Monday, August 15, 2011

Showers and thunderstorms overnight into Tuesday..

Here we go again.. another weather system will be pushing into southern Manitoba tonight into Tuesday spreading showers and thunderstorms into the region. The big question is.. will Winnipeg finally see some significant rainfall out of this or will precipitation skirt the city as it's done the past 6 weeks or so? At Winnipeg airport, only 20 mm of rain has fallen since June 23rd, with no daily rainfall greater than 5 mm in that time. (note that some areas of the city have had more rain) The last thunderstorm to hit the airport was back on July 4th. So it's been a long stretch of dodging convective weather systems over the northern RRV. Will this next round be the same story? For tonight, thunderstorms are expected to develop over North Dakota and southwest Manitoba, some potentially severe, which are forecast to spread into the RRV overnight into Tuesday. Some of the rain could be heavy with local amounts of 20-40 mm possible in thunderstorms. The unsettled weather is expected to push east of the RRV later Tuesday with breezy and cooler conditions Tuesday night into Wednesday. Hit or miss for Winnipeg? Let us know in Rob's Obs latest poll!

54 comments:

  1. Very nice PASPC update this morning by Dave and Justin. Really highlights the pro's and con's of tonight very nicely.

    I'm interested in seeing how the lower shear values affect the potential. SPC really doesn't seem to think it's going to be a major downfall. 30% wind and hail probabilities, 2% tornado.

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  2. I am finally glad to say this after a long time. My weather findings on this storm system that will hit us tonight and tommorow conclude that we have a decent chance and by decent I mean a 80-90% P.O.P of seeing either a damaging supercell storm or just your typical severe summer storm by tonight/tomorrow morning. Why you ask?

    Well, we have an approaching montana low that will enter SE Sask and SW MB Tonight. This System will encounter heavy moisture allowing for SBCAPES to rise up to 3000+ J/KG allowing for possible convection to continue eastward throughout the night, reaching the RRV by 09Z-15Z. anything that fires between these fronts will be very severe maybe even supercellish. Conditions are there for that to occur as a Moist LLJ will feed into the convection. The threat for severe storms start in SW MB around later evening,south central overnight, and RRV-SE MB throughout the day. this system is expected to clear by on wednesday, but not before firing MCS or thunderstorms tonight and tuesday. SPC has us on the gun for severe storms as well, including EC.

    Feel free to comment.....

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  3. Mike, the potential is definitely there for some strong to severe storms tonight into tomorrow morning.

    SBCAPE is already up to 3,000 J/KG in extreme southern MB this afternoon. MLCAPE between 1,000 and 2,000 J/KG. Capping isn't terribly strong right now but we don't have a good trigger.

    We'll have to wait for the system and frontal boundary to push across for widespread storms. Would like to see better shear tonight but a decent LLJ combined with 1,500-2,000 J/KG of MLCAPE ahead of the front bodes well for regenerating convection overnight.

    Hail and strong wind gusts are the biggest threats. Heavy rain may be a problem with slow moving activity.

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  4. Hate to say it but I don't like what I am seeing in models like NAM and GFS. They hint at another possible split in precipitation. Convection may organize into two main areas.. one in association with an upper wave that will pass to our NW (GFS farther north than NAM)and on the nose of a weak LLJ ahead of the disturbance over N Dakota. 850 hPa flow looks anemic over our area, and with wave passing to our NW.. I do not really see much support for convection to survive the nite. Dry slot moves in quickly tomorrow during the day, sweeping away best moisture to the east. Hopefully something can survive feeding off of the left over instability from today

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  5. As Daniel said, it's not quite so clear a setup for tomorrow. Hopefully it pans out though, I'd love some rain! I've written a large writeup over on my blog if anyone's interested:

    http://aweathermoment.tumblr.com

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  6. We will have to find out whos right. I forgot to mention that some of the details came from FOCN 45 at 2:00PM. Although I think you guys have more experience at forecasting severe weather, as EC has been known to get their forecasting wrong. Will I be right or will I be wrong stay tuned to find out.

    PS: thanks for the comments I enjoy reading your thoughts and ideas.

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  7. looks like EC mentioned a good chance of storms after midnight, and they will last until near noon tomorrow.Although NAVCANADA says otherwise, storms will only be a 40% chance in the morning,TWN at 100% chance of storms,accuweather 60%chance. I don't know who to beleive. Any opinions?

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  8. With storms in south west North Dakota, and east Sask. I have a bad feeling things will split, and we will be left with barely anything here. Knowing 2011, why wouldn't it happen again... What did we do to anger mother Nature so much lol...

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  9. Could it be because I stayed up late last year everynight to see storms? the flooding making mother nature realize we need it to be dry. Or just a bad year overall.
    The best bet would be to blame LA NINA for cold snowy winters and hot dry summers which EC predicted all along. whatever I give up!
    Can't wait for 2012 storm season to come along.

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  10. It's really starting to hit home on how quickly our severe weather potential is closing.

    Even If we got a goood light show tonight I would be happy. Even just a flicker...just a flicker.
    (Better start praying to the weather gods).

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  11. Don't lose hope yet people storms have fired south of the border in montana and are headed this way. As I said earlier A Moist Southerly LLJ will feed the storms overnight. we are still under the gun late tonight. Will have to see if things weaken or strengthen, with the cold front passing in the morning.

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  12. agreed Mike, potential definitely still there for the morning.

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  13. Do you think EC will be right for once after all our misses this year? I feel bad for there incorrect forecasts,as I may work there oneday.

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  14. +35 Next week Monday according to TWN. Hah!

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  15. Once again, a wave over the Dakotas seems to rob energy from storms forming further north over southern MB/RRV.. We'll have to see if anything can get going on low level jet overnight, but current lack of activity over SW Manitoba is a concern. I really thought there'd be more storms over there by now..

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  16. I'm sorry guys but we have kept thunderstorms out east...

    Montreal has received 102 mm since August 1. After a disappointing July in terms of t-storms (only 59.2 mm but second warmest month ever with an avg temperature of 23.1C), we have more than made up this August with t-storms almost every day and plenty of sunshine in between.

    I hope we send some of that your way so you can enjoy the storms with us.

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  17. Thanks for making me 100% jealous.

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  18. Storms finally firing up along the low level jet this morning.. but mainly north and east of Winnipeg. Not a drop here. Unreal..

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  19. Looks like mother nature found a new way of torturing us... All the storms develop AFTER the line has come through. Today's miss so far is such a discouragement, much bigger than the last couple since storm season is closing as Daniel P mentions.

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  20. Luckily it isn't over yet, still some lighter activity west of Steinbach...

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  21. Storms now firing south of us moving north towards us, while I'm working, geeze. Well I'll have to slip out i guess.

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  22. The storms have weakened once again. looks like rain for now. While I'd better move to oklahoma.

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  23. We need a good rain sooo bad. This is a true drought... Cracks in the yard are getting bigger and bigger, to the point where watering the lawn isn't even helping anymore...

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  24. WOW!
    I cannot believe it!!!
    Everytime I get excited for some storms and then watch everything fall apart..... WHY, WHY????
    Oh the HUMANITY.....(SOB) (SNIFF)
    ...No really, I'm not crying.....
    WAHHHHHHHHH!!!!!

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  25. I guess we'll have to wait for it this fall and next summer. i agree with you we need the rain.Your not the only one suffering here, i am too.

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  26. A few of the lower leaves on a few on the trees on our street have already turned color. Drought stress no doubt. Normally these trees start their initial turn to fall colors first week in September. I assume the sub-terrainian water levels are a tad below normal. Anybody know who & how this is measured??

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  27. WOW...Can't believe how all of those storms missed, poping up all around us. I am thunderstorm deprived.

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  28. Even this morning JS is still calling for 25mm over Winnipeg! Time to ditch that WSI software he uses.

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  29. l0l anonymous. Ya quite frankly any rain over 1 mm is quite a miracle.

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  30. *BREAKING NEWS*

    There are eyewitness accounts of something falling from the sky in Winnipeg....What's that??? Rain???
    Can it be....????

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  31. I'm also interesting if JS's forecast of 50 gusting 70 will come to pass today. It's by far the strongest wind forecast of all the sources I've seen.

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  32. Thank you Daniel P, I needed that laugh to get the miss out of my head =)

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  33. Some significant rainfall amounts overnight into this morning from west central Manitoba into the northern Interlake with 55 mm in Roblin, over 20 mm in Dauphin, 40 mm in Ste Rose, and 20-35 mm over central and northern Interlake north of Gimli. Further south, 50-100 mm of rain with storms last night over southern ND including over 60 mm in Bismarck. In between, very little over southern MB/RRV with minor amounts (< 5 mm) in showers this morning. Unless we get some locally heavy downpours this morning, Winnipeg airport's streak of days with rainfall less than 5 mm will be 55 and counting.. remarkable for a summer season..

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  34. I'm Not complaing about the wonderful sunny summer weather,we ve been having. we just need that stubborn jetstream to shift north and bring the wicked weather before the end of august. We'll survive until next years storm season if not this summer.

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  35. I'm Not complaing about the wonderful sunny summer weather,we ve been having. we just need that stubborn jetstream to shift north and bring the wicked weather before the end of august. We'll survive until next years storm season if not this summer.

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  36. What gives?? That's all I have to say

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  37. Daniel p your comment is hilarious.

    YAY I recieved 0.8mm of rain out of all that! Certainly not the first time this year I'm looking ahead in desperation for the next system to strike.

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  38. I've gone through the online records and noted all the thunderstorm hours observed at Winnipeg airport since 1953. And right now, summer 2011 is on track to being the least thundery summer in Winnipeg since then. Of course, anything can happen; though it's very unlikely, for instance, there have been instances where September sees more thunderstorms than August. (Incidentally, 1958, the year I believe is the current record-holder, didn't see its first thunderstorm until June 28th!)

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  39. Anonymous,

    Which year was the busiest for storms in Winnipeg?

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  40. Same pattern repeating itself again.. main shortwave passing to our north and best warm advection of tropical air and LLJ split off well to the south (all the way down to the Iowa/Missouri border) as the systems hit a high pressure ridge to our east.

    The entire summer has been characterized by this split flow in which very warm, dry air associated with an upper ridge/ omega type block has been entrenched over Manitoba and NW Ontario. The deeper tropical airmasses and plains LLJ have been suppressed south.. while larger synoptic disturbances are deflected north.

    It has made for wonderful summer weather (many days in the high twenties often with tolearble humidty) but ofcourse is also causing our drought conditions. It seems similar to 2006.. wonder how many past droughts fit a similar pattern.

    We'll have to see if we can get a more unified strom track (allowing for better linkage between upper waves and LLJ) as we transition into the fall season..

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  41. Daniel,

    It's been an interesting but frustrating summer to follow. I, like many of you, am a big storm fan. 2005 and 2007 are two of my favorite years in the past decade. 2005 was really the year that got me into storms.

    The comparison to 2006 is interesting. That was a hot, dry summer but I do recall August being quite busy stormwise.

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  42. Rob!
    You stated in an ealier post that our next best chance to MISS out on storms was on Tuesday(today)!!

    That was a good one!
    It's when we least expect it that we get rains of biblical proportions (Like they had in New York city over the past weekend with almost 8 inches of rain).

    Oh so that's where all the rain went!!!

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  43. Derek - at a glance it looks like 1977 was the most active year, mostly due to a very unusually active May.

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  44. I just want to emphasise, though, that that's at a glance - '77 definitely looks like the most active, but I haven't systematically counted the hours for every single year yet. :)

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  45. @ Derek

    Yes I recall that as well.. I think the pattern shifted during the late summer. I was hoping for something similar this year but so far no luck.

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  46. Yeah even by now in 2006 we were getting storms

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  47. It's too bad. This year has featured many systems pushing across Manitoba. We've had generally a zonal flow aloft with a peristent west coast trough. You don't have to go far for a good severe weather year. North Dakota has been busy, especially sourthern sections. I can't count how many times I've seen a big storm roll through the Bismarck area whether it be an MCS or a supercell. Shift the pattern slightly north and we've all got a smile on our face. Although, too much severe weather may not be a good thing either.

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  48. We have our share of severe weather, but it mostly depends on earth climate cycles. As with this year we have a la nina pattern which allows for hot and dry weather to occur, but it also pushes the storm track more to the south allowing for the storms to travel across the northern plains. on the odd ocassion we may get a nasty system move west to east across the prairies. Generally the most travel south of us. even Southern Ontario has the same issue we have here. They just may get more rain, not a lot. years similar to this pattern we have today were back in 2006 and 2009, to my knowledge. On the other end we have el nino which causes warmer and wetter weather as the storm track is more northerly, with that we get storm by storm by storm hit us such as what they have been seeing in north dakota. and by far the years 2005,2008,2010 stand out. so we can have bad years and good years it really depens on the summer storm track. look on the bright side it's not a official end to our summer storms we have a ton more to come over the years. Agree?

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  49. Please reply to my above comment before writing on the new article. I would very much appreciate it.

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  50. The 3 month running mean of ERSST v3b SST anomalies in the Nino 3.4 region, for both AMJ and MJJ indicate ENSO-netural conditions. While atmospheric circulation may still reflect remnants of La Nina, this summer's weather in southern MB can't be explained solely by generalized La Nina weather patterns.

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  51. what else could this pattern be explained by? Could it be the position of the LLJ which could make sense.

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  52. We've been under a neutral (or near-neutral) phase for some time now (since late June or so). So really, we haven't been under the effects of El Nino or La Nina this summer.

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  53. I'd like to blame it on La Nina too but I believe its the ridge in NW Ont/MB.

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  54. agreed, if we had a larger ridge that spread up to norway house for example we'd be the one to see storms,and not ND. I guess It's there turn this year,and not us. Although i'd love for it to build further north before seasons end.

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