Thursday, October 02, 2014

Big change in the weather pattern Friday into the weekend.. strong winds, colder temperatures and possible snow..

Wind and wave impact maps for south basins
of Lakes Winnipeg (right) and Manitoba (left)
Severe impacts are possible Friday Oct 3rd
along south shorelines (in red)
(image from province of Manitoba)
It was a pleasant Thursday over the Red River valley with mainly sunny skies and afternoon temperatures up to 19C. But a major change in the weather is arriving tonight in the form of a strong cold front that is pushing across western MB late this afternoon. Showers and even some isolated thunderstorms will accompany this front this evening, followed by a northwest flow of much cooler air tonight into Friday. Friday will be a much colder day, with temperatures some 10-13C colder than today along with occasional rain or drizzle and strong northwest winds gusting to 70 km/h. The rain may even mix with some wet snow over higher elevations of the western RRV Friday. Northwest winds will be especially strong over Lake Manitoba and Lake Winnipeg overnight into Friday morning with gusts to 80 km/h at times. The province of Manitoba has a issued a severe wind alert for Lake Winnipeg and Lake Manitoba warning that strong northerly winds and significant wave action may cause lake levels to rise up to 5 feet over the south basins. Note that lake levels are higher than normal due to excessive summer rainfall, especially over western MB. Lake Manitoba is at 814.2 feet while Lake Winnipeg is at 715.6 feet above sea level. The higher than normal lake levels together with strong wave and lake seiche action will lead to shoreline erosion concerns particularly along the southern and eastern shores of the lakes.

Video:  See video footage of waves at Twin Lakes on southeast shore of Lake Manitoba Friday. (from CBC)






Snowy scene Friday afternoon near Lake Brereton, MB
in the Whiteshell Park area, just one week
after experiencing 30C temperatures 
As the main precipitation shield from this system pulls away Friday, narrow bands of lake effect showers will develop over and to the south-southeast of the MB lakes. In fact, it's possible these lake effect showers may change over to snow inland from the lakes as temperatures drop Friday night into early Saturday, with the potential for accumulating snow in some narrow bands southeast of the lakes. Cold and blustery conditions will persist through the weekend with temperatures some 5-10C below normal for early October.

14 comments:

  1. Here's the wind set-up forecast by the province for tomorrow (see second map):

    http://www.gov.mb.ca/mit/floodinfo/floodoutlook/forecast_centre/flood_sheets/2014/manitoba_lakes_october_2_2014_WindAlertMap.pdf

    3-5 foot set-ups possible for Gimli, Grand Beach, and Victoria Beach. 5+ feet possible at in the St. Laurent/Delta Beach areas of Lake MB, and the southern tip of Lake Winnipeg.

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    1. Thanks for the link. I added the map image on the post. Hope things aren't too bad for those folks on the south shorelines.

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    2. Saw some pictures of the shoreline taking quite a beating right now. Winds are as bad as forecasted!!

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  2. Sure is frosty out there tonight, with temperatures already down to -2C

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  3. Is it bad if I call the new Environment Canada site layout that got applied to the rest of weather.gc.ca the Windows 8 of websites? Because let's be honest, I think it's the Windows 8 of websites (completely okay on mobile devices, garbage on keyboard/mouse), and many others have similar thoughts too.

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    1. Yeah, not a lot of positive feedback on the new design. Personally, I find the site is awful on my 5S iphone, but is OK on an ipad or PC desktop. Site navigation is worse than before because EC had to comply to govt of Canada "common look and feel" guidelines with this release (which has GOC links at the top, totally unrelated to weather) An update to the Weatheroffice site will be coming out in December that will hopefully address some of the navigation issues. But overall, I find the Weatheroffice site more and more disappointing as it struggles to adhere to GOC standards and still try to be relevant as a weather website. Compared to other weather service websites however, we are way behind.

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  4. Perhaps they should just hire a graphic designer? The site is awful, unfriendly and looks like its from 1998.

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  5. ROB Your map image and the hurricanes approaching Bermuda [Gonzalo] and Hawaii [ Anna ] remind me of how accurate long range forecasting has become. W Undergrounds Dr Jeff Msters Blog has excellent links to data and Webcams for this afternoons Expected direct hit of the Cat 3 or Cat 2 near 200 kpmh sustained winds . at

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    1. Don.. Yes, hurricane forecasts have become exceptionally good.. with increasingly smaller errors in storm trajectories and evolution. That makes it a lot easier for people to prepare well in advance with minimal loss of life, and an ability to minimize damage as much as possible.

      I've been watching the live streaming webcam and radar from Bermuda today with great interest as Gonzalo approaches.. whose eye is about 6 hours away from a direct hit on Bermuda, likely as a Cat 3.. similar to Fabian in 2003.

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  6. Rob, do you know what happened to the University of Manitoba Weather Central website ( desktop version ) ?

    All the weather links are working, but the main home page does not list the current conditions or forecast anymore. I used to love their layout of there homepage and visited that website rather than go too EC's site.

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    1. I'm not sure anyone is in charge of the site anymore. The site webmaster has left Winnipeg and it appears that no one is maintaining the site any longer.

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  7. Cloudy cool day today as an extensive area of low cloud spread into southern MB/RRV overnight from the north and east. Hopefully we get some sunny breaks this afternoon although it will likely be tonight before we totally clear out. Tomorrow looking nicer with sunshine and mid teen temperatures but those gusty southerly winds will make it feel a little cooler. Clouds return Wednesday with a threat of showers as a trough moves across southern MB, then clearing out again for Thursday and Friday with nice temperatures in the upper teens. All in all, a nice looking week coming up for late October.

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  8. Rob, how are the daily forecast's written over at Environment Canada. The updated forecast at 11:00 today says just CLEARING. Are the forecast for that day typed by hand or is it just a pre-selection of words that are too choose from?? According to your latest blog entry ( and the latest satellite image ) we know that the clouds won't clear out to late this evening. By then the 4:00 forecast is out and people are reading that one. I've know many times when you have been frustrated with the wording on the forecast and I would like to know how it's done for day ONE.

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    1. Anonymous.. The wording of the forecasts is automatically generated by software that takes various weather elements (like clouds, precip, wind,etc) that are manipulated by the human forecaster. But the auto-generated wording of the forecast that comes out is not always what the forecaster may have intended. In today's case, a better forecast would have been "clearing this afternoon' or "becoming sunny this afternoon" rather than the vague "clearing". It's unfortunate that the human forecaster no longer has control of the forecast wording like they used to years ago. But that's the sign of the times with automation and less resources (although I think we can have better text generation software)

      If you click on the "24 hour forecast" link on EC's forecast page, or today's date, you will get an hourly forecast for the next 24 hours which has more detail than the worded forecast shows. In today's case, the hourly forecast showed Winnipeg going to a "mix of sun and cloud between 1 and 4 pm, then clear by 5 pm which seems reasonable. In fact, latest satellite imagery shows that low cloud starting to dissipate quite rapidly over the RRV, so perhaps that "clearing" trend for this afternoon will work out after all.

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