Saturday, March 19, 2011

Forecasters Generally Tight-Lipped on Possibility of One More Snow Event Next Tuesday/Wednesday

It looks like there may be one more snow in the works for next week. However, local forecasters are not getting too specific with possibilities at this point. We're beginning another recap on this possible snow event. KSTP suggests that "accumulating snow is not out of the question," whereas KARE notes that, "it's looking like mostly rain at this point."

The predictions for the week's warm up are now complete. A quick glance reveals that the Strib's predictions stand out for two reasons: 1) the forecast temperatures often rose and fell considerably in successive days, and 2) in two instances, forecast highs for four days in advance were 10 and 13 degrees above the actual temperatures recorded. The remaining forecasts, without benefit of number crunching, appear to be fairly solid and closely batched together.

Seems to us that for any future analysis of temperatures we should simply go with a 3-day out or 4-day forecast. In general, it seems that all outlets are bunched together inside of three days and are typically close to the mark with the increasing model agreement.

69 comments:

  1. Bill trending whiter now,forecasters still seem on edge,but chikage this morning threw out 'several inches' statement and Kare11 now has changed its tune on its website blog going with rain changing to snow on Tuesday night and snow on wednesday,since not so much talk about i have a feeling this one is going to sneak up and put an hurtin on us,just an hunch cuz everyone is being too cautious,you getting that feeling?

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  2. If you want snow, you are going to be inclined to interpret and bias for snow. If you don't, you will be inclined to interpret and bias for rain.
    The only consensus seems to be that it probably isn't going to be a huge storm, but with the inaccuracy of predictions, who the heck knows... you simply can't predict the future.

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  3. With all of the forecast outlets and models available, I find that I search for the one that fits what I would most prefer to see and latch my focus onto that one. The truth is, there is a great deal of uncertainty and many times you don't know what you'll get until you are right in it - but the human mind sure wants to know, though it is incredibly inaccurate at discerning truth. Just looking at the outlets today and comparing, as this website does for us, there is no consensus - one that I saw (which is the one I've latched onto because it is what I would prefer) keeps us in the rain sector of the storm (chief meteorologist for Accuweather) in southern MN with the snow accumulating only a few inches in northern MN.
    NWS is showing my least desired option which is the coldest temperatures of any forecast I've looked at, but just says 50% chance rain on Tuesday, "rain/snow likely Tuesday night" and "snow likely Wednesday" with no percentages yet for Tuesday night and Wednesday's graphics. Another site I watched said "probably no more than a few inches at most after the changeover late Tuesday night into Wednesday morning". It does look to be cooling down, back below average for a few days on the other side of it, which while not my preference, might possibly help with the flooding concerns?

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  4. Plymouth Weather LoverMarch 19, 2011 at 3:49 PM

    Anonymous says: "If you want snow, you are going to be inclined to interpret and bias for snow. If you don't, you will be inclined to interpret and bias for rain.
    The only consensus seems to be that it probably isn't going to be a huge storm, but with the inaccuracy of predictions, who the heck knows... you simply can't predict the future."

    Well, no kidding! Be a little more insightful in your posts. If you want to see the NWS percentages when they don't list them on their page, go to WCCO.com and click on weather. The percentages when you click on the day of the week are the actual NWS percentages, not the WCCO percentages. At this time, they are saying 70% on Tuesday and Tuesday night and 60% on Wednesday. March storms are hard to predict with warm air at upper and lower levels, how much snow has melted to add moisture/warmth to the atmosphere and the track of the storm. Novak says "maps look really wet." I hope that PD gets back soon as well as Dave Dahl. They give us many angles and I love how PD gives us all of the information whether we agree or not. How can one disagree with a model run? It is what it is.

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  5. Plymouth Weather LoverMarch 19, 2011 at 3:53 PM

    By the way, Anonymous, Accuweather is very inaccurate when it comes to local forecasts, unless you are speaking about a storm out east. They simply have ranges, etc. Even are their detailed pictures forecasts they struggle.

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  6. plymouth weather lover I couldnt agree more,accuweather does suck they are so east coast bias its not funny,if you look at their so-called experts/bloggers they have one for east coast,south and west coast as well as canada but no one for midwest(that Henry Magursity on their is a joke),and their local forecats never match with what any of the bloggers are saying and the 15 day is a joke,changers every 6 hours and not just a little..And it also sucks that PD and DD are not around they give the most info,for anonymous above,NWS has snow likely with 60% or better from Tuesday into Wednesday,guess its up to the track to see what we get,but March storms are very unpredictable could be 2-10 inches easily when your talking wet snow

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  7. For those of you that argue about model maps...here are three that show what the total precipitation should be through 7am Thursday, Just copy the link into your browser.

    The GFS model: http://wxcaster.com/CONUS_GFS_SFC_ACCUMPRECIP_120HR.gif

    The Japanese Model (JMA): http://grib2.com/jma/CONUS_JMA_SFC_ACCUM-PRECIP_120HR.gif

    The Canadian Model (GEM) http://grib2.com/gem/CONUS_GEM_SFC_ACCUM-PRECIP_120HR.gif

    as you can see the GFS under cooks the precip for MN compared to the other two...but why? There is going to be a strong ridge setting to the ne of us, the gfs tries to flatten the ridge out by bring the center of the low into MN, where it gets kick out the se of us within 6 hours. The other two bring the center of the low just to the Iowa border and than slides it to the east underneath the ridge, which to me makes more sense.

    BTW the ECMWF has the same solution of the JMA and GEM.

    I have no clue where the rain/snow border will be' but it will be somewhere near us

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  8. Plymouth Weather Lover - sorry to disappoint you, which simply means you don't like what I had to say... just pointing out a truth not all recognize... everyone on these blogs is biased - you included, me included, and not everyone recognizes that tendency in our psyche. Objectivity is bogus, especially when it comes to the weather and weather forecasting.
    Big Daddy - Accuweather's 15 day forecast has virtually identical to PD's/Star Trib's 15 day model, neither of which are very accurate, and both change dramatically throughout the day. Also, while I agree Accuweather isn't usually the best, lately I've noticed that their local temperature forecast has been as or more accurate than most of the local forecasters which is why I've been looking at it more recently. And the more I pay attention to forecasting and what actually manifests, it just further affirms for me it is all a crapshoot.

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  9. This is my opinion on the whole long range forecasting deal. I assume what they do is look at the averege temp and start from there. Than they look at all the factors that would differ from the averege, including precipitation, wind direction, fronts, and all that. That stuff can be so unpredictable more than 5 days out, hence it changes quite a bit.

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  10. Marc: your right....a model just shows a snapshot of what it thinks the future will hold, the key is how consistent is a particular model in their run to run solutions? and does it compare well to other models?

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  11. bill why is it that you include MPR in your grading,for 4 days now they have nothing on sensible weather,all it is flooding and flooding and flooding,i got it already,these poor people in fargo got it too,we would like some forecasting regardless of the precip type,possible thunderstorms tommorrow and snow on tuesday/wednesday you dont think that would effect flooding?

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  12. Plymouth Weather LoverMarch 19, 2011 at 10:59 PM

    Lots of moisture coming. Seems like rain snow line may set up just birth of cities. But with recent trending south of storms, it could mean snow for msp. Thanks for the model links randyinchamplain. You are all over it.

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  13. Plymouth Weather LoverMarch 19, 2011 at 11:01 PM

    I mean north not birth. Getting tired!!

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  14. looks like storm tracking too close to msp,translation more rain,less snow!So randyinchamplin but why?(your always good at explainations)looks like trend lately is further north not south like last few storms,randy any chance it goes further south for more snow!

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  15. Plymouth Weather LoverMarch 20, 2011 at 11:10 AM

    I agree with you big daddy. Still a ways out, but current snow melt and exposed ground will make it harder to keep the atmosphere cold enough to make all snow during the time of most intense precipitation. However, these things always change, but storms this time of year can be quite fickle. NWS is saying 2-4 inches across central mn. This morning, Fox said a couple of inches as did Mike Fairbourne last night after the games. Novak on Twitter says that there will me mostly rain for Cities (Southern MN). Maybe PD will return and offer his opinion.

    By the way, I love tihs weather site, Bill. Thanks for hosting it.

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  16. My neighbor, Roger, is forecasting mostly rain from this system. Possible 1-2 inches of slushy snow and then he thinks we'll get a little warmer by the weekend than most others are predicting. He says low to mid 40's for highs as opposed to the upper 30's that seem to be more prevelent in the forecasts. Then look for a pretty quick warm up the start of the week of March 27.

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  17. Do you suppose that the south metro might experiance mainly a rain event, while thnorth metro might experince mainly a snow event, considering the snow line?

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  18. randyinchamplin when reading the nws discussion page it seems that there is still alot of uncertainity,with winter storm watches as close to the metro as hinckley,i know what the current models are suggesting but spring storms can be very unpredictable anything in any of the other information you look at that may suggest an southern shift to the wintery precip,also whats your consesus on next weekend

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  19. Shocked there is not a dense fog advisory issued here. (Red Wing) It is REALLY foggy.

    Looks like the storm on Tuesday could dump quite a bit of rain down here in my area, with under an inch of snow when it gets cold enough on Wednesday.

    Next weekend looks pretty cold. Not what I wanna here.

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  20. Ah, looks like one was just issued.

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  21. so anyone know how much snow will fall in metro,nws has up to 2" overnight Tuesday,but also snow likely wording right thru wednesday evening,so how much will fall wednesday,anyone have that answer,most outlets uncommimtely at this point!

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  22. I thought the GFS had dropped the snow fall a little south but I wanted to wait until the 0z map came out...

    GFS 18z http://wxcaster.com/gis-gfs-snow-overlays2.php3?STATIONID=MPX

    GFS 0z http://wxcaster.com/gis-gfs-snow-overlays.php3?STATIONID=MPX

    Beware that is before compaction so measured amounts will be less since the official reporting station only submits amounts every 6 hours....But that seems to be more in line with the ECMWF

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  23. Todd's forecast from the Strib: WEDNESDAY: Much colder with snow. EARLY LOOK & LIKELY TO CHANGE, DON'T BET THE FARM (total accumulations from Tuesday thru Wednesday) - 1" to 2" in the Metro, 3" to 6" across central Minnesota, 6" or more and up to 12" in spots across northern Minnesota. Winds: ENE 15-30mph. Low:28. High:34

    The best part is that all-caps line is also in bright red.

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  24. Bill,just a heads up if you want the full NWS wording on each forecast day you need to go to wcco(so some reason the nws doesnt show it on their website)but the newest totals for snow from nws is 'up to 4" inches' for tuesday night and 1-2" wednesday,so their current total forecast to me would read 5-6 inches for the metro,is that not correct?,I still say no one really has a great handle on the storm and an monkey wrench seems to be hanging around,nws even says in their winter storm watch wording"that great uncertainity in track and intentisty remains"to me that an out clause and an red flag that anything is possible,with the southern shift in winter storm watches this morning(as close to the cities as bethel,which is 35 miles north),I wouldnt be surprised if the metro is included this afternoon,the transition zone is oh so close.

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  25. Sorry all, I've been away for a few days tending to a family matter.

    You have to love this time of year. So many questions, few answers. Spring storms are so difficult to forecast yet they often prove to be quite large and eventful. This one will not disappoint.

    I'm very concerned about tomorrow & Wednesday because of the amount of moisture that will likely fall over much of MN. It appears likely since there will not be a massive T'Storm outbreak south of MN as the storm evolves. In other words, little opportunity for a moisture "steal" south of the warm front located in Iowa. Moisture will be able to pool along and north of the front and this will be come a logical focus for heavy precipitation late tonight and tomorrow. I wouldn't be surprised if flashes of lightning accompany the storms in southern MN late tonight and tomorrow.

    As far as snow is concerned, the thermal profile simply doesn't support snow for the MSP metro until early Wed. AM. However, a quick changeover will occur by sunrise and it will accumulate especially in the extreme northern metro. We need to keep a close eye on the 700mb low. If it tracks 50 miles further south, then all of the metro would receive a blanket of snow by late Wed. I don't think that will happen, but we just don't know yet. The HPC paints the axis of heavy snow 12"+ from near FAR to BRD to GRB with a sharp cutoff in the northern MSP metro. I definitely agree with this synopsis.

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  26. other words of uncertainity:Patrick Hammer comments on the area of watches on the 11am broadcast,no watches in area....for now(suggesting still the possibility)as well as our MIA mpr guys(finally an forecast from them in almost 5 days)when showing the NAM projected snowfall map,PH comments that heaviest snowfall totals of 6"+ stays north of metro....for now(again suggesting the possibility of southern shift of heavier snowfall) UNCERTAINITY is a key word for now!

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  27. Novak you not agreeing with the NWS forecast then,suggesting snowfall of 5-6inches for the metro,what are they looking at that your not or vice versa.

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  28. guys, i know you want heavy snow but as of now it doesn't look to be in the cards. the nam is seen as one of the 'colder' models with this system and even it doesn't switch msp to snow until wed am by then the heaviest precip is to the east. That rain/snow line is tanatalizing close, but the trough is now in the US, not over the pacific, the odds of this storm shifting is decreasing with each model run. I won't say it can't happen, but odds are against it. The main snow band is going to be about 100 miles to the north.

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  29. so anonymous i'll ask you like i asked novak,what is the NWS looking at then then rest of you,when they are suggesting upwards to 6" for the metro,are they just that wrong,or the rest of you just that smarter?

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  30. does anyone believe we will hit an high of 50 that most outlets are suggesting for today,we've been stuck at 38 all morning,if we dont warm as much as predicted today,will that have any effect on the upcoming storm and types of precip.

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  31. Ok hot off the press from the 0z runs....

    Nam: http://wxcaster.com/gis-snow-overlays.php3?STATIONID=MPX


    GFS: http://wxcaster.com/gis-gfs-snow-overlays.php3?STATIONID=MPX

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  32. randyinchamplin,
    does he update the 06 and 18z runs or just the 0z and 12z runs? What a cool tool!

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  33. Truthfully, I'm a bit surprised that MSP is so robust with their metro snow total forecast. It appears that they are expecting a more expedited change-over than what I'm expecting.

    If the change-over occurs by Tue 10pm, then I could see heavier totals in the metro. I'm simply not buying that scenario right now and I would expect a change-over around sunrise Wed.

    We will know a lot more after the 00z runs come in.

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  34. Novak:

    Soundings from bufkit tool, Nam changes to sleet at midnight, snow by 1am

    GFS changes rain to snow between 7am and 10am

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  35. What the impacts of this rain and snow on the flooding probs? Sounds like its purely going to be run-off...

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  36. Looks like winter storm warnings have been issued.

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  37. NWS no longer robust on metro snowfall,dropped totals to 2-3inches as of now,with an cavaet in their winter weather briefing"snow line transitions south during the evening,final snowfall totals highly dependent on when the transition occurs,I work the graveyard shift I'll be the first know when that occurs,time will tell,if its the NAM or GFS! side note Ron Trenda(wcco)threw out metro totals of 3-5inches at the noon hour broardcast,thought you should know bill for grading purposes(they same to be the most robust at this time)

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  38. Thanks for all the info, particularly you, big daddy.

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  39. no worries,anything to help Bill. This storm not going to help the cause on flooding though,especially the fargo area i was in over the weekend,any more precip is not good,and they should be all snow so when that melys not good news

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  40. I have to admit, I'm nervous about this one. I could see the rain/snow line setting-up further south than expected especially when viewing the latest 00z NAM run. I'm starting to believe that the north metro is a lock for 3" - 6" of snow. As usual, a 50 mile shift south in the 700mb low would make a world of a difference and that could easily happen.

    Patiently waiting for the GFS and WRF to come in. 12z ECMWF showed a window of opportunity for accumulating snow Wed. AM. Change-over is the key and difficult to predict.

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  41. Novak I appreciate your honesty,its been touch and go for awhile with this storm,I keep saying uncertainity is the word of the day,change-over is key I agree with you there,and I believe it to be sooner rather then later,we see what happens.

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  42. interesting DD said... things are changing, he said he may have to move the heavier totals south....waiting for his 11:15 forecast

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  43. On the 11 p.m. news, Dave Dahl upped metro totals to 3-5 inches for metro.

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  44. I saw that, but I think he said 3-5 for the south metro, which I would assume means the airport...I think he closer to 4-6 for north metro, thoughts?

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  45. Ok here goes, my snowfall total for this storm based on the NAM coming around to the ECMWF solution, which it has been somewhat consistent in. This will be based along the I-35 corridor.

    North of 694 to Northern Anoka county..8-10"
    South of 694 to 394 6-8"
    South of 394 to 494 4-6" including the airport
    south of 494 to Lakeville 3-6"

    but Like Novak said....any change in the track of the upper low could change everything, but my confidence level is 7 out of 10

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  46. PD(is back)he has upped startribunes snowfall,calling for 1-2 south metro,2-5 north/west metro,even 8" for far north metro,and the boys at MPR had an midnight update with increased snowfall now at 2-4",I got to tell you guys this is not feeling comfortable,I think an even further shift south may occur,I told you the word of the day was uncertainity,it will be interesting to see what the NWS has to say in a few hours!

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  47. wow randyinchamplin,good stuff,I like how precise you are with the snowfalls,incredible how things have changed with your numbers shouldnt we see an winter storm warning posted for the metro by morning! Randy I have to ask but why the southern shift,you always seem to have an explaination

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  48. big daddy:
    to me it's not all that big of a change, the ECMWF has shown this solution the last couple of days of it's runs...it did add a couple of inches in the far northern burbs...but it has been pretty steady at the airport...between say 4-6". The Nam just caught onto that solution, that's all.
    During the change of seasons March through April, historically the ECMWF has out preformed the domestic models and btw, with the NAO going in the tank, once we drop below freezing will may not see a reading above 32° until the end of the month. (insert crying smiley face)

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  49. oh I forgot to answer why the shift...as always with this system our snow producer has been the 700-500mb low passing across the state from the nw to se...the nam just droped it south is all. And in my opinion the GFS is now a complete outlier...I don't know what it did, but it now shows the heaviest precip on a north to south axis as opposed to east to west like every model shows.

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  50. well dont know whos correct,but NWS doesnt see the need for any change in their morning discussion in fact proably only forecasting at most an inch of snow for metro now,they are using the GFS40 model.So randyinchamplin NWS not buying into any of last nights changes,going to be an interesting day I guess!

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  51. Off topic, in the title where you say "snow event" reminds me of a George Carlin joke.

    "I heard on the news that Louisiana is expecting a rain event. I said holy s***, I hope I can get tickets to that!"

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  52. Radar trends over the Upper Midwest appear to be showing a southern shift to the precipitation shield. With that being said, portions of northern MN will likely experience a big time BUST in their snow total forecast.

    Originally, the models had the heavy snow axis stretching from Minot to GFK to DLH. However, it appears that the axis will run from just north of BIS, to AXN to BRD. This would place the northern MSP metro in a favorable location for heavier snow bands.

    This southern shift would also bring a quicker change-over for much of the MSP metro. I find it amazing that we could receive 1" to 2" inches of rain followed by a half a foot of snow. But, it is Spring, and weird things happen this time of year.

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  53. Weather Wx for Hennepin and Ramsey Counties, Winter Storm Warning now for Anoka and Washington Counties.

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  54. bout time

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  55. Randyinchamplin you aint kidding about time,your interstate predictions may very well come true,going to be an wild night and I will have an front row seat since i work the graveyard shift,it would seem to me everything will be caked in white with such an wet snow.So Bill when is your cutoff for grading,storm actually started last night but snow wont fall till after midnight tonight and there has been some numerous changes in the forecast in between that time,the NWS to name a few.

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  56. I live in Red Wing like I've said earlier...anyone know how much snow I'm gonna get? I consider myself pretty good at navigating through the various weather sites and I even look at the models myself a lot but have no idea how much will fall. You guys seem to know your stuff, so if you could maybe give me a link or two to a snowfall model site, would be much appreciated.

    I should add, everyone is saying it won't swtich to snow until late, but all 5 of my thermometers at my house or hovering right around 34 and Cannon Falls nearby is reporting light snow. Thought that might alter the total accumulation thinking.

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  57. Marc:

    Here is a link explore and enjoy!!!
    http://wxcaster.com/models_main.htm

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  58. Weather.com keeps upping their snow predictions. They're not very reliable, but they've raised possible totals to 4-6 inches in the SW metro. Is it possible we're going to get an unexpected dumping after all? I'm ready to be done with winter...that thunder lat night was music to my ears!!!

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  59. latest from the Nam...don't know if I believe this or not....but this is what it shows

    http://wxcaster4.com/nam/CONUS1_MESO-ETA212_SFC_ACCUMSNOWFALL-KUCHERA_24HR.gif

    yikes if that verifies

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  60. Weather.com is now up to 5-8 SW metro. Paul Douglas also just updated his blog. The three runs he's looking at from 6 pm suddenly say 17.5, 20, and 14-18. He said he needs a nap. I think he needs a drink. He's leaning toward 4-8" for now, stating that a shift this big needs another model run to be verifiable. I am not pleased. I'd just put away the skis and pulled out the running shoes!!!

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  61. http://wxcaster4.com/gfs/CONUS2_GFS0P5_SFC_ACCUM-SNOW_24HR.gif

    but the gfs tends to confirm it

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  62. If MPX hasn't hoisted a winter storm warning yet for Hennipen county...I would expect one soon

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  63. Randyinchamplin...thanks much. I can get more info from you and everyone on here than the local outlets! Thanks for the links and to everybody else: Thanks for making predictions and giving the model info and all that. Makes it a very enjoyable read, and I rely more on this for updates than anywhere else!

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  64. Crap. Did I mention I just put the skis away? Should have figured, with the boys state tournament starting tomorrow!

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  65. Anonymous two model runs are verifying this...I don't think that its time to wait for one more run...raise the the flag

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  66. ...or take the skis back out. Ah well, Afton should be open this weekend. :)

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  67. New blog post just added. Suggest further storm comments go on that posting. Enjoy the ride!

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  68. I don't know why this is turning out to be a big surprise. GFS/NAM/SREF were clearly showing temperatures rapidly dropping tonight as the main short wave moved across MN. Enough lift and moisture advection going on to generate at least 6", if not 10", across most of the Metro area when all is said and done.

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  69. For those interested, the 2011 Minnesota Skywarn Workshop will be in Minneapolis on April 9. It sounds like several of this site's frequent visitors will be there. Details: http://www.mnskywarnworkshop.org/agenda.html

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