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Departure from normal precip (mm) across Prairies since
Apr 1st. It's been notably wet across the far south |
The frustrating weather pattern that has plagued southern Manitoba with frequent precipitation events over the past 6-7 weeks continues to linger into mid July with yet more rain today. A large storm system tracking through northern Manitoba will bring cool, windy and unsettled conditions throughout southern Manitoba today, making it seem more like a day in mid September than mid July. But once this system finally starts to move eastward tomorrow, a gradual improving trend is expected later this week through the weekend and possibly through much of next week with a warmer and drier pattern setting up. Long range models are indicating the development of a massive dome of hot and stable air that will be setting up over the central US plain states next week, that hopefully will edge northward into southern Manitoba. The core of the heat will be south of the international border over states like Iowa, Nebraska and South Dakota where temperatures of 35-40C are likely in what will be an extended heat wave next week. Some traditionally hotter spots there may be seeing temperatures as high as 43C (110F) In Manitoba, temperatures will likely be above normal with temperatures of 25-30C expected with a trend towards less frequent shower and thunderstorm activity. However, given that southern Manitoba is expected to be lying on the northern edge of the heat dome, there will likely be periodic thunderstorm activity as impulses round the upper ridge (aka "ridge riders") One potential type of severe weather threat with this type of upper pattern is the "derecho" - a cluster of powerful long lived thunderstorms that ride along the periphery of the upper ridge and produce widespread wind damage along its path, often at night.
Large upper ridge expected to dominate weather pattern over central US next week bringing widespread heat over much of the US edging into southern Canada
A pattern change to drier and warmer weather is desperately needed over southern Manitoba. After a dry start to the growing season, the overall pattern turned wetter and more unsettled in late May and has persisted through much of June through the first half of July. Some places in the Red River valley have seen over 2 times the normal precipitation since June 1st. Lettelier for example has recorded a whopping 313 mm of rain from June 1st to July 12th, some 260% of normal. Since May 23rd, Winnipeg (and much of southern MB) has had only one stretch of 4 or more days with no measurable rain (June 13-16) otherwise, rain has been occurring every other day or two over the past 6 weeks, often heavy at times. Farmers are hoping that drier and warmer weather will salvage what could be a very good crop this year.
A pattern change to drier and warmer weather is desperately needed over southern Manitoba. After a dry start to the growing season, the overall pattern turned wetter and more unsettled in late May and has persisted through much of June through the first half of July. Some places in the Red River valley have seen over 2 times the normal precipitation since June 1st. Lettelier for example has recorded a whopping 313 mm of rain from June 1st to July 12th, some 260% of normal. Since May 23rd, Winnipeg (and much of southern MB) has had only one stretch of 4 or more days with no measurable rain (June 13-16) otherwise, rain has been occurring every other day or two over the past 6 weeks, often heavy at times. Farmers are hoping that drier and warmer weather will salvage what could be a very good crop this year.
Well.. so much for our dry weekend. Area of showers and tstorms blossomed over North Dakota and SW MB today, and naturally spread into the RRV this afternoon.. even though most models were showing all of this stuff staying mainly in ND. Seems like any system or impulse passing close to southern Manitoba ends up giving more widespread precip over us.. instead of staying isolated or missing us all together. A truly maddening past 7 weeks, and one of the more frustrating summers I can recall in terms of our inability to get a decent dry spell of any reasonable length.
ReplyDeleteWe get another shot of showers and tstorms Sunday as a cold front passes through, then a decent Monday before the big warmup begins Tuesday. But given what our past 7 weeks have been like, I wouldn't be surprised to see our heat spell this week interrupted by tstorm activity yet again. Boy do we need a nice dry stretch for a while.. hopefully we move into a drier pattern for the 2nd half of summer.
Rob Do you think a poll around the longest stretch of dry weather in what remains of our summer, will give you an idea of weather your new roof will be finished before the snow flies?
ReplyDeleteDo you think Your memory of this type of summer might have been better if you had not ventured to Italy one summer ?
do you remember this........
ReplyDeleteFinally! - Extended stretch of sunny warm weather ahead
It's been a rarity this summer, but it looks like southern MB will have an extended period of sunny warm weather ahead this week.. possibly lasting right through the upcoming weekend. A large upper ridge of high pressure is forecast to build over the Prairies this week which will help to maintain sunny and stable conditions from the Rockies into northwest Ontario.. a nice change from the persistent unstable airmass that has brought almost daily shower and thunderstorm activity across the Prairies this summer. Temperatures in southern MB will be pleasantly warm this week.. in the 25-27c range climbing into the upper 20s to low 30s over the weekend. The GFS is even indicating a high of 33C for Winnipeg by Sunday. Perhaps YWG airport will finally hit that elusive 30C mark yet this summer! Whatever the case.. it finally looks like some nice beach weather ahead this week and weekend over southern MB.
Posted by rob at 11:26 AM August 6, 2008
Ha ha.. you may be right Jim. I had the good fortune of being in Italy during the summers of 2004 and 2009, both of which were downright miserable here. 2009 was especially memorable since September ended up as our warmest month that year.. making up for a terrible summer. So yes, my recollection of poor summers here may be tainted by being AWOL for some of the worst ones! :)
ReplyDeleteCoincidence? ..I think not!
DeleteCells trying to form out ahead of the large supercell near Portage. Some Mammatus and interesting undulating cloud structures (likely mammmatus getting sheared by winds) over central Winnipeg.
ReplyDeleteRoll cloud also spotted off to the northwest.. very perturbed sky.
DeleteI was hoping jj took some pictures in St Vital . Extremely interesting clouds there at 245 315
ReplyDeleteDid anyone else take pics
ReplyDeleteTricky convective forecast for overnite..
ReplyDeleteThe supercell that dived south along the Pembina Escarpment is now down around Grand Forks. That area may expand in coverage and move further down into the LLJ. The jet axis and moisture transport will shift east overnite, so the focus for elevated cells and large-scale convection will be mainly over NW Ontario and Minnesota.
However, models develop another line of storms along a trough axis (best defined at 850 hPa) which would move through at around 4 AM. Lots of uncertainty - plenty of remaining instability, but no forcing from LLJ, and increasingly diffuse surface reflection (limited low-level convergence).
Tomorrow it appears the surface trough will stall/ wash-out with it finally pushing through late in the day.. giving a chance of surface based convection. Not much support from LLJ as it remain well to our south and east again tomorrow evening.
Lots of stratus down over N Dakota and Minnesota this morning which is just now starting to burn off. This is keeping temperatures down there in the mid 20s. With southerly flow out from under that cloud shield continuing.. will be difficult to truly heat out and destabilize the atmosphere locally.
ReplyDeleteArea of strong to severe convection forming off to our west. Northern end of line looks at least partially elevated, but discrete supercells capable of producing tornadoes have formed in SW Manitoba (south of the Trans-Canada) and N Dakota.
ReplyDeleteQuestion is organization/ evolution of convection this evening. Main LLJ coming up from the plains is well to our SE, however weaker SW LLJ (30-40 kts) develops which should provide decent forcing/ low level shear for storms to hold together (along with support from upper jet, short wave, and extreme instability).
Line is moving slowly so heavy rain is a threat, along with large hail. Isolated tornadoes with discrete cells possible. Main threat should be through Winnipeg by 1-2 AM, as surface trough and LLJ translate east.
and right on cue Woodlands stopped reporting from 1930 to 2000h.
DeleteWhen I was watching the severe thunderstorm walloping our city at my kitchen's window at my home, I felt like this storm's heavy rains and fierce winds looked like those from Super Typhoon "Haiyan" (Yolanda), which swept through the eastern section of the Philippines in November 2013, where it destroyed much of that area, especially in Tacloban City and its immediate surroundings and it claimed more than 6000 innocent lives.
ReplyDeleteAfter tonight's storms swept the city and our immediate surroundings in the RRV like Selkirk, Lockport, Morris and the border town of Emerson, let's hope we get a nice weather for Saturday and the chance of precipitation only be pegged at 30 percent, especially on the day of Folklorama kicks off at the Memorial Park by the Legislative Building on Memorial and Broadway. Keep our fingers crossed!
ReplyDeleteJust a thought but could Multiple Anonymous entries id as anon1 anon 2 anon 3 so we can follow a thread or a commentor or not?
ReplyDeleteRob, after tonight's onslaught of severe thunderstorm, it's time for us to see several weeks of nice weather without any single drop of rain, between now and early September, especially in time for Folklorama (July 31st to Aug 13th), Filipino Street Festival (Aug 20th), Labour Day long weekend (Sept 3rd to 5th) and Manyfest, Banjo Bowl and Sherbrook Street Festival weekend(Sept 9th to 11th). Let's hope we don't see another severe thunderstorm swept on us and the rest of RRV for the remainder of the summer. I wish they just swept on us in the middle of September, instead of the traditional late June to early July time-frame, when the outdoor events are done for the season.
ReplyDeleteAnother round of active weather for this weekend..
ReplyDeleteCurrently seeing a high over low pattern at the surface.. with a warm front down over S Dakota separating extremely hot and humid conditions (with PWATS ~= 50 mm) from a warm airmass with shallow moisture locally.
Low pressure area will track from Montana to the NE and start dragging that higher moisture and instability northwards again. Models hint that convective development may organize into two main areas overnite: on the LLJ along the Manitoba/Sask border (ahead of the mid-level disturbance), and along the surface warm front down over N Dakota.
Potential for surface redevelopment tomorrow over our region along trough line/cool front, but a lot of uncertainty as to position of low and warm sector placement. Even if we do get into the warmer airmass, there may not be sufficient clearing as the LLJ/ moisture transport axis will be right overhead during peak heating. As a result there will likely be a lot debris cloud and weak elevated convection to deal with.
However, the potential for any clearing to further destabilize the airmass bears watching tomorrow as the surface trough line approaches. Activity should not linger much past evening with the main LLJ translating well off to our east by Saturday night. Non-severe wrap-around showers possible on Sunday, as the parent upper low moves over ahead.
Double barreled low pressure system with main low over Saskatchewan, and weaker low down over S Dakota. Surface trough connecting the two. Narrow swath of clearing between the complex of showers and rain from this morning, and the cool frontal trough. Line of convection west of Portage having a tough time getting going..
DeleteProblem is two-fold.. easterly flow locally would enhance low level shear, but also is producing outflow form the the clouds and rain to our east. This is causing the highest instability of around 1500 J/Kg to actually be post-frontal. The other issue is that the low down in S Dakota - along with an MCS over the Twin Cities - has bottled up the highest dewpoints (22-23 C) further south. Dewpoints are only 18-20 C over the western RRV in the clear air. Threat of any storms should be over by about 7 PM.
Line of non-severe showers and t-showers has formed from Headingly back thru Carman.. and will move the city through shortly.
DeleteRob, I hope we need a dry pattern to dominate Winnipeg and Southern Manitoba with less heat and humidex, especially for everyone, for the rest of July and most of August, during Folklorama and the Filipino Street Festival on 20th of that month, during the post-Folklorama weekend. We don't want to see anymore thunderstorm activity until the middle of September, soon after the Manyfest, Banjo Bowl and Sherbrook St Festival have taken place during the weekend after Labour Day (September 9th to 11th).
DeleteIn the past two years, the period between late August and early September, have been dominated with severe thunderstorm activity here in Winnipeg and Southern Manitoba.
It's not uncommon to witness thunderstorms, regardless if its severe or non-severe as late as the middle of September beyond Labour Day. By then, all of the outdoors events are done for season.
Keep our fingers crossed!
Finally looking like a drier, more stable pattern across southern MB this week.. we may actually go 5 days in a row without rain for the first time since May! About time! Hopefully this is a sign that the wet unsettled pattern of the past 8 weeks is finally turning around.. we sure need it.
ReplyDeleteI just hope this doesn't mean we won't get any thunderstorms for a long time. Part of enjoying summer is a few good storms. Sunny warm weather is a given but thunderstorms are a lot more elusive.
DeleteRob, I know you like to stay away from long range predictions as it is certainly difficult especially in the summer months, but what are indications as far as August is concerned for us here in Southern Manitoba?
ReplyDeleteAbove Normal or Below Normal?
Current CPC outlooks suggest a warm start to August will trend towards cooler than normal conditions by mid month, with generally below normal weather for the latter half of August. But I don't have a lot of confidence in the outlook for the rest of the summer.. no clear signals how it's going to go. Hopefully our recent dry spell sets the trend for the rest of the summer..
DeleteRob, Is there an increased threat of severe weather for Winnipeg and Southern Manitoba at some point this weekend or next week with the heat and the humidity returning to the region?
ReplyDeleteYes, looks like a line of severe tstorms are expected to develop over SE SK late Sunday pushing into SW MB by Sunday evening, before continuing across the RRV after midnight. Once again, big hail and damaging winds look like the main threat initially before evolving into a heavy rain/wind threat over the RRV. Could be quite the light show as well Sunday night.
DeleteHeat warning issued for much of RRV (including Winnipeg) and SW MB today for humidex values near 40 this afternoon. But most guidance don't have Winnipeg or RRV hitting those values today.. Our dewpoints should stay in the 16-19C range today in the RRV which combined with 30C temps would produce humidex values only around 35C. Better chance of 40C humidex readings over SW MB where dewpoints will be higher (20-22C) For Winnipeg to hit 40 humidex today with a 30C high, we'd have to get a 23C dewpoint which is not likely for us today.
ReplyDeleteToday will not be a repeat of July 20th here when our dewpoints soared to 26C (oppressive!) resulting in 43C humidex readings..
Severe tstorm threat remains for tonight.. again, storms developing over SW MB this evening and pushing into RRV tonight (midnight or later) Mainly a heavy rain/wind threat by the time storms reach RRV..
Peak humidex of 36 this afternoon in Winnipeg.. temp 29 over 19 dewpoint. Dewpoints in RRV stayed generally in the 17-20C range today.
DeleteStorms have largely split north and south around the city lol. Only 1-2 mm of rain in central areas so far. The far south end stands the best chance of getting brushed with heavy rain and other severe parameters..
ReplyDeleteYeah was a bit disappointed with the outcome of last nights storms here. Good thunder and lightening but as one twitter commenter perfectly put it, it was all fart but no poop!
DeleteAgain last night only the south end was brushed.
DeleteFor the August 3 event, low resolution radar data from weather underground showed an anomalous region of reduced to no returns relatively stationary over the city as the storms moved past.
Next system will track a bit further south than most this summer. Again, it will be a double barrelled feature with southern wave tapping LLJ from the plains, and a larger northern stream upper low.
ReplyDeleteLLJ remains focused well to our SW for tonight. However by afternoon and evening tomorrow, it expands to the NE and provides decent forcing/convergence for southern RRV and SE Manitoba. Accordingly, models depict rain band lifting north and stalling somewhere over northern N Dakota or southern Manitoba.
LLJ fades and shifts east by Thursday morning, but we will have to contend with dynamics and forcing from the main upper low as it moves overhead. Model information suggests deformation band setting up somewhere over the Interlake to Bissett regions.
Uncertainty with placement of these bands, but potential exists for Winnipeg to see limited precipitation. We could actually use some rain at this point after having missed the last two rounds of convection. Combined with yesterday's wind-tunnel conditions.. topsoils have actually started to dry out fairly rapidly in our region.
Lots of clearing today in the wake of last night's MCS which moved across N Dakota..
DeleteCurrently have low in S Dakota with a warm front ENE from there into central Minnesota. Another low over Saskatchewan with trough line between the two. Strong LLJ and moisture transport focused over central Minnesota in vicinity of warm front.. where strong convection is ongoing.
For tonite.. models having a tough time resolving surface and 850 hPa wind pattern due to double barrelled nature of the system. Seems like there will be limited phasing with models like the HRRR showing the potential for a split or bifurcated LLJ supporting multiple MCS's overnite. Ongoing complex over Minnesota and main branch of LLJ will continue, while another branch and complex develop over western N Dakota which will track along the int'l border (ahead of the northern low). In any case, looks like enough forcing for elevated convection in border regions of southern RRV and SE Manitoba, with just stratiform rain (and maybe some embedded thunder) for Winnipeg (if anything). Convection should move off after 4-5 AM.
As the northern low wobbles east tomorrow.. it will push a trough line through the RRV giving a chance of convection depending on sufficient instability/clearing and forcing.
I don't like the sound of that. So tired of the far south always getting everything.
ReplyDeleteWhile the border regions of SW Manitoba and the southern RRV have seen much above normal precipitation.. generally speaking, the city and most points north have been a lot closer to normal (if not even below for some regions of the Interlake).
DeleteLol love the tongue and cheek tag line in the special weather statement for Southern Ontario EC has issued. Has it really been that bad over there?
ReplyDeleteA rare weather event expected for Southern Ontario Tuesday: a rainy day.
Just when we expect the end of this inch a week 18 week rainy season to end the better part of another inch drops in. What happenned in Letellier today.?
ReplyDeleteAnother 22 mm last evening in Letellier.. they're up to 550 mm since May 1st (21.5 inches) Seems like they get hit with 25+ mm storms with every system that passes through. Tough year for them down there..
DeleteWhen we had a thunderstorm last Monday, that prevailed late in the afternoon and once again late at night, I wasn't concerned about it anymore, as I said to most of the people, when I was commuting from work, it was a perfect timing to face these storms, shortly after the 2-week multicultural festival called Folklorama has ended this past Saturday. I didn't want the rain to occur during that festival, so people can spend lots of hot summer nights outdoors for food, entertainment, etc.
ReplyDeleteFor me in my own dreams, I wish we will have a great summer with constant blue skies with no rain prevailing from May until the middle of August. The period after Folklorama, especially late August is the right time of the year to be swept by thunderstorms, severe or non-severe in Winnipeg, instead of late June through mid-July period.
we did that many years ago and the grass everywhere turned brown, the dust in the air was unbelievable and the only rain darnit as the may and august long weekends .1980 or 81. Water rationing. No your dream turned into a nightmare.
DeleteActually the July and August long weekends. Total in just over 6 months 137mms of which 63.4 mm came on those weekends
ReplyDelete.( july long weekend was actually june 27-30 August was aug 01 to 04
Less than 6 inches in 6.1 months. Since april this year we have just under 400 mm in 4 months 4 times as much.
Interesting scenario.. elevated convection along warm front and on nose of LLJ affecting SE Manitoba, with surface based convection along a cold front off the west.
ReplyDeleteLLJ will continue to advect considerably more humid air (with Td's in the 22-24 C range down in N. Dakota and Minnesota) as cold front approaches. Evolution towards elevated MCS is possible, but its track is also uncertain. Depending on if LLJ remains south of the border, storms may dive towards their moisture source in N. Dakota..
Hey Rob!!
ReplyDeleteWhat are your thoughts for the upcoming winter season?
Lots of forecasts predicting more snow than previous years.
Thanks
Jeff.. Way too early to say. With no El Nino this year (and likely a La Nina developing), it's pretty safe to say that this winter will be colder than last year (which was very mild) That doesn't mean however we'll see more snow. That will depend on the mean storm track which is impossible to predict at this point.
Delete