Monday, May 23, 2011

Joplin.. a terrible reminder of what a violent tornado can do in an urban center..

The Joplin tornado disaster should serve as a wake-up call for us in the Prairies as to what an F4 or F5 tornado is capable of doing when it moves into a populated area. By strong tornado standards, the Joplin tornado was relatively short lived.. lasting only about 20 minutes with a track length of about 20 km (often, violent tornadoes can track 100 km or more and last 1 or 2 hours or more). But much of those 20 km were right over a densely populated and commercialized area of a moderately sized city, leading to the deadliest single tornado event in the US in over 60 years. Even with today's technology and advanced warnings, these violent tornadoes are not survivable unless you're in a reinforced shelter, or underground. Although rare, F4 or F5 tornadoes can and do occur in the Prairies. We're fortunate that we have a lot of open space that's sparsely populated.. but it only takes one violent tornado hitting a populated area to do what we saw in Joplin. F4 tornadoes have occurred in Regina and Edmonton, and an F5 tornado struck just west of Winnipeg in Elie in 2007. The odds are remote, but they're not zero. It can happen here..

21 comments:

  1. Sobering pics and coverage in the Atlantic ..I selected your Pic.
    Rob are there any initiatives by Environment Canada to enhance warnings or is that a 2 edged sword attracting the morbidly curious to the location

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  2. Don..

    From what I understand, EC is waiting for implementation of a national alerting system that would automatically feed weather warnings over a variety of communication devices, including TV, mobile phones and devices, email, etc.. Unfortunately I haven't heard the status of that plan or when it may be implemented. That's unfortunate, since a tornado warning is useless if you don't hear about it. That's particularly important in Canada since we don't have tornado sirens or the media coverage like they do in the States to get the message out..

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  3. Unfortunately, more severe storms tomorrow through Oklahoma and Kansas.. SPC talking about possible high risk in that area tomorrow with another tornado outbreak. What an insane severe weather season they've had down there this year..

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  4. Rob do you think frost will be an issue in Winnipeg tonight?

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  5. A Tornado/Funnel cloud report Tolley ND 841pm Sunday. Near Sask Border and Souris River

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  6. Mr Farms

    I think Winnipeg will be safe from frost tonight.. we have an extensive area of low cloud over us extending all the way up to Norway House this evening. That cloud will gradually clear from the north tonight, but will likely stay over Winnipeg/RRV through much of the night which will keep our temperatures above freezing. Plus we have some brisk northerly winds through this evening that will prevent our temperature from dropping too quickly.

    Still, not a pleasant end to the holiday weekend, after that nice stretch last week. I'm beginning to wonder if we'll ever see summer weather stick around this year..

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  7. Rob,
    There is one question I always wanted to ask you.
    I know you have been a weather forecaster for a very long time but when you read the Storm Prediction Center DISCUSSION regarding their thoughts on the next days storm chances, you have a good idea what they are talking about???

    " A very diffluent upper flow regime will overspread the the plains as 30-60M 12 HR height falls edge EWD"

    "H5 Speed MAX approaching 80 -90 Kt."

    How is the general public supposed to understand these terms??
    Are these discussions written for the public or forecasters??

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  8. 45% tornado and 60% hail contours in Oklahoma in the latest SPC outlook. Incredible numbers.

    The April 27th Alabama outbreak had 45% tornado probs. It's extremely rare they go this high.

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  9. A pocket of very cool dry air has snuck down the RRV with a dewpoint of -4 C at YWG. Sharp gradient in moisture with Td's of 5 and 9 C at Grand Forks and Fargo. Hopefully some mid to high level clouds from a system down in the central plains will spread far enough north to keep us from totally bottoming out, but it looks like areas north of Morris might be in for a damaging, hard freeze..

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  10. Sounds like more massive damage and more deaths being reported tonight in Oklahoma!
    Just never ending for this tornado season!

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  11. daniel..

    The forecast discussion has always been mainly geared towards other forecasters and expert users, who are familiar with the terms used in the discussions. They were never really intended for the general public, which was never an issue before the internet age made them widely accessible. Nowadays, most people who access them have a fairly good grasp of meteorology so the discussions remain fairly technical.. although there has been some talk about making them more usable for the general public (like not using abbrevations for example)

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  12. An Oklahoma mesonet site near El Reno OK recorded a wind gust to 151 mph this afternoon as a massive tornado was tracking by the station, just NW of Oklahoma City..

    Click on my name for station graph..

    Report seems legit (tornado was showing F4-F5 numbers on radar). Station still operating. Impressive..

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  13. Now more tornadoes going through Dallas Metroplex, another round of severe storms for Joplin... I guess our frost warning is the big weather talk!!!!

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  14. Rob, you made a comment a couple days ago about wondering if we'll ever see any summer weather. With forecasts of another cool wet weekend coming, can you explain what is responsible for the cool wet pattern we seem stuck in right now i.e. lingering La Nina, blocking pattern in place etc.? Is there any light at the end of the tunnel and is it too soon to conclude we're in for a poor summer ?

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  15. I hope accuweather is wrong in their summer forecast!!

    They are calling for a wet and cool summer!

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  16. Mark..

    I think we're stuck in this perpetual La Nina type weather pattern with a strong and active jet stream to our south (partially responsible for the record severe weather season down there), even though La Nina itself is pretty much over right now. We're probably in a lag effect from the La Nina pattern of the past year or so, but with La Nina fading now, I think we should see improving weather for the latter half of the summer after a cool unsettled start. This is what CPC in the States is suggesting, and I think it looks reasonable at this point. Ideally, we'd like to move into a strong El Nino pattern which would give us better odds for warmer and drier weather for us (esply winter) but ENSO forecasts don't predict one over the next few months (they even hint at sliding back into a La Nina pattern by January, but I'll ignore that for now)

    Botom line.. I think we're in for a slow start to summer (we already are..) but I'm cautiously optimistic things will improve and we'll some better summer weather for the latter half of the season.

    Whether you're waiting for summer weather, or an announcement of the return of the NHL, Winnipegers need a lot of patience this year!

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  17. I just wanna see some thunderstorms already! These days it seems you have go and chase them in order to see any at all! Oh well summer is still coming!

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  18. Looks like a major warmup by the middle to end of next week with July-like temperatures!

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  19. So what the consensus on the weather for late Sunday? The U2 concert is Sunday eve and there are over 50K people showing up at the stadium. Forecasts seem to be all over the place.

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  20. I think late next week and on will be our first chance at seeing some legitimate thunderstorms up here in southern Manitoba. Models continue to show a big central/eastern ridge developing and pushing the jetstream north.

    Also, I'd keep an eye on this Saturday. If we can get a bit of sunshine, an upper low closeby may bring enough vorticity for a cold core funnel or two.

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  21. Anonymous,

    My opinion is that Sunday has the best chance of being dry in the Friday-Tuesday period. We should be in between systems.

    Big rainmaker likely on Monday.

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