Monday, April 21, 2014

Wet weather moving in for mid week..

More typical springlike weather has finally become established across southern Manitoba as the winter snowpack has pretty much disappeared across most areas. This is allowing the late April sun to warm up the surface more easily, with temperatures reaching more seasonable values now.  Tuesday looks to be a beautiful day with lots of sunshine and temperatures reaching the mid teens.. pretty much normal for this time of year. The nice weather however will be short lived as a large storm system developing over the western Prairies brings a widespread area of rain across southern Manitoba during Wednesday, reaching Winnipeg by late afternoon or evening. Rain will become steadier and heavier Wednesday night, with a good soaking of 15 to 25 mm possible through Thursday, likely our most significant rainfall since last October. Rain will taper off Thursday night, possibly changing to some wet snowflurries by early Friday as colder air works in behind the system. Cooler than normal weather will follow in the wake of this system through the weekend into early next week. This will ensure that April finishes below normal by a good 4-5C, the 7th straight month that has ended up below normal in Winnipeg. The last month that was above normal here was last September which finished 2.5C above normal. Hopefully, May can finally break the below normal streak..    

33 comments:

  1. Im hopeful to see the big precip numbers stay north of us. We dodged a couple of Bullets earler this month One more should do it A repeat of nineteen Fifty Is not a pleasant thought

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  2. I don't think we're going to get that much rain that flooding would be a concern (especially on a 1950 scale). Some rain to clean up the winter dirt and get rid of whatever snow is left would be nice.

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    1. Between April 22 and May 4 1950 there was 80mm of rain and snow equiv and another 25 by may May 9 .

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  3. You might think differently if your car was six inches below the water line already and no prep was done

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  4. Wow anon,
    WHEREV DO YOU LIVE FOR THAT KIND OF FLOODING?

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  5. No kidding. Flooding like that is news to me. From what I heard there isn't much of a threat to anybody.

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  6. Very nice day out there today. Light winds, full solar and temps in the mid teens.

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    1. And to think we're actually BELOW NORMAL!

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    2. Slightly above today actually.

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    3. Hard to believe it was only 14C out there this afternoon.. (15C at my place) Felt a lot warmer than that with that beautiful late April sun, and light wind. Felt more like 20C in the sun. Great day to start on that spring yardwork and sweep out the garage!

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  7. Rob, please tell me i'm wrong but if i've interpreted this right it looks like a colorado low is threatening a major snowstorm for us Monday-Tuesday.

    Is that correct?

    Thanks, anon

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    1. Euro model has that storm system staying to our south, while the others give us some rain or snow, but main energy of storm staying stateside. I'm hoping the Euro is right.. and if not, that most of the precip will stay as rain..

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    2. Models coming into better agreement that midwest storm early next week will stay well south of us, with minimal impact for the RRV and Winnipeg. Hopefully it stays that way..

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  8. A good thing is that April 2014 will have been warmer than April 2013.

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  9. Hey rob,

    Do you think that rain will fill in on the radar and pick up for Winnipeg, or do you think the rain will stay mainly north east of the city?

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    1. Given latest radar trends, it looks like most of the rain will remain east of the Red River valley and north of the city through the Interlake regions. Winnipeg will see some lingering light rain or drizzle this afternoon but additional accumulations should be minimal for us, perhaps 1 - 3 mm. There's a chance that some of that rain to our east may build back towards us this afternoon which could give us a period of steadier rain, but at this point, it looks like most of it should stay mainly to our east.

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    2. Radar shows rain has picked up again over the city on western flank of rain shield as of 5 pm. That could give us another 5-10 mm through this evening and tonight before it tapers off. I'm currently up to 10 mm since last evening.

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  10. how much rain did we get over the last 24 hours??

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    1. As of 11 am, I've picked up 8.6 mm at my station since last evening.. while the airport has had 7.4 mm. Generally looks like 5-10 mm has fallen across the city so far.

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  11. Rob, does that storm for late Sunday into Tuesday still look like a miss for us in Winnipeg/RRV?

    Thanks, Anon

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    1. Models have been back and forth with how that system will affect Winnipeg/RRV.. Yesterday they were trending dry with most of the rain to our south and west. Now today they're all trending wet for us, including the Euro who was the lone hold out up to now that we would stay dry. Now they're showing 20 mm of rain for us Monday.

      It looks like main system will still be tracking to our south, but it will be sending up a large swath of moisture into the southern Prairies by Monday. At this point, it looks like we will be getting precip out of that system, and it should be mainly rain, which is good news. Unfortunately, it could be an extended period of rain for portions of southern SK and southwest MB.. with up to 100 mm of rain in some spots which will obviously be a concern for rivers and streams in the area. But models have been having issues resolving how this system will impact us so we'll just have to see how they trend over the next few days. But certainly starting to look like the potential for a significant slow moving system with lots of rain in some areas.. hopefully not over the Red river basin.

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  12. Thanks, Rob. Rob, would there be a risk of thunderstorms for us with that storm system as well?

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    1. Slight chance near the US border, but most of it should be south of the border.

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  13. I guess mother nature did not get the memo about no more snow till next season.

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  14. Rob, looks like an Omega block pattern setting up, as that low pressure system from this weekend is just spinning around and actually retrograding back to the west a bit.

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  15. Rob, looking at the latest GFS run, do you think we could see 40 mm of rain between Sunday and Monday?

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    1. GFS is currently the wettest for rainfall totals in Winnipeg with that 40 mm. Other models are more in the 15-20 mm range for us. 40 mm is possible for Winnipeg, but I think those kind of amounts are more likely to the south and west of Winnipeg (southern and western RRV, southwest MB..)

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  16. That huge cutoff low is just going to be drawing in the chilly air into southern Manitoba for around the next week. Yesterday the forecast high on Wednesday was 17C. Now it is 7C. The way this spring has gone, I would not be surprised it was saying 0C and snow on tomorrow's update. Big warm....where are you???

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    1. Yes, it's quite disheartening. No signs of above normal warmth through the first week of May at at least. And latest outlooks suggest a cooler than normal May to follow our cold March and April.. which is supported by statistical correlation based on previous years. (For Winnipeg, May has a 55% chance of being cooler than normal after a cold March and April, vs 30% chance of above and 15% near normal) Correlative analysis has been bang on this spring, correctly predicting March and April averages to within 0.5C. We'll see if the trend continues in May. But the way things are going, I wouldn't count on a big turn around anytime soon.

      We can take some solace from the fact that once we break out of this prolonged below normal pattern, things can turn around dramatically. After going 9 straight months below normal in 2009, Winnipeg had its warmest September on record to end the streak. The cold winter and spring of 1996-97 was followed by the second warmest winter on record in Winnipeg the following winter. After the terribly cold spring of 1979, the spring of 1980 was one of the warmest, driest and sunniest on record with record heat in April and May. The extremely cold winter of 1935-36 was followed by the scorching summer of 1936 that produced the hottest temperatures on record in much of central and eastern North America, including Winnipeg's all time hottest day of 42C. And if you look globally, pretty much the entire planet was above normal in March.. except for central and eastern North America (lucky us!) So I'm optimistic that once things change, they could change quite spectacularly!

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  17. As I recall 1980 Was so dry it only rained on long weekends a d the grass in Assinniboine Park didnt turn green until August. Seems to me we had a lot of grass near Wilkes and Parker. What causes those weather syztems to stay that long. Winter 79 and then summer 1980? Don

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    1. Don.. Extended weather patterns of abnormally warm, cold, dry or wet conditions are usually the result of what is known as "blocking" in the atmosphere.. that is, the atmosphere gets locked in a particular pattern for an extended period, often weeks or months, due to a very stable and persistent flow around the globe. This results in a series of upper ridges and trofs around the globe that get locked in certain locations for a long while, resulting in persistent warm/cold or dry/wet conditions depending on if you're under a ridge or trof. These types of patterns occur periodically every year, sometimes longer and more frequent, sometimes shorter and less frequent. There is some speculation that the growing loss of Arctic sea ice is resulting in more frequent blocking patterns due to a weaker polar jet stream (which can result in a wavier jet stream that is more prone to developing blocking patterns)

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    2. Those were grass " fires " along wilkes

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  18. Thnx Rob Just in from Sask and it resembles.East central Mb in a wet spring more like a marsh n swamp than a wheat centric prairie.Rain n cold from Reginia to Virden Didnt warm up til Brandon.

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