Saturday, June 01, 2013

Cool start to June with frost risk tonight..

After a soggy end to May, a ridge of high pressure will bring clearing skies and drier weather this weekend over southern Manitoba to start off the month of June. Temperatures however will be below normal, with daytime highs only in the mid teens today and Sunday, some 7C below normal for this time of year. As the ridge builds in over southern Manitoba tonight, clear skies and diminishing winds will give ideal conditions for areas of frost overnight across much of southern Manitoba including Winnipeg. Temperatures will be dropping to the 0 to +2C mark tonight, with a good risk of frost overnight into early Sunday in many areas. Sunny skies and light winds will make for more pleasant conditions Sunday, as afternoon temperatures climb to the 16C mark. Dry weather is expected into early next week before another disturbance brings a threat of more rain by mid week.      

47 comments:

  1. May was officially thunderstorm free for Winnipeg. Last time we had a thunderstorm-less May was in 1997 but then had a recorded storm on June 1st. Our next best chance of seeing any storms is Tuesday-Wednesday. If that doesn't happen then this will be the second slowest start to our thunderstorm season since 1958 when a thunderstorm wasn't recorded that year until June 28th!

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  2. Frost warning issued for western MB and central interlake area for tonight where surface ridge will be parked much of the night. Here in Winnipeg, temps will drop quickly once winds decouple after sunset, with lows at the airport probably approaching +1 or +2C by morning, and patchy frost possible. NAM has Winnipeg with a low of -0.5C early Sunday, while other guidance have lows in the +2 to +4C range for Winnipeg. Dewpoints remain fairly high so that may save us from frost, and we may get more dew than frost overnight. But patchy frost still possible, especially outside the city overnight.

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  3. May in Winnipeg will finish with an average temperature of about 11.1C, which is only 0.3C below 1981-2010 normals (11.4C) So even though it seemed a lot cooler than normal, in reality, it was an almost average month temperature wise.

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  4. Rob, what are are the reasons or factors as to why we simply can't warmup here this season and is there any hope that we might finally get some sustained warmth somewhere down the road?

    And, are we looking at possibly some more substantial rainfall and possible storms Tuesday and Wednesday?

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  5. Anonymous..

    Blame a stubborn jet stream that has been locked to our south. The jet stream has not shifted north for any length of time to get us into a sustained period of warm weather. So basically we've been stuck in generally below normal temperatures all spring with an increasingly wetter past couple of weeks with more frequent storm ssytems passing through the Dakotas.

    So.. the big question is.. when will this pattern change? And the simple truth is.. I don't know. Until I see some evidence of a major pattern shift (which I don't right now) then I assume status quo for the next little while. That doesn't mean things won't change.. it's just that I don't see much hard and consistent evidence right now to support a trend to warmer and drier weather for us in the immediate future.

    For Tuesday/Wednesday.. GGEM is the wettest of the models showing 15-20 mm for Winnipeg. All other guidance show system a little further south with bulk of precip over Dakotas. Will have to keep an eye on which models trend which way.

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  6. Rob, so this basically means that we are in for yet another below normal month?

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  7. Anonymous said...Rob, so this basically means that we are in for yet another below normal month?

    No, not necessarily. The pattern can chnage quickly even though we don't see much evidence of it right now.

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  8. Rob, do you know why the Hourly Data for the airport hasn't been updated online since mid-January? I'll be mighty irritated if they're simply not going to bother updating it anymore. I use it extensively.

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  9. Evan..

    The station changed to a NavCanada station in mid January, and the hourly data is now available at

    http://climate.weatheroffice.gc.ca/climateData/hourlydata_e.html?timeframe=1&Prov=XX&StationID=51097

    The annoying thing is that daily summaries are not available from this NC site, just hourly data (no idea why) To get daily data, you need to call up the Winnipeg AWOS site at..

    http://climate.weatheroffice.gc.ca/climateData/dailydata_e.html?timeframe=2&Prov=XX&StationID=47407

    Keeping track of Winnipeg climate data has become a real mess over the past few years with all the changes to our monitoring sites.

    You can access these various climate data links on my main webpage under STATS>>CLIMATE DATA>> which will list Winnipeg climate data under various categories (hourly, monthly, past data, Forks data, etc)

    Hope that helps..

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  10. LThe unfortunate thing about the new hourly data site is that it has plenty of missing data every single day.
    That's why I don't even bother using it anymore, I prefer using archived metar from now on when it comes to hourly obs. There are plenty of these archives around, ironically not from Environment Canada but there is one from NOAA.. LOL

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  11. Rob - Thanks for the links!

    Anonymous - Looking at the new observation site, I have to say you're right. It's appalling how many "NAs" there are. On some days it's half the hours. I wonder if this will improve over time, but if not it's practically useless.

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  12. It looks like according to the NAM Model and accuweather that mid week this week the jet stream is going to push further north, North of the Border and the nam is showing 20 - 23 degree temps this week and the GFS is showing almost 30 degrees next week around the 8th.

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  13. Mike (St.James,Winnipeg)8:02 PM, June 02, 2013

    Jetstream finally appears to be drifting north of the border around the 12th to 13th, what are your thought's on this image rob?

    http://www.twisterdata.com/data/models/gfs/3/maps/2013/06/02/18/GFS_3_2013060218_F288_WSPD_500_MB.png

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  14. Well, according to GGEM the forecast for the 8th is for temps nowhere near 30C, hence EC's forecasting only 20C and rain. Although it would be nice I don't see that kind of major warmup for us over the next while so i'd say GFS is an big time outlier at this point.

    Rob, do you see temps warming up to near 30C even though it would be brief as in 1 or 2 days next weekend or during the week of the 10th?

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  15. Mike.. As much as I'd like to believe it, I just can't take too much stock in a 288 hr GFS outlook. At this point, it's just another model solution, and until I start seeing some greater consistency and agreement, I wouldn't put a lot of faith in a deterministic model solution that far out. But if it keeps the same story run and after run, and other models agree, then I'd have a little more confidence in that solution working out.

    As for 30C this weekend or next week, I don't see it at this point. Looks like we have another significant system crossing southern MB Sunday into Monday with more locally heavy rain possible, followed by a cooler start to next week then gradually getting warmer through the week. Hopefully, we get back to seasonably warm weather in the mid 20s by middle to end of next week. But I still don't see a lot of evidence of 30C weather at this time.

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  16. Rob, you mentioned a significant system with heavy rain possible Sunday the 9th into Monday the 10th. Does that look similar to the system that affect us late last week and are we expecting a better chance of thunderstorms with this system?

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  17. Still too early to be specific, but current guidance hinting that next weekend's system may track a bit further north than the last one. That may bring a greater threat of thunderstorms over southern MB, but still way too far out yet to be more definite.

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  18. I'm moving back to Winnipeg on Friday, June 7th! I've been living in England for the past two years, so I'm quite interested in what the weather might bring from that date on... Weirdly, England's decided to give us a beautiful, fairly warm, sunny and dry stretch of weather before we go.

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  19. A bit off topic but here's a nice streaming webcam from Prague. Comparing with streetview stills the river looks a good 6 to 8 M higher in the video.
    http://www.camscape.com/view/35415

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  20. We are officially into our second slowest start to our thunderstorm season in 60 years. Not only that but we're also approaching the most amount of days since our last recorded thunderstorm for Winnipeg in 60 years. So far we are at 282 days since our last recorded thunderstorm on August 24th last year. 1990-1991 went 283 days between the last and first recorded thunderstorms of those years respectively, and 287 days in 1957-1958 (1958 was our latest recorded first thunderstorm in a year on June 28th). I don't see any chances of thunderstorms this week, which likely means that this year will have been the longest time since we have last seen a thunderstorm here. Tough times for thunderstorm lovers (like myself) in the last couple of years for Winnipeg.

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  21. Winnipeg airport was a couple of weeks frost free faster than last year. That is quite surprising!

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  22. Rob, what are the chances for the season's first thunderstorms for us here in Winnipeg/RRV this weekend?

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  23. Rob, how much rain are you expecting this weekend? Another drenching like the last 2 storms or more of a scattered shower here and there?

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  24. Looks like we have at least the potential for some thunderstorms here in YWG/RRV on Saturday, along and ahead of a trough of low pressure moving through southern MB. NAM is indicating that bulk of instability will be stateside, but we could see some storms in the RRV, especially southern areas. Models are painting some hefty rainfalls of 15 to 35 mm over Winnipeg Saturday into Sunday, but that may be overdone due to model bred convection. However, it does point to the possibility of some heavy downpours with any showers or thunderstorms that do develop.

    At this point, I expect a band of showers and local thunderstorms to push through YWG/RRV Saturday afternoon into Saturday night, with bulk of precip pushing into Interlake/Whiteshell areas Sunday. Powntial for 15-25 mm of rain for YWG/RRV locally higher with any storms. However, I don't see this event as heavy as the previous two as the main upper low is moving north of us and passing through more quickly.

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  25. I noticed EC and TWN are now showing nothing but sunshine on the weekend, then warmer temperatures after that. Showers with risk of a thunderstorm for tomorrow afternoon. Is this changed forecast believable, especially for the weekend? I land in Winnipeg late in the evening tomorrow so I'm quite interested in what the weather will bring from that point on.

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  26. Evan..

    Yes, that's quite the forecast change from showers to sunny for the weekend. Normally, I would be very suspicious of such an abrupt change in a forecast like that, but other models have backed off significantly on the precip as well for the weekend, although not completely. Hence, I'm skeptical about a perfectly sunny dry weekend.. I think both Saturday and Sunday will see at least a chance of showers for Winnipeg/RRV, with varying amounts of clouds and sun.

    The reason for the change is that models are now showing a split in the weather system affecting southern MB for the weekend.. with a main low taking a slower track over Saskatchewan (more rain), while a southern wave tracks through the Dakotas (showers and thunderstorms). That puts southern MB in a less favourable area for showers in between these two systems, although I think we still have a chance along a trof linking these two areas.

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  27. Here we go with split flows again. This will become the curse of 2013,much like the curse of 2011 and 2012! We just can't seem to catch a break around here!

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  28. Rob, do you think those forecasts for temps into the upper twenties for next week are too optimistic or possibe?

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  29. More severe storms expected in SK/AB.. Season just seems beyond hopeless here, can't even get one single setup worth talking about. At least it's still kind of early... but with this split system this weekend, it brings flashbacks of the past 2 droughts summers.

    We'll see, it's still relatively early.

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  30. You're right.. It's still early. Peak season is still a good 4-6 weeks away here, and this year is off to a delayed start almost everywhere. Consider how slow the severe weather season was down south in tornado alley up through mid May... before all hell broke loose. Things can change awfully quickly with severe summer storms...

    By the way, apologies for the lack of posts and updates.. but things have been very busy for me these past couple of weeks. Hopefully there'll be more free time, and more interesting weather, by mid month.

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  31. One more day, we'll have tied the longest period between the last storm and the first one of the year (287 days). This year will likely be the longest time since we've last seen a thunderstorm. With stats like that, it definitely makes you wonder if we'll ever see anything. Good thing it is still somewhat early. I think storm enthusiasts/people who are passionate about extreme weather are just a bit frustrated because you have this to add on top of the last 2 disappointing years if you're into storms (last year and the year before saw a lot fewer storms and some periods where we went over a month during the summer without seeing anything) and when you have such a short season then it gets a bit disheartening so for those of you who are annoyed with us, bear with us! It has been a slow last few years so if you had as much as an interest and didn't want to drive a 1000 miles to go see a storm, you'd understand :)

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  32. Rob, could we see an increased threat for severe weather at some point next week with the temps climbing into the upper twenties or will the instability mainly remain south of the border?

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  33. Getting closer!

    Line of showers and thunderstorms popping up both east and west of the city this afternoon. Not much motion on them as they appear to be forming along stationary convergence boundaries (perhaps terrain induced).. but enough to get some some convection going. Winnipeg in the dry slot between these two boundaries..

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  34. Anonymous.. Haven't had a chance to look at next week, but you also need increased humidity and a trigger (front, trough, upper short wave, etc) to induce lift to get those storms going. Certainly warmer temperatures will elevate the chance of storms, but that's not the only factor, especially for severe storms.

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  35. Looks like south west quadrant of the city might be getting some precipitation...hoping it comes into St James.

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  36. Some showers here now. Judging from reflectivity, these ones are pretty slow.

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  37. Heard one rumble of thunder in La Salle. Then a bit of rain.

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  38. It poured in southwest Winnipeg, there must have been about 10mm, even starting out with mini hail. But the airport hardly got a drop - streets are dry.

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  39. Rob, what are the chances for thunderstorms for us here in Winnipeg/RRV for Sunday and Monday, if any?

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  40. >>Anonymous said...Rob, what are the chances for thunderstorms for us here in Winnipeg/RRV for Sunday and Monday, if any?

    Small chance tomorrow afternoon as a trof moves through southwest MB. Another chance early Monday as some nocturnal tstorms pop up over southern SK and track into the Interlake areas. Overall though, doesn't look like anything major this week..

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  41. Rob, what are your thoughts on the latest potential at thunderstorms? Especially now that EC is calling for 60% chance of showers or thunderstorms for the Winnipeg area....

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  42. Thunderstorm chances look slim today for Winnipeg/RRV as clouds spread in from weakening trof to our west, bringing a chance of a few showers for us this afternoon/evening.. otherwise not much. Better chance for some scattered thunderstorms this afternoon over western MB around Dauphin/Swan River/The Pas areas where they will get some clearing, and dewpoints are still high enough with some low level convergence to help with convective initiation.

    Models still showing potential for some elevated tstorms tonight over southern SK as an impulse moves through aided by a strong westerly jet max.. with storms spreading into western MB and interlake areas Monday morning before weakening as they spread east towards RRV.

    After that.. rest of the week looks pretty quiet.. with a building upper ridge giving us a nice stretch of mainly sunny and warm weather, possibly into Friday.

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  43. Light snowshower reported at the airport at this hour... Another example of poor data quality these days.

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  44. Obs corrected to light rainshower now.. Good thing since snowflurries weren't in the forecast!

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  45. Has anyone done some looking at why we can't get t-storms this year? Could it be a lack of temperatur contrasts/fronts? Because it seems like we have had similar daytime highs for a while.

    Sorry to bring the topic once agan, it's just that when you think about it the lack of storms has been remarkable this year so far, I cannnot remember a year like this ever.

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  46. Daryl..

    Probably a slow start to the season due to the prolonged winter, and subsequent delay to the start of the growing season which has put plant and crop growth some 2 weeks behind schedule. There's a good correlation between thunderstorm activity and evapotranspiration contribution from crop development, so it's not too surprising that we've had a lack of thunderstorms so far.

    However, as we get warmer and crop growth accelerates, we'll see an increase in humidity levels which will ramp up chances of tstorm development. We're already seeing more frequent tstorm activity over the southern Prairies over the past week or so (albeit weak), so things are starting to pick up. Our peak severe weather season here is from late June through early August, so there's still plenty of time for some severe storms, even with the delayed start this year.

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  47. Good point, thanks Rob. I guess I had assumed crops have been growing already considering things are growing nicely in the city.

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