Friday, January 19, 2018

Probabilistic Thinking

As some of you know, I'm a big fan of probabilistic forecasting and the work of the Capital Weather Gang when it comes to snow forecasts. Here are the high, low and expected snowfall forecasts for MSP as of Friday morning for the Sunday/Monday event.





Did you miss our last video with Novak Weather?

Happy storm track monitoring!


201 comments:

  1. It's basically 2-12", I don't like it. But too each its own.

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    1. But that's the reality of probability. The Vikings had a 2% chance of winning the game with 10 seconds to go. If you have the mindset of ignoring probability, then you are saying we should declare it a loss before the game ends. Weather isn't exact; there is no crystal ball. I like the probability. It tells me "you'll need a shovel, there's a good chance you may see delays and have to trudge through a mess, and there's a small chance this thing will be big enough to cause cancellations." What more can people realistically expect 3 days out?

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  2. 12z Canadian: 8-12" metro, all models holding tight with their 12z runs

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    1. Not all models! In the " I told you so department" the 12z EURO shifted so far south that the metro is barely 1-3" now. Before long MSP will be lucky to pick up an 1" with this thing. Sorry snowlovers, but it was bound to happen, MSP's snow climate has changed the sooner you realize that the less disappointed you will become.

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    2. Exactly right.
      I cannot understand how people can still really believe that MSP can get heavy snow ever again.

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  3. So a downgrade from that winter storm watch should be coming soon, that's a HUGE shift south on EURO.

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  4. Something we should keep in mind is I don't think Euro is the best when it comes toward accounting for the warmth in this system. Something NAM does very well, and that warmth I think will push the low further north than what Euro is showing.

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  5. NWS has expanded the watch south. Things starting to shape up like usual.

    Come on, snow gods! Throw us a bone here. Unless, of course, all of your power is currently being re-routed through the football gods. Then by all means, proceed.

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  6. 3-5 Sunday night, 5-9 Monday via NWS forecast for here in Red Wing.

    8-14. Haven't exceeded a foot since the May of 2013(?) storm buried us under ~18 inches.

    We'll see what happens.

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  7. True that, but (for Bill’s reference) the most likely snowfall for the metro has been increased from 8 to 9 inches.
    And this was after they saw the 12z euro shift south.
    Everything of course can change, but I find that interesting...

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    1. I don't think the NWS are taking Euro into consideration as much for two reasons. The warm air that will associated with this storm plus where is the cold air to suppress the system further south? That's right there isn't, so I would be very surprised to see Euro continue to advertise the heavy snow in the far south east part of the state.

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  8. Could it be the 18Z NAM and GFS are holding steady with the heaviest snow over the metro? Do the 6Z and 18Z runs have significant input into the forecast this far out? 0Z's for these models should be interesting. I assume the "Low" will be on-shore. DK... Thoughts?

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    1. My last line should have been.... "IDK... Thoughts" - Sorry

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  9. Nws will use a blend at this range of models. And the warm air comment really makes no sense because its all about the track and strength of the storm to draw that warm air in. Euro is more south and weaker then the other guidance therefore the band is more south and cooler. The euro has support in this area with the ukmet, mpas and withen its own ensamble system

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  10. 18Z American models still holding strong over the metro:
    NAM 12-16"
    GFS 8-12"

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  11. Does anyone notice the NWS forecast is off....the current forecast for most of Wright county is 6-8" on the probabilistic map but they are not in the watch area. I just feel there is not a lot of confidence behind the watch area, the metro is on the western most edge, easily dropped if models go south.

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    1. Low was pushed south on the 0Z run but the band of snow didn't really move much, and WOW those totals from NAM 12K are stupid... like actually stupid.

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  12. Plymouth Weather LoverJanuary 19, 2018 at 9:14 PM

    What are the stupid NAM totals? I want to know. Bring It!

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    1. 28 inches of snow for MSP.....

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    2. That would rival the Halloween Blizzard!!! Trapped for days.

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  13. So the 00z NAM...um WOW just WOW....cant be true can it?!?!
    18-24" for the entire metro! Something tells me that's a blip

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    1. Keep in mind that change happened when the system came on shore too! and the ICON model from what Randy said which is based off of Euro has been trending north throughout the day and now includes the whole metro with heavy snow!

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  14. 0Z GFS is coming down now

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    1. Am I reading the new 0z GFS correctly? Track further north? Heaviest snow cuts off through the southern metro. Core metro on north in on the heavy stuff.

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    2. The low is tracking further south but I assume the upper levels are pushing the moisture further north to compensate, and no the cut off looks to be around the Rochester area.

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    3. Interesting. What source do you use to track the low? Do you mind sharing?

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    4. tropicaltidbits

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  15. NWS point forecast is 5-11” for Eden Prairie. Remains a long storm but looks like it may finally be the real deal. Would expect warnings to come out tomorrow.

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  16. Running my chances for a major winter storm to impact the Upper Mississippi Valley up to a 9 in 10 chance now that the system has been better sampled.

    For the metro area getting into the higher snow bands time to get more aggressive as well. Looking like a solid 6 in 10 chance.

    The evidence is now getting stronger. Yes the surface low seems to be tracking a bit further south, but almost all models from 500mb on down are showing a very strong area of vorticity along or north of the I90 corridor, indicating spin in the atmosphere. Often times heavier snowfall can occur just north of the area of highest vorticity values. With the counter clock wise rotation of the surface low, its likely to throw precipitation back into the trailing stacked mid level storm.

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  17. Even the UKMET is strongly hinting at the heaviest snow bands setting up over the se metro area.

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  18. Euro is starting to shift north with the 0Z run. I do think it may be a little too far south still with the band by just a little bit. But at least we know that the chance of significant snow for the metro is increasing.

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  19. The lastest Canadian GEM model(00z) supports the NAM, it has 16-20" as a bullseye right over MSP. I don't know what to think anymore, we are roughly 36 hours from first flakes and to think the models are showing a storm of this magnitude is insane. I feel like something is a miss the core metro always seems like it misses out on big storms,I hope I'm wrong....I wont be the pessimist though so come on Mother Nature give us everything you got.

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  20. Latest 06z models for the core MSP:
    -GFS...10-15"
    -NAM...12-18"
    -CMC(00Z)....16-20"
    Yet admittedly the NWS in their discussion say they are being conservative and have 6-10" for those in the watch area. I believe they are gun shy with so many near misses and metro busts over the last few years that they are taking this conservative approach. We'll see what happens

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  21. What a frustrating season so far and what a waste of cold air. I looked outside this morning and saw lots of bare spots on the ground (western burbs). Given our dearth of snow this season, these mini warmups really take a toll on our snow cover. It's next to impossible to build a decent snow pack, because what little we have gets significantly erased by 3-4 days in the 40's.

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    1. It looks like we have another 40 degree day on the way today, and maybe a couple more next week. If we don't get any real snow from this storm, it is going to look pretty bare around here real soon.

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    2. Relax yourselves only one 40 coming late next week and that's if your backyard doesn't get 8-12". Colder teens again after next weekend and the ECMWF weeklies shows arctic air again in the first week of February. But nobody really wants arctic air just cold enough air to let it snow like this Monday.

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  22. 12Z model update:
    GFS 8-12" for core metro
    NAM 14-16" for core metro
    For two days now the NAM has been consistent, this can't be disregarded, but let your guard down on the higher totals. This storm will have some surprises on the high side I believe.

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    1. Last Euro report from PD keeps the heaviest snow in far south metro, around 5-8 for the core.

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    2. Thats encouraging. The 1/20 0Z Euro is further north than the 1/19 12Z Euro. 1/20 12Z due out in about an hour or so.

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    3. I'll clarify - The setup for snow is further north. The track of the low is a different story.

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  23. Plymouth Weather LoverJanuary 20, 2018 at 11:04 AM

    Hey Dr. Novak -- Truly waiting on pins and needles for your snow totals forecast map. I know you like to wait until about 36-48 hours out and here we are. Bring it!!

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  24. You guys be the judge.

    I know there is life outside of the metro, but for the sake of this comparison lets use the heart of Ramsey / Hennepin Counties:

    https://www.dropbox.com/s/5miyep4sjinozpa/Screen%20Shot%202018-01-20%20at%2011.01.24%20AM.png?dl=0

    Last two Euro Runs - Same time period (through 0Z Wednesday 1/24)
    -Left Image: 1/19 12Z = 2-4 inches maybe.
    -Right Image: 1/20 0Z = 6-10 inches maybe.

    lets see what the 12Z has in store for us. Let the back yard forecasting commence.

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  25. Plymouth Weather LoverJanuary 20, 2018 at 11:15 AM

    I love this page on the NWS weather site. It kind of relates to Bill's points in the lead-in to this thread. I am sure you have all looked at it, but it is interesting as it puts percentages on how likely certain amounts of snow are based on greater than a certain number of inches. On this site (as of the last update at 6:00 am), it has the Twin Cities as a better than 50% chance of getting 8 inches or more. What is interesting is that the largest percentage to get 18 inches or more is right over the metro. It is a small number but not that small. However, it is the largest number of anywhere in the state. What is interesting is that the metro is NOT the largest percentage on the smaller inch totals. Strange as one would think that it would be based on the thought that the bulls-eye would narrow as you pinpoint the largest snow totals. Anyway, very interesting. http://www.weather.gov/mpx/winter

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  26. 12Z Euro - Interpret as you will

    https://www.dropbox.com/s/zczljy5d1grlegv/Screen%20Shot%202018-01-20%20at%2012.32.34%20PM.png?dl=0



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    1. Or visit http://www.pivotalweather.com/model.php?m=ecmwf&p=sfcwind_mslp&rh=2018012012&fh=0&r=conus&dpdt=

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  27. it looks like there is a general agreement between the 12z ECMWF and 12z GFS, for a solid swath of 6-10.
    All these projections are based on 10:1 ratio and I am wondering whether because of the warmer air, at least at the beginning, ratios may be closer to 8:1.
    I expect NWS to upgrade to Winter Storm Warning in their afternoon updates.
    6.4” inches at MSP? How does that sound to people? Too high,too low?

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  28. Alright lets dis regrade Nams 18Z run.

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  29. From 28” inches yesterday to 0” today.
    That’s what you call a robust and reliable model.
    Maybe the government shutdown has something to do with it?

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    1. Which model is saying 0"??? NOAA has upped the totals in the metro. "Rats" if there ends up being 0".

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  30. Newest NAM went way south. It’s the difference between the metro being in a watch v warming. The NWS newest discussion outlines their newest thinking.

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    1. Okay. Thanks. That's sad if it veers off. I'll go hunting for the latest discussions. I appreciate the quick answer.

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  31. Why, why, why is there always a sharp snowfall gradient over the metro? At this time it looks like Lakeville will get bombed with snow while Albertville might be lucky to get a couple of inches.

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    1. The metro core will be very very disappointed again, between now and when the snow starts the heavy band of snow will continue to drop south on the models and everyone's forecast to the point that MSP measures just 1-2". Another boom or bust forecast with the heavy snow band within reach and on the Twin Cities radar where those living in core can reach out and grab it.

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    2. You're probably right...unfortunately

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  32. Forecast amounts are all over the place, especially north of the south metro. For example, Kare is saying 1-3 inches for Maple Grove, while the NWS graphic released at 3:22 PM this afternoon is showing 8-12" for Maple Grove.

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    1. I don't put much stock in KARE's forecasts. They aren't known for their accuracy. Also, their temperature forecasts are often 3-5 degrees higher than the NWS.

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  33. The NWS point forecast for Medicine Lake/Plymouth says 100% chance of heavy snow Monday with 6-11 inches. However, there is still a winter storm watch for Medicine Lake/Plymouth. My understanding is that a watch is still in place because the NWS is uncertain whether at least 6 inches of snow will fall in the watch area. Therefore, if that is the case, then how can the NWS forecast 100% chance of heavy snow 6-11 inches. Is it technically splitting hairs? Am I missing something?

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    1. Your not missing anything, NWS leaving the door open for a drastic change tomorrow for the core metro. 1-2" will be what MSP measures. Snowlovers in metro duked again!

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  34. Novak's map is out; the tight gradient is there. It will be fun to see how this storm unfolds. I hope we all get a bunch of white stuff.

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  35. Plymouth Weather LoverJanuary 20, 2018 at 7:35 PM

    I am concerned for Plymouth. Dang it. Bring it!!!! I need to dance more!!

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    1. Southern/Tight gradient shift is on! Those that live in the 694/494 loop enjoy your 1-3", north of 694 enjoy the 1" and those living south of Lakeville enjoy the "real storm"

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  36. Keep in mind that the 18z/06z GFS & NAM runs don't include balloon data that is critical to model accuracy. Hence, those runs often skew from the trend. You should never be swayed by one weird looking and/or dramatically changed outcome from a 18z/06z guidance run. I would consider the latest 18z guidance as 'rogue' & I'm confident that the 00z runs will come back north some with the snow band.

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    1. Mr. Tom: It does look like the 0Z NAM bounced back on the northern end. Are you noticing this as well?

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    2. Well you are absolutely right NAM did indeed come further north.

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    3. Interesting to see if WSW's are put up now. Per the last discussion they held tight due the prior run of the NAM.

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  37. NAM 0z has tracked further north in line with Euro. So my prediction is the NW metro will receive 2-5 inches. Metro 7-13, SE Metro 9-15. I think i'm a little conservative on the NW side but its really hard to pinpoint where that sharp gradient will be.

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  38. The sharp gradient is going to be a real problem. There will be a ton of disappointed people in the northern MSP metro, especially in Wright & Anoka counties. Some will be lucky to get 1" of snow out of this as you hit Monticello & Cambridge, etc. Meanwhile, Dakota & Scott could easily be shoveling 12"+.

    However, I'm truly worried that this band is going to shift just a hair. If it does, that little 20 to 30 mile shift is going to make a world of a difference in the MSP metro.

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  39. Shift south that is.

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    1. Of course it will shift south. Heaven forbid a snowstorm actually hit the core metro. Minneapolis Snow Curse rears its ugly head again?!

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    2. Tom:

      I agree with this idea, I went last night with a 6 in 10 possibility of the metro core getting heaviest bands, I'm going back to a 3 in 10 chance. I know that the metro may have good mid level support. However something has been gnawing at me so I want to run it by you. As per the previous thread about this storm, I fully expected the surface low to track from near the Quad Cities to somewhere near Chicago, in this case it turns to be a bit north to near Milwaukee.

      The question: Is the deformation band affecting the metro as depicted by the models a bit further NW from the surface low than you would typically see? I'm still thinking that winter storm warning totals will primarily affect the SE metro. Best guess is that the majority of the core metro will see between 3-5". However unlike summer storms the NWS doesn't issue winter storm warnings with polygons that split the county. Therefore I would expect that Hennepin and Ramsey county would be under the winter storm warning when it gets expanded. It very well could verify with the airport getting to 6".

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    3. It all comes down to forcing as the storm explodes on Monday AM. If we can get the jet streak that is south of us to increase in intensity, more than depicted by guidance, we will get heavy snow across ALL of the metro. I don't like it when a mid-level low quickly cuts-off like guidance is showing right now. That would tend to create that sharp NW/SE snow gradient & shunt the snow band a bit further south.

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  40. also, it will be interesting to see if a mid-level frontogenic band of snow develops tomorrow near or in the MSP metro. The forcing beneath the jet streak in northern MN should provide enough lift to develop a narrow band of intense snow.

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  41. Call me crazy if you want, but there is some evidence that that this system will slow down on Monday afternoon. Some of the modeling is showing the surface low slowing down just nw of Des Moines IA, one model actually retrogrades it. Thinking now is that a very narrow band of 20+" is possible from just SW of Mankato and NW of Albert Lea to around Blooming Prairie to NW of Rochester in to the Red Wing area. This is also the area that I call Minnesota's Tornado Alley. For some reason both in the summer and winter fronts like to sit in that area.

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    1. Minneapolis snow bubbleJanuary 21, 2018 at 12:13 AM

      Randy are you really saying 60 miles south of Minneapolis will get 20+, while Minneapolis gets virtually nothing! Stick that dagger into the hearts of snowlovers why don't you. Winter sucks Minneapolis!

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    2. For as long as I can remember, Red Wing has seemed to get an unusual amount of bullseyes, in the form of winter storm hotspots, heavy rain events, and even severe storms. Glad to see someone else seeing it that way, especially someone not local to the area.

      My hunch is we get 20+ here, which would be the second time in ~eight years, if I remember correct. (Domebuster & May ~2013(?) -- which knocked out power for three days & took hundreds of trees down with it).

      Looking forward to seeing what happens.

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  42. 00Z NAM: Puts the entire metro core and points south under 12+" snow area. Thoughts? Trend? or we just disregarding it?

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    1. I think its going to come down to one of those storms you just have to wait till it starts... I know it sucks

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  43. Why doesn't the NWS just drop the winter storm watch north of the current winter storm warning/blizzard warning area and put us out of our collective misery? We all know that north of that line is going to get next to no snow...as usual. The Great Metro Snowstorm Shield is doing its job once more.

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    1. Bob in snowlessvilleJanuary 21, 2018 at 9:11 AM

      I live in the Twin Cities. When I grow up I want to live some place where it snows!

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  44. The new cam models..nmm..arw..nssl show a very extreme gradient in metro. Those are better models to follow now then operational ones..It's going to he close

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    1. What are those models reflecting for inside the 494 loop?

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    2. Only the Nssl geta into that area and even then its on the edge..They have light snow at times for the core but the very intense stuff stays south

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    3. where is a good place to find this data? I only can find the nam and gfs... none of the cam

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  45. I just got up and checked the forecast. Unfortunately, I was not surprised. Sadly it is what I expected it to be. I am renewing my question from yesterday. Does anyone know why there always a sharp snowfall gradient over the metro? Why doesn't that gradient exist north or south of the metro, for instance? My follow up question is whether sharp snowfall gradients have pretty much always existed over the metro?

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  46. The current probabilistic forecast shows a 90% of 5+" of snow at MSP. That sounds crazy given the current forecast.

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  47. What am I missing? The recent NAM paints a foot of snow over the metro.

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    1. The nam is only one model. The cams and models like rap and hrrr are what start need to follow now. also models like high rez gem and new gfs showt he same cutoff. If i had to say i dont think nws pulls the trigger on the watch today based on the cams. Thats just my guess

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  48. A suugestion to all for clarification: ‘metro’ means different thing to different people.
    In potentially tight gradient situations like this it is useless to say NW metro vs SE metro without specifying what that exactly means.
    So try and be more specific.
    TV meteorologists of course do this on purpose because they have no interest in being too precise because they need to be able to spin it after the fact so thay always look right, but at least here on this blog I think people can try to be more precise in what they exactly mean when the say metro or se metro or nw metro.

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    1. Good idea. Lets select certain cities to roughly represent different geographic sections of the metro (e.g. Maple Grove, Elk River, Burnsville, Hastings, Eden Prairie, Minneapolis).

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  49. still a painful gradient, but its appears 12Z runs of the GFS/NAM/NAM3K all seem to bring higher totals to the metro (ramsey, hennepin, northern wash, and so. anoka) vs the prior runs this morning.

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    1. Thanks! What figures are those models suggesting for the areas you mentioned?

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  50. When I say core metro I am referring to any city inside the 494/694 loop(MSP=airport....and that's inside the loop)...everything outside the loop should be NW/NE/SW/SE....don't you think?Thoughts?

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    1. Even still, that’s what, 30 miles or more?

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    2. I know, but what else can we do when Mother Nature screws with us in this way. ;)

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    3. I think that's a good guide. And from northwest (Maple Grove) to southeast (Inver Grove) must be maybe 20-25 miles as the crow flies?

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    4. I usually go by this rough guide:

      NW - Maple Grove
      N - Blaine
      NE - White Bear Lake
      E - Woodbury
      SE - Hastings
      S - Rosemount
      SW - Shakopee
      W - Minnetonka

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  51. 12Z NAM: Gives the entire metro 12-18", just saying!

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    1. Crazy isn’t it. NAM seems to be on steroids. The 12Z run should be pretty good by model standards so curious if the warning is moved a bit north. If the NAM 3K is right, biggest storm in a long time.

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    2. By how much is the NAM the outlier?

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    3. NAM 3K has 14” at MSP. GFS around 4.5”

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  52. Here you go. Because I am bored and trying to kill time before football:

    Left Image prior run. Right most current

    NAM3K Last two runs (10:1):
    https://www.dropbox.com/s/gqinhy6cyigiijg/NAM3K%20Compare.png?dl=0

    NAM last two runs:
    https://www.dropbox.com/s/ld3pa0n34g9w7as/NAM%20Compare.png?dl=0

    GFS last two runs:
    https://www.dropbox.com/s/mh0h38af7tw1ysm/GFS%20Compare.png?dl=0

    ECMWF last two runs: (newest run just released)
    https://www.dropbox.com/s/vt47csoympg47n8/ECMWF%20Compare.png?dl=0

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    1. Fun! Those all look fantastic...except the NAM3K. That gradient is frightening.

      But this is the same thing that always happens right before the storm begins. A slight bump north, giving us hope, followed by the storm taking the original, more southerly track.

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  53. I understand the skepticism, but it is not exactly the same situation like previous storms. 24 hrs before the event, the operational euro and gfs had already shifted well to the south.
    Now we are basically less than 24hrs before and you have a general good agreement between them that put most the core metro (loop) in at least 4-6 inch.
    When was last time that this was still the case so close to the event?
    Of course, all is fluid (it always is with weather) but at least the premises are not as a bad as in previous situations.

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  54. The NWS, as of its 11 AM winter storm watch update, doesn't appear to be too excited about high snow totals north of the southern/southeastern burbs. They appear to be leaning towards a general 3-4 inches for the core metro.

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  55. Check out Novak's video update from a couple of hours ago. https://www.youtube.com/watch?v=KfKTK6zyXwE

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  56. NWS 12.30pm aviation forecast update saying they are favoring a blend of the gfs and the NSSL and going for ‘around 6” at the airport’.

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    1. Plymouth Weather Lover, as a new Plymouth resident who moved from the far southern burbs, I must say that I'm not feeling very confident about getting much snow up here. This is one time that I wish I still lived down south! lol At any rate, I will start dancing and hoping right along with you and the others! Bring it!

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    2. Dancer harder! NAM 18Z is not being very nice but it also could be NAM on crack again like it did yesterday on the 18Z run.

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    3. Yep. Saw that. Both NAM and 3K remove just about all snow from the core. Woof.

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    4. NAM rocks! As Novak said yesterday, the 12Z and 00Z are the important runs. Need to wait for the 00Z.

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  57. That's it the NAM was the last Domino to fall, now the NWS can drop the watch, insert the token advisory and MSP can enjoy the token 1-2". And everyone can enjoy the Vikings

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    1. Euro model??? Boy you need to stop being so negative about snow around MSP.

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  58. They actually just upgraded to warnings.
    Nobody gives a crap to the NAM anymore, especially the 6 and 18z runs.

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  59. The warnings for MSP means nothing, NWS took so long to put them up because of low confidence, their confidence is still low. MSP will measure 1-2" when all is said and done.

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  60. Replies
    1. Dude relax, read the warning!
      Basically calling for 2-10" and also saying conditions will be drastically different within 10-15 miles. If that's not oozing with low confidence I don't know what is. They had to do something with the watch because they held onto it too long. I believe the right call would have been advisory for Hennipen and if and only if the heavier snows go further north then expected tomorrow then upgrade to warning. They have upgraded to a warning during a storm before .

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    2. True, but I assume their preference is to downgrade from a warning to an advisory rather than vice-versa as they'd rather "overwarn" than "underwarn."

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    3. Euro is showing almost an inch of moisture for MSP. The warning for Hennepin is more about the southern part of the county. Based on the current data looks like the right move. Big question now is the temp and when the snow starts. I like how the NWS has handled this. Obviously we can grade it Tuesday.

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  61. You can really see the storm exploding over Nebraska right now!

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  62. Where are all the experts??? Novak, Randy,..........................

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    1. What do you want them to say? This will be a classic case of the radar lighting up with the band of heavy snow moving up from southeast towards the metro and pretty much stalling at the core with the snowlovers begging and pleading for it to move further north but to no avail

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    2. Just got off work, not much more to add. Unless track of surface low moves unexpectedly north and west this storm is acting as expected.

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  63. Well the Vikings are getting their butts kicked right now. But on the bright side for snow lovers the 0Z NAM run is looking very promising!

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  64. Unbelievable!
    Unbelievable Vikings game, like they never showed up
    Unbelievable NAM, like it can't make up its mind.
    Whatever is going to happen now is up to the good Lord and Mother Nature


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  65. The NAM 3K is amazing and really has been pretty consistent for the 12Z and 00Z runs. Moved a little further north this run but still nothing for far north Hennepin, 10” airport, and 14”+ Scott and Dakota counties. Wow. All that in less than 24 hours.

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  66. Ian Leonard just said 1-3 inches Maple Grove/Plymouth/Minnetonka; 3-6 inches Minneapolis and 6-12 inches Burnsville and points south.

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  67. MPR says 5-10" for the core downtowns.

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    1. Are you going to be making another video before the snow starts?

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  68. Numbers are all over the place!

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  69. I find it interesting how this monster is mainly relying on 'Dynamic Cooling' to cool the air column in an effort to produce snow. There is little in the way of Arctic air available. Quite frankly, this is usually considered a major red flag but this storm is so strong that it will likely overcome this issue.

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    1. That is a very good point. I have been wondering where the cold air is to support this storm. Is it still looking like points north of Minneapolis are for the most part out of luck on receiving more than an inch or two of snow from this system?

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  70. Frustrated Snow LoverJanuary 21, 2018 at 10:06 PM

    It's looking like last Sunday's clipper will be a bigger event than this storm for people who live in Maple Grove. Some day, some year a big snowstorm will actually hit the entire metro, maybe.

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  71. It's strange that the last comment was over 9 hrs ago. Snow is really picking up here in Farmington. NAM, NAM3K, and HRRR all are showing 18"+ for Dakota co.

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  72. Still a gradient as dirty as Philadelphia’s fan base but the hi-res models are definitely increasing totals on the northern side. We might be pleasantly surprised depending on where you are.

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  73. The pivot is already pretty pronounced on the radar. My question is...how far west and north into the core and west metro will it be able to push? Progress already seems to be stalling on a line from about Shakopee to Woodbury.

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    1. We missed out again here in the northern burbs. Maybe next year. Heck, the Cubs eventually won a World Series. I just hope it doesn't take 100 years for us to get a snowstorm up here.

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    2. Not snowing in Woodbury...yet.

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    3. I hear you. It's bone dry here in Coon Rapids and unfortunately it's going to stay that way. Lots of bare ground showing up. What little snow we have on the ground will likely melt on Friday when it's back into the 40's. This winter held so much promise with the La Nina. It's going to be colder than the past 2 winters, but it's still going to be very disappointing due to the lack of snow. Southern metro, enjoy your snow and build a snowman for us "have nots".

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  74. It been snowing very steady in Apple Valley for about 90 minutes now. I’d say we have about an inch so far. Just made the commute to Eagan where not a flake is flying.

    Based on my untrained eye, I’d say this storm is doing exactly what was expected, just started a bit later than first thought. However, I am curious what the mets think. Now that the storm is here, and currently grazing the south suburbs, from a “sciency-perspective”, is this storm doing what you expected. I hear people on this site talk about storm variables such as dry slots, deformation bands, S jet streaks, 850mb, low pressure tracks, NW quadrants, thunderstorms robbing moisture, etc. While I understand what these things are, I don’t understand how they work together to bring us the storm that we are getting. Can anybody comment on the current state of the storm? Are you currently seeing any variables that could weaken or strengthen the storm that you had not expected?

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  75. It's pretty clear that the northern half of Hennepin County will be lucky to get a flake. I guess there is a winter storm warning out for the entire county because the NWS does not post warnings for portions of a county? Either they post a warning for a county or they don't?

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    1. That is correct. They don't for now.
      I actually asked the NWS about this and they told me that they are testing and evaluating the possibility of moving to winter storm warnings and such for portion of counties like they do for severe weather events.
      So, it will soon come.

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    2. Thanks for your response!

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  76. Just like I said yesterday @anonymous at 4:46pm, the pivot has started just south of the core, those living north of 494 the bust is rearing its ugly head. You can just stare at that radar and plead and beg but to no avail. On to the next tight gradient snowstorm because you all know it's coming!

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    1. WRONG!! I live north of 494 in Golden Valley and it's snowing moderately as I type. You sir(or she) should be feed to the weather gods....dilly dilly!!

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    2. Core metro is definitely in the band. Not sure what radar you are watching.

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  77. Snow really starting to pickup in Woodbury now.

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  78. Snow (finally) started in NW Maple Grove at 10:25 - I hope we can get a few inches out of this one at least!

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  79. As I mentioned earlier about the HRRR and NAM models, the most current model runs continue to lay down insane amounts. I've learned the the HRRR and NAM 3K are very reliable within the 24hr sampling window. Can I really expect 16-20"+ here in Farmington/Dakota co?

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  80. 1" in Golden Valley....heavy snow currently! 11:45am

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  81. Snowing steadily in Plymouth. Wind is blowing about 15 mph with higher gusts. Estimate one inch has fallen as of this time.

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  82. Only additional comments are snowfall rates will approach or
    exceed 1 to 1.5 inches per hour during the afternoon, and possibly
    last through 00z. Confidence is high that LIFR/IFR conditions
    will remain, with vsbys as low as 1/4SM in heavy snowfall/blowing
    snow. There could be a short period of cigs/vsbys near airport
    minimums during the height of this storm. Northeast winds of
    16-18 kts, gusts to 24-28 kts, with slowly become more
    north/northwest this evening/overnight and decrease in speed.
    Total snowfall through this event could exceed 12 inches before 06z.
    That is from the 11am aviation update from the NWS discussion page....wow!...exceed 12" at MSP that's saying a lot because it's been awhile since we saw numbers like that.

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    1. This is because I'm in town over the winter for the first time since the winter of 2013-14. :-)

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    2. Blizzard Warning expanded and now touching, but not including, Scott and Dakota counties. Owatonna has reports of 10", and NWS has uppped there total for core metro to "10". This is a whopper...

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    3. Owatonna just hit 12 inches now! WOW

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  83. Plymouth Weather LoverJanuary 22, 2018 at 1:46 PM

    Just awesome!! Bringing it! Wet my pants several times.

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  84. We'll probably match the Halloween Blizzard of 1991 snow totals here in Faribault. 10" and probably another 4 or so on the way.

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  85. GR 3 radar is lit up with very heavy snow right now 1-3"/hr rates

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  86. Heaviest snow I've ever seen from my office. The radio towers that are across the highway have disappeared into the white.

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  87. Just saw 12.5” in Northfield already. Storm in playing out like the NAM predicted yesterday. Models overall have done really well with this.

    Driving in the south metro is nasty right now lots of stuck cars from this heavy wet snow. First direct hit in a long time.

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  88. We have 8.5 in Eagan and 10 in Apple Valley. Snowing harder than it has all day.

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  89. I need a comment from Ed please...
    "The warnings for MSP means nothing, NWS took so long to put them up because of low confidence, their confidence is still low. MSP will measure 1-2" when all is said and done"
    Please give us a statement, a press release..
    Can't wait to hear from you

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    1. “It never snows in the Twin Cities”

      We are about to ya e amounts outta hand!

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    2. Yup, that is the worst forecast for any actual forecaster. Being under totals by that much causes chaos and panic.

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  90. Congrats to those in the N/NW burbs that thought they'd only get a dusting. Quite a nice surprise for them.

    Here in the S metro it is crazy. Let's see if we can top a foot in Rosemount...

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  91. Reminds me of the 1991 Halloween Blizzard. "Good thing it's supposed to stop tonight" or else........ doesn't help, too, that noaa sites are down due to the government shutdown. Schools, colleges, universities, even businesses are closing up. I'm in St. Louis Park and just got the robo call for snow emergency. "Let it SNOW!" I shoveled part of it once and can't even tell.

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    1. The NWS sites were not impacted because of the shutdown.

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    2. Updates seemed really slow in coming today, including their message that they would continue to update. Thanks for that info.

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  92. Radar clearly shows TC in the twist directly over head right now.

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    1. Would you mind explaining what that means? Does that mean we are getting heaviest snow right now? Thank-you

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    2. I believe it's a reference to the location of where the "deformation zone" is setting up. More on that can be found here: https://nynjpaweather.com/public/2010/02/27/an-overview-of-mesoscale-banding-and-the-impacts-on-snowstorms/

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    3. The storm is pivoting directly over the T C and actually moving heavy bands of snow over us from Wisconsin. I could demonstrate but this blogger is junk with links and photos
      . Out dated 2000s website

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    4. Thank-you. I see it on the radar now.

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  93. Just bringing this up since what we're seeing now was never supposed to happen.


    "Anonymous January 5, 2018 at 9:10 AM

    I will try to lay it down once (and hopefully for the last time) as it seems people continue not to get it and cling to 'hopes' and 'expectations' of singificant snow in the Twin Cities metro that are baseless.
    The Twin Cities will never get heavy snow this winter and hardly ever again in the future, for these basic reasons:"

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    1. Attaboy(gal) dustball. +1

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    2. Seriously. Hopefully we don't have to hear anymore from all the Anon Party Poopers on how it's never going to snow in the Cities again.

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    3. That Anonymous was me. And all snow lovers should thank me. I am a snow lover too and I so I decided to put myself up for ridicule in order to make it snow.
      I hoped it would work by challenging Mother Nature and it did.
      So I am happy to be exposed to ridicule but, again snow lovers should thank me.
      How long have we been waiting for a snowstorm like this in core TC?

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    4. Two years since that surprisingly prolific Groundhog Day storm for the core metro.

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  94. What a pleasant surprise to have the heavy snow band come farther north than expected. Us snowlovers in Plymouth are pretty happy as a result! Always have faith and never lose hope. You just never know when Mom Nature might bring you a welcome surprise! I would like to give a shout out to Novak, who I think did an excellent job forecasting in spite of all of the very tricky challenges.

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  95. Am I seeing things, or is the deformation band setting up over the core metro?

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    1. It's been slowly sliding north all day. Looked more like Mankato to Hastings this morning but is ending more Shakopee to Taylor's Falls.

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    2. That's exactly what's happening Joel...rejoice!
      At 6:00 in Golden Valley I measured 8"....I snowblowed the driveway while snowing hard and now 7:00 and the driveway has another 1"...so up to 9" now

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    3. Unbelievable!!!

      I’m very happy, but the 2:40 commute home sucked.

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    4. So what does this mean for the rest of the night for MSP?

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  96. WOW! up to 10" in Golden Valley and still snowing pretty hard....finally a nice snowstorm!

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  97. Well I guess the Paul Douglas thing about dividing snowfall models by 2 didn't work so well? Nice to see the snow!

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  98. I think it was very considerate of all of you to welcome Bill back to Minnesota with a blizzard. Now please make it stop and make it all go away... Bill, to fully appreciate and embrace this experience, you're welcome to drop by and shovel everything...including my roof... MM ;-)

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  99. I motion that Bill must move back to Minneapolis....when he was here we got a lot of good snowstorms and then he left and our winters were blah and now he's in town and look at all that white powder out there! Bill it is time to comeback!

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    1. I second that motion! Thanks, Bill!

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  100. Snowiest January day at MSP since the famous January of 1982.

    What a fantastic storm for the metro!

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  101. I tell you what, the NAM, although overestimating amounts, almost nailed the position of the heaviest snowfall a couple days out.

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  102. Weren't those a great couple of days?
    17 inches one day and then another 20 2 days after...
    I remember it as of it were yesterday

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  103. Yes, and people including pro forecaster were skeptical of the NAM given it missed the mark lately.
    Overall I think it was a well forecast storm, although very few people anticipated that the west side of town almost outperfomed the east side, given persistence banding.
    I think a few would have predicted that KMSP was going to get more than KEAU.
    What I found interesting is that there was no arctic air (maybe that was screwing the metro up), just cold enough for all snow with no precip type issues.
    So the depth of the storm even more than the track seemed to have helped (I mean we had had previous storms especially last year where the track was favorable and yet we had precip type issue).
    it was in the 40s leading up to this storm, so it was really susprising to me to have no such rain/snow line hovering nearby.
    It really never was in question that it was going to be all snow.

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