Tuesday, April 5, 2011

First Stormy (Severe?) Weather of the Season This Weekend?

Updated the forecast highs for the weekend (in red). In two days, Fox has raised its forecast high for Saturday by a whopping 16 degrees. Most outlets have raised forecast high temps as well, but not to the degree that Fox has. However, interestingly enough, the late Strib update reflects skepticism that temps will get out of the 50s on Saturday, making it the only forecast to reverse the trend.

Forecasters are suggesting a thunderous weekend may be in store this weekend with the season's warmest temperatures to date. We're not sure exactly how to grade and assess such a forecast, but it's worth a discussion. So, discuss away.
An impressive sunset on Monday evening.
Here's a quick weekend temperature forecast (Saturday/Sunday) from your various favorite weather outlets as of Tuesday evening (Thursday evening):

WCCO: 64/62 69/67
KSTP: 64/68 70/72
Fox: 54/57 70/66
KARE: 62/60 66/68
NWS: 58/63 63/65
Strib: 64/67 58/73

Note the largest temperature variance is between Fox and KSTP.

68 comments:

  1. A high of 60 on Saturday, and 66 on Sunday according to the NWS (for RW) Holy crap! Every day it seems they keep warming us up a few degrees. I bet some locations in southern MN could reach 70 or heck, maybe even 75. How warm does it have to be for severe weather?

    Just hope it steers away from Saturday, have a pretty big event happening through the day all outdoors.

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  2. NWS mentioned one model putting us well into the warm sector of this system, with 80 degree temps along with it. They aren't forecasting that high yet, but if that trend continues, the trend up in temps should continue. As far as how warm does it have to be for severe weather...well, there is really no set temperature before we get storms. It really does vary on a case by case basis. We can be in the 90's and get nothing, and we can be in the 70's and get tornadoes. It is really dependant on how much of a cap there is, and how much warming will have to take place to errode the cap. A pretty good set up is certainly showing up at this point, but there are still a few days to really pin down what could potentially happen.

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  3. Taken from various severe weather forecast contests --- you can award points first if a watch is issued. You can then award points for any warnings in the area or within xxx miles of a given point. The verifier is usually a severe weather report that the NWS issues in the form of a Local Storm Report (LSR). You can have points for that as well. The more warnings and/or verified LSRs to more points? Would have to be within xxx miles of the Twin Cities and/or within the viewing area.

    I am sure there are those on here who have some experience with NWS verification practices that could throw out some ideas, too.

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  4. It's still too early to comment on likelihood of severe weather locally, but it's possible. Need to see more model runs since the models tend to be a little goofy this time of the year. Moisture return will be the big X factor here.

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  5. You can get severe weather in the 50s if the conditions are right. Instability (rapid cooling of the atmosphere with height) and shear (along with other factors) determine severe risk.

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  6. @NovakWeather on TwitterApril 6, 2011 at 10:28 AM

    Hell, you could get severe weather with temps in the 30s or 40s. Often, especially in the Spring, elevated convection can produce severe weather. It may be cool at the surface, but much warmer at mid-levels. This usually occurs just north of a strong warm front that contains a ton of Warm Air Advection (WAA) at 850mb/700mb.

    I'm not sure what Fox is looking at when viewing their predicted highs for this weekend. Even the MOS guidance has MSP around 70 for Saturday. I could see us NOT warming as much if the warm front does not reach MSP, but that appears highly unlikely right now.

    The severe weather opportunities look interesting, even this far out. Jet structure looks good, significant WAA in low/mid levels AND a strong front near by. Should be fun to watch this thing evolve on Saturday especially when considering that the 'SkyWarn' conference is in Minneapolis during the day. Wouldn't that be appropriate? I hope to see you all there.

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  7. Is it just me having had too many beers, or the 12z GFS has almost obliterated the whole thing for Saturday/Sunday?

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  8. Rigil Kent

    no your not seeing cross eyed, that's the way it looks to me as well. At any rate whatever should happen on Saturday I think will be a nocturnal event. The GFS is pretty stingy on the precip amounts, but the ECMWF looks a bit wetter with maybe a inch of precip....we will see

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  9. The first actual outlooks are out from the SPC, valid for Saturday. The two links are the risk areas, and the likely hood of where the storms could be, at this point.

    http://www.spc.noaa.gov/products/outlook/day3otlk.html

    Don't count anything out yet, as the new GFS is bringing more instability back into the area. Still looking very interesting for the weekend.

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  10. I have to admit that I'm excited for this weekend's storm. There is always something special about our first potentially large severe wx outbreak.

    You have to like how the models are trending, especially the last couple of runs. The warm front will likely set-up near or just north of MSP on Saturday and move little on Sunday. This should give much of southern MN and WI 2 days worth of severe wx opportunities. If the warm front does indeed set-up north of MSP, then some of the T'Storms will likely become rooted in southern MN which would increase the tornado threat.

    I would expect the first outbreak to occur Saturday evening and overnight. Then a break Sunday AM before another round of storms develop Sunday afternoon and evening.

    As far as media outlet predictions are concerned, I'm still surprised that some outlets keep temps in the 60s this weekend. I can't imagine that most areas will not hit or eclipse 70 degrees.

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  11. Just looked at the video forecast on the web for the sites that TMF grades. All are doing a decent job of letting people know that a severe threat is out their, that's the good thing. On the flip side most people I think would like to know where the best chances is, therefore I feel at the very least, put up the categorical map from the SPC, if not the probabilistic map. Therefore the best grade that I could give them now would be a C across the board.

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  12. and yes this weekend looks very interesting indeed. The GFS and the ECMWF are in good agreement through 1am Sunday morning, showing the strongest storms along the I90 corridor and points a little north of there from Albert Lea to the Mississippi sometime between 7pm Saturday evening and early Sunday morning. After that time frame there is little agreement. For Sunday, I would think there could be a chance for severe in Eastern MN, but I think more likely that it will be in WI from Eau Claire to the Illinois border, with the best chance south around 4-9pm, but confidence in Sunday is low at this time.

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  13. btw MPR just posted the SPC maps, way to go!!!

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  14. Why would you guys be rooting for severe weather(Novak post,getting excited for this weekends weather)severe weather brings tornado outbreaks which ruins and destroys lives and property and cause deaths,you guys are sick and twisted,yeah bring on that severe weather! Give me an old fashion snowstorm anyday it least it's not known to kill you if your smart enough to stay inside during a blizzard,if it's not going to snow then keep the severe weather away as well,regular old rain and downpours would be fine.

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  15. You can't do anything to stop it so who cares if someone enjoys following it?

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  16. If the weather forecasters AND the public pay attention, then, in theory, nobody would lose their life. That is what makes this exciting.

    Weather forecasters have the opportunity to save lives. Think about that. To me, that is an adrenaline rush.

    Also, it is fun to watch the dynamics of severe wx come together in an effort to pinpoint where a meso-scale system will wreak havoc. It is not an exact science, but it is getting there. Each year provides weather researchers more and more evidence to chew on. This weekend will likely be no different.

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  17. For RST, the 12z NAM cranks out a high around 80, dew point in the 60s, CAPE above 2000 j/kg and some twist as you go up in the atmosphere.

    Still a long ways off, but that is optimal conditions for severe wx, especially in April. If a triple-point were to develop near the area...Watch out!

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  18. Plymouth Weather LoverApril 7, 2011 at 12:51 PM

    Anonymous--At least attach some user name. No one that I have read on this site is twisted. When you love the weather, which I do, all weather excites you, especially the power of weather. There is nothing else like it. No man-made power source can do this type of thing over such a wide range area. No one wants people to die or get hurt and your assuming so is pretty sad. Clearly you must not have the appreciation for what all of us who follow this site have--passion for the power of the weather. It is awesome. Bring it on. You can't stop it anyway, so be in awe of it.

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  19. Did anybody watch JB video on weatherbell website? He compares the GFS and EURO for the 15/18 April time frame and he mentions "arctic" outbreak? I played it twice and he really did say that.
    Is he just nuts? Any thoughts?

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  20. Plymouth Weather LoverApril 7, 2011 at 6:00 PM

    I think there should be a minnesotaforecaster.com contest on predicting how much snow we will get between now (April 7) and the end of the snow season in June, or whatever the official end date is, as measured at the airport. The winner could get a minnesotaforecaster.com t-shirt or something. We could wear it with pride. How does that sound, Bill? I will make the first predication. I say it will be 6.3 inches.

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  21. Plymouth, so that we would even out at 91 inches :)
    I like the idea.
    Here is my prediction: a trace.

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  22. anonymous (1:05pm) btw have I mentioned that I dislike all the anonymous people ( I know it's your right but..man up) I have seen some of Joe B's post in the past, if there is anyone who knows the shortcomings of the GFS model, and makes his thoughts public, it's him, and he seems more right than wrong. I know he is arrogant but he does know his stuff.

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  23. Joe B's former employer, Accuweather, is not known for being accurate. Check this sample assessment from ForecastWatch: http://www.forecastadvisor.com/Minnesota/SaintPaul/55116/

    Added a quiz question regarding predictions of any remaining snowfall.... of course people can leave their own predictions on here.

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  24. Plymouth Weather LoverApril 7, 2011 at 10:14 PM

    Thanks, Bill, for adding the survey. Still would love to see specific predictions listed by people.

    I say....watch out for around April 15-18. Rain/Snow is possible and it could be cool enough for late season snow. 6.3 inches......here we come. Follow my gut.

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  25. All model runs now appear to be placing a triple point near southern MN on Sunday. Should get very interesting later this weekend.

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  26. Agreed. Sunday is starting to look far more interesting than Saturday.

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  27. Baroclinic_InstabilityApril 8, 2011 at 12:11 AM

    Hello folks. I am a moderator on a popular weather board, an NWS meteorologist, and a weather fanatic originally from MN. Would love to have more MN forecasters on our board. Here we are discussing the severe threat. http://www.americanwx.com/bb/index.php/topic/16568-april-7th-10th-severe-weather/page__st__400

    BTW I know you Ryan--I am from Shakopee too. We emailed each other a few times earlier this summer.

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  28. Sunday is looking down right nasty, the GFS has a positive tilted system at the surface, with a ever so slightly negative tilt at 500mb....Hmmm

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  29. OK hot of the press, we are in a Moderate risk area for Sunday....yikes..

    http://www.spc.noaa.gov/products/outlook/day3prob_0730.gif

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  30. Very rare does spc put out a day 3 moderate risk. Spc indicating possibility of strong tornadoes near warm front. Other problem might be strong deformation zone on nw side of low with moderate-heavy rains over red river valley basin.

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  31. Plymouth weather lover,
    I could see snow happening next weekend(16-18th time frame),I also saw that Joe B. blog about artic air(I did a double take,but he did say artic air into the northern plains,I guess we'll see)If I had to make a prediction I'll go with 2.3 more inches,does anyone know what the greatest snowfall from one storm was at MSP for the month of April.

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  32. Big Daddy: it appears the largest single day snow fall for April is 13.6" on April 14th

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  33. wow thats huge for April,Thanks randyinchamplin,temps look colder by next weekend,I,m seeing some low 40;s for highs,I guess snow can be possible if everything falls right or wrong depending on your flavor.

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  34. Sunday indeed looks mighty interesting across southern Minnesota and western Wisconsin after a glance tonight. Twins baseball games have me a little preoccupied as I flew up from Atlanta to see the series. I'm wondering if the chase will be on Sunday after the game as triple point sets up across southern MN? The last few model runs are now getting a better feel on current situ in the West as the trough begins to move inland. As Novakweather stated, the MN SkyWarn workshop on Saturday will definitely be good timing. See you there!

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  35. End of next week,looking chilly(40's for highs,low 30's for lows)with several damp/dreary days,wouldnt be surprised to see snow if you believe the chilly euro,just dont run out to your local Home Depot yet to buy you plants we havent seen the last of jack frost!

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  36. For Sunday from the SPC.

    "THIS COMBINED WITH STRONG INSTABILITY WILL RESULT IN A SIGNIFICANT POSSIBILITY FOR SUPERCELLS AND TORNADOES ACROSS THE MODERATE RISK AREA. AN UPGRADE TO HIGH RISK APPEARS LIKELY ACROSS A PORTION OF THE UPPER MS VALLEY IN LATER OUTLOOKS."

    A high risk in April in the Upper Midwest is almost unheard of.

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  37. There are storms developing in SW Minnesota...they have some imprssive VIL levels

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  38. If what I'm waking up to is a sign of what's to come today, I'm going to give the Strib a win for its prediction that Saturday's weather could turn into a cloudy, drizzly, 50s-ish dud.

    Clouds - check
    Drizzle - check
    Cool - check

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  39. The storm looks like it might be on a weakening trend as it works its way to the Twin Cities

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  40. The real storms won't develop until after 7pm tonight.

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  41. SPC focusing tomorrow's event now more over the southern half of wisconsin and northern illinois. I will say tho that these spring storms are notorious for moving slower than the models show. Going to be an intense 24 hours over the upper midwest starting tonight.

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  42. The NWS says that a watch is likely within an hour or two for parts of Iowa and Nebraska.

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  43. Ah got to love raw data,anyone buying the GFS printing out 15" inches of snow Friday,man the GFS has been so wild the last couple of months,but living in Minnesota anything is possible(I recall about 10 years ago,it hit a high of 91 and 5 days later we got 6 inches of snow,it was April 20th)so yeah anything is possible,but to cool that much for that much snow for this time of year the planets would all have to line up,but if you recall I stated a few days ago after this weekend we will have 'cooler' storms capable of ending as snow,we will see what happens,any thoughts anyone.

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  44. Props to MR.Paul Douglas,when everyone was going warmer for saturdays high he called for an east wind/clounds and temps get stuck in the 50's,high in MSP was 58,for all the crap PD gets,we should at least acknowledge something,that no one else did.

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  45. Agree with you there big daddy.

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  46. But in true fairness, the Strib did predict a high of 68 yesterday in the morning. So his Saturday prediction of 58 (made on Friday) was far more accurate than the updated Saturday one....

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  47. It's warming up very quickly in the west metro. Upper 60s with hazy sunshine and smelly, humid air. The forecast high is 72, but at the rate we're going, we may hit that by noon.

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  48. Pushing 80 here in Red Wing. It's VERY muggy and uncomfortable outside. You can tell from just stepping out the door there will be some firey storms this afternoon. Anyone got any details on what time this is supposed to get going?

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  49. Marc, NWS says after 4pm...now the wind has picked up in the last half hour...still nice and warm...

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  50. Speaking of NWS, I live in Lake City, which is in two counties, and in two different NWS forecast areas...TC/Chanhassen says 78, LaCrosse says 82 for a high...do I split the difference?

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  51. It may be windy at airport, but it's from the southwest and not the south. I'm no meteorologist, nor do I play one at home, but I think that suggests the stronger storms won't happen at MSP.

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  52. Hey big daddy,

    NWS NOW HAS MENTION OF SNOW FOR FRIDAY NIGHT,THEY EVEN MENTION IN THEIR DISCUSSION IF THE GFS VERIFIES IT WILL BE COLD ENOUGH FOR SNOW,SOMETHING WORTH WATCHING FOR SURE!

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  53. Atmosphere Is still capped. Storms still few hours from firing. Probably will impact only the easternmost counties of MN.

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  54. Its going to exactly as forecasted the past two days. Mostly a Wisconsin storm with only counties such as Dakota, Goodhue, Wabasha, Winona, ect impacted.

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  55. MD396 suggests tornado watch by 3pm


    MESOSCALE DISCUSSION 0396
    NWS STORM PREDICTION CENTER NORMAN OK
    0130 PM CDT SUN APR 10 2011

    AREAS AFFECTED...EXTREME SERN MN...NERN IA...NWRN IL AND MUCH OF WI

    CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY

    VALID 101830Z - 102030Z

    OUTBREAK OF SEVERE STORMS IS EXPECTED THIS AFTERNOON...INITIALLY
    FROM ERN MN THROUGH NERN IA...THEN SPREADING RAPIDLY EWD THROUGH WI
    AND EXTREME NWRN IL. SUPERCELLS WITH STRONG TORNADOES...VERY LARGE
    HAIL AND DAMAGING WIND WILL BE THE MAIN THREATS. A TORNADO WATCH
    WILL LIKELY BE ISSUED BY 20Z.

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  56. Anonymous thanks I saw that at NWS about the potential for snow,even PD mentioned in his blog last now and now even DD calls for the potential for snow by friday,let's see what happens

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  57. I think a T-storm is devloping north of rochester...radar is echoing a top there

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  58. Definitely a storm in the Red Wing area. Not much yet, but developing rapidly. In the meantime, the west metro is falling into the 50s as the front passes over.

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  59. Watch is being issued now. Don't think any metro counties included.

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  60. And it is the very rare PDS type tornado watch.


    URGENT - IMMEDIATE BROADCAST REQUESTED
    TORNADO WATCH NUMBER 120
    NWS STORM PREDICTION CENTER NORMAN OK
    320 PM CDT SUN APR 10 2011

    THE NWS STORM PREDICTION CENTER HAS ISSUED A
    TORNADO WATCH FOR PORTIONS OF

    PARTS OF NORTHEAST IOWA
    PARTS OF WESTERN NORTHERN MICHIGAN
    SMALL PART OF SOUTHEAST MINNESOTA
    MUCH OF WISCONSIN
    LAKE SUPERIOR

    EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 320 PM UNTIL
    1100 PM CDT.

    ...THIS IS A PARTICULARLY DANGEROUS SITUATION...

    DESTRUCTIVE TORNADOES...LARGE HAIL TO 4 INCHES IN DIAMETER...
    THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE
    POSSIBLE IN THESE AREAS.

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  61. Lets all get past this severe storms and warmth,mostly an wisconsin deal anyway,I just happened onto this website(very cool by the way)I'm more a snowlover,very interested with big daddys post on the snow friday,tell me more.....

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  62. jim55433,
    you want more on the snow,go to weatherbell.com(Joe Bastardi blog)take a look at the canadian model for late next week,he says snows for the northern plains as far south as I-80,enjoy!(I warn you he is an snowlover as well,but his long range forecasts usually pan out)

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  63. This has bust written all over it,wisconsin gets the action,late week storm looking very interesting,GFS has snow for two runs now by Friday,is this at all possible it will be April 15th for god's sake.

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  64. Spring? What spring? New post to track snow possibility for Friday.

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  65. 58 @ MSP, 72 @ LaCrosse; guess that front's gone through.

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  66. Oh, storms...I hate storms! And I hate the whole atmosphere of constant fear and restlessness they bring...When I was a kid I wanted all good people to avoid storms. I still hope for that...

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