Sunday, May 30, 2010

Thunderstorms swamp Winnipeg, southern Manitoba for second day..

Strong to severe thunderstorms pummelled southern Manitoba once again Saturday, dumping very heavy rainfall across much of southern Manitoba along with hail and wind gusts over 100 km/h. The Red River valley was particularly hard hit with 50-150 mm of rainfall recorded (see image from Grand Forks NEXRAD showing radar rainfall estimate over southern Red River valley). Winnipeg was swamped with 50-100 mm of rain Saturday causing numerous problems with flooded basements and underpasses, and rapidly rising river levels. (see time lapse video of storm as it moved through downtown Winnipeg late Saturday afternoon) Northeastern parts of the city including East Kildonan and Transcona were particularly hard hit with city gauges reporting up to 108 mm of rain Saturday through Saturday night. The rain comes on top of the heavy rain that fell across the northern Red River valley Friday when 50-80 mm was recorded in some areas. Below are some rainfall totals for the past 24 and 48 hours recorded up to 6 am this morning.

Location            total rainfall     total rainfall
Last 24 hours last 48 hours

Winnipeg, the forks 73.6 mm 95.0 mm
Winnipeg, airport 57.5 mm 82.6 mm
Emerson 102.2 mm 110.4 mm
Portage la Prairie 89.8 mm 91.4 mm
Pinawa 80.6 mm 87.8 mm
Brandon 63.0 mm 63.0 mm
Carberry 46.2 mm 46.4 mm
Carman 23.4 mm 49.4 mm
Gimli 18.0 mm 26.0 mm
Sprague 13.2 mm 48.4 mm

Other reports from past 24 hours..

Pembina ND........... 170 mm (6.73")
Emerson..................165 mm (unofficial but reliable)
Winnipeg Charleswood.. 71 mm (108 mm past 48 hours)
Oakbank............... 91 mm
Selkirk............... 78 mm
Beausejour............ 75 mm

8 AM MAY 29 - 8 AM MAY 30

Rainfall graph from Rob's Obs, Charleswood showing precipitation past 24 hours. The rain came in two waves, with 24 mm between 8 and 10 am, then another 42 mm between 6 and 11 pm. This comes on top of the 37 mm recorded Friday morning between 5 and 10 am.


  1. Whew. The biblical rains have now ended for Winnipeg. Luckily my basement here in east Charleswood survived any flooding, but by the sounds of it, I could very well be in the minority. So blew the dust off the rain gauge and received another 51.0 mm since 1 PM on Saturday. Add the 54.8 mm from Thursday afternoon to 1 PM Saturday and the grand total here in east Charleswood is 105.8 mm. I can almost here the masses of mosquitoes hatching as I speak.

  2. In Silver Heights I got: Friday 45.2mm, Saturday 56.4mm, Sunday to 11am 5.8mm, for a total of 107.4mm. Thanks to the sump pump, my basement did not flood - but it was close.

  3. My basement didn't flood thankfully. but it was close, but I'm sure some of my neighbours did. Anyone know some statistics about how many people got flooded?
    lol, I think my rain gauge recorded a little higher than true, because my total from Thursday to right now is 149 mm! But never know, maybe it's not wrong =D

  4. Rob, I'm starting to wonder what the "bigger picture" will look like this summer. Is it too soon to tell? Are there any significant blocking sysytems in place and/or what do you foresee? As a pool owner the past 2 weekends haven't given me much hope. Thanks

  5. Mark.. I hear you.. kind of depressing after that taste of summer last week. Honestly though, I have no idea what the upcoming summer will bring.. long wave patterns are too tough to predict especially for the summer months.
    Climatologically, this kind of wet weather pattern is common in May and June for southern MB as warm and humid airmasses push to our north. In fact, June is our wettest month on average because of this. I'm thinking that the June rains got a jump start this year since everything was 2 or 3 weeks ahead of schedule. If so, I'm hopeful we can get back into summer-time swimming weather by mid June.. One thing to note though.. surface moisture is the most important parameter for summertime convection in the Prairies. The wetter the ground, the more likely to get more showers and thunderstorms in the summer months. Hopefully though we don't get a repeat of last year. Note that NWS Grand Forks issued their outlook for the upcoming summer and they suggest a more variable summer with near to above normal precipitation. Click on my name for details.

  6. Total of 55.1mm of rain over the last two days in Steinbach. Sounds like a small number compared to what has happened in Winnipeg. Total for May is 121.1mm, which is about twice the average.

  7. For anyone who's interested, yesterday I was inspired by the outrageously quick-moving low-level scud generated by moist outflow from thunderstorms to the north of the city, so I decided to do a time-lapse video of the afternoon. What I got was an amazing example of shear through an inversion, direction-dependent low-level moisture transport, and a 100km/h + gust front that ripped through the city. Not bad :) It covers about an hour of real-time, with frames every 5 seconds. You can see it at:

    Also, on my way to work today I noticed that the Assiniboine is about as high as I've ever seen it since I moved here. Nobody's using the river walk for a while...

  8. Cool Time Lapse video! Thanks. What direction was the camera facing? I'm guessing NW?

  9. Straight down Main Street, so I think that's pretty much north.

  10. Interesting video... I intercepted the line at Inkster and Oak point Hwy. Well defined and ominous looking shelf cloud along with greenish cast in the clouds above (visible in your video). I wonder if there were reports of hail north of the city. Gust front knocked down many small branches along Inkster.

    Earlier while driving down Pembina I spotted an interesting inflow structure associated with the isolated storm that passed NE across the city approx 4 PM.

  11. Cool video Brad! Love how that gust front plows through! I've added the link to my post..

  12. Interesting video.... what stood out for me was the scud clouds moving in the opposite direction to the higher clouds. How does this happen.

    As for basements, whoever invented window wells has a special place in hell waiting. Water was coming in every orifice and it would have just been a nuisance except for the water which ran down the exhaust pipe into my furnace. Still drying it, don't know if it did any permanent damage. That was certainly the last thing I expected.

  13. Excellent video Buff. Also enjoyed the mirror view of the big 3 at P&M. Infinitely better defined than my view from Bishop Grandin and Pembina Hwy and a lot safer than brief glances while driving.

    The Assinniboine in Charleswood is a few feet higher than this spring and but 4 to 5 feet lower than 2009

    March 28th 2010 Charleswood level was 21.32 St James was 19.43 and Osborne 19.60

    April 16th 2009 Charleswood level was 28.25 St James 24.74 and Osborne 23.75

    You can see the Winnipeg live stats updated 6 times an hour at City of Winnipeg River Levels

  14. Box134:

    The different directions of clouds happens quite often near warm fronts. Here's a quick science lesson:

    Suppose you have a warm front oriented from west to east. For example, a warm front that is aligned parallel to and along the international border. Two features will be dominating the wind patterns. The first is the warm air being pushed north. This air is being pushed into colder air and gets lifted up and over it. This results in a flow from the south that rises up over top of the cold air.

    Second is the surface wind near the warm front (within a few hundred kilometers). This wind, due to complicated calculus and physics, would run exactly parallel to the warm front towards the low center, however because of friction, it curves towards the warm front. This means often if you have a W-E warm front, you'll have a NE wind ahead of it. If it were aligned SW-NE, the wind would likely be from the N.

    These two winds are separated by an inversion. An inversion is when the temperature increases with height instead of decreases. This is a very stable feature, and in this case, represents the transition from the cold air mass into the warm air mass.

    The Winnipeg SPC did a balloon launch yesterday, and got a good measure of temperatures and winds. I've posted and marked up the sounding here:

    If this looks a little messy that's because it is. Pay attention to the red line. That's the temperature. Starting at the bottom, if you follow the line up, you get further away from the ground. If the line moves to the right, it's warming up, if it moves to the left, it's cooling down. I've marked out where the inversion is for those interested. It also clearly shows the drastic switch from easterly winds to southwesterly winds via the wind barbs on the right hand side.

    One last note: the sounding is actually from 1900Z, not 1800Z as COD has labeled it.

  15. So officially 60 mm at Winnipeg airport over the weekend, and 75 mm at the Forks.. so technically, the 50-75 mm poll choice was the correct one. However given the reports of 75-100 mm across parts of the city, I will also accept those who chose > 75 mm. 12 out of 33 respondents chose those 2 categories.. kudos to you!

  16. RUC indicates CAPE of around 1000J/kg over SE MB today. Combined with an approaching cold front, we could see some marginally severe storms. Bulk shear is around 50kts and EHI is around 1-2, so tornadic activity is possible, but very unlikely. Key is getting temperatures into the low/mid twenties and tds in the mid teens. If this happens, this afternoon could be interesting.

  17. Scott is your SE area South of Hwy1,12,or 308??

  18. Rob you mentioned how upsetting it is to predict 15mm and record 70-100.

    I speculate on what its like for river forecast(er)s
    Wednesday---11 feet by June 5 forecast ---Actual 11 feet by Friday May 28th 2 days early

    Friday May 28th 2 pm forecast "If monsoon comes" 16 feet by Jun 5th forecast--- Actual 16 feet by Saturday May 29th Eve 7 days early

    Sunday May 30th 2 pm Forecast 18 feet by Tuesday or Wednesday ---Actual 18 feet Monday 820am 1 day early half the time to prepare

    Wishcasting by the pros ?? or ??

    As someone on another blog said, predicting ETAs for storms already appearing on the Radar from 1 to 100Km away shouldn't be that difficult.

    Repeating it every year??
    Now thats

    PS Do you think they've forgotten the new speed limit on Hwy 75 ??

  19. Is that another cold'n wet weekend coming

  20. Chris - Windsor Park10:14 AM, May 31, 2010


    This next disturbance will seem like a walk in the park compared to this past weekend.
    The kicker will be what the models are showing for late next week and the weekend of 13-14. Two lows back to back being advertised. Of course its too far out to tell so I wouldn't cancel any plans just yet.

  21. For those with flooded basements..

    Keep your receipts...In the July and August 2005 monsoons the City and Province reimbursed for the replacement and damage repair including an allowance for personal time spent on cleanup.

  22. So weekends 1 and 2 of June at a distance look remarkably similar to weekends 3 and 4 of May...except now we have lots of ground moisture to do what ROB and Chris

    and summer starts on the 21st ----Riiiight!

  23. Free Press is reporting unofficial amounts from Emerson's mayor of 165 mm Saturday evening. This jibes with Pembina's 6.73" total, and also with NEXRAD radar accumulation. Here's a webcam shot of Emerson during that monsoon around 6:15 pm Saturday evening. Note the flooded fields. Probably 200 metres or less visibility in heavy rain. Normally, you can see Hwy 75 in the background.

  24. I'm in Steinbach, anonymous.

    Severe thunderstorm watch issued for SE MB. CAPE of 500 to 1000J/kg. Tds 12-13C and slowly rising. Expect to see some storms pop up along cold front early this afternoon. Large hail and gusty winds are the main threat, since there are very cold temps aloft. SPC removed the 2% tornado risk and with EHI only expected to be around 0.5, I agree.

  25. The Buffalo Seven.... thanks for that explanation. That really makes it understandable. I've looked at those sounding charts from time to time and they are quite a challenge, but I see where the temperature rise occurs. Fascinating stuff. Makes me wish I had become a meteorologist. Too bad the UM doesn't have a program.

  26. Very heavy hail in Steinbach this afternoon. Marble to dime sized hail covered the ground. Storms are very photogenic.

  27. HI ROB!!!!

    I'm back from Minneapolis and by the sounds of it I missed storms of epic proportions!!!

    Sturgeon Creek is very high right now!
    The highest I've ever seen it!

    I believe we got quite the wind storm here at my place by the Grace Hospital with large tree branches on the ground~

    It sucks that I missed this event cause you know I would have been going crazy !!!!

  28. Crazier than normal Daniel P???

    Oh and Box134...If by UM you meant the University of Manitoba, they do have a program in Atmospheric Science through Physical Geography that is a pretty great (and growing) program. I'm currently in it and nearing completion! In fact, several meteorologists at the Winnipeg Weather Office have come through this program.

  29. Rob!

    The media is stating this rainfall is 1 in a 50 year event....

    I recall getting this much rainfall before just a few years ago!!!

    50 year event????

  30. The official totals seem too low especially YWG... impressive amount of standing water in fields around YWG visible from the air today.

  31. I agree with Daniel.. 1 in 50 year event seems low, but that's probably based on Winnipeg airport's rather meager 60 mm reading Saturday. Northeast parts of the city had closer to 100 mm of rain which would have a much longer return period.. perhaps 1 in 200 years or more. And then there's Emerson.. if that 165 mm is true, you're looking at a 1 in 500 year event or more.

    This rain has had a tremendous impact on society.. in terms of flooded basements, flooded transportation routes, ruined crops (MB agriculture calling it the worst event in 5 years), etc, etc.. Hail and high winds usually take precedence with severe thunderstorm warnings, but this event clearly shows the impact that heavy rainfall with thunderstorms can have, sometimes much more extensive than hail or wind damage.

  32. Who exactly has said it is a 1 in 50 year rainfall? I saw it reported on the City of Winnipeg press release. Does anyone have a more credible source?

    Plus, how are they figuring that? Is it over a 2-day period? The daily amounts for Winnipeg, by themselves, are certainly not 1 in 50 year events.

  33. The last thing we need in Southern Manitoba is more rain....

    By the looks of things Thursday night could be stormy!!!!

    Oh by the way, looks like some massive heat is building in Southern U.S! I wonder if that will ever make it up here????

  34. Can anyone tell me how the month of May ended up in terms of rainfall???

    Are we in the top ten wettest Mays ever in Winnipeg ???

  35. daniel.. I'll have updated May stats by tomorrow. Winnipeg airport finished with 160 mm for May, a little shy of the all time wettest May of 1977 with 177.7 mm

  36. Take a look at the CTV webcam!!!

    (O) (0)

    The water on the Red River is almost up to the top of the bridge!!!

  37. The latest GFS is showing a band of heavy band of showers and storms on Thursday night!

    Must keep an eye on this one as any rain will aggravate this flood situation!

    I just came back from Elie today and can attest to the fact that many farmers fields are under water!!!

  38. Rob .. remind you of 2004 August rains? If so, are we as someone suggested, setting up for a long spell of wet weather

    It was a storm like this weekend that motivated me to check out your OBs website in August 2004.

    Winnipeg received close to 100mm of rain from Aug 23 to 26th. We hosted the RCGA Mid Am championship at Breezy Bend Golf Course in that biblical event (1 in 50?).

    The next year 2005 saw equally devastating rains just west of there for farmers and other Elie and Portage La P. residents. To some it appeared that there were 2 travel choices on the Trans Canada HWY for most of that summer . From Portage la Prairie to Elie by Boat or Car. Bowes Mobile homes on the Eastern edge of PLP became known as Bowes Marina for most of the summer.

  39. Jim!

    I to have noticed that these so called "1 - 50 year event " and

    "Biblical floods" are happening a little more than every 50 years that the media have us believing !

  40. Rob!

    In the morning PASPC discussion they state that severe convection may be possible tomorrow!

    Hopefully there won't be any training of thunderstorms over the same area or for some places this could the nail in the coffin!!!

  41. I don't think we're going to see the training cells like we did on the weekend with this next system Thursday night into Friday. The dynamics aren't there compared to the classic signature on the weekend when there was a strong low level jet overriding a sharp stationary warm front tapping a very pronounced source of warm and moist air to our south. This next system is pushing in from the west with a more progressive motion and less low level moisture, so rainfall won't be as heavy or as persistent. In addition, models hint at a better chance of elevated thunderstorms through the Dakotas into Minnesota Thursday night which may rob some of the moisture over us.

    That being said, models show precipitable water values rising to 30 mm over SW Manitoba Thursday night, with marginal dynamics and lift, so locally heavier showers and thunderstorms are possible, but not to the extent of the weekend. Current ensembles suggest a 50% chance of 10-15 mm for Winnipeg Thursday night into Friday, with a 25% chance of 20 mm or more. The more critical factor for flooding concerns will be the intensity of the rainfall when it occurs.. 10-15 mm over 24 hours is probably manageable and would have little impact, however 10-15 mm in an hour would likely cause more serious flooding problems. Too early to say right now, but we'll be watching..

  42. BTW, Winnipeg airport's 160 mm of rain in May makes it the third wettest May on record behind 1977 (177.7 mm) and 1911 (162.1 mm) Records began in 1872. May 2010 is also Winnipeg's wettest month in 10 years, going back to June 2000 when 177.4 mm fell. The wettest month in Winnipeg's history was June 1901 with 255.8 mm.

    Note that rainfall in May was heavier in other parts of the city, especially over EK, St.B, and Transcona where monthly totals of 200 mm were recorded thanks to that late month deluge. The city wide network of about 30 rain gauges had a monthly average of 175 mm. I picked up 186 mm down in Charleswood, so the airport's 160 mm reading was actually on the low side compared to the rest of the city. The Forks station had 163.5 mm in May.

  43. Here's hoping to a dry and hot June.... Ya right ( sigh)

  44. "Oh and Box134...If by UM you meant the University of Manitoba, they do have a program in Atmospheric Science through Physical Geography that is a pretty great (and growing) program." CS

    Interesting.... I was under the impression that they only had a pre-meteorology program. Glad to hear you are close to graduating.

    When I was in university I knew one guy who was hired by the Environment Canada of the day. The requirements were high, they had to be Honors Physics types and they had to do a stint at a remote place like Rankin Inlet.

  45. b was the 200mm last July a Charleswood event only?

  46. Jim.. yeah, I recorded 200 mm last July mainly due to two heavy downpours that were much heavier than the airport got (57 mm on the 9th, and 67 mm 5 days later that resulted in lots of flooding in Chwd) This goes to show the variability in convective precipitation even within the same city (as we saw yet again last Saturday)