Sunday, July 07, 2013
Showers and thunderstorms likely Monday night into Tuesday.. then turning warmer and drier for end of week..
After a stormy end to June with bouts of heavy rainfall, Winnipeg has yet to see any precipitation in July as a drier and warmer weather pattern evolves. Strong thunderstorm activity last evening over western MB pushed into the RRV overnight, but only managed to produce a few raindrops in the city as the storms weekened or split. The next threat of significant rainfall for the city will be Monday night into Tuesday as a storm system from Montana tracks into North Dakota. This system will likely spread an area of showers and thunderstorms along the US border which will push into southern MB Monday night into Tuesday. Some of the rain will be heavy with these thunderstorms with rainfall amounts of 25-50 mm possible in some areas, along with the potential for hail and frequent lightning. Things should clear out Tuesday evening with a return to drier and warmer weather for the latter part of the week.
Posted by rob at 6:02 PM
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E.C. has confirmed that a tornado touched down about 10 km South of Roblin yesterday evening. That I beleive is the first confirmed tornado touchdown this year in Manitoba.ReplyDelete
That tornado was based on an eyewitness report who saw it on Hwy 83 south of Roblin. Lasted 5-10 minutes, and uprooted some trees, otherwise no other damage reported. Will probably be ranked an EF-0 if confirmed. And yes, it would be the first tornado of the year for Manitoba. Note that the same storm produced at least one tornado on the SK side of the border near Kamsack.ReplyDelete
We'll be driving down to the North Dakota border for an errand, leaving Winnipeg early tomorrow morning. It should just be light rain by then? Or is severe weather still a possibility?ReplyDelete
There could be some heavy thunderstorms around in the morning, especially towards the border, but the severe threat should be minimal at that time in terms of hail or wind. Locally heavy downpours with rainfall amounts of 25-50 mm would be the main concern.
Please stop hogging all the storm action.
Hi Rob....how do you see this Friday playing out? A wash-out or just a scattered shower or two and mostly sunny?ReplyDelete
Just came back from fishing at Lockport. We left just as a storm passed through. It was raining so hard I whydroplaned doing 80 kph on the highway! I have never had that happen before. My wipers were on the fastest setting and it was still hard to see.ReplyDelete
Hydroplaned - not whydroplaned! Damn fat fingers.ReplyDelete
Pretty much a dud event for southern MB. We had a few tstorms pop up late last evening which prompted a severe tstm watch for our area, but not much came of them. Only about 5-10 mm of rain over southern RRV with a COCORAHS report of 25 mm in Emerson.ReplyDelete
Nothing compared to that 126 mm deluge in Toronto! Now THAT was impressive! 90 mm of that fell within 90 minutes between 430-6 pm local. That will certainly screw up your commute home!
Yeah, I travelled south to the border and back this morning. I'm kind of glad the weather wasn't too inclement. There was a light sprinkling of rain down there, which soon cleared too. That was all.ReplyDelete
Not sure if this is common knowledge about hydroplaning but according to the RCAF pilot handbook on runway surface contamination:ReplyDelete
Hydroplaning is initiated at very low speeds, the value is based on tire pressure; 9 times the square root of the tire pressure. So for most passenger vehicles that speed would be 50 miles per hour. (5.5 x 9) Chris in Westwood.
Yes some rain possible this afternoon. We have some showers to our north west over Lake Manitoba sprinting towards us. Should be weakening as it comes here but we could see some light showers this afternoon.ReplyDelete
Rob what are your thoughts on the weather that is coming into southeastern sask and south western Manitoba for ThursdayReplyDelete
Looks like a good risk of severe storms over SE SK late Thursday with possible supercells evolving into a squall line of tstorms over SW MB with potential wind/hail threat. Lots of energy available as temps get towards 30C and dewpoints near 20C, with SBCAPES of 3000+. Only issue will be fairly strong cap that will suppress tstorm development until cold front or storms break the cap from the west. Could be interesting..
Meanwhile.. central AB, including Edmonton, looking good for severe weather today with very favourable setup for supercell development later today into this evening. Large hail, strong winds and possible tornado threat with some cells.
Rob, what does the severe weather threat look like for us here in Winnipeg and the RRV for Thursday night and/or Friday?ReplyDelete
What causes storms that look like they are going to hit the city split into 2 and miss us? Seems to happen quite often.
Re: Severe threat for Winnipeg Thursday night/Friday..ReplyDelete
That will depend a lot on how convection fires up to our west over SE SK into SW MB. Those storms will likely fire up late afternoon due to a fairly strong cap that will inhibit convective initiation much of the afternoon. Once they get going and the cap starts weakening, I would expect a transition to a squall line across southern MB reaching Winnipeg by midnight or so if it stays intact. Best bet for severe weather would be over SW MB with large hail or strong winds, and possibly an tornado threat initially, evolving into a mainly wind threat for RRV later in the night.
>> Anonymous said... Rob, what causes storms that look like they are going to hit the city split into 2 and miss us? Seems to happen quite often.ReplyDelete
Perhaps this graphic will explain.. click on my name. :)
That's pretty funny.ReplyDelete
Humid evening out there with dewpoints climbing into the low twenties. Cluster of convection in western N Dakota as far south as I-94 ongoing.. question will be how they transition to elevated storms, and their southward extent. Region will be favorably situated on the nose of a moisture transport maxima at 850 hPa, and along the northern fringe of mid-level cap (using the 12 C isotherm at 700 hPa as a rough indicator). Given those parameters, best chance for significant convection would be Winnipeg and points north and west... unless cold pool from convection could break cap further south. Main threats would be heavy rain given the high moisture - and possibly wind if bowing segments can get organized. Some models also show potential for post frontal convection tomorrow afternoon..ReplyDelete
Area of elevated convection behind front over southern RRV and SE Manitoba - in an area of mid-level frontogenesis and moisture. We'll see if outflow and cold pool can trigger surface based convection to fire off the SE between Grand Forks and Fargo. Looks like an active pattern setting up over the next few days with front stalling and continued moisture-feed..ReplyDelete
Interesting temperature event on Friday. The temperature peaked around noon,fell into a valley between 2-4 o'clock, then rose to the day's high around 6:30. What would cause that, a front passing through?ReplyDelete
XKCD is always relevant. Good laugh!
Looks like things are rock and rolling just west of Brandon.ReplyDelete
With almost the same parameters in place as the previous night - save for 700 MB temps a degree or two cooler.. strong MCS moved thru the twin cities last nite giving 100-200 mm of rain in some areas. Surprising how far SE into the drier, stable air it progressed before finally weakening.ReplyDelete
Severe convection ongoing currently off to our SW. 20 to 30 kt LLJ ahead of a disturbance tonite may be enough to keep elevated storms going north of a surface warm front. Areas north and west of Winnipeg stand a better chance of seeing something. Threat should diminish after 2 am. At the same time, main central plains LLJ will be pointed again at S Dakota and S Minnesota..
Rob, what does the thunderstorm potential look like this week for Winnipeg/RRV? Are severe storms anticipated at some point during the week?ReplyDelete
Stalled front and LLJ to our southeast leading to persistent area of convection from eastern South Dakota up thru Thunder Bay - with 50-100 mm being reported in several locations since last night.ReplyDelete
Front will return north late Monday as plains LLJ links up with an upper disturbance moving across central Prairies. This sets the stage for another round of elevated storms during the overnight period. Mid-level temperatures will be cooler - below 10 C, so would expect fairly good coverage for convection. High amounts of precipitable water and relatively slow movement of LLJ will lead to a heavy rain threat.
Not surprisingly, the front and LLJ will stall just to our SE during the day Tuesday. We'll see if our lucky streak of avoiding severe weather and heavy rains continues..
Doens't look too exciting this week over southern MB. As Winnipeg Weather alluded to, we may see some thunderstorms overnight tomorrow but the main focus and energy for those storms will once again be over southern SK and SW MB, before they come here in a weakening state which has been the case for much of the summer so far. After that looks pretty quiet the rest of the week, until perhaps Sunday when GFS shows a more significant system possible affecting southern MB.. but that's still a ways out to be more specific.
Well I wouldn't call it a lucky streak, more like an unlucky streak depending on who you talk to.ReplyDelete
Rob any insights as to why the storms keep tracking over the same area over and over again and why they just can't seem to hold itself together by the time they reach here? We're talking our 3rd summer in a row here of this happening. There has to be something behind it.
Anonymous... I can't really say if this is just an "unlucky" streak or if it's due to some larger scale pattern change that is giving a consistent trend of more frequent severe thunderstorms over the western Prairies. Thunderstorm activity can be very streaky... and highly variable from year to year. Keep in mind also that SK and AB generally have more events than southern MB on average due to their more favourable location/geography for severe storms, plus their larger geographical area compared to southern MB. In addition, we're much more aware of every ominous shelf cloud than ever before thanks to social media, modern technology and a growing storm chasing fascination. Put all that together, and it becomes quite easy to think that the RRV is missing out on severe thunderstorms when possibly, it's just a greater awareness of storms elsewhere.ReplyDelete
That being said, thunderstorm activity has been slow here in Winnipeg/RRV the past few years with below average severe weather incidents. But again, I just don't know if that's just an "unlucky" streak or a trend to something more persistent. 3 years isn't long enough a sample to draw conclusions at this stage.
Pet peeve of the day - I wish EC and CBC, both funded by our tax dollars, could have a united effort when it comes to forecasting weather.ReplyDelete
CBC's graphic for the EC weather is showing cloud and showers tomorrow. However the actual EC forecast is for POP 30% in early morning, then clearing already in the morning. The EC graphic is better showing both cloud with a little shower and sun.
It's bad enough that our tax dollars are being used by individual CBC stations to hire forecasters who use American weather software and models, giving forecasts which often contradict EC. But at least get the EC forecast correct, using the same graphics.
Anyway, looking forward to see what happens in SK today, and western MB.
Thanks Rob thats a good explanation. You are definitely right that social media and technology make you more aware and so you see what you miss more easily (ignorance maybe is then bliss in this case!). And that is true that Alberta and Saskatchewan do get more events in terms of tornados and hail storms, but only marginally more. On average both Saskatchewan and Alberta have 12 tornados in a year where as we only have 3 less, at 9 per year. And although their location does have something to do with it, they also are more influenced by the rocky mountains rain shadow so the environment is drier (pallisers triangle), whereas by the time you get to Manitoba, there's more of an influence and access to gulf moisture. Historically in my mind, thunderstorms are more frequent here because its reflected on our higher annual average precipitation amounts then out west, which is received mostly from summer heavy rains from storms. When you don't get storms, its dry. Look at July last year and the year before, and so far this year. All well below normal because we kept missing out on everything. And it seems like when its dry and storm evasive here, its wet and storm targeted out west, at least in the last while anyways.ReplyDelete
As a proud storm enthusiast, I hope we can wash off this storm repellant we've seem to put on over the last few years. In my mind, you'd expect a much greater frequency of storms then this, based on the recent historic trend so it leaves you pretty disappointed when it doesn't happen, and when you're prime storm month is half over without really anything to show. As fall approaches in September, your chances drop off to pretty much nil chance of getting anything, then its waiting through the long cold winter till the next short season. Theres still some summer left but if things don’t turn around soon, it’ll the 3rd straight disappointing year for storms. As someone mentioned previously, you'd think after 3 years there'd be some change to this. But it is weather after all.
Sorry for the long post. I hope others can sympathize. The last 3 summers have just sucked for storms here so you get a bit antsy. Maybe I should start my own blog dedicated to storm enthusiasts like myself and who like to rant and get upset when you keep missing everything. I'm glad I'm not the only one anyways here :)
Anonymous.. I hear ya! Lots of folks getting antsy for some good storms. Explains why most of MB chasers are in southern SK today!ReplyDelete
As you say, you'd think YWG/RRV would have a better chance of some decent storms given our more humid climate. But low level moisture is just one parameter needed for severe thunderstorms. You also need good wind shear, a good jet, and a trigger. Those things seem to be lining up better over AB/SK recently than further east thanks to more frequent long wave upper troughs setting up over western NA. Those upper troughs would have to push further east to give better wind shear and jets over southern MB, but upper troughs are generally more transitory once they get east of the Rockies.
But yeah, it would be nice to see a good ole fashioned rip roaring thunderstorm here once in a while, (that doesn't hurt anyone or cause damage of course!)
Here is some text, from Environment Canada, from a storm warning in Saskatchewan. Still early in the day, and already things are getting bad.ReplyDelete
AT 10:45 AM CST, METEOROLOGISTS ARE TRACKING A LINE OF THUNDERSTORMS
CAPABLE OF PRODUCING HAIL LARGER THAN TENNIS BALLS, POWERFUL
DAMAGING WINDS GREATER THAN 120 KM/H, AND FLOODING DOWNPOURS. STORMS
ARE MOVING NORTHEAST AT 50 KM/H.
THIS IS A DANGEROUS AND LIFE-THREATENING SITUATION.
Yeah I miss the good years: 93, 94, 96, 2000, 2001,2004, 2005, 2007, 2010. The years in between still had some decent storm frequency as well.ReplyDelete
We just have to have hope and patience in the timeframe where we don't have storms, after all it is the hard times that teach us the most in life and I guess the past and possible future bad luck will teach us to wait and really admire those moments when we get storms. There is hope for change and it will come, we just have to get through this roadblock in what we call (storm busts). -Mike McGReplyDelete
Forgot to add that we did see a thunderstorm on Saturday in the city, it came in with a nice shelf cloud with the ocassional lightning flash. It sure made up a fuss when it passed over my house, huge bolt of lightning gave off a boom of thunder that shook our house. The whole thing retrograded north over the city, so we are still getting storms (just not as frequent). More luck will come! Just you wait....ReplyDelete
Appreciate the positive attitude Mikey thanks!ReplyDelete
Just wondering why no one has mentioned geoengineering as the main problem. This would explain perfectly why the west of the province is getting moisture and the eastern part isn't. It's so obvious - all you have to do is look at what has been happening not only on our continent but around the world. Places where there isn't enough rain then places where there's too much of it. It's no longer a theory, it's happening. Just you watch there will not be rain tonight in the western MB just like other previous "forecasts." Time to wake up!ReplyDelete
As interesting as severe weather can be, I would rather avoid tornado damage and flooded basements etc..ReplyDelete
The trend in recent summers has been for severe outbreaks to our NW and extreme precipitation events to our SE, due to the long wave pattern we have experienced of late as Rob mentioned.
As for tonite, HRRR depicts a line of thunderstorms moving up from central N Dakota.. likely associated with the nose of the plains LLJ that will link up with an upper trough passing to our NW. Same model shows convection weakening as it reaches Winnipeg, but with parameters in place such as: 750-1000 J/kg MUCAPE, persistent 30-40 LLJ, PWAT of 45 mm, mid-level temps below 10 C... would not discount possibility of elevated storms (possibly some isolated strong cells) affecting the area. Best chance will be during the midnight to 5 am timeframe.
Cold front gets hung up somewhere near Grand Forks tomorrow afternoon, as it becomes oriented parallel to upper flow. Models really downplaying any precipitation with minimal forcing, but expect at least some showers along and behind the front tomorrow.
Pretty big heat wave going on in Eastern Canada.ReplyDelete
38.6C recorded in Beauport, Quebec with the humidex reaching 44.6 at 4PM. That's the highest it's been this year in Canada.
Windsor's 25.0C dewpoint is also the highest this year in the country.
Even places in New Brunswick were within 2C (as high as 37.3C) of the all-time provincial record (39.4C in 1935)
How long does it usually take for Environment Canada to confirm a tornado, and provide a rating if they're able to survey damage? I was just wondering 'cause I've read that they've confirmed 3 tornadoes touched down in Saskatchewan yesterday, but so far as I know Pipestone is still unconfirmed from Saturday. Though with lots of damage reported and even a photo of it that's now surfaced, I'd expect it to be confirmed and rated soon.ReplyDelete
If there's verifable photographic proof of the actual tornado, then that will qualify as a "confirmed" tornado.. but photographs or videos of the tornado itself are not sufficient to rate the tornado *strength* if damage is reported. An on the ground damage survey is required to rate tornado strength.
In cases where no photos or video of the tornado is available and damage is reported, then a damage survey needs to be done before a tornado can be "confirmed", to determine if damage was due to a tornado or straight line winds. This was the case for Pipestone, which had good damage photos.. but none of the actual tornado itself (at the time). If verifiable photos of the tornado turn up, then EC would likely "confirm" it as well. Based on damage photos and radar signatures, it's quite likely it was indeed a tornado at Pipestone. I suspect we'll hear something soon..
Rob, is that more significant system you eluded to for us Sunday still in the cards or has GFS backed off on that?ReplyDelete
Thanks for the answer Rob. I was sure someone had uploaded a photo of the alleged tornado on Twitter, but I can't find it there now. It looked real enough to me (fakes tend to be obvious or *too* photogenic, which this wasn't), but maybe not since no one else has picked up on it and it doesn't seem to be there anymore...ReplyDelete
In any case, what do you think of Thursday's potential?
Thursday potential.. Looks like possible elevated warm frontal thunderstorms over southern MB/RRV as a wave passes through North Dakota, aided by a fairly good jet aloft and vorticity maxima. Main threat would be some heavy rain.. maybe hail. Trailing cold front may bring severe threat over SW MB by Thursday evening depending on how much morning cloud/convection clears.ReplyDelete
Potential threat for Sunday has backed off, with a cold front pushing through Monday that may trigger some thunderstorms.. but too early to say how strong if any.
Note that Thursday forecast has no mention of thunderstorms anywhere over southern MB. This is because automated forecasts for Day 3 and beyond never include thunderstorms, just a probability of "showers" or "rain". Even if the forecast calls for 35C temps and 20C dewpoints, thunderstorms are never mentioned in the automated forecast beyond Day 2. Note that thunderstorms will likely show up in tomorrow's forecast when Thursday becomes Day 2.ReplyDelete
So if you ever see "showers" or "rain" in the EC forecast for Day 3 and beyond and the forecast high is 25C or more, assume that thunderstorms are also implied.