Tuesday, January 14, 2014

Grading Jan. 13-14 Storm (and what was Chris Shaffer thinking?)

It’s been a while since we’ve graded forecasters. In truth that’s because there hasn’t been much interesting weather (i.e., snowstorms) and because there’s been little forecaster variance. This time, however, we feel compelled to highlight the particularly poor forecast by WCCO’s Chris Shaffer.

Here’s an excerpt from Shaffer’s forecast on the 6 p.m. news last night on WCCO. He said that “most of us will see less than an inch.” He went against all others and consistent model data. It seems he looked at one rogue model solution and ran with it. With the 4.4” of snow that fell, we think that most viewers would call this a poor forecast.

Chris Shaffer forecast from 6 p.m. WCCO newscast.

While a bad forecast is one thing, coming out 24 hours later and implying it was just what you expected is harder to swallow. Here’s a video capture from a segment of his 6 p.m. weathercast from Tuesday night. There’s the clear implication that the storm was what he expected (“just a little snow) yet he actually brings forth reported totals that are in excess of the totals he’s trying to validate. And how can he continue to call this “not much snow” when it caused snow emergencies in both major metropolitan cities? The fact is that we received one of the biggest snowfalls of the season with 4.4” and much of the metro received 3-5”. That’s a solid snowstorm in most peoples’ books.

Not surprisingly, we have to give Chris Shaffer’s forecast an F. Here are our grades for the efforts of other local forecasters:

WCCO: F. A poor forecast and an even poorer follow-up self assessment.
KSTP: B. More aggressive than most with a 2-4” forecast, but not aggressive enough. Also emphasized 2-3" with "spots seeing 4".
KMSP: C. Too conservative at 1-3 inches.
KARE: C. Same as KMSP
NWS: B+. They were consistent in forecasting 2-4” and, appropriately, issued an advisory.
Strib: C. Todd Nelson’s 1-3” forecast was too conservative.
MPR: C. While noting forecast volatility, was too conservative at 1-3”
Novak Weather: A. Refer to this video (beginning at 11:45).

48 comments:

  1. I think Shaffer deserves an F-. The minus comes from that absolutely ridiculous aftermath self assessment. Unbelievable!!

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    1. Well he did have snow in the forecast. :-)

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  2. Unbelievable that such an incompetent is still on the air while Patrick Hammer has been fired by KSTP.
    With all due respect, yes metereology is not an exact science but busting a forecast less than 12 hours before the event and then trying to spin as he did.
    Ridiculous!
    @Bill... happy to see that grading is back! Since most of those mets follow you on twitter if I am not mistaken you should tweet them your grades

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  3. Thanks @Anonymous. The grades are obviously subjective and, as much as anything, I think the "body of work" when it comes to grading lays in the collection of comments from blog visitors.

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  4. Clapping loudly for Dr. Novak. Well done sir!

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  5. Based on the reports not just MSP airport, but the many COOPs, NWS Chanhassen, etc across the metro, a 2-4" forecast would actually fall into at least a B+ to A- category as most amounts were in this very range. Anything saying 4"+ across the entire metro would be A-/B+ as only the airport and extreme NE metro had reports above 4.0". But, overall, most forecasts were reasonable.

    *From best I can tell, the rogue model on the number 4 was the RPM from WSI. I have worked plenty with the RPM and it has its issues in snow and rain qpf forecasts. But, it looks best on tv with the more granular data and 4km resolution.

    Traffic was definitely jacked up this morning in the snow --- one of many reasons I take the Xpress bus from srn suburbs into St. Paul as I could chill, listen to tunes on my iPhone and check the latest news/etc on Twitter and FB. 'Course I had to finally darken screen and listen to the music-only as the commentary/comments regarding the TWC/DirecTV situation was pretty ridiculous.

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  6. Good points, DDwx. Like I always say, grading is subjective (at least for me). One thing I find interesting is that people/mets often don't agree on the snowfall categorization even AFTER the snowfall. I've heard people say the snowfall was 1-3, 2-4, 2-5 and 3-6.

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  7. Nice work, Novak! And congratulations on (hopefully) buying yourself a few days from getting slammed by the Anonymous trolls on here!

    Keep up the GREAT work...

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  8. We all know that when Tornado Warnings and Severe Thunderstorm Warnings are issued, those particular conditions are occurring or have been sighted. So why is there a Blizzard Warning already issued for western Minnesota for Thursday? Isn't a "Watch" the term they are looking for? It's no wonder some members of the public are confused with the terms.

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  9. Anonymous,
    I believe the NWS issues a Warning when dangerous conditions are "imminent". A watch is more of a heads up for the "potential" of dangerous weather.

    In other words, the NWS believes that there is nearly a 100% chance of ground blizzard conditions in the warned area. What is surprising is that they were confident enough, 24 hours out, to issue the warning. Wow!

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  10. In 25+ years of weather coverage, I can't recall a weather pattern like this one that features so many strong 'Clippers' tracking over the same area in such a short period of time. If my counting is correct, by early next week, we will have had approx. 5 'Clippers' track over the Upper Midwest/Great Lakes within a 10 day period. That is not to mention the 'Clippers' that will likely hit the area later next week & weekend.

    I'm not surprised with the consistent NW flow that we've been experiencing for well over a month, but, the 'Clipper' train is absolutely fascinating to me.

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  11. Didn't we have a similar pattern last year starting in February as documented at the time by Bill's blog entry "The clipper train is rolling"
    So the question is: is this pattern becoming more common or not?
    It seems to my untrained eye that the frequencies of Panhadle Hooker or Colorado Lows type of storms are decreasing (or trending warmer) so that an ever bigger proportion of total winter snowfall for the area comes for Clipper type storms embedded in the north-west flow?

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  12. New video out: https://www.youtube.com/watch?v=MOkizX_jaXw

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  13. The local met out of Chicago mentioned that they were in line for a Manitoba Mauler. Never heard of that one before for this area.

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    1. Interesting. From Wikipedia: Two variations of Alberta clippers are Manitoba mauler or Saskatchewan screamer.These two types of systems are far less common than clippers, and even when they take place they are still often referred to as clippers. The main difference among the three is from which Canadian province they begin their southward trek.

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  14. Has anyone else been following the other weather blogs the past couple days and seen the hype building for "Polar Vortex 2"?!

    Huttner: http://blogs.mprnews.org/updraft/2014/01/winter-on-steroids-blizzard-warnings-and-polar-vortex-part-two/

    Weather Centre: https://www.facebook.com/TheWeatherCentre (post from about an hour ago)

    Anyone have any thoughts on either what the models are saying or what the author's are saying?!

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    1. Whne looking at today's 12z GFS the thing that grabbed my attention was that it is much colder for Sunday with highs for MSP not exceeding 22 degrees as opposed to mid 30s a few days ago, so that would be interesting to see.
      As far as the polar vortex I find annoying that Huttner changes his blog with every new model run: first he mentioned it could be even colder than the early January outbreak, then the 6 hr later the new GFS run was less cold and so he mentioned it again, now since I noticed today's 12z GFS is pretty cold again I am expecting him to change tack again?
      I am personally more interested in the sudden change for Sunday which is relatively short term. Maybe the GFS is just the outlier here...

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    2. I just looked at the 12Z GFS myself, and even if it is 10 days out, that is pretty scary to imagine what would happen if we entered into double digits below zero for 7+ straight days!!!

      http://wxweb.meteostar.com/sample/sample.shtml?text=KMSP

      Just looking at the temps in the bottom half of that page makes me shiver!

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  15. Anyone think this was over forecast? In particular, KSMP, flashed forecasts of winds 40-60 mph. They later redefined that, saying that was for outside the metro. I suggested that KMSP was rather wild high. Steve Frazier responded by saying 52 mph was the highest he could find at an official reporting station, even said, "It falls into the 40 - 60 mph range." C'mon!!! What a crock.

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  16. Concerning the Polar Vortex Version 2,( PV v2). I would suggest you open two windows, then minimize them so you can see the maps and my comments about what I'm seeing. The first window should be opened to this link:

    http://www.meteo.psu.edu/~fxg1/CMCNA_12z/hgtcomp.html

    The second window should be open to the current site your reading.

    http://www.minnesotaforecaster.com/2014/01/grading-jan-13-14-storm-and-what-was.html#comment-form

    The maps show the average 8-10 day 500mb height anomalies over North America. Red equals ridging (blocking) and warmer temps, blue equals troughs and cold temps. These are ensemble forecast means and not operational forecasts. The GFS and GEM ensemble means are made up of 21 members and the ECMWF (Euro) a astounding 51 members. The Euro is on the left, the GFS (American) is in the middle and the GEM (Canadian) is on the right.

    The first item of interest is the higher heights (red) over or very near Greenland, while maybe not a classic negative North American Oscillation (-NAO blocking) it is close enough, as the lower heights (blue) that are seen over eastern Canada can not rotate out as the higher heights to the north east block it.

    The second area of interest is the very strong positive heights shown over the west coast of Canada and Alaska, that is indicative of a strong -EPO which has been our driver so far this winter and it also sets up a strong area of blocking, not allowing the negative heights over eastern Canada to move more towards the west. So the negative heights can't move east or west, a classic blocking pattern. So the cold gets stuck and has to move somewhere, and that's to the south.

    Keep in mind that area's of cold (blue) anomalies have a counter clockwise spin and area's of red (warm) have a clockwise spin I believe you can see where the winds will flow and effect our area, straight out of Siberia.

    So what is the result???? As you can see with this final map showing the 850mb temps about 5000 ft above ground level, it could get very cold here according to the GFS model.

    http://meteocentre.com/models/gfs_amer_12/TT_GZ_UU_VV_240_0850.gif

    Given the good model agreement this far out, I would give this about a 7 out 10 chance of happening, so this forecast of brutal cold temps towards the end of January is high at this time.

    If when this arctic air moves down and we have clear skies and light winds, record cold temps are possible.

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  17. A winter weather advisory will likely be posted for Saturday for the Metro if current trends continue. 2-4" is likely.

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  18. Another sneaky strong 'Clipper' screaming south out of Canada. This disturbance has some nice dynamics to work with but, as usual, little moisture. However, since the dynamics are solid, the system will be very efficient at squeezing-out any moisture that is available. I will not be surprised if a 30-50 mi. wide band of 4"+ of snow streaks S/SE from nw to se MN, roughly on a line from BJI to STC to RST.

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  19. Plymouth Weather LoverJanuary 17, 2014 at 1:01 PM

    I dread the talk of another visit from Mr. Vortex. Polar can stay away. I very much like extreme weather (snow mostly), but the idea of another extended cold snap is really making me weary. I know it is a little ways out, but when things start to show in the 7-10 day models, especially cold trends, there tends to be some truth to it. Thoughts?

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    1. Hope its not as cold so school gets cancelled again.......image school being cancelled at least 3 times in one school year for COLD.....not snow!

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    2. Hey PWL looking at radar it looks like you've got a nice heavy snow band over you. Should see some nice totals from it. You are right though regarding models and temps. They seem to do a pretty good job with air masses in the long term. Actual temps will fluctuate but the general consensus is that a couple more arctic shots are on the way. The worst may happen over the weekend so schools may luck out. We will keep watching to see if the core of the cold does come overhead or if it ends up sliding off to the northeast of us.

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  20. Too bad most of you are asleep....I'm watching this nice snowfall currently....coming down at least an inch an hour.

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    1. Man what a burst of snow.....4" in 3 hours in Eden Prairie....still snowing!

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    2. 5" now......still snowing.....way too be ultra conversative there KARE11!(you don't do the public any good by downplaying snow events)

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    3. Was up early taking dog out and he was a bit shocked at the snow on the ground. :) Great snow event that came together. Forecast guidance was pretty decent but will say the NAM and WRF were once again a bit off on the exact track of sfc low and max precip area. GFS/GEM/ECWMF were the better models. The WSI RPM used by various stations is based off the NAM-based WRF so was evident in the displays yesterday on stations of the westward bias. I discounted that in my personal fcst to friends/etc and glad I stuck to correct GFS/ECWMF/GEM. A big clue even yday afternoon was initialization was best on GFS vs NAM/WRF for the snow in nrn/ern NoDak.

      Looks like about 3-5" in the yard but going to head out now and make the measurements to verify and submit a report here in the Rosemount/Apple Valley area. May shovel,too. THIS is the reason I moved back home from ATL. :)

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  21. Good discussion from the guys at Chanhassen this morning on this clipper.

    WE WILL KEEP THIS SHORT AND SWEET GIVEN THE SNOW EVENT IS ALREADY
    IN PROGRESS. ONE THING THIS EVENT HIGHLIGHTS...IS THE DIFFICULTY
    IN FORECASTING MESOSCALE VARIABILITY EVEN IN THE SHORT TERM. THE
    HEAVIEST SNOW BAND OF 3-5" IS GOING TO END UP BEING MUCH NARROWER THAN THE AREA COVERED BY THE WINTER WEATHER ADVISORY - WE KNEW THAT WHEN WE ISSUED THE HEADLINE YESTERDAY. WE WILL LIKELY END U BEING TOO HIGH WITH THE SNOW FORECAST ON BOTH THE EASTERN AND WESTERN EDGES OF THE ADVISORY.

    AN IMPRESSIVE FGEN BAND DROPPED DOWN FROM NW MINNESOTA...
    RIGHT DOWN /TO JUST SOUTH/ THE I-94 CORRIDOR...AND INTO THE WEST
    METRO. 1-2" PER HOUR SNOWFALL RATES ACCOMPANIED THIS BAND AND WE WILL LIKELY END UP WITH SOME BORDERLINE WARNING-TYPE SNOW AMOUNTS OF 6"...COMPOUNDED BY THE FACT THAT IT MOSTLY FELL WITHIN A 3-HRWINDOW. JUST BE GLAD THIS WASN'T A WEEKDAY.

    Just goes to show you the weather still has surprises.

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  22. Its a shame I can't get my Stephanie Abrams fix anymore, damn you DirectTV!

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  23. Apparently Paul Douglas thinks the Super Bowl will be played on a Wednesday(those ratings would suck), take a gander of his blog page. Whats also just as sad is Star Tribune doesnt proofread his blog post entry in todays paper.

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  24. Plymouth Weather LoverJanuary 21, 2014 at 5:19 PM

    This cold is getting old, but I do love the surprise snowfalls! Saturday morning was awesome. Nice blanket of 5-6 inches in Plymouth with perfect weekend temperatures. Now I read in the NWS discussion page that the models are showing the cold pattern continuing into the middle of February!! What in the world! I need to start dancing. I need the big one!!

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    1. The rest of January is looking quite cold (except for Friday and into the weekend). Impressive temperature gradient could set up across the state with a 15 to 20 degree difference in temps within a 30 to 60 mile distance. Once we get into February, I think a flip is coming. How long this flip will last remains to be seen, because I've been told that once we get into a pattern for a while it can be difficult to break it.

      I do believe February will provide more frequent and larger storms and that more troughing will set up in the west. Cold shots will still probably come in, but the later we get into February the more difficult it will be for the air to be as cold as it was in early January due to the suns angle becoming more favorable for heating. A solid snow pack would obviously still hinder the heating but you get my point. Warm air will try to make its move north but the cold will still try to come south as well. Could end up leaving somewhere in the region in a favorable battle zone for some good snows.

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  25. Looking back at my rather technical post of Jan 16th, it appears that the GFS operational has finally come into good agreement with it's ensemble members, and the operational runs of the GFS and ECMWF and their respective ensemble members. The depth of the cold will not be as deep as Polar Vortex Version 1 that we saw at the end of the 1st week of January, but it will last much longer. We could see some warmth Friday through Sunday but than once again we go into the deep freeze. The blocking is there over the top, both over Alaska and Greenland, there is no where else for the cold to go.

    The GFS operational temps shown here:

    http://wxweb.meteostar.com/sample/sample.shtml?text=kmsp

    They may be just a couple of degrees to cold but you get the idea.

    Here are the GFS ensemble temp anomalies for the 1-5 day, 6-10 day, and 11-15 day, in that order, based on the 1/22 0z ensemble forecast, these are average anomalies for each 5 day period including this Friday-Sunday temps.

    http://www.tropicaltidbits.com/analysis/models/gfs-ens/2014012200/gfs-ens_T2ma5d_namer_1.png

    http://www.tropicaltidbits.com/analysis/models/gfs-ens/2014012200/gfs-ens_T2ma5d_namer_2.png

    http://www.tropicaltidbits.com/analysis/models/gfs-ens/2014012200/gfs-ens_T2ma5d_namer_3.png

    Looks very cold to me.




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    1. opps line three should read GEM and ECMWF sorry.

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  26. Wow! The storm system later this weekend really, REALLY looks mean. I'm expecting a massive Blizzard to develop over much of the Upper Midwest by Sunday that should last into Monday. This will be a kind of blizzard that we haven't seen in many, many years. It will not be as much the snow, but the WIND & plummeting temps. I won't be surprised if much of the Upper Midwest is shut-down by late Sunday into much of Monday.

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  27. New video out reflecting Tom's sentiments above: https://www.youtube.com/watch?v=cuh7zHQgO0M

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  28. Tom (NovakWeather) -- I got plans this weekend, darn it! :) Sunday I have a ticket to TwinsFest as the biggest Twins fan in Georgia now resides here in Minnesota so he is going, blizzard or not! Latest guidance, GFS, definitely indicating a wicked pressure gradient as very strong high builds in behind the Sat night-Sun Clipper. And, butt-cold temps to greet us and close schools again. Biting my tongue.

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  29. Tom and Bill, great video. And Tom I agree with your thoughts that this clipper scheduled to come in Saturday night and into Sunday morning could be stronger than currently modeled. I've been watching it the last couple of days, and what concerns me is that the low pressure dropping in from the Northwest will be traveling along the strong temp gradient that you pointed out at the 850mb level, known as a baroclinic zone. As it moves down it should be able to ingest warmer air from the SW into the circulation, warmer equals higher QPF amounts. This could very well act to strengthen the low and slow it down. I'm concerned that the low pressure center might be 2-4mb stronger than currently modeled. I wouldn't be surprised if somewhere near the Metro to Rochester could see a quick 6" + out of it. Your thoughts?

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    1. I couldn't agree more Randy. I'm confident that a narrow band of 4"+ snow will streak southeast thru the heart of MN & WI. Not exactly where yet, but if you combine this with the snow that falls tomorrow, that will mean 6"+ of fluffy snow over a good chunk of the Upper Midwest by late Sunday.

      Of course, my greatest concern involves the wind & dangerous windchills. There is no doubt in my mind that a major Blizzard will develop over MN on Sunday. This could prove to be one of the Blizzards in quite some time, especially when it comes to low visibilities & dangerous cold in rural areas.

      Weather outlets should be hitting this hard, yet many of them have not as of yet.

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  30. School closing #3 today.....with #4 and #5 possible Monday and Tuesday......since my kids were old enough to start attending school(2006) there hasn't been one school closing due to the cold until now and we may end up with 5 in one month.....incredible!!!!

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  31. Plymouth Weather LoverJanuary 23, 2014 at 12:31 PM

    Bring the snow and the blizzard!! Why the heck not? Let's make this epic and memorable! #dancing

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    1. Love the attitude, PWL! It's January in Minnesota...this is the kind of weather we SHOULD be having!

      I know it doesn't work like this, but I hope there's a little weather karma out there that we are earning, so hopefully this nasty cold and active weather means we'll actually have a nice spring to enjoy this year!

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  32. new thread on potential blizzard this weekend?

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  33. Fresh video here: https://www.youtube.com/watch?v=CNkLtpOcor4. Will start a new thread....

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  34. I love winter. But it gives always a rise to my asthma problem. Now it's not working because I have Weather measuring instruments for life for taking advance preparation for cold.

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