Saturday, January 21, 2012

Forecasters Scramble to Figure Out Sunday Snow Scenario

We haven't gathered all the various forecasts for a possible snow event Sunday night into Monday but it appears to be a particularly fluid situation. Some have suggested close to an inch of snow while others have suggested closer to the possibility of 2-4 inches (MPR mentions that possibility in a late Saturday night post.)

This forecast may well separate the men from the boys!

31 comments:

  1. That's saying a lot,since PH is usually conservative and keeps things tight to the hip

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  2. Pretty much every storm that comes through has a bust potential to it. It is just the nature of, well nature. However, I think this storm moving in for Sun/Mon is one that has a higher bust potential with it than the norm. First off, the NAM is finally starting to look like the other models as far as the surface low track goes (per the 06z run), however there are still noticeable differences between the 00z GFS, European, and Canadian forecast runs. The difference isn't really in the track, but the amount of QPF that makes it up here. The GFS has been trending stronger, and looks like the GEM. The European and the NAM match up with a lesser amount, so this makes the forecast challenging. There may be other players involved in how much makes it up here, but the big thing to watch will be the evolution of the severe weather across the south. The more moisture those storms rob, the less we'll have to work with up here. All I can say is good luck forecasting amounts with this system. It can be tough enough when you are talking about freezing drizzle/rain/sleet/snow all mixing. Adding on continued model disagreement just adds to the challenge. At this point, the arrowhead area of MN down into the Duluth area are the bulls eye for me. Not sure how much lake enhancement will be there since this isn't a bitter air mass coming with it, but it could still play a part. Good luck everyone!

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  3. Taking a quick peak at the 06z GFS, it continues to show a deformation zone to the NW of the low pressure system moving through. At this point, this would mostly affect areas from around Rochester, to the NE through western WI. I saved an image from the 06z GFS and circled the area where just maybe a nice little snow band could set up. This is largely dependent on the change over to all snow happening soon enough, and as I mentioned above, the precip making it up and around the low.

    http://i105.photobucket.com/albums/m203/duanewolter/06zGFS.png

    This area could see 2-4 inches of snow if it does actually pan out with this look. I'm not saying this will 100% happen, but it is something to keep an eye on.

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  4. This winter has been a bust consistently with near misses,a lot have looked good days in advance only to become diffcult forecasts or busts to the south or east of us,why should this be any different,just cuz we all want a decent snowfall doesn't mean it will happen cuz its close.........then again since its close snow COULD be heavier on metro and points east,yet again we are still in a drought.........tread carefully Duane,Novak,Randy when you call your forecast.......NWS is playing it conservative but left a window open to many possiblities including their explanations of advisories.....a day full of football and weather how wonderful!

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  5. 06z NAM drops 4"-6" of snow across the MSP metro while the GFS deposits 2"-3". Meanwhile, the GFS dumps 9" of snow in RST. Regardless of what QPF comes out of these models, they all seem to agree that an accumulating snow will develop over our area tonight. With dynamics like this, anything could happen. I find it interesting that the HPC neglects to highlight any of our area for snow concerns.

    Anxiously waiting for the 12z data to come down.

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  6. Bill-- this is what I have seen so far,now that we are in inside 24hrs of said event:

    Kstp. 1-2
    Accu. 1.6
    Weather.com. 2-3
    NWS. 1-2(officially) 4-6(possible in discussion page)

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  7. You gotta love combing through model data while sitting by the fire on a cloudy Sunday AM with a cup of coffee. Does it get any better than this?

    Anyway, the 12z NAM data is a bit more clear, but not clear enough. There is HUGE bust potential for anyone who predicts significant snow over the area. However, a forecaster would be crazy not to predict at least some accumulation when considering the dynamics in place. I concur with previous posts that it will all come down to how much moisture is stolen by T'Storm activity over the mid-Missiissippi River Valley. This storm will wrap-up so quickly that it could easily draw-in too much dry air essentially cutting-off any appreciable snow across the Upper Midwest. On the other hand, you can't ignore the likelihood of a trowal/deformation zone developing over our area tonight into Monday am as the 700mb low passes right over southeast MN.

    This storm should dump several inches of snow in or close to the MSP metro. If it doesn't, then MSP truly has the worst luck in the world this winter season. But, you can't fault MSP forecasters for being trigger-shy given our record this season.

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  8. Also Startribune has 1-2"(Todd Nelson subing for PD)

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  9. Plymouth Weather LoverJanuary 22, 2012 at 9:37 AM

    Keep the discussion going. I love it! We can't keep having busts, can we?

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  10. Wcco is forecasting the change-over to be around 5:00. Predicting a couple inches, while confessing that the forecast is tricky and we could wind up with up to 4.

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  11. I think the mid-south activity will zap the majority of the moisture this system has to work with. At the most, we're probably talking a couple tenths of water for snow making. One to two inches of snow looks good later today.

    Someone wake me up when a real storm impacts us.

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  12. @Ryan Schwartz I feel the same way this big daddy of a bear has been in hiberation too long,but at least 3-5inches the kids could enjoy making a snowman and I would enjoy taking them sledding

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  13. Abit of a concern,that warming they advertized doesn't look like it is materializing,temps are stuck in the low 20's and this freezing drizzle out there is getting slick,was just outsde and a thin layer of ice has formed on most surfaces,if temps stay this cool I can see the changeover to snow happening sooner when the forcing and low get closer

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  14. where can I find this graph? Paul Douglas and MPR uses it. Thanks for the help!
    http://minnesota.publicradio.org/collections/special/columns/updraft/assets_c/2012/01/7%20mett.shtml

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    1. You can find that graph here:
      http://www.meteor.iastate.edu/~ckarsten/bufkit/image_loader.phtml?site=mpx

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    2. groundtechmn its here, just click on the site you want to view, than chose visualize data. enjoy

      http://www.meteor.iastate.edu/~ckarsten/bufkit/data/index.html

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  15. Hey Randyinchamplain or Novak,pull the trigger already,nothing like waiting for the last minute,what you say what's your forecast?

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  16. Accuweather up to 2.1 snowfall

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  17. NWS just increased the amounts significantly in Red Wing, 1-3 tonight and 1-2 tomorrow as opposed to 1-2 tonight and none tomorrow which was earlier today.

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  18. Paul Huttner,following just model data,but his 1:30p update says snowy morning commute.....2-4+ snowfall in the metro

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  19. Why are our in house mets in here so quiet,snake bit by all the other storms the reason?,Novak,Duane ,Randyinchamplain speak up!just call for 1-6inches and you'll be safe.

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  20. NWS changed freezing rain advisory to WWA,upped snows to 2-3inch totals,but with a out clause possibly more or less depending on track and speed of surface low,duh isn't that always the case,if track changes so does snowfall even a rookie like me knows that

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  21. The forecast at weather.gov (updated at 4:02) for St. Paul (zip code 55116) calls for 1-3 inches overnight and 1-2 inches tomorrow, so a total of 2-5. Yet, the Winter Weather Advisory (issued at 3:41) seems to say 2-3 inches for the Twin Cities. A little confusing....

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  22. Haha...while I'm flattered to be considered an "in house met" I have had no formal meteorology training. I said yesterday that I thought the arrowhead area of MN down towards Duluth would probably see the most from this, but this deformation zone that shows up on the GFS and GEM could drop 3-5 across extreme SE MN and into western WI. Otherwise, the metro area is probably going to see 1-3, barring the change over to snow happens quickly enough, and the storms to the south don't cut off too much of the moisture. That being said...the bust potential is still there due to the southern convection factors talked about in previous posts.

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  23. Would someone be able to direct me to a website that has the forecast maps for projected snowfall totals for each forecast model? (Similar to the maps that Paul Douglas uses on his Star Tribune posts).

    Thanks guys. Great website! The discussions are always interesting.

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  24. Links coming your way anon...

    00z/12z NAM: http://wxcaster.com/gis-snow-overlays.htm
    06z/18z NAM: http://wxcaster.com/gis-snow-overlays2.htm
    00z/12z GFS: http://wxcaster.com/gis-gfs-snow-overlays.htm
    06z/18z GFS: http://wxcaster.com/gis-gfs-snow-overlays2.htm

    Just click on the box over the metro, or whichever area you want to look at and you're good. Hope that helps

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    1. I also use this one, it updates by each 24 hour period, sometimes its faster, it also works good when more than one snow event is forecast in a 84hr period for the nam, or 120hr period for the GFS.

      http://wintercast.tripod.com/id14.html

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  25. It is just cruel how moisture starved this storm is right now. However, that will change in the next 6 hours as the trough plugs into Gulf moisture and develops T'Storms over the mid-Mississippi River Valley. That deep moisture will likely NOT make it into MN. However, as the mid-level 700mb low pivots NE into the Upper Midwest, it should ring-out all the moisture that is available right now. This mid-level low will intensify during the next 12 hours and that should aid in the snow development.

    With that being said, this is not going to be a widespread heavy snow event. On the other hand, there will be some banding of snow along the trowal/deformation zone over eastern MN and northern WI. I'm comfortable with a general 2"-4" snow across much of the MSP metro. There may be some areas of western WI and southeastern MN that gets more than this, but it is hard to say exactly where.

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  26. Sure doesn't look like much right now, despite what any outlets are forecasting for the next 12 hours. Unless snow fills in rapidly, that "snowy commute" everyone is talking about isn't going to materialize at all.

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