Tuesday, March 1, 2011

Forecasters Honing in on Thursday Event and Possible Storm for Next Week

*Late Wednesday night update*
Thursday's forecast snow event: Several forecasters have downgraded snow prospects for Thursday as of late Wednesday night. WCCO, KSTP and the Strib are now calling for a dusting to less than an inch.

Wednesday evening update
Thursday's forecast snow event: As of Wednesday evening, virtually all forecasters are calling for 1-2 inches of snow on Thursday with the heavier amounts in the east metro.

Potential snow event for next Tuesday/Wednesday: All forecasters continue to watch for the possibility of a significant storm next week.

Tuesday evening update
As winter drones on and on and on, so do the forecasts of snow. Through Tuesday evening, most forecasters see some sort of snow event for Thursday while the majority are also eying what could be the third really big snow of the season that keeps giving early next week.

There is some variability in the snow forecast for Thursday. Most weather outlets are currently forecasting 1-2 inches. MPR is predicting 1-3 inches at this point while others see most of it falling to the south (KARE) or across the Wisconsin border (WCCO says the 1-2 inches is most likely across the border). KSTP mentioned the possibility of 3-5 inches just across the border.

The progressive forecast can be found here. Note that given the various "datelines" of each forecast, we've inserted the time of the obtained forecast to reflect that some weather outlets may be accessing more recent weather information than others.

Like us on Facebook and follow us on Twitter and you may just get an advance copy of your forecaster information.

Props to everyone for talking among themselves and providing updates on what all the forecasters were saying while TMF was checking out the snow drifts in Cancun.

69 comments:

  1. Welcome back, Bill. Never figured I would be the first to comment on a blog so I guess here is my chance. ;-) Thursday still looking decent for some accumulating snows across ern/sern MN into wrn/ctrl/nrn Wisc overnight into Friday morning. Despite no significant surface low its pretty evident a decent inverted trough will form with evidence in 700mb and 500mb forecasted patterns. Inverted troughs, as we know, can be very efficient snow-makers. Add in a nice 850mb theta-e gradient over the area this does looks pretty snowy especially E of the Cities. Still thinking 1-3" in the metro (more on St. Paul side to Wisc) rising to 2-5" into wrn to especially ctrl/nrn Wisc with a few areas possibly higher if inverted trough intensifies with upper PVA energy.

    I am a snow hound like the rest of us, but the expected pattern of the next few weeks does not bode well for the spring flood season. Granted, the GFS can be ambitious on winter storms, however, it really makes me nervous.

    ReplyDelete
  2. Thanks for the welcome back, DDwx. It was a hard-earned return, though, as yesterday's stormy Atlanta weather proved challenging for someone making connections at Hartsfield.

    Appreciate your informed input into the blog!

    ReplyDelete
  3. Hartsfield is very challenging even in perfect weather.... PDs 15 day forecast shows nothing as far as snow goes...even for next tuesday

    ReplyDelete
  4. Ouch, the ATL was not a fun place to fly into yesterday. Rush hour on the ground was no treat either especially I-75 NW as I sat in it for a bit while a tornado warning was going on straight north about 6-8 miles. No touchdown, but the cell did mix down some straight line winds causing damage and power outages. I'll take MN snow any day over tornadic weather in the hilly terrain of metro Atlanta and North Georgia as well as the horrific traffic the city possesses.

    Keep up the great website -- fun to keep up with weather in the homeland.

    ReplyDelete
  5. did i read Updrafts blog right?...8 to 14 on Tuesaday?..is that what his graph shows?

    ReplyDelete
  6. It's nice that there are people on this blog with a more technical look at these systems. I am nothing more than a weather enthusiast, and am trying to learn and find these things people speak of. I know some of the basics, and have been messing around with Bufkit a bit, but all in all I have a ton to learn. That being said, DDwx predictions seem to be accurate with what I was initially thinking. The 00z GFS does look scary for early next week, and I just checked P.D's blog, and he does mention that system. This system looks a bit similar to the two larger storms that hit the metro, but as is normally the case with storms a week away, I'm sure many changes will be seen with it.

    ReplyDelete
  7. Where is this storm now? Over the ocean somewhere? Europe? Where is it that they can see it a nearly a week away?

    ReplyDelete
  8. Right now this storm is just an event that shows up in the computerized weather models. It hasn't formed yet, and won't for another three or four days.

    Having said that, I'm not nearly as qualified to answer your question as a lot of the constant commenters to this blog are, and you will probably get a different answer from them. I'm just an amateur geek.

    ReplyDelete
  9. @NovakWeather on TwitterMarch 2, 2011 at 9:26 AM

    Truth be told, at this point in the game, you kinda have to go with a gut feeling on what will happen early next week. The model consensus is that a classic "March like" storm will develop but what will it be?

    My gut feeling is that central & northern MN are due for a snowstorm. That would leave southern MN, including the MSP metro with rain.

    However, there remains many days ahead to ingest all the weather data that will be thrown at us.

    ReplyDelete
  10. Thursday system seems to have the best lift and higher vorticity values in the Eau Claire area.

    Therefore, for the metro a Trace far west burbs, to as much as 2" for the far east burbs, with Eau Claire having the best shot at 2-4". What concerns me the most is the chance of freezing rain from Rochester to the Lacrosse area.

    Idea's for next week will come in about a hour

    ReplyDelete
  11. at the airport going with 1-1.5" at this time

    ReplyDelete
  12. I'm surprised that tomorrow's snow is not receiving more love. Granted, it may tap into more moisture as the storm moves east, but the lift and dynamics warrent more than a 1" snowfall prediction I.M.O.

    ReplyDelete
  13. What was originally good model agreement for next weeks system has turned into several different outputs. In regards to the track of the systems, the 12z models still have pretty big differences. The 12z GFS takes the low from western Kansas to southern Iowa to southern WI then up to the northeast into Canada. This would keep Minnesota and western Wisconsin in the cold sector of the storm, bringing a significant snowstorm to the area. The upper level dynamics of this system are quite good. This track is a little different from what the 00z run showed last night, but remains cold enough for snow. The 12z European model, however, continues to track the low up from northwest Kansas to west central Minnesota, then to the northeast through the arrowhead region. This track would put the metro and western WI in the warm sector of the storm, and have it be mostly rain, while giving the Dakotas and northwest Minnesota a significant snowstorm. 12z GEM matches up a bit better with the GFS, but this model has been bouncing around as well. Certainly something to watch over the next several days to find out if we are in for some potentially heavy rain, or potentially heavy snow.

    ReplyDelete
  14. Discussion on the systems Sunday through Thursday:

    Sunday through Tuesday morning the GFS and the European our remarkably similar. A clipper system will drop in from British Columbia out ahead of our main system and will affect the gopher state late in the day on Sunday and into the overnight. The precipitation should be all snow, but how much and where?? That is still to be determined.

    As the main system enters the Pacific Northwest, a piece of energy will break off and also affect Minnesota on Monday and into the overnight, again amounts and location to be determined

    As the main low starts to strengthen in the lee of the Rockies and gets kicked out towards us is where the models start to diverge. As Duane said the GFS takes the low over Iowa to southern Wisconsin and keeps eastern Minnesota on the cold side. On the other hand the European cuts the low up over Western Minnesota leaving Eastern Minnesota on the warm side with the greatest snow accumulations just where we don't need to see it, from Fargo south along the Red River Vally.

    The question is why the divergence? As the main system approaches us the GFS has a pocket of colder air dropping south out of west central Canada into Montana and western North Dakota which pushes the low to our east. Conversely the European has the cold air following behind the system which is allowing it to cut up.

    Which solution has the best chance to verify?? Based on how the European has handled tomorrow's system, I am inclined to lean towards it at this time.

    ReplyDelete
  15. A little side note on my previous comment. Now that all the ensembles are in as well, there seems to be quite a good clustering of the models taking the low up into southeast Wisconsin, with the operational run of the Euro the only one taking the western MN track. Normally I would be sold on the Euro being the outlier model, but this particular model has done wonders so far this winter, so I'm not counting it out yet.

    ReplyDelete
  16. Bill, Are you still going to give "grades"? The 'Report Card' hasn't been updated since the end of January.

    ReplyDelete
  17. I am going with 10-17 inches Thursday based on my feeling in my right knee. I was shot in the 1st gulf war 20 yrs ago. Statistically this knee if graded by TMF would be at 80-100%.

    Now what the knee is telling me for Mon-Tues is quite different. I am feeling in the knee is bad, I mean bad. I feel a large surface low of 890 millibars or something like that. Katrina style low pressure feel. So the knee is being squished bad here folks. I am going with a gut feeling of 17 to 37 inches of slush with 40 to 60mph surface winds. We will break the record. St. Paul will cripple and we can all relax and know the record broke!

    That's what the knee is saying on the first oulier from the Rockie

    OOH RAH!

    ReplyDelete
  18. @NON, thanks for the comic relief!
    @Anonymous... promise we'll get to the grades in the next day or two. Ultimately, by the way, they all seem to be falling into the same general category.

    ReplyDelete
  19. I have to agree with Non... my knee & hip are saying something similar, and had I been born 100 years earlier I'm pretty sure I'd have made a decent weather-witch.

    ReplyDelete
  20. For those interested in assessing our chances for breaking the snow record, MPR's Paul Huttner wrote this in yesterday's MPR blog: "Looking at the weather maps over the next two weeks and doing the math leads me to believe there is now at least an 80% chance this will end up as the snowiest winter on record in the Twin Cities."If Paul were also a bookie, I'd bet on the under with those kind of odds. Twenty-three inches or so left to cover is not chump change.

    ReplyDelete
  21. DD is going way out on a limb speaking of a storm for the following weekend....that in no way has formed yet...how is it possible to predict such things?

    ReplyDelete
  22. I agree John, and particularly the way he says it with such seeming certainty. The bull's eye has already been identified!

    ReplyDelete
  23. how can computers detect storms that havent formed yet?

    ReplyDelete
  24. http://www.research.noaa.gov/weather/t_modeling.html

    That link is a good starting point, John. I finally know what some of the acronyms mean that get tossed around here.

    ReplyDelete
  25. The Models analyze upper air patterns and other types of data to create a dataset. So While the gfs may say that another storm could form 2 weeks out it may not necessarily be the case, each model interprets its dataset in its own right. Forecast models get pretty speculative over 5 days out but when more than one model latches on to the potential of a storm, it starts to give forecasters more confidence that the potential could become a reality. That said if look at the 18Z run of the gfs it shows 3 potential storms affecting our region in the next two weeks, of course this will likely change but it make some sense considering the storm track is beginning to shift north as warm air tries to come our way this time of year

    ReplyDelete
  26. i am curious what the 2 numbers before z means...Thanks to all for your explanations

    ReplyDelete
  27. Military time, Gfs comes out with 4 runs daily 0z 6z 12z 18z

    ReplyDelete
  28. thank ytou Matt...that clears up alot.....is gfs not as accurate as the others?

    ReplyDelete
  29. Jon that is Universal Time Coordinated (better known as Zulu time) right now 0z=6pm, 6z=midnight,12z=6am and 18z is noon.(24z btw also is 6pm...hope that helps, it will be changing when we go to Central Daylight Time. as in spring ahead and fall back

    ReplyDelete
  30. thank you Randy.....it does help....are we still expecting an inch or 2 tommorow?

    ReplyDelete
  31. There are several different things programmed into these forecast models that do try to predict what it thinks will happen. From what I understand it uses tons of information loaded in from data gathered from weather balloons, aircraft, etc. Forecast models, however, become less and less accurate the further you go out, because there is important data missing from their solutions...data that is usually obtained once the system reaches the west coast and gets into our weather network, and the NWS can launch weather balloons into it to get a more accurate forecast. This is a big reason, from what I understand, why they fly hurricane hunters into tropical systems...so they can gather this other data that we usually don't get until the system makes landfall. I don't know a ton about exactly how forecast models come up with what they do, but I do know that really beyond 3 or so days, they start to get less and less accurate. Going out on that much of a limb is certainly risky. I will say that even though DD does do that, I think he keeps it general enough that it isn't thought of as a guarentee.

    ReplyDelete
  32. well it seems to work....they were spot on with our last mega snow....Hurricaane hunters mostly check wind speed speed of the storm..direction of travel....and barometric pressure

    ReplyDelete
  33. It is so frustrating when the models change their tune as an event approaches. Such is the case with the NAM on tomorrow's potential snow. Now the NAM shows very little if any upper air support for Thursday's storm. Hell, if you were to base your forecast strictly off the NAM, you would expect hardly a flake tomorrow. I'm beginning to wonder myself.

    Yesterday, the NAM was showing 3"-5" of snow.

    ReplyDelete
  34. DD just down graded tomorrows event to just a coating for the TC

    ReplyDelete
  35. I'm going with a Trace to a half inch....I was busy tonight, i didn't see any forecast, however would not be surprised if nothing fell

    ReplyDelete
  36. As NovakWeather states, it is frustrating when the models change their tune within 24 hours of an event. But, the key is to keep looking at the satellite, surface and upper air data and see how they are verifying compared to models. Obviously, models are seeing something but at times they over or under react to subtle changes. I still see the energy coming across the NW US/swrn Canada so hate to just rule out snow completely. It will be interesting to see what takes place Thur night. I think I mentioned 1-3" with the higher end toward far eastern metro into western Wisc. I hate to yank precip amounts completely based on one model run. Rather, a slight trend saying maybe 1/2 to 2" or so as things can change on 06z and 12z runs. The 12z run will be the most trusted so will see what it says in the AM.

    Next Tuesday -- uff-dah. I refuse to give accumulations that far out -- irresponsible in my opinion as too much can change especially this time of year. 10" of snow can rapidly turn to 1" of rain in March events in a volatile pattern. A significant winter storm is definitely likely in the Upper Midwest and I will stick to that for now. That should be enough to make folks start to think and plan for it. Amounts to come in a few days.

    ReplyDelete
  37. Well, that 00z run was certainly an interesting one. The GFS is pretty much sticking to its track, only is a bit stronger and is therefore dragging more warm air up with it. Could be a whole mix of precip if that were to verify. The GEM made a bump to the east, bringing the low up through the metro area (its ensemble takes it north of Chicago), and the Euro made another big leap back to the east again and drops a good amount of snow with it too. At this point (and a lot can change, of course), it looks like a potential low snow ratio event, meaning the snow will be wetter and heavier in nature. Still lots to sort out with this system, but the models are actually closer to a similar solution than they were even 12 hours ago. Keep an eye out :)

    ReplyDelete
  38. DDwx....and Congress want's to cut the budget of the NWS by 30%? If we only were to get upper air analysis once a day or every other day? The forecast could turn out to be something like the armistice day blizzard. YIKES

    ReplyDelete
  39. Euro has come more line with the consistent GFS,looks like a dumping of snow in the making(at the very least half way to our record snowfall)also alot of wind with this storm,with the wet nature of the snow everything will be caked in white,possible look duration snow to(that comes in pieces)from late sunday to wednesday. Anyone notice how PD used the word 'fizzle' and got it correct(had to wait 12hrs before the event unlike last time when our 2nd major snowstorm fizzled 6 days prior and now hes throwing out amounts near a foot 6 days out)

    ReplyDelete
  40. With all the models coming to somewhat of an agreement for next week.....I predict major dumpage for the metro, rain snow line by Albert Lea, Roch, and La Crosse.

    ReplyDelete
  41. Hey Bill, maybe you can put a link page up for all these models people are discussing, because I only have the "knee" to predict weather. Even Mr. Google doesn't goive the info up easily. And I am all about easy. Actually I need to get the Netflix queue update for the mid week mega storm next week when all the schools close.

    ReplyDelete
  42. PD never, I mean NEVER uses anything but hyperbolic language in his reporting. It's either the end of the world or it's a "fizzle". Terrible habit in my opinion.

    ReplyDelete
  43. Annon....There's a plethora of sites for WX models. But, here is the NCEP site for WX models. It's beta now (experimental) but will be operational on April 10, I believe. click on model guidance tab.

    http://mag.ncep.noaa.gov/NCOMAGWEB/appcontroller

    ReplyDelete
  44. Sweet, now I know where PD gets his pictures from.

    ReplyDelete
  45. Thank you for the link. Now I have more to learn!!!!

    ReplyDelete
  46. Seriously, I'm damn near ready to throw the NAM out the window. This flip-flopping is absurd!

    ReplyDelete
  47. Anyone know where PD gets his texture models? Paul Huntner also has them on his blog sometimes. I was wondering if those were open to the public or not. They are the ones that he often points out "potential thaws" or "Potential Cold Snaps" with.

    ReplyDelete
  48. Marc....goggle gfs 16 day text forecast, it will be your first choice...there will be a box next to where it says gfs 16 day plots, clear that box out and insert the air port code for the minneapolis airport, that code is kmsp

    enjoy

    ReplyDelete
  49. Marc you can also go here http://en.wikipedia.org/wiki/List_of_airports_in_Minnesota...to get the other airport codes, airport codes are always 4 letters and all begin with the letter K. often times you will see them referd to by only the 3 letters such as MSP

    ReplyDelete
  50. randyinchamplin...that's what I've been looking for for a while now. Thanks much!

    ReplyDelete
  51. Marc...your welcome

    ReplyDelete
  52. Mr Novak...the nam has been sitting in the snow bank here for some time....I retrieve occasionally but more often times it ends up right back where I got it from lol

    ReplyDelete
  53. however I do like the nam moss for temps etc

    ReplyDelete
  54. DD says the tuesday wednesday storm has a chance to fall apart...any reason why he thin ks this?

    ReplyDelete
  55. John, he said that because it is still a ways away and plenty can happen between now and then. I don't think he sees anything that would make him think it would fall apart, it's just the usual uncertainty of long range forecasting. Most of the major models, however, are pointing at a pretty good size storm...so that is going in a snow lovers favor.

    ReplyDelete
  56. Updraft is talking about the possibilty of heavy rain week after next....yikes...Thanks for the insight Duane..

    ReplyDelete
  57. John,updraft(Paul H) speaks of heavy rain cuz he is looking at one models long range forecast that shows a high of 56(10 days from now)Paul Douglas does that often as well looks 10-15 days out and says things like 'extended thaw coming?' but the very next day the temps cool off,we very well may have heavy precip then but could fall as snow then,temps arent going to warm up that drasctic(I could see 40's,but also colder then normal temps are in the cards for late March-early April(according to several long-long range forecasts.

    ReplyDelete
  58. I noticede PDs 15 day forecast is constantly changing..and often contradicts his blog...why bother..

    ReplyDelete
  59. TRULY UNBELIEVABLE! the numbers that PD just threw out on his blog,we are roughly 4-5 days out from this potential 'blizzard'( term was used by DD in his evening blog) and he is saying 12-20 inches(based off the current models I know),but man is this thing blowing up or what! he even mentions the storm after this one(that DD spoke of yesterday) and get this(using info from another website)he puts a graphic showing southern mn(including metro) with snow totals of 30-53 inches between now and March 18th.like I said truly unbeleivable March we have ahead of us if these storms pan out,that record wont even stand a chance,oh and that thaw that Mr. Paul H(mpr) was calling for starting weekend of 3/12 with a high of 56 a few days later,GONE!why to hype the warmth Paul,mother nature isnt giving up winter easy like it did last year,nothing higher then 35 degrees next 15 days,and if anybody is looking for another record to break(as if 98.6 inches of snow wasnt enough)we are 44 days away from breaking the concusetive days in a row with at least 1" of snowcover.WOW what a winter,I guess I'll be filling sandbags next week! Enjoy the snow and the falling records,something you can tell your grandkids.

    ReplyDelete
  60. Concerning next week

    The European and the GFS are now on almost the same track bringing the surface low over the Qaud Cites area of Iowa up over the WI IL border, but I noticed that the Euro only has .72" of precipitation in it as compared to 1.37 for the GFS. That peeked my curiosity to say the least so I went digging deeper and found 3 major differences.

    #1
    As the surface low passes over the WI IL border the GFS has it at 1000mb which is slightly deeper than the European at 1004mb so the GFS has it stronger.
    #2
    Both models have a upper level low accompanying the surface low, this upper level feature on both model moves into sw SD. From there the European dissipates this feature while the GFS allows it to move into sw MN and extends it to the Brainerd Lakes area early Tues evening to Wednesday morning. It is no small coincidence that during that time is when the GFS puts down almost a inch of the 1.37" storm total.

    #3
    Because of the presence of the upper level low (at 500mb heights) the Vorticity Max is in the +8-12 range on the GFS and only around +2 or so for the Euro. In addition at that same time frame the 700mb vertical velocity is in the 10 plus range on the GFS as compared to the 0-2 range on the Euro.

    Because of these differences I may have to lower my snowfall prediction from the 10-15" range to 8-12". We will see what tomorrow afternoon brings.

    One a side note, there are 3 other medium range models that create a near miss or a miss altogether with this system. However I don't give them much credence at all because they have performed very poorly this year at best, when this far out.

    ReplyDelete
  61. Big Daddy
    I hate to burst the snowmaggedon bubble but my confidence level on the 2nd storm is 3 out of a possible 10, the European puts the precipitation down across WI at this time, but it is something to watch carefully

    ReplyDelete
  62. Randyinchamplin,
    Thank you for your through post(very informative)but the Euro has been back and forth and very wishy-washy with regards to the first system,while the GFS has been very consistent with its solutions,with almost every run the last 3 days,I can see the total QPF come down some but nothing less then 1 inch,with time the Euro is coming inline with the GFS,not the Gfs coming inline with the Euro,but either way you look at it it will be a dumping of at least a foot,I know the second storm is in the models dream state right now but it is close and like you said worth watching,what did you think of that 53" figure(did you read PD's blog)but with temperatures below average thru most of the month most of these systems will fall as snow.

    ReplyDelete
  63. Do you guys sleep?! Don't get me wrong, I love that you guys are up all night watching the models and giving me something weather-realted to read when I get into the office!

    I do want to thank you guys for level-setting all the various forecasts out there. You are shedding light on the fact that weather forecasting is difficult and nowhere near exact. It's like all the weather guys out there are playing in the same sandbox with the same raw data, but they're all building their own sandcastles.

    Phunnyfarm

    ReplyDelete
  64. The previous comment above from 'Anonymous' is fantastic and so true. We all have access to the same data and it is interesting how we all interpret the data and come to our own conclusion.

    What I find interesting over the last month or so is how close the Polar Vortex is to the lower 48. Whenever the Polar Vortex is close to MN in March, that usually means trouble. Often, the Polar Vortex will oscillate from one area (Gulf of Alaska, Yukon) to another (James Bay, Siberia, etc.). However, it seems like northern Canada and James Bay has been the bullseye for the Vortex (cold core of air) much of this winter season. My bet is that Siberia has been much warmer than average over the last few months.

    ReplyDelete
  65. Weather on the front page of the Stat Tribune. Too soon for totals?

    ReplyDelete
  66. @NovakWeather on TwitterMarch 4, 2011 at 10:39 AM

    Something smells with next week's storm. Do you see how the 12z GFS blows this thing up in the Plains on Tue. then cuts off the moisture source a bit as it heads east into the Midwest on Wed.? It appears that the Jet dynamics outrun the storm by mid-week. I know we shouldn't put too much faith into one model run, but this is a bit alarming.

    Definite BIG snows (12"+) west of MN, but here? I would be cautious on this one at this juncture.

    ReplyDelete
  67. Novak

    This could be a anomaly, we will have to see, i don't know if the upper level jet outruns the storm or not, but I do know upper level jet (200mb) has dropped to the south, and now the track has taken a more southern and easterly dip

    ReplyDelete
  68. GFS pecip is now at about .65

    ReplyDelete
  69. I suggest moving future comments to the most recent blog post.

    ReplyDelete