Friday, September 13, 2013

Warm and breezy day ahead.. cooling off for the weekend..

It will be a beautiful end to the week today as clear blue skies and southerly breezes push temperatures into the mid 20s this afternoon, some 8C above normal for mid September. Southerly winds will steadily increase today from 20 km/h this morning to 30 gusting 50 km/h by mid to late afternoon, especially in Winnipeg as southerly winds funnel up the Red River valley.  A cold front will push through southern MB from the north overnight ushering in cooler temperatures for the weekend as winds shift into the north Saturday. High pressure will build over western MB by Sunday morning, bringing chilly morning lows in the single digits, as well as a threat of frost over western MB and the interlake areas. Warm and dry conditions are expected to return again early next week before an increasing chance of showers by Thursday. Overall, it's been a fine late summer in southern MB with temperatures averaging some 4C above normal since mid August.  

24 comments:

  1. "I was talking yesterday about a cloud-free sky today and that’s exactly what we have." - guess who. Must have been a tough call with that ridge passing over.

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  2. I'm liking the looks of the 8 to 14 outlook. I don't think summer is over quite yet.

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  3. Hey Rob - Your thoughts on a possible FROST WARNING for Winnipeg Sunday nite/Monday AM would be appreciated. Chris in Westwood

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  4. Chris..

    Surface high moves into NW Ontario/Minnesota Sunday night with a return southerly flow developing in Winnipeg into early Monday. I think that will keep the frost risk at a minimum for Winnipeg, although there will likely be a higher risk east of the city and towards the Ontario border.

    For tonight, greatest frost risk will be over western MB towards SK border as well as Interlake region where surface high will settle by early Sunday morning. Lows of 0- to +3C in these regions with some ground frost possible in some areas. Dew points remain fairly high though this evening in the area, so it's possible there will be more dew or fog patches than frost early tomorrow morning.

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  5. Quite the temperature drop at YWG airport this morning from +6C at 6 am to 0C at 7 am. The dramatic drop was accompanied by a subtle shift in the wind from a light NE flow to a light NW, which is a cold air drainage flow at YWG airport. All other reporting sites in Winnipeg were in the +3 to +7c range at the same time. I don't think i ever recall such a dramatic temperature drop in a clear and relatively calm setup at ths time of year.

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  6. Frost warning issued for RRV and eastern MB, including Winnipeg. Clear skies and light winds will allow temperatures to drop to the 0 to +2C overnight with ground frost likely by Monday morning. Here in Winnipeg, the airport may be saved from lows near 0C as our winds become light southeast overnight which is off the warmer city core. Areas near and outside the perimeter have the best shot at frost overnight, especially areas towards southern and eastern Perimeter and north of the city.

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  7. So did Winnipeg airport hit 0.0 C last night or was it just slightly above 0C?? So I assume we did not get the first frost of the season at the airport LAST night??

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  8. Official low at Winnipeg airport this morning was +0.5C. The collocated XWG station had a low of +0.2C. Regardless of which one is used, a low of 0.0C or lower was not recorded yet at YWG airport.

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  9. Mb-Ag weather stations in the RRV and southern Interlake all appeared to bottom out at around 2-3 C Sunday morning, with locations in SW Manitoba between 1-2 C. Below freezing temps were confined to areas of the central Interlake back through the Parklands area of the province. If the above - combined with a 6 degree temperature drop in one hour - is not a red flag as to an unrepresentative sensor location (including XWG), I don't know what is..

    As for tonight.. greatest risk of frost will be in SE Manitoba, where lingering high pressure, combined with the sandy soils (having low heat capacity) will allow for ideal radiational cooling..

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  10. A low of +3.3 at YWG airport this morning.. light SE flow off the city overnight saved the airport from any frost threat, or precipitous 6C temperature drops like the night before.

    Outside the city however, there was patchy frost with lows near freezing over the RRV and SE MB, as well as southern interlake. Sprague was the cold spot with a low of -1.9C early this morning.

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  11. Officially, Winnipeg growing season is still ongoing, with no reading of 0.0C or lower at the airport yet. Last year, first fall frost was Sept 14th, so we are a little later this year. Mind you, we had a much later start to the growing season this year after that dreadful April. Our growing season this year began on May 13th, after a low of -7C on May 12th at YWG airport. So as of today, our growing season stands at 127 days and counting based on YWG obs. This is actually a little longer than the average growing season length of 121 days at Winnipeg airport, between the average last spring frost on May 23rd and average first fall frost on Sep 22rd. Surprisingly, last year's growing season at YWG airport was only 106 days, thanks to a light late frost on May 30th (-0.1C) However that stat is a bit misleading as there were only 2 days of light frost in May, and a more representative start to the growing season was on April 27th after a low of -7C on the 26th. That would make last year's growing season more like 140 days.

    Nonetheless, given the late start this year, the growing season has really come around with a fabulous late summer stretch that has helped produce one of the best crop yields in many years for area farmers, even better than last year in some areas.

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  12. Rob, what's the latest on Wednesday's storm potential? Are severe storms possible in Winnipeg and the RRV?

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  13. Rob, I think this upcoming weekend looks to be our first freeze of the year, with quite the impressive cold front coming through on Friday!!

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  14. >>Anonymous said...Rob, what's the latest on Wednesday's storm potential? Are severe storms possible in Winnipeg and the RRV?

    Intensifying low over western ND forecast to track into western MB Wed night into Thursday. Heavy rain threat west of low track over SE SK into western/central MB, while there is a slight risk of severe tstorms over ND possibly pushing into far srn MB Wednesday evening. Severe threat may be too far south/too late before they reach Winnipeg, but it's too early to say at this point.

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  15. Extensive deck of low cloud over eastern ND spreading north into southern RRV this morning. Strong southerly flow is pushing cloud up the valley towards Winnipeg.. which could interrupt our nice sunny day for awhile through midday. Cloud will likely be more persistent to our south and east through early afternoon before they start thinning out. Gusty south wind will make things feel a litle cooler today than the high temperature of 23-24C would suggest.

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  16. Well those clouds came in thick and fast.. certainly spoiled what should have been a nice sunny day for us. As satellite photos show.. low cloud covers much of RRV and SE MB while western MB is sunny and cloud free.

    Southerly flow should maintain the cloud skies over us much of tonight, although we may see some breaks overnight especially over western RRV.

    For tomorrow, some morning sunny breaks will give way to increasing clouds in the afternoon with some showers or thunderstorms by evening. Better chance of storms to our west, with heavier showers and tstorms possible through Wednesday night.

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  17. Just received word today that the YWG AWOS station (operated by EC, not NavCanada) will cease operation as of Oct 1st 2013. That means data for this site (WMO ID# 71852) will no longer be available after Sep 30. As of Oct 1st, hourly data will be taken by the NavCanada AWOS site and XWG autostation (ID #71849), while daily summaries with official highs, lows and precip for Winnipeg will be available only from the XWG site, operated by EC.

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  18. In other words, does that mean the ''A CS'' station will now be the official station for temperature and precipitation?

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  19. Yes, that's right. The Winnipeg A CS site is the XWG autostation owned and operated by EC. It will be the official source for highs, lows and precip for Winnipeg airport as of Oct 1st.

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  20. Another dud for Winnipeg.. promising line of tstorms over western MB last evening with good support, but line completely fizzled by the time it got to Winnipeg early this morning. Not even a shower on it. Now left with some patchy fog and drizzle early this morning which will be lifting as winds shift into the NW behind cold front.

    By the way, EC will be releasing a new radar colour scheme on their Weatheroffice website today. It will feature a reduced 8 scale colour palette, down from the 14 colour scale currently used. This is being done to meet national compliancy standards for colour blind people. It's a definite step down in resolution compared to what we have now, but the good news is that you will still have the option to select the higher 14 colour scale if desired.

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  21. Rob, do you think that there could be some Lake effect showers tomorrow with the cool winds coming off that still warm lakes ??

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  22. Hi Rob,
    I was if you could help me recall a wind event that happened a long time ago here in Winnipeg. It happened in the fall season and I believe it happened in NOVERMBER. I do know that the strongest wind gust was recorded at the airport at 113 km/h. I remember the wind was so strong at work that I barely could stand upright! I have little other information on the date other that It was AROUND 10 years ago and it was in November I believe. Can you tell me more about this event please if you can find out more. Thanks so much.

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  23. You're probably referring to November 1, 1999 when a strong cold front pushed through southern Manitoba and winds gusted to 113 km/h (61 knots) at the Winnipeg airport just after 10 AM that morning. The winds were so strong I remember that skyscraper windows downtown were blown out. Click on my name for observations from the Winnipeg airport that day.

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  24. First official frost of the season as measured at YWG airport with a low of -1.3C this morning.. ends 2013 growing season at 131 days, or 10 days above the average length of 121 days. Lake effect cloud cover off Lake Winnipeg spared northern and eastern sections of the city and areas to the north and east. Overall though, after one of the latest starts to spring on record, the growing season this year did quite well, and in fact, has helped to produce one of the biggest crops in years in southern MB. Record yields being reported by area farmers thanks to the longer growing season and overall favourable weather conditions this year.

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