Tuesday, July 12, 2011

Chilly morning.. building heat wave expected by late week

It was a chilly Tuesday morning over southern Manitoba with temperatures falling well into the single digits overnight. At Winnipeg airport, temperatures fell to 6C this morning, the coolest temperature of the month so far. Temperatures will warm up nicely today under sunny skies with afternoon highs around 25C. Another chilly night is in store tonight with lows near 10C, but then a significant warming trend is set to develop by mid to late week as a large upper ridge of high pressure builds over the central continent allowing hot air from the United States to flow north. Temperatures over 30C are likely by the weekend into next week along with increasing humidity levels that will likely send humidex values over 40C. There may be some scattered thunderstorm activity as we get into the building heat later this week, but overall hot and humid conditions are expected through the weekend with long range models hinting that the heat wave may continue through the middle of next week. So enjoy those comfortably cool temperatures while they last.. heat and humidity is on the way!

46 comments:

  1. NWS grand forks is concerned of heat index's of 100F-110F over the valley this weekend! For us, Humidex warning criteria will almost for sure be met!

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  2. This could be our longest stretch of very hot weather in quite some time! A true heat wave!

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  3. Hopefully we get some of that heat here in Montreal as well. I love heat and humidity.

    We're currently under a severe thunderstorm warning if anyone cares.

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  4. Official defintion of a heat wave in Canada is 3 days of 32C or more, a carry-over from the old 90F threshold which is the standard NWS uses across the northern states. One can argue that much of Canada including the Prairies should use 30C as a heat wave threshold since 30C is considered a "hot day" for climatology purposes, and it's a nice round number, but for now, 32C is the threshold. The upcoming heat wave will be accompanied by oppressive humidity levels (dewpoints near 25C) which may keep the actual temperatures from soaring too high, but humidex values will be well into the mid 40s. Stifling..

    As far as I can tell, the last time Winnipeg had an official heat wave was 4 years ago in July 2007, when we hit 32C+ on 4 consecutive days between July 22-25th, and then another 3 days from July 29-31st. Maximum was 35.3C recorded twice.

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  5. A beautiful day out there today.. just about perfect weather with low humidity, a nice breeze and temperatures near 25C. Things will be getting increasingly more uncomfortable over the next few days as the dewpoints start climbing tomorrow into the mid teens.. then 20C by Friday along with temps approaching 30C. We'll be into the steambath over the weekend into next week with dewpoints in the low to mid 20s (oppressive humidity), temps in the low to mid 30s, and humidex values in the 40-45C range. This looks like it could be a prolonged period of hot and humid conditions.. perhaps lasting 5 days or more.. which will be an increasing health risk to the elderly and those without air conditioning. One or two days is tolerable for most people, but when you get 3 or more days of high heat and humidity with warm muggy nights, the health risks can rise dramatically. This is especially true for this upcoming event given we really haven't acclimatized to hot and humid conditions this year.

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  6. Thanks for the heads up!
    This could be a dangerous situation!

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  7. Don't rule out some sneaky thunderstorm complexes developing Friday through the middle of next week. The cap will likely hold much of the day but models are showing us on the northern periphery of the ridge.

    The northern US has seen some hefty MCS activity under the same general pattern. Now that the ridge axis is expanding, we could get in on some of that stuff in the next week.

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  8. One more cool day and then the heat wave begins!If the dewpoints were not so high we could potentialy be hitting the high 30's
    Either way this is gonna be a doozy!

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  9. Rob, you answered my question before I asked it. I was wondering when we had our last "heat wave". On July 23, 2007 I recorded 35.2 C in my back yard and on the 24th, 36.8 C.

    I recall our pre-air conditioning days.... extended heat was something to dread. The only place to get relief was the basement or at work. On one occasion, during an extended heat wave, the curb expanded to the point where it popped up and made an arch to relieve the pressure.

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  10. you can really see the forest fires burning in northwestern Ontario on visible satellite. This prolong heat wave is not good news.

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  11. Good eye there, anonymous. Fires mainly in no mans land between Pickle Lake ON and Manitoba border. But continued hot weather with occasional lightning from thunderstorms will not help situation. The saving grace is that humidity levels (as in dewpoints) will be on the increase, and winds should lighten up..

    Speaking of which.. we could use a bit of rain here ourselves (did I just say that?) I've only recorded 13 mm (1/2") of rain in the past 3 weeks. A welcome drying out of the soils for sure, but this upcoming heat spell will likely put some stress on crops.

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  12. Michael M (New Guy)9:23 PM, July 14, 2011

    I'm from winnipeg, we seem to have had a fairly cool summer overall, I have been waiting for this heat all year, let the heat wave begin! PS. Rob try and bring me some storms within the next few weeks thanks buddy!

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  13. Michael M (new guy)9:30 PM, July 14, 2011

    Sorry Rob I meant to say we haven't experienced any big storms this year so far, I waited all year for them to come. When could we get some storms here in the short/ long range? Hoping a few cross the border tonight.

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  14. Hi Michael M, welcome to the blog!

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  15. Given the coming hellish wx, why hasn't E.C. at least issued a special wx statement. No guts no glory.

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  16. Micheal..

    There are some storms to our south in the Dakotas likely associated with the warm front that will be bringing us our hot weather. That warm front pushes across us tomorrow into Friday night, so perhaps we could see a thunderstorm as that passes through. But they will be hit and miss.. so not everyone will see one. I washed both my car and the wife's today.. so maybe that will trigger some storms for us tomorrow! :) Gotta admit.. I wouldn't mind seeing a good heavy tstorm after all this dry weather.. (but not too heavy!)

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  17. If all holds together, Winnipeg should be getting a good soaking this morning!

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  18. Dewpoints of 20C in Southwestern Manitoba already.

    Hallock, Minnesota is also at 20C.

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  19. This is going to be one huge heat wave...

    Currently 79F(26C) in Hallock with a dewpoint of... 79F(26C)

    That's 100% humidity folks!!!

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  20. TWN predicts humidex of 51 in Fargo Sunday. Wow

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  21. That Hallock MN dewpoint of 26C looks suspicious.. seems unlikely that it's still 100% RH at midday with sunshine. Everyone around them is reporting dewpoints around 20C which seems more reasonable..

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  22. Hallock was overcast. Now that the sun is out temperature has gone up to 81C(27C) and dewpoint is down to 77F(25C).

    BTW- Newton, Iowa has a DP of 81F(27C) and it's not even the highest I've seen there.

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  23. The humidity is oppressive outside feels like a sauna good environment for supercells with high dewpoints and CAPE Levels haven't seen a storm in ages except for a few lightning flashes no thunder though over the past few weeks. I'm predicting a humidex of 53 on Monday with the heat very welcoming!

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  24. Capping looks to be an issue today. If we get to 30C or so we might have a shot.

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  25. Michael M is now named "Mike M"3:28 PM, July 15, 2011

    Looked at the Noaawatch forecast map loop looks like on Sunday at 00Z we could get some real nice storms here in the peg if anyone cares. check it out!

    http://www.hpc.ncep.noaa.gov/basicwx/bawx_nav.php?imgtyp=ter&arrval=4&vtime=Sun_00Z&ptime=Sat_18Z&ntime=Sun_12Z

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  26. Looked at the Noaawatch forecast map loop looks like on Sunday at 00Z we could get some real nice storms here in the peg if anyone cares. check it out!

    http://www.hpc.ncep.noaa.gov/basicwx/bawx_nav.php?imgtyp=ter&arrval=4&vtime=Sun_00Z&ptime=Sat_18Z&ntime

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  27. When I left the house this morning the forecast was a high of 25C
    Today's high of 30C was a bit of a surprise!
    Let the heat wave begin!

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  28. There is talk of potential 115-120F heat index readings in part's of North Dakota and Minneasota this weekend! We won't be far behind!
    That's just downright dangerous!!

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  29. I was out for my evening constitutional and I thought the humidity was climbing. Sure enough 90%. A harbinger of things to come?

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  30. Rob!
    Here is a good poll question!

    How many 30 + days in a row will Winnipeg see in this heat wave???

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  31. I'm heading to the Peg for a few weeks tomorrow and I've looked at the models. Great ingredients are in place for multiple episodes of severe weather but the only limiting factor is that darn CAP. It looks huge for an extended period of time. I think with this setup we should just expect hot/sauna like days and late night elevated thunderstorms. I think that's great. Alberta has been quite active, but it's been cooler there lately and they are shooting a movie there for the newest mosquito horror flick so I'm glad to leave it behind for a few.

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  32. Justin, it sure does look like we're in a good spot for some solid ridge riding MCS activity. One good thing is that the cap is quite a bit weaker here in southern Manitoba as opposed to North Dakota and Minnesota. We seem to be on the fringe of the cap which is a great place to be in these set-ups.

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  33. 31C and 45% humidity...definitely better than other places when it comes to the mugginess. Dewpoint at 18C. Makes for a humidex of about 37.

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  34. Severe thunderstorm watch in effect for SERN MB, including Winnipeg. Pretty much your average mid-summer watch: hail, strong winds, and downpours being main threats. The SPC in the US says that a tornado or two is also possible.

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  35. Dewpoints definitely worse to our south with 23-24C dewpoints along the US border, and plenty of 23-27C dewpoints over Minnesota and eastern ND. We're not too bad with 18C dewpoints here in Winnipeg.. which is allowing us to get hotter air temperatures.. up to 33c as of 2:15 pm.

    Our dewpoints may climb towards 20-21c later today, but overall looks like the most oppressive dewpoints will stay to our south through Monday. We'll be hot.. but not oppressively hot and humid like areas further south. Higher dewpoints and humidex readings return Tuesday for us before cold front moves through Wednesday.

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  36. Dewpoint of 24C and a humidex of 41 in Emerson.

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  37. Reports of 37 and 38 (not Humidex)a few minutes ago in Tyndall and Beausejour.

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  38. I checked the sattelite on U of M Weather Page looks like a storm is trying to initalize out by Pilot Mound somewhere it's taking on some supercelluar characteristics. I think it's moving to the NE areas such as Carman, and then Winnipeg could see it hit. Keeping A very close eye on it. PS. Rob I'm a weather geek as well LOL!

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  39. Supercell characteristics? It's not even showing up on Radar yet!

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  40. Tornado watch out for much of North Dakota and northwestern Minnesota. The watch box extends right up to the International Border.

    First development now north of Bismarck.

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  41. As Derek noted, tornado watch issued for much of ND and NW Minnesota for this evening. Concern is that extreme instability (CAPES of 4000 J/kg or more) and low storm bases can lead to isolated tornadoes. Cell NE of Bismarck has been tornado warned with a funnel cloud spotted..

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  42. I know Carman MB had that dewpoint of 30C (86F) back in 2007!

    I assume that is probably the maximum that we could ever see!!??

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  43. Hook echo showing up really good on the L2 NEXRAD. http://www.wunderground.com/radar/radblast.asp?zoommode=zoom&num=1&delay=15&rbscale=0.125&scale=0.125&noclutter=0&ID=BIS&type=L20&lat=0&lon=0&label=you&showstorms=10&map.x=394.5&map.y=284.5&centerx=286&centery=523&lightning=1&smooth=1&showlabels=1&rainsnow=0

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  44. Spotters CONFIRM a tornado on the ground with the latest warning for that cell in ND.

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  45. Rob!
    I'd say there is a fair chance that we could break a few record highs this week! According to your stats page, record highs are around 35!!

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  46. Record high for Winnipeg tomorrow is 35.0C (1936). I don't think we'll beat that one, but the 34.4C records Monday and Tuesday are likely within reach. Tuesday is looking like the hottest day of the bunch.. After some potential early morning thunderstorms, 850 mb temps of 25C are forecast to spread into RRV which would translate to around 35-36C for us. That along with dewpoints around 23C would give humidex values around 45c.

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