morgan December 10, 2015 at 2:24 pm - Reply

    Models two weeks ago were showing this warmth. So yes, we can put some stock into long range model projections, given the persistently warm pattern we’re in. Transient cold shots that last three or four days is what we’ll have to live with this year. Let’s hope it’s stormy when that happens.

    • heat miser December 10, 2015 at 3:23 pm - Reply

      Just because it showed warmth two week prior doesn’t mean there is a correlation to accuracy…it’s just as often wrong about that

  17. Mr. Pete December 10, 2015 at 3:05 pm - Reply

    No arctic air for the middle of next week from what I see.

    • Heat Miser December 10, 2015 at 3:26 pm - Reply

      Yeah, I think going out a week is as risky as we can even realistically contemplate with the model runs…going out to two weeks is pretty much just taro cards and crystal balls

  18. terry mercer December 10, 2015 at 3:29 pm - Reply

    From Gary dated December 8th blog A big change in the next 5 days. So the models are going to go back and forth until at least Sunday so the models will not be consistent on what they are predicting as of right now.

    • Dale December 10, 2015 at 4:16 pm - Reply

      Lol that’s four days ago. A ton of things change in four days.

      • Alice December 10, 2015 at 6:08 pm - Reply

        Dale,
        That was 2 days ago, not 4.

  19. f00dl3 December 10, 2015 at 4:32 pm - Reply

    Hate to say this but I think it’s safe to say that Gary’s first inch of snow date (16th) and his 90% chance of us getting our first inch of snow by Christmas are both wrong. I think right now it’s more likely we will have a tornado before Christmas than snow.

    • Rockdoc December 10, 2015 at 4:44 pm - Reply

      You do mean a “tornado blizzard” don’t you, or is that “blizzard tornado”❄?❄

  20. terry mercer December 10, 2015 at 4:37 pm - Reply

    Wrong Dale and that was not four days again. This is the second day.

  21. stl78 December 10, 2015 at 5:37 pm - Reply

    Crickets after the 18z, hmmmm. Relax terry, it’s just one run.

    • terry mercer December 10, 2015 at 5:55 pm - Reply

      Yeah but it the same way they take one run and run with that. I’m right about that?

  22. Dale December 10, 2015 at 5:44 pm - Reply

    I sense backpedaling from Gary. He seemed very sensitive about the anchor claiming he said it would snow before Christmas. He said we were in a warm pattern…oops! That almost guaranteed snow seems to be going away with each model run.

    • Gary December 10, 2015 at 5:48 pm - Reply

      No, I wasn’t backpedaling at all. The anchors like to put words in my mouth when they should just ask questions. They shouldn’t start by saying, “Gary you guaranteed snow before Christmas”. When that never came out of my mouth. Now, I did say there is an 80% chance that the snowflake contest ends by Christmas, but I never used the word “guarantee”. Seriously though, I love those two anchors and really don’t mind it. As long as it’s real and genuine. I am just myself out there. If that is what she is thinking, then I don’t really mind if she says it.

      Now, onto the snow chances. Everyone needs to take a deep breath. First of all, there is nothing we can do. Secondly, this is rather obviously a warm pattern. And, thirdly, the NAM model still has the changeover to snow Sunday evening. It could really be close even though we obviously have the chance at 20% right now.

      Gary

    • Alice December 10, 2015 at 6:21 pm - Reply

      That is why I picked Feb 6 for our first inch. With the “don’t jump to conclusions” warm pattern that we have been in since the new LRC started forming.
      And we have been in the warm pattern most of the time since.
      I thought about Dec and Jan typically not being snowy months, but we have had some big snows in February.
      I know I am probably wrong, and the first inch will probably happen long before Feb 6, but I think most of the (KSHB forecast of 23 inches ) will happen after the middle of January.

  23. stl78 December 10, 2015 at 6:09 pm - Reply

    That was the first time I looked at the nam…..interesting

  24. Rockdoc December 10, 2015 at 6:12 pm - Reply

    Good Evening Gary. As you had indicated earlier, the storm system is just now approaching the west coast. The way I see these systems, and I believe you had mentioned this, is that until they are over land and weather measurements can be taken and fed into the models, the models have a hard time projecting forward. Especially with the “buckling” of the jet stream, and development and shifting of the surface lows can be a pain in the rear. This being said, I’m impressed that these models can take into account all of the data parameters and model in 3D since our atmosphere is 3 dimensional. Pretty neat computationally! They actually do quite well at times depending on the complexity of the various systems rolling our way. But models are not perfect, and that is why we need professional mets, like you and the weather gang, to get into the weeds so an accurate forecast is made.

    Cheers, and have a nice evening.

    Rock

  25. Bill in Lawrence December 10, 2015 at 6:14 pm - Reply

    Gary:

    Good evening to you sir!!!!

    Thanks so much for the kind response above….I have always so enjoyed this blog…always enjoyed how you take time to teach and explain things…it is awesome!!!! 🙂

    Well…that didn’t take long did it…flipped in two runs!! As I said this morning….with the GFS running four times a day I would not be surprised to see 6-7 runs between now and Sunday with us in the 50’s for mid to late next week. I would not expect a consistent performance until at least Sunday…maybe 12Z Sunday but probably 0z Sunday.

    I am still sticking with my thoughts from this morning in thinking that the 0Z last night had the correct ideas going into the next 7-10 days. It may well have been wrong in the details but correct in the overall pattern recognition.

    I fully understand how many would think that I am just wish-casting with all of this and I would not blame you at all if you do. Let’s face it…this is an extremely overall very warm LRC so logic would dictate that to bet on a warmer solution is the way to go. However, there are times in this LRC when cold air can make it in here….maybe even arctic cold. There are 3-4 instances where the AO dips to negative/neutral for a day or two and there is the one instance at the beginning of the cycle where it dips fully negative and stays there for 3-4 days and then rockets back up. That is what I believe we are seeing mid to late next week into Christmas and I think the models are going to have a very hard time locking onto it until it is right on top of us.

    So, as hard as it is with the models and even the overall LRC barking warm warm, I stick to my have baked idea that next week is one of the best overall windows for us to have winter weather-the idea that even in this warm LRC there are moments and that this is one of them. Of course I could be way off on all of this and be totally wrong in which case the crow will taste wonderful!!!

    Have a great night everyone..

    Bill in Lawrence

    • Rockdoc December 10, 2015 at 8:47 pm - Reply

      Uncle Bill, hope you don’t mind me calling you that. Any links for monitoring the AO and NAO? Sources please. Hope all is going well there in Lawrence.

      • Bill in Lawrence December 10, 2015 at 10:11 pm - Reply

        Rockdoc:

        Google CPC AO and that should take you to the pag and Gary has posted it in the blog entry. You can also access the NAO and PNA from that site. I have always thought that the PNA is another good indicator. These sites will also give you acess to data of each index going all the way back to the 1950’s.

        It is interesting to look at the archived data. I keep thinking of 1989 and how positive the AO was for most of November which translated into an incredibly warm month and even into first wek or so of December….and then the AO tanked. I need to look at October but I would guess that there would be a negative drop in that month which then cycled back through in December and brought about the record cold. Only cycle 2 really produced that winter accept for a freak March snow in Lawrence right before Spring Break.

        Okay…enough from me!!! LOL

        Have a great evening…

        Bill in Lawrence

        • Rockdoc December 11, 2015 at 7:30 am - Reply

          Thanks?

  26. Alice December 10, 2015 at 7:57 pm - Reply

    https://www.ncdc.noaa.gov/news/historical-probability-of-white-christmas

    It’s better living here, where there is at least a small chance of a white Christmas, than living someplace where there is no chance. Been there, done that. Living in Hawaii for 3 yrs, then Guam was nice, but I missed the 4 seasons ! Any chance is better than no chance

  27. Dale December 10, 2015 at 8:49 pm - Reply

    00z NAM shows no snow for our area.

    • Gary December 10, 2015 at 9:23 pm - Reply

      The NAM, if it’s right, had almost no rain. I say it’s wrong. The NAM has these horrible runs at times.

      Gary

  28. Mr. Pete December 10, 2015 at 9:08 pm - Reply

    I really do think that all of this snow will verify in one whopper in February.

  29. rickmckc December 10, 2015 at 10:07 pm - Reply

    What a gorgeous December day. Played golf this afternoon and it felt like mid-October. I love El-Nino!

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