Will Toronto see an overnight low of -20C (-4F) this winter and Ottawa a daytime high of -20C (-4F) this winter?

[Roger Smith]

I would say it's looking quite good for these temperatures or lower next week, will say -25 C at YYZ and a max of -24 at YOW during the week, and possibly lows into the -30s in eastern Ontario.

 

 

[Ottawa Blizzard]

I would say it's looking quite good for these temperatures or lower next week, will say -25 C at YYZ and a max of -24 at YOW during the week, and possibly lows into the -30s in eastern Ontario.

I would say it's looking quite good for these temperatures or lower next week, will say -25 C at YYZ and a max of -24 at YOW during the week, and possibly lows into the -30s in eastern Ontario.

Roger, do you think Toronto or Markham could see a high around -15?

[cbmclean]

You guys may remember me being skeptical about the cold air being "locked away" in northern Canada.  Well, it hasn't been warm by any stretch of the imagination, but it really is just healthy "average cold" which, given the warming trend for that of the last 30 years, is about all we can expect.  

[Roger Smith]

I think highs will be -13 to -16 C in Toronto region and -21 to -24 C in Ottawa around Monday and Tuesday. Lots of lake effect snow and some additional frontal snow between tomorrow and Sunday will change the general snow cover picture enough to prevent this cold spell from wimping out. Flow is going to be northerly or NNE at low levels so warming effects of Lake Huron will be confined to a few counties near the lake.

[Ottawa Blizzard]

I think highs will be -13 to -16 C in Toronto region and -21 to -24 C in Ottawa around Monday and Tuesday. Lots of lake effect snow and some additional frontal snow between tomorrow and Sunday will change the general snow cover picture enough to prevent this cold spell from wimping out. Flow is going to be northerly or NNE at low levels so warming effects of Lake Huron will be confined to a few counties near the lake.

I like the sound of this. NNE and NE winds are the best winds for bringing cold into the GTA. I hope some lake effect now can make it into north Toronto.

[Ottawa Blizzard]

Well, next week is the week if  overnight low of -4F in Toronto and a daytime high of -4F or below in Ottawa are going to occur. Need to kill off some bugs!

 

I'm not sure if downtown Toronto will see -4F due to the urban heat island, but think Toronto Pearson airport and Markham Buttonville might. 2" of snow would certainly help, and hopefully we can get that on either Friday or Sunday. Environment Canada is calling for rain and 35F on Saturday though.Hoping Roger Smith is going to be right!

[Roger Smith]

Not looking quite as cold on today's guidance but should easily get to -18 or -20 C at YYZ by Monday morning and could then be colder during the week. Ottawa still looks good for daytime -20s. Agree it would be 2 C with drizzle or wet snow in southwest winds on Saturday ahead of the cold front, not a very mild warm sector but then Sunday it should fall steadily to about -8 C in strong NW winds and the Georgian Bay and Lake Huron snow belts will see 20-40 cm snowfalls some of which will at least whiten the ground near YYZ if not downtown. A deeper snow cover would be nice for radiative cooling but that first inch is the most important one for getting colder overnight readings. The east wind snow belt ideas for Monday seem to be gone now as there's a secondary low dropping down in the northwest flow so continued squalls in west to northwest winds more likely. At least it will start to look and feel a lot more like winter. We were crushed by a 2 cm fall here on Monday, chaos followed.

[Ottawa Blizzard]

Not looking quite as cold on today's guidance but should easily get to -18 or -20 C at YYZ by Monday morning and could then be colder during the week. Ottawa still looks good for daytime -20s. Agree it would be 2 C with drizzle or wet snow in southwest winds on Saturday ahead of the cold front, not a very mild warm sector but then Sunday it should fall steadily to about -8 C in strong NW winds and the Georgian Bay and Lake Huron snow belts will see 20-40 cm snowfalls some of which will at least whiten the ground near YYZ if not downtown. A deeper snow cover would be nice for radiative cooling but that first inch is the most important one for getting colder overnight readings. The east wind snow belt ideas for Monday seem to be gone now as there's a secondary low dropping down in the northwest flow so continued squalls in west to northwest winds more likely. At least it will start to look and feel a lot more like winter. We were crushed by a 2 cm fall here on Monday, chaos followed.

Thanks Roger. What are your thoughts as we move into February? Is this cold transient, or will it hold as it did in February 2003 and 2007?

[Roger Smith]

My research says look for major warming after 10th of February to end of month, possibly a brief return to winter after that. Could see record warmth similar to 1930 or 1954. Toronto has various daily records from those years but further southwest readings were well into the 60s F in old money around Woodstock-London area in 1930. There was some cold weather in January that year and in 1954 there was a bitterly cold few days in mid-January, otherwise it was not much of a winter (although somehow Toronto managed to get both an all-time monthly record high and an 8" snowfall in one 24-hour period mid-month!).

 

Just looking at 48h RGEM, Ottawa and Toronto are close to 486 dm thickness by 18z Tuesday -- that is currently the value near Trout Lake in northwestern Ontario where max today was -28 C. Factor in slight warming effects of solar angle and bare ground near YYZ plus some minor warm advection from Georgian Bay and would say 18z Tuesday temperatures could be -24 C Ottawa and -18 C YYZ. Rarely see 492 dm thickness or lower into the northeast U.S., could be -15 C (5 F) daytime in southern New England from the looks of the guidance although bare ground might boost that to -12 C (10 F). NYC heat island will probably prevent sub-20 F max there but you never know.

 

Snappy cold in other words.

[Ottawa Blizzard]

My research says look for major warming after 10th of February to end of month, possibly a brief return to winter after that. Could see record warmth similar to 1930 or 1954. Toronto has various daily records from those years but further southwest readings were well into the 60s F in old money around Woodstock-London area in 1930. There was some cold weather in January that year and in 1954 there was a bitterly cold few days in mid-January, otherwise it was not much of a winter (although somehow Toronto managed to get both an all-time monthly record high and an 8" snowfall in one 24-hour period mid-month!).

 

Just looking at 48h RGEM, Ottawa and Toronto are close to 486 dm thickness by 18z Tuesday -- that is currently the value near Trout Lake in northwestern Ontario where max today was -28 C. Factor in slight warming effects of solar angle and bare ground near YYZ plus some minor warm advection from Georgian Bay and would say 18z Tuesday temperatures could be -24 C Ottawa and -18 C YYZ. Rarely see 492 dm thickness or lower into the northeast U.S., could be -15 C (5 F) daytime in southern New England from the looks of the guidance although bare ground might boost that to -12 C (10 F). NYC heat island will probably prevent sub-20 F max there but you never know.

 

Snappy cold in other words.

Wow, that would be impressive when you consider EC has Toronto with a high of -11C and Markham with a high of -14C. Hope you're right!

[blizzardof96]

We just hit a low of -20C tonight in toronto, it is freezing outside!

[donsutherland1]

Some frigid readings in Ontario...

 

Lows that I've seen this morning (we'll see what EC posts as the final numbers tomorrow):

 

Ottawa: -28.5°C (-19°F); coldest since January 16, 2009 when the temperature fell to -30.3°C (-23°F)

Toronto: -20.7°C (-5°F); coldest since January 24, 2011 when the temperature fell to -20.7°C (-5°F)

[ORH_wxman]

It looks like the high at Ottawa so far has been -23C or -9F. It may have gotten warmer than that between obs but almost certainly did not warm to -20C. (the threshold for this thread)

[Roger Smith]

Tomorrow will do just as well for Ottawa's high, I think ... Toronto may not get below -20 C tonight because of cloud from the Great Lakes thermal low but it could be getting colder just around sunrise from cold advection behind that feature and not get much warmer during the day with a N-NE wind developing. Expecting some heavy lake effect on the south shore of Lake Ontario late tonight and Thursday once that wind sets in (pulling in the -25 to -30 C air mass north of the lake). The meso-scale low is just a bit too far north for Toronto to see a lot of potential but there could be a brief burst of 1-2 cm snow this evening, was thinking earlier that if it tracked a bit further south the surface wind could turn easterly and create some lake effect for western parts of the GTA or maybe Scarborough, but wind now looks more likely to turn SSW for a few hours then go variable and northerly.

 

This is not quite as cold as 1-15-1994 or 1-22/23-1976 both of which I remember from living in central Ontario, we had a morning temperature of -40 C on both those occasions and daytime highs around -27 C. Then there was 1-22-1857 when the high in Toronto was -24 C. So this is not quite record-shattering cold, but the uppers were pretty impressive (-36 C at 850 mb LOL).

[donsutherland1]

It looks like the high at Ottawa so far has been -23C or -9F. It may have gotten warmer than that between obs but almost certainly did not warm to -20C. (the threshold for this thread)

-23°C was the highest reading I saw.

[ict1523]

I know Montreal is not part of this thread, but they did dip down to -21F on January 22nd. I believe it was their coldest reading since 1994, as 2009 only dipped down to -19F and 2004 to -20F. 

[QcSevereWx]

I know Montreal is not part of this thread, but they did dip down to -21F on January 22nd. I believe it was their coldest reading since 1994, as 2009 only dipped down to -19F and 2004 to -20F. 

-27°C or -17F  this morning. 9am  . dewp of -34°C crazy

-39  wind chill

http://www.meteo.gc.ca/trends_table/pages/yul_metric_f.html

 

 

But look at that .

http://www.meteo.gc.ca/trends_table/pages/yuy_metric_f.html

-43°C

[donsutherland1]

Status of my guesses from #6:

 

Toronto:
Overnight low of -20°C: Yes (67% probability): Lowest: -20.9°C (-6°F), 1/23/2013
15 cm snowfall over 24 hours: No: PENDING (No such storms through 1/23/2013)

Ottawa:
Daytime high of -20°C: No, but it's almost a 50-50 proposition: Incorrect. Lowest Maximum Temperature: -22.3°C (-8°F), 1/23/2013
30 cm snowfall over 24 hours: Yes (67% probability); Largest 24-hour snowfall: 34.2 cm, 12/21/2012

 

Note: I had a typo in my post. I was referring to 30 cm of snow in 24 hours in Ottawa as per Ottawa Blizzard's question and accidentally typed 15 cm in my response.
 

[donsutherland1]

In terms of Quebec, Montreal had a low temperature of -27.3°C (-17°F) yesterday. That was the coldest reading there since January 24, 2011 when the temperature dipped to -27.9°C (-18°F). Last winter's coldest reading in Montreal was -24.1°C (-11°F) on January 15, 2012.

 

In Quebec City, the temperature fell to -29.6°C (-21°F). Last winter had a minimum temperature of -30.7°C (-23°F) on January 21, 2012.

[Ottawa Blizzard]

Two years ago I started a thread similar to this one and watched as Don Sutherland and others mets chimed in on the possibility of these two Canadian cities hitting a low of 0F (Toronto) and adaytime high of 0F (Ottawa). As the start of astronomical winter approaches, i thought I'd start a similar thread and see what people have to say/predict. Below are the benchmarks I'm looking for this winter.

1) Will Toronto, Ontario record a nighttime low of -20C (-4F) and experience a snowstorm which drops 6 inches (15cm) of snow in 24 hours?

2) Will Ottawa, Ontario record a daytime high of -20C (-4F) and experience a snowstorm which drops a foot (30cm) of snow in 24 hours

The cold temperature anomalies were non existant last winter for the most part, so it will be interesting to see if mother nature can deliever this year. Note that these are temperatures without the windchill factored in.

There is a chance this could be accomplished in the not-too-distant future.

[donsutherland1]

There is a chance this could be accomplished in the not-too-distant future.

I hope so.

[Ottawa Blizzard]

We did it. We've received well over 6" in one day. Regardless of what Pearson airport is reporting I have measured a foot of fresh snow since the snow started yesterday, with 9" of that coming today. Someone out in Pickering, just east of toronto measured 10" a couple of hours ago according to local met Anthony Farnell's twitter. Amazing storm.

[tmagan]

What was the final snow total for the airport?

[Ottawa Blizzard]

What was the final snow total for the airport?

About 10", but it's nonsense. Most areas of Toronto got between 12-14".

[snowstormcanuck]

What was the final snow total for the airport?

 

9.8" at the airport but it's an inaccurate reading because as we've discovered they're using a nipher gauge to measure at Pearson rather than a snowboard and a ruler. 14.4" fell on downtown Toronto.