Tuesday, September 24, 2013

Dry spell continues as rain eludes Winnipeg/Red River valley

Rainfall in Winnipeg over
the past 30 days. Only 6 mm
has fallen since August 19

Showers and scattered thunderstorms brought some beneficial rain to western Manitoba and the Interlake regions Monday with general amounts of 15 to 30 mm recorded, but for Winnipeg and much of the Red River valley and SE Manitoba, it was another dry day as rain from the system bypassed the area to the west and north. It's been a dry September in Winnipeg and much of the RRV, with only 4 mm of rain recorded at Winnipeg airport this month, and only 6 mm over the past 6 weeks. The last significant rainfall in Winnipeg was during a heavy thunderstorm on August 18th when 30 mm fell in about an hour. Since then, rainfall has been scarce with minor amounts falling on a few days, with heavier showers often bypassing the city.  Normal September rainfall is 45.5 mm in Winnipeg (based on 1981-2010 averages), so we are running well below normal for the month.  This is very similar to last fall when Winnipeg recorded its second driest September on record with only 4 mm falling during the entire month. 

As for this week, the next chance for precipitation in Winnipeg will be Thursday as a storm system pushes across western Manitoba. Once again however, it looks like the bulk of precipitation with this system will be mainly west of the Red River valley. Models are indicating the possibility of a second system bringing more widespread rain to Winnipeg and the RRV Friday night into Saturday, which hopefully pans out as we can use the rain.  Last fall, tinder dry conditions in September led to several wildfires in early October, including one near Vita MB that damaged several homes and forced the evacuation of the entire town.       

              

18 comments:

  1. Any insights Rob as to why the rain has been so elusive here?

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  2. Anonymous...

    It's just been bad luck more than anything. There have been several occasions over the past month where bands of heavier showers and thunderstorms have just skirted the city, but I don't think there's a physical reason why they keep missing us. Just random chance. Also, we haven't had a good synoptic rainfall event for awhile where everybody gets a good soaking... we've been in convective mode well into September which also limits the overall rainfall distribution. Lastly, fall in the Prairies can be quite dry as convective activity winds down,while the synoptic storm season is still a few weeks away.

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  3. Winnipeg airport YWG station picked up 1.0 mm of phantom rainfall yesterday, bringing our monthly total to 5 mm. The colocated Winnipeg A CS station (which will become our official recording site as of Oct 1st) correctly showed no rain yesterday, with a monthly total of 3.6 mm so far. The YWG site will be decommissioned as of Oct 1st which will thankfully put an end to those spurious 0.5 and 1.0 mm readings that are so common with that station (due to a weighing type precip gauge that is prone to this type of error especially on windy days)

    The CS station has a different type of precip gauge, called a GEONOR system. Although it does better with warm season precip (ie rain) it seems to have a notable dry bias with winter precip (ie snowfall)

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  4. Random? Bad luck?! C'mon! Just look at what is happening worldwide. Way too much rain in MANY MANY places (this is causing and will be causing insane sinkholes btw) then not enough rain in other places where fires are common place. Tornadoes in places where they've never been seen before!? Snowing in places when it should be raining? But things could always be worse here but thankfully it's not. Kudos to you for at least acknowledging how dry it is (the local or national msm don't mention this AT ALL, I mean the boulevards are brown, soil is cracking, etc..) but this cannot be explained unless you understand what is really going on worldwide as chemicals are used routinely for destruction around the globe and then we wonder why things are changing!? It's not a surprise at all. Especially when the US Gov't has a plan to control the weather by 2025, cloud seeding programs, not to mention HAARP witch is worldwide not just in Alaska. This is all documented, look into it. Tesla technology is being used by madmen, it's only in recent years have we have begun to seen this, now it's undeniable. Ever heard of HARRP pulses or rings? They show up on radar. If not you should look into it.

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  5. ^ Yes. Exactly. Governments are manipulating the weather so that thunderstorms miss Winnipeg. It's a conspiracy I tells ya! *spins around in chair making googly eyes*

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  6. Anonymous..

    The precipitation patterns you're describing (too wet in some places vs too dry in others) are consistent with a scenario where there are more frequent blocking patterns setting up in the atmosphere compared to before.. possibly as a result of a "lazier" jet stream these days that isn't quite as strong due to an overall warmer climate and decreased thermal gradient between the equator and the poles. This leads to a greater frequency or liklihood of more prolonged warm/cold/wet/dry patterns than in previous decades. Not sure that's the whole reason, but it seems to make sense and is consistent with current climate change theories.

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  7. Big discrepancy between US models and Canadian/European models regarding rainfall potential for Winnipeg Friday/Saturday. Models indicate a developing system in the Dakotas Friday will spread an area of rain to the north and east. GGEM and ECMWF bring that rain area into Winnipeg and RRV Friday into Saturday with significant amounts of 30-40 mm being forecast (at least on last night's runs). On the other hand, NAM/GFS take bulk of rain mainly east of Manitoba into NW Ontario with little or no rain indicated for Winnipeg/RRV. We'll see if there's convergence towards one solution over the next day or so. Regardless, looks like little threat of rain for Winnipeg with tomorrow's system (too far west) and possibly a miss to the east with Friday/Saturday system. How much longer can Winnipeg keep dodging these systems??

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  8. Rob, out of all the weather models that you use to forecast the weather , which one is your personal favorite??

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  9. >> Anonymous said... Rob, out of all the weather models that you use to forecast the weather , which one is your personal favorite??

    Overall, I'd have to give the NAM the nod for most reliable short term model.. but that depends on the situation, and the RGEM can be quite good as well, often as good or better than the NAM. In the longer range, I actually find the Canadian Global model to be quite good, although the European model has the best reputation for long term skill. Overall, it's difficult to say one model is better than the others consistently, as they all have their strengths and weaknesses, and performance can differ from day to day, and event to event.

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  10. Rob what is our cumulative precipitation right now and what should we be at?

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  11. >> Anonymous said...Rob what is our cumulative precipitation right now and what should we be at?

    Using raw numbers from the YWG Richardson AWOS autostation (which haven't been officially quality controlled yet so they could be off a bit) Winnipeg has seen about 352 mm of rain and melted snow since Jan 1st. Using 1981-2010 normal precip values, we should see about 437 mm of total precip by the end of September, so currently we're about 85 mm below normal (or about 81% of normal) through the end of September assuming we don't get more in the next 5 days.

    Keep in mind that's based on Winnipeg airport obs. Other localities outside the perimeter, and even within Winnipeg itself have had more or less than that amount.

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  12. XWG says we've only had about 280mm so far. That's quite a bit lower than YWG and they're not located that far apart.

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  13. New guidance from today converging towards a more consistent solution regarding Friday/Saturday rain chances for Winnipeg. GGEM/ECMWF have shifted a bit east, while GFS has shifted a bit west.. Upshot is that current model concensus has bulk of rain falling east of Winnipeg, perhaps as close as eastern RRV/SE MB, with Winnipeg on the western edge of the rain shield with perhps 5-10 mm, but likely not the 30-40 mm earlier predicted from some of last night's runs. We'll see if models stay that course, or shift again in the next few days.

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  14. >> Anonymous said... XWG says we've only had about 280mm so far. That's quite a bit lower than YWG and they're not located that far apart.

    Probably due to some missing data, as well as a notable dry bias with winter precip (ie melted snow)

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  15. Hi Rob,

    I know that you are not a hurricane expert, but do you have any thoughts about why there has been such a shortage of hurricanes in the Atlantic basin this year??? I believe they were calling for an above normal year...

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  16. Anonymous..

    No, I wouldn't have much insight into why there's such a lack of tropical storm activity this year. But I do know it's one of the quietest Atlantic seasons in many years. I would recommend reading some of hurricane expert Jeff Masters posts on his Weather Underground blog for more insight into this years hurricane season.

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  17. Getting some rain showers here in SW Winnipeg as small area of convection over western RRV moves north. Even has some embedded thunderstorms near Carman pushing north. Area should be passing through over the next half hour with 2-5 mm possible, locally heavier amounts west of the city.

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  18. 5.5 mm of rain at YWG airport in this morning's "deluge" (5.2 mm at Winnipeg A CS site) which is just over the total amount of rain we've had all month. Monthly total in Winnipeg now up to 10.5 mm, still well below normal for the month.

    We'll see if we can add to the total tomorrow into Saturday as a couple of waves ride up a nearly stationary frontal boundary setting up over western Minnesota into NW Ontario. Models show a good swath of 25-50 mm possible over SE MB into NW Ontario Friday into Saturday with a sharp dropoff in rain over Winnipeg and the RRV (more east, less west) Where that deformation axis sets up will determine how much rain Winnipeg gets over the next couple of days. Right now, looks like we'll be on the western edge of the main rain shield with 5-10 mm possible into Saturday with heavier amounts to our east, but if deformation axis sets up a little further west, Winnipeg and RRV could see higher amounts.

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