Tuesday, January 16, 2018

Unlikely Possibilities?

A shocking Vikings victory has the local populace thinking all things are possible. Might this include a significant snowstorm for championship weekend?

93 comments:

  1. 6-10 inches of snow is looking quite likely over the upper Midwest. Now the real question is did the Vikings break the curse for sports and weather!??

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  2. As a few people already pointed out on the previous post, being in the core of the heavy snow shield 5 days out has not been, traditionally, a good sign for the Twin Cities.
    However what seems slightly different this time is that it is the Euro that says it and not so much the GFS that was well to the south until this morning's runs.
    I don't seem to recall that for those recent storms BOTH models had the Metro in the heavy snow zone.
    I am still skeptical. I am also skeptical of that fact that this storm follows warm air Wed-Fri and so I am afraid that if it comes north enough we may have precip-type issues. And as much as I love snow I'd rather be high and dry rather than having a mix in January.

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  3. 12Z GFS upped the ante now paints the metro in the 12+" category. I will just chalk this up to its-way-too-soon-to-get-excited category.

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    1. Seems like a fair viewpoint. Liking some trends though with this. As long as the split flow doesn't kill us again and pull this weaker and south.

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  4. Where do you go to see all of the models?

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    1. tropicaltidbits.com or pivotalweather.com

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  5. A lot of talk and shifting models, some showing a bunch of snow, but Novak is eerily quiet everywhere! Surprising!

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  6. Those of you who saw my post on the previous thread early on the morning of the 13th, might have seen me say the trough presentation for this storm looked better and that there was a 2 in 10 chance that this storm would develop.

    A couple of times this year in 5 to 7 day period the model QPF output looked promising, but in reality it wasn't supported by what was going on aloft. That is not the case this time as we finally have the models showing a closed low from H5 down to the surface ejecting out most of the energy in one piece. In addition it looks like the lower level jet may just tap into the western gulf soon enough for the system to ingest some gulf moisture.

    Looking to east there appears to be a strong sub tropical ridge in place over the SE US, which will block this system from taking the southern route and cutting up the east coast.

    One thing that bothers me at this point is that the trough really doesn't take on much of a negative tilt as shown by the models, which would indicate even a stronger system. Given the strength of the sub tropical ridge and the system ingesting some western gulf moisture, I think the models are incorrect in depicting a neutral tilt to the trough and will eventually start ejecting it out with a negative tilt.

    Time will tell where the heaviest bands of snow will set up, it now looks like this system has a 3 or 4 chance in 10 of developing into a major winter storm somewhere in the Upper Mississippi Valley.

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  7. Plymouth Weather LoverJanuary 16, 2018 at 9:48 PM

    I like randyinchamplin's posts as they relate to the x number in 10 chances. Seems more more accurate that the NWS saying snow likely one forecast and then changing it to 50% chance of snow the next forecast (12 hours later) and then back to likely, etc. Randy is onto something there. I also like his thorough analysis of storms. Thanks for adding this to the conversation. Would LOVE to hear from Novak. We are about 4-5 days out. Time for a video including what the positives are and what flies are in the ointment. In the meantime, I am dancing and prancing. Bring it!!!

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    1. Plymouth Weather Lover:

      The flies in ointment are there in my post. 1.) Will the trough close off? I give that about a 6 in 10 chance at this time. 2.) Will the SE ridge be strong enough? I would give that about a 7 in 10 chance that it will. 3.) Will there be enough of a moisture feed from the GOM? Its really close at this time, call it at best a 4 in 10 chance. 4.) Can we avoid a split flow and establish a full latitude trough from the northern border to the GOM in time at the H5 Level? Currently it looks like by 12z Sunday we will still be seeing a split flow, transitioning towards a full latitude trough at 0z Monday and completing the transition by 12z Monday. I would give that chance happening no better than 4 in 10 based on this years pattern.

      So that's how I get to the three in four chance that a major storm will hit the Upper Mississippi Valley. Points 3 and 4 are critical for the heaviest snows to effect the metro, will they happen soon enough? Current thinking is about a 2 in 10 chance of that happening, although I think there is 3 or 4 out of a 10 chance that the metro could see warning criteria snowfall.



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  8. Can someone explain negative tilt of the trough?
    Is it the opposite of what I, in my rather meager knowledge, call a ‘progressive’ storm, one the pushes through rather than spinning up.

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    1. http://www.theweatherprediction.com/habyhints/127/

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    2. a neutral trough is one that essentially orientated straight up and down from the northern border to the GOM. Hope that helps you to envision it.

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  9. NWS has "snow likely" for Sunday night. Two Sundays in a row, Vikings and snow, nice combination!

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  10. The latest 06z GFS continues to paint 10-12"+ in and around the metro with totals exceeding 18" just south and east into Winsconsin for Sunday into Monday. If we just get half of this it will easily be the largest snowstorm of this winter season! Hang in there snowlovers we all know a lot can and will change with this but we are now inside of the 108hr window, safe to say a storm is coming question is where will the heaviest snow fall?

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    1. When would we expect the air mass to be "onshore" and picked up by the models? The Friday 12z run?

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    2. Well the front of the system will be coming onshore tonight and won't be fully onshore till Friday, so yeah probably the 12z run.

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  11. I think actually this storm will end up going to our west instead of south leaving the Metro with ice and rain.

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  12. paging Dr Novak, paging Dr. Novak

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  13. 12z model runs going hog wild:
    GFS now puts heaviest snow thru metro 12-20"
    Canadian Gem puts down 8-12" for metro and a ridiculous 24-36" snows for central MN.
    What is going on? Bill can we request a video please.

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    1. We're at that crucial 4-5 day range in which if a storm is forecast to hit the metro, it will shift and diminish in short order.

      Let's see if that happens this time.

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    2. We may do a video tomorrow... stay tuned.

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  14. What's happening is that as always models (especially the GFS) tend to overestimate qpf. And so you should divide by 2.5 as Paul Douglas always recommends. Which would mean on current mean tracks 4-7 inches for the core metro.
    However, it is also certain that the track will change because it always does so from 5 days out, otherwise we would have 100% correct forecasts 5 days out which we do not with our current technology and models.
    The question is will it shift more to the NW? to the SE? or totally disintegrate?
    It looks like upper level dynamics are more favorable for the storm to stay together, but the absence of arctic air both before and after make me believe that we are in for a suprise. Neutral to even positive tilted trough which will make it track more to the nw.
    I agree with anon@10.09am. It will go Nw of the metro which means rain and ice for most of the event with the usual paltry half an inch at the back end.

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  15. Anon:

    With all due respect, a positive tilt of the trough would allow the storm to pass to the se of us. A more negative trough would be pulled to the NW.

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    1. you're correct. I stand corrected... I realized that a few seconds after writing
      but aside that I do believe this storm will be pulled more to the NW.

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  16. This system to me is taking on the characteristics of an "panhandle hooker" which if you know the tracks of these they usually move from the Texas/Oklahoma panhandle area north-northeast thru NE Iowa and thru the heart of Wisconsin.....classic snow dump track for the metro area, yes maybe initially a mix of rain/sleet/snow maybe realized in the begin due to temps at or just above freezing but with a track like that cold enough air(20's) will be drawn south for this to be a mostly all snow event. Also the storm seems to be slowing and deepening in its approach to the upper Midwest which could lead to blizzard criteria conditions being met somewhere in the CWA and with a slower moving storm the duration of snowfall will be longer which could lead to the large numbers. This will be a fun one to track and watch over the coming days, at the moment I'm going to say the core metro(which I know the most of us cares about) has a 60/40 chance of at least seeing 4+". Stay tuned and stay positive snowlovers!

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  17. I'm really tempted to run up the chances of a major winter storm effecting the Upper Mississippi Valley region to a 6 in 10 chance, however I will hold off until this evening model runs start coming in.

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  18. Novak sent a tweet/FB posting out about this potential storm earlier today. Dave Dahl mentioned the potential of a snow storm Sunday on the 6 PM news, but didn’t really get into it. Dahl showed a 70% chance of snow Sunday - no totals.

    If the models nail this thing this far out it would be amazing. Interesting numbers the NWS put up. MSP 15” below normal for snow this year, Eau Claire 5.6 below and St. Cloud 7.6 below.

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  19. I really REALLY like the jet structure with this storm Sunday & Monday. Plus, model consensus is there. All medium range guidances agree that a classic 'S' structure will evolve with impressive lift in the Upper Midwest. However, there are some red flags:
    - With such a strong & deep trough, will too much warm air be advected into so. MN?
    - Where is the Arctic air? It is lifting out of our area as I type.
    - Dry slot. I would expect a large tongue of dry air at mid-levels to surge towards MN/WI on Monday.

    Regardless, this storm looks impressive & it should not have any problem accessing Gulf moisture. If the Arctic air more stubborn than expected, that will mean trouble for much of MN/WI.

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  20. Frustrated Snow LoverJanuary 18, 2018 at 6:42 AM

    There is less good news this morning for snow lovers. The dreaded "R" word (RAIN) is starting to be used by many forecasters. Please don't tell me that after all of this arctic air and after all of these storms shifting south, this storm is going to go north and RAIN on the metro!! NO!!!!

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    1. Don't lose hope! This is an excerpt from the LaCrosse NWS this morning: "This storm system is still in its infancy in the Gulf of Alaska and much could change. Better data sampling for model should take place Friday as the system makes landfall over CA. Will continue to monitor the evolution of this system and potential impacts on our region."

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    2. This will NOT be a rain event for the metro, sure it can rain some Sunday evening when precip first starts but this will be a mostly snow event as depicted by the NWS with snow likely all of Sunday night and all day Monday. As mentioned by Novak we need to keep an eye on the dry tongue that can screw up a good snowstorm

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  21. I hate to be that guy, but models have sucked it up for amounts and placement of snow unless you're looking 6 hours before the storm. Sure, they might have a general idea that there might be some precipitation around the area, but it's irresponsible to be dancing and hopping around this early in the game.

    Someone said before it's all about the public perception. The public perception is that meteorologists have completely struck out predicting snow this year. They'd be wise to wait a bit before betting the house on the storm and being off by 9 inches.

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  22. I don't think it matters much what forecasters say 4 days in advance because 'much can of course change" and so it is just informed guessing at best.
    What matters is how the weather actually works:
    We know that in this new pattern we've been for the past few years for any storm from the SW strong enough to bring its precip shield to the core metro it is also warm enough to bring mostly rain.
    So I disagree with bigdaddy and others.
    It WILL be a mostly RAIN event for the metro.
    Watch as the models lift the surface track more and more to NW of us.
    Believe me: seen this, done that. Several times.
    This is a classic scenario.

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  23. It’s sll guessing and needless conflict until Sunday Morning. Meanwhile I will pop the popcorn and have fun watching you “experts” argue! Fun times.

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  24. One thing that's been consistent, regardless where the heavy snow ends up is the coverage of 6+" of snow. It looks to be 150-200 miles wide so, it appears we won't be dealing with the dreaded "sharp gradient"

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  25. 06z GFS: 8-12" metro wide

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  26. Plymouth Weather LoverJanuary 18, 2018 at 10:16 AM

    Anon @8:37: I usually don't respond to anonymous posts, but this one got me wondering a question. If you are being critical of what the mets are saying and the speculation that comes with predicting snow and amounts, that how can you possibly say that "It WILL be a mostly RAIN event for the metro"? What are you basing that one? And aren't you simply a victim of your own criticism? Maybe I am missing something here so if there is are response that can help me understand better, than Bring It.

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    1. I had a professor in college who would say, after we made a comment during class discussion, "What's your evidence?" I think the same applies here: if contributors want to critique another's forecast/prediction, please present your supporting evidence (and evidence does not equate to anecdotes or opinions; meteorology is a science, after all).

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    2. Tight gradients across the metro area (which is huge, granted) with a majority of storms in recent memory would seem to be supporting evidence of a strong pattern.

      Or is that anecdotal?

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    3. I've called those posts out for years, now I just cruise right past them because they provide zero insight. It's just a nobody "knowing" when they have no clue.

      There was one a couple years ago that KNEW MSP would only get 1.3" (or thereabouts) on some system. We ended up with 6" and they were nowhere to be found...

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  27. Anon@8:37 in response to PWLJanuary 18, 2018 at 10:47 AM

    @PWL and @DirtyC
    I do not believe I am necessarily criticizing forecasters as they would be the first to agree with my statement that 4 days out "much can and will certainly change". We do not have the technology to predict the weather with 100% accuracy 4 days ahead, and that's fine. Maybe in 50 years we will, who knows.
    My point, and my evidence comes from a different philosophy about trying and predict the weather, which makes me confident in saying that this will be a mostly rain event for the metro.
    My approach is based on pattern and what happened in the recent past in similar situation. I am a very strong believer that the most accurate law of meteorology is 'repetition' and what happened in the past has a higher chance of happening again in the future.
    And since most (if not all) of the recent Panhandle Hooker type storms have resulted in too much warm air being drawn north to make the event mostly rain for the core metro, I believe this is what is going to happen this time.
    In the eye of professional mets forecaster it may sound unscientific, but there is actually a lot of evidence that meteorology actually does follow the law of consistency and repetition.
    Personally I go the WPC and CPC pages and look at past analogs rather than the latest runs of the GPS/ECMWF etc..
    That's just my opinion, I stand by it, and more than happy to respect the opinions of those who disagree.
    After all, this is a blog about weather forecasting and I am giving my forecast based on an approach that I feel confident about.

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    1. I agree somewhat with this post. There appears to be no doubt that recent trends suggest that more warmer air is drawn into storms that dig into the central U.S. It could be just a blip on our radar screen or it could be the normal due to climate change. Regardless, I would not be at all surprised to see this storm send a wealth of warm/moist air north into southern MN. It seems that surface low pressure centers are tracking further north than usual too, especially when considering it is JAN for God's sake.

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  28. Speaking of analogues (which is a good approach in my opinion) the current top analogue is 01/4/1997 which mostly slammed West Central and Central MN (28" in Brown Valley; 21" Alexandria). MSP reported 4" in that storm.
    We'll see if things change...

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  29. In the snowlovers won't be happy department, both the GFS and Canadian models shifted the axis of heavy snow north of MSP with MSP getting only 2-4". Trend or model inconsistenty

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  30. Euro 12Z still shows heavy snow over the MSP area keeping rain near or south of Rochester. A setup I hope comes true because those totals its showing is gold!

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  31. New top analogue out of 12zruns is now Febraury 11th, 2013.
    That day MSP had a high of 35, with a rain to snow event which totaled around 3".
    NW Minnesota was in the bull-eye.
    I start to believe this will be a 3-4 inch storm for the core metro.

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  32. Good. Not having the metro in the bulls-eye 3-4 days before is a good sign.
    Since the models will inevitably shift (and usually south) maybe the metro will be in the heavy snow by Monday.

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  33. Models are not reliable guys. Keep this in mind.
    The 12z GFS has a temp of 33 for MSP at 3pm.
    It's going to be 40 or even higher.
    And we want to go 4 days out?
    Come on man!

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    1. Shut your face! Let it snow! Dilly Dilly!

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  34. Here's another factor. Thunderstorms are now showing on the NAM for Missouri and Arkansas. If these indeed form, would it not draw energy and moisture out of the storm for Minnesota?

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    1. Quite sure that was already thought of, ever since I saw the storm and because the system is riding on a negative tilt. There is usually thunderstorms associated with it, but I don't think it will be enough to rob all of the moisture.

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  35. Programming note: planning to do a video this evening with Dr. Novak.

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  36. I fully expect Winter Storm Watches out for the entire CWA sometime tomorrow. This storm is a beast and will be very impactful!

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  37. Here you go kids! https://www.youtube.com/watch?v=wrZg1BuN7aE

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  38. Nice video. I didn’t pay for the Euro this year so it was interesting to see what it is predicting vs the GFS. I’m guessing around this time tomorrow we will have a much better idea of where this may ultimately track.

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  39. Wow... GFS just took a HUGE shift south! So right in line with Euro. Big time snow MSP now?

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  40. Thank you for the video, and go Euro!

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  41. Thanks for the video guys nice job as usual.

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  42. I'm going with a 6 and 10 chance that a major snow storm will impact the Upper Mississippi Valley region(at this time). I almost pulled the trigger and went with 8 or 9, but will hold off at this time.

    However I will go with a 4 in 10 chance that the heaviest snow bands will effect the metro area, as a matter of fact I almost went with a 3 in 10 chance.

    I'm still very concerned that this trough does not go negative at 500mb soon enough to pull the surface low to the NW. As a matter of fact I have seen this happen many times during the severe season. The result is that surface low moves to fast to the east or south and out runs it's upper air support.

    There is a new global model develop by the Germans that has a much higher resolution (on the order of 7km vs the Euro/GFS that I believe is around 13km) that depicts this quite well. It can be seen on Tropical Tidbits under the global tag labeled ICON. The 01/19 0z run is the second in a row that moves the surface low from near the Quad Cities to Chicago area, this would put Albert Lea to Wabasha to south of Eau Claire in the heaviest snow bands.

    This will be fun to track for sure.

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  43. The 01/19 0z run of the Euro is in and it makes 2 out of the last 3 runs that it has taken the storm to the south and east, that couples nicely with the last two runs of the German model. Plus the GEM and GFS made a significant move to the SE as well with 01/19 0z runs moving the snow bands from NW of the Metro to the core of the Metro. The evidence is leading me to believe that a SE shift is in the cards for those models as well.

    At this time I will stick to 4 in 10 chance that heaviest snow bands will impact the metro.

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  44. Now this is fun. Just as Novak pushes his chips in on the Euro (after prodding from Bill)the GFS shifts very close to the Euro the NWS has also posted a Winter Storm Watch for a fairly narrow band. They appear to be buying into the Euro (I haven’t read their latest explanation yet).

    I wish they would have held off on that a little longer since this is looking more Monday than Sunday night and it will be all about enough cold air. We’ve just seen too many changes once these storms are monitored onshore.

    Early NWS snow total is 5-8. Rant keep up the posts - I am enjoying them.

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  45. Well, game on!....As alluded to last night Winter Storm Watches are up for the metro. NWS is going with a general 5-8" in the watch area, but when reading the discussion some places could exceed a foot.But also when reading the discussion I feel there can be a big boom or bust potential even with those areas under a watch because they mention the snow will come in 2 waves and if your not under one of them I could see a bust. Anyway as a snowlover I'm hoping for the best, should be an interesting 96 hours...the first 48 hours tracking any changes to the going forecast and the second 48 hours seeing what the storm actually does.

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  46. I believe it is safe to say that northern MN escapes this snow system. Draw a line from Red Wood Falls to STC to DLH, this will be the northern extent of snow. I'm relatively confident that the surface low will track a touch further south than what model guidance was expecting. We should see this slight shift with future runs.

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  47. 06Z NAM: 6-10" metro

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  48. The southern shift has just begun, as usual.
    Heavy Snow will be pushed out of the metro by tomorrow, exactly as it happened with the last 'storm'.

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    1. There is certainly potential for this & it is No doubt a concern. However, guidance (esp. the Euro) has been amazingly consistent with placing the deformation snow band from MSP to RST. This should be the corridor of heaviest snows, including the southern MSP metro.

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    2. Also note that with the last storm, the models shifted the snow out of the metro, but we still ended up with the same amount of snow as Rochester (which the models had getting much more snow).

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  49. Not liking the looks of this at all. If models continue this south trend I will get screwed yet again and Rochester will steal another one. Same story, different day.

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  50. Come on guys. I understand snow lovers' frustration but we all knew that this was going to happen sooner or later because it always does.
    I guess what will make it particularly bad this time is that the shift occurred slightly closer to the event, when it seemed it was holding this time.
    As soon as I saw the NWS pulled the trigger with WS Watch I know the metro's fate is sealed.
    They kind of jinx it all the time...

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    1. Yes. Southward trend, with a bump to the north about a day or 12 hours before the storm to give us hope, then back to the south.

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  51. The south trend has began, same ol song and dance, it will continue south till MSP picks up its token 1", SAD(ala Trumpism)

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  52. Latest Euro for reference -

    https://www.dropbox.com/s/gm82yiz0c7khb36/Screen%20Shot%202018-01-19%20at%209.25.11%20AM.png?dl=0

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  53. Latest 12Z NAM says screw that southern shift, holds steady over MSP and doubles down on snow forecast...calling for 12-18" metro wide!!

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    1. Except the NAM is well-known for biasing to the NW and has been abysmal the last 2 years.
      On the last storm it had 8 inches of snow for MSP the night before and we all know how it ended up: 2.4".
      So I am not sure I would put any faith in it.

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    2. Just telling you what I see, I have no faith in any one model.
      Now 12Z GFS holds steady as well core of heavy snow runs through the metro ....10-16".

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  54. The Euro still paints around 7-8 through the core metro. Yes, less in the north metro, but I'd take this any day if it were to hold.

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  55. GFS and NAM both painting 12+ over metro core.

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  56. Reserving judgement until sampling finally starts on this thing; probably a bit on 00Z and for sure by the 12Z suite tomorrow. At this juncture consistency is our friend.

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  57. One thing I have seen in a while is the plotted forecast positions of the low pressure center. I always enjoyed looking at that.

    Can someone show me where to find it?

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  58. 12Z GFS coming down. Holding.

    https://www.dropbox.com/s/4wx9o42vb09l3nt/Screen%20Shot%202018-01-19%20at%2010.04.49%20AM.png?dl=0

    back to work now.

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  59. The 12Z Euro does take the Low through north Missouri / Southern Iowa right through Chicago. That looks farther south than the 0Z run. Thoughts?

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  60. The real Paul Douglas tweeted the Euro move south. I think it was a retweet from Bill. GFS isn’t budging and that makes it interesting. Last winter the GFS seemed more reliable than the Euro.

    Euro takes snow totals down since the storm would cross warmer air.

    As we all have been saying, need this thing on shore. I want to see the first GFS after that happens.

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  61. First model runs worth watching are tonights 00Z runs.

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  62. Looking at the 00Z GFS and it has shifted it slightly north with the bullseye on the Twin Cities. NWS point forecast for Eden Prairie is now 5-11”. If the Euro shifts north we may actually have our first real snow storm. Looks to be a fairly long storm.

    Plymouth and Novak where are you?

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  63. Just waiting for the models to jump south like usual.

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    1. And there you have it! Bye. bye storm.

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  64. Not looking good for snow lovers in the core metro and north...as usual!

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  65. One model run and one bump south...and bring on the "I told you so" butt-hurt Anonymous posters! If we had an inch of snow for every one of them, the snow lovers would jump their sleds on the drifts!

    Bring it!

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