Category: Forecasts

Sun Breaks Through For A Mild Weekend

Brad Leave a comment

Winnipeg will see a reprieve from the damp, cloudy weather this weekend as the clouds clear out later today and clear to mixed skies move in. Alongside the sun, daytime highs over 5°C above normal will remain in place, continuing the likely record-setting above normal temperature trend seen for the entirety of November so far.

Today will start off cloudy, however throughout the afternoon the clouds should begin to break up as some drier air moves in from the southwest. Without the persistent fog and mist in place, temperatures will have a bit more mobility than they have the past couple days, and Winnipeg should see a daytime high near 3°C. Winds should remain fairly light through the day out of the south to southwest. Expect clear skies giving way to a bit of cloud on Friday night, with temperatures dipping to a low near -3°C.

Saturday morning will start off with some cloud in the area as a warm front pushes through, but then we should see clearing and some sunshine for the afternoon.1 Temperatures should climb to a high near 3°C again with light winds out of the south to southeast. Skies should remain fairly clear on Saturday night with a low near -3°C again.

Sunday will bring increasing cloud to the city through the day as a significant weather system begins organizing south of the border. While skies will be mixed, temperatures will still be pleasant with highs yet again near 3°C. Winds will be out of the southeast at 10-20 km/h. Cloud cover will increase on Sunday night with temperatures dipping down to around 0°C.

Record Warmth

So far this month, Winnipeg has had an average high temperature of 8.1°C. With the forecast temperatures ahead, November will end with an average high temperature near 7.1°C and a mean temperature2 of approximately 2.6°C. The average high temperature will likely end up taking the or spot for warmest Novembers by average high temperature.

RankAverage
Daily High (°C)		Average
Daily Mean (°C)		Average
Daily Low (°C)
17.2 (2016)3.1 (2016)-1.1 (2016)
27.1 (2009)1.3 (1899)-3.2 (1923)
36.4 (1999)1.3 (1923)-3.3 (1899)
45.8 (1899)1.0 (1981)-3.3 (1922)
55.8 (1923)0.9 (2001)-3.5 (1981)
65.7 (2001)0.8 (2009)-3.6 (1917)
75.5 (1981)0.6 (1999)-3.7 (1953)
85.3 (1939)0.5 (1917)-3.9 (2001)
95.2 (1904)0.2 (1922)-4.3 (1918)
104.6 (1917)0.1 (1953)-4.3 (1944)

So far November has had an average overnight low of -0.8°C, with a forecast month-average of -1.0°C. This is a whopping 2.2°C above the previous record of -3.2°C set in 1923. The monthly mean temperature is forecast to end up at about 2.6°C, which crushes the previous record by 1.3°C. To put that in perspective, Winnipeg is forecast to break the previous monthly mean temperature record by the same amount as the spread from the current record to the 10th place entry.

Long Range

The start of next week threatens another winter storm for the region as a Colorado Low moves into Minnesota. Again there’s quite a bit of uncertainty as to how progressive the system will be and whether it will back into the Red River Valley or end up further east and missing the province. The general agreement is that the Red River Valley will be hit by this system, but how much precipitation will fall is a wild card.

The big challenge with this system, should it actually hit the Red River Valley, will be what will actually fall out of the sky. Best indications are that much of what falls may actually be rain rather than snow, but it’s far too early to put too much stock in any particular forecast other than saying that this system, should it hit Winnipeg, will likely bring a wintery mix to the region. We’ll be keeping an eye on it as the system develops!

Winnipeg’s seasonal daytime high is currently -5°C while the seasonal overnight low is -13°C.

  1. Most forecast models show clear skies in the afternoon behind the warm front, however a few outliers want to keep things cloudy. At this point, with a broad southwest to westerly flow expected in the warm sector, I think that skies should manage to clear out, but we’ll keep an eye on things incase pesky cloud manages to stick around. ↩
  2. The mean temperature is an average of high and low temperatures of each day. ↩

Mild Conditions Continue

Brad 2 Comments

The remainder of the work week will be marked by daytime highs climbing above 0°C, continuing an above-normal temperature trend that has persisted through every single day so far this November.

Today will be damp but mild as stratus cloud bringing drizzle and fog lingers throughout the region. A few isolated flurries may also be thrown into the mix as well, but we’re done with any accumulating snow for now. We should reach a high temperature of +2°C, which will continue to melt the snow that fell yesterday morning across the city. Winds will be light out of the northwest at 10-15 km/h. Expect cloudy skies tonight with a continued chance of drizzle or freezing drizzle alongside fog patches. Tonight’s low should be near -1°C.

Thursday will likely be more of the same with low-level moisture trapped under a slack flow. Temperatures will reach a high near +2°C with light winds. There will be a very slight chance of some patchy drizzle or fog. For Thursday night, skies will remain mostly cloudy until some clearing begins working in late overnight. Temperatures will dip to a low near -2°C.

This forecast sounding for Thursday afternoon in Winnipeg shows a deep layer of saturated air in the lower atomosphere.
This forecast sounding for Thursday afternoon in Winnipeg shows a deep layer of saturated air in the lower atomosphere.

Friday will likely bring some sunshine back to the region with more above-normal temperatures on tap as the daytime high climbs to +2 or +3°C. Skies will gradually clear through the day and things should finally start to dry out a bit. Winds will be light out of the south.

Tuesday Snow Breaks Record

While the actual snowfall event that began early in the morning on Tuesday November 22 was unimpressive with just 2-5 cm of fresh snow accumulation across the city, it managed to break a long-standing record: the latest day of first measurable snowfall.

RankDate of First Measurable Snowfall (≥ 0.2cm)Year
1November 222016
2November 211963
3November 201953
4November 191931
5 tie
5 tie		November 18
November 18		1880
2015
7November 171890
8November 161977
9November 151903

Yesterday’s snowfall was the latest in the year Winnipeg has seen its first fall/winter snow in the 144 year old record that dates back to 1872.

Long Range

The weekend looks quite nice with a fair amount of sun and mild temperatures with daytime highs continuing slightly above the freezing mark. Heading into next week, though, it appears another significant winter storm may be brewing. Some long-range models are hinting at the possibility of 10-25 cm over the Red River Valley through the first half of next week, but it’s still too early to really comment on how accurate any of those predictions will be.

That said, the continued significant story is the above-normal temperatures that have been in place the entire month of November and continue to be forecast through to the end of the month. If we do indeed see high temperatures close to what is currently forecast, November will be in the contest for the warmest November on record!

Winnipeg’s seasonal daytime high is currently -4°C while the seasonal overnight low is -13°C.

Will Our First Snowfall of the Year Come This Week?

Scott Leave a comment

Will our first snowfall of the year come this week? That is the question that meteorologists are trying to answer as a complex weather system potentially brings accumulating snowfall to southern Manitoba tonight.

An inverted trough pattern associated with a strong system to our south may help bring snowfall to southern Manitoba
An inverted trough pattern associated with a strong system to our south may help bring snowfall to southern Manitoba

This Week

Today will start out cloudy and cool with temperatures hovering near the freezing mark. Change is coming, however, as a strong weather system moves off the mountains and begins to produce snow over the northern United States and southern Prairies. This is a complex system, with the strongest part well to our south over the midwestern US. A secondary part of this system will move across the southern Prairies and likely produce accumulating snowfall along part of its track. At this point it appears probable that snow will begin to develop over southern Manitoba on Monday night as moisture and lift begins to push into the region. The question is whether conditions will come together just right to produce significant snow over all of southern Manitoba, or whether the system will only begin to produce significant snow as it pushes into northwestern Ontario.

Weather model simulations generally begin to produce light snow over western Manitoba late on Monday afternoon, before the snowfall intensifies as it moves into the Red River Valley and southeastern Manitoba. This would likely result in 1-4 cm of snow over western Manitoba, 4-8 cm over the Red River Valley, and 5-10 cm over southeastern Manitoba. However, an alternative solution would have only minor snowfall (if any) over western Manitoba and the Red River Valley, with slight accumulations of 2-4 cm over southeastern Manitoba. The former solution is most favoured at this time, with about 5 cm expected in the Winnipeg region, with slightly higher amounts to the east and slightly lower amounts to the west. The most likely outcome may change as the system develops today, therefore you should stay tuned for more details.

A map of the currently favoured snowfall outcome is shown below, showing the probability of at least 5 cm of snow; note that Winnipeg has a 70% chance of receiving at least 5 cm. Some blowing snow is possible, due to southeasterly winds of 30 km/h gusting to 50 km/h today, however blizzard conditions are definitely not expected. Winds will taper off by Tuesday, alleviating any blowing snow that does develop. The first major snowfall of the year is always one of the most challenging as drivers adapt to the changing conditions. Regardless of whether it snows tonight, this is probably a sign that you should get those winter tires on if you haven’t already!

Probability of at least 5 cm of snow according to the NAEFS (ensemble)
Probability of at least 5 cm of snow according to the NAEFS (ensemble)

Snow will taper off on Tuesday morning, should it materialize in the first place, leaving Tuesday with cloudy and cool conditions. Temperatures will once again sit near the freezing mark under mainly cloudy skies. The odd flurry is possible during the day, but generally quiet weather is expected. Winds will be light from the west.

A quiet weather day is expected on Wednesday as well, with mainly cloudy skies and just a lingering chance of flurries. Temperatures are likely to be around or just above zero. Winds will be northwesterly at 20-30 km/h.

Long Range

The long range outlook will be partly shaped by how much snow falls this week. If we manage to avoid major snow, it is likely that the remainder of November will remain generally warmer than normal. Because a blanket of snow on the ground reflects most of the incoming sunlight, it is more difficult for us to heat up during the day. The longer we avoid snow the longer we’re able to keep that darker, exposed soil which helps to absorb the limited sunlight that we do receive at this time of year. Should we receive significant snow with this upcoming system, we’ll likely see normal conditions through month’s end. Regardless of how much snow falls this week, this November is likely to end up as one of the warmest, if not the warmest, Novembers on record in Winnipeg.

Cooler Weekend A Seasonal Reality Check for Winnipeg

Brad Leave a comment

Temperatures will be startlingly colder this weekend than we’ve seen through the first half of November, but despite the shock to the system, Winnipeg will simply be seeing temperatures closer to typical values for this time of year.

The weather through the weekend will be relatively benign overall, with the major storm system forecast once upon a time to slam the Manitoba Red River Valley now taking a significantly more southwards track, instead tracking across central Minnesota into Northern Ontario. With that major system moving through to our south, we’ll be left with cloudy skies and a brisk north wind to 30 gusting 50 km/h. Temperatures will be much cooler with a high near +1°C

As cooler air slumps southwards through the day, narrow bands of lake-effect snow will fire up off of the south basin of Lake Winnipeg. At this point, it appears that the line will run north-south and primarily impact a line between Selkirk and St. Clements southwards towards Springfield. Beausejour may end up just east of the main band, but slight shifts in the wind direction could shift the heaviest band east or westwards. Lighter flurries may make it all the way south of Steinbach. By the time the lake-effect tapers off on Saturday morning, anywhere from 5-15cm of snow may accumulate under the heaviest axis of snow.

If you look to the northwest of the massive Colorado Low blob, a narrow band of lake-effect snow accumulation can be seen east of Winnipeg.
If you look to the northwest of the massive Colorado Low blob, a narrow band of lake-effect snow accumulation can be seen east of Winnipeg.

Skies will begin to clear out on Saturday night, save for locations that see cloud streaming off the lakes. Winds will taper off and temperatures should dip to a low near -6°C.

Saturday will bring a ridge of high pressure to the province, quashing the lake-effect snow and bringing a bit of sunshine and light winds. Highs will reach around 0°C under mixed skies. Saturday night will be partly cloudy with a low near -5°C.

Sunday will bring increasing cloud ahead of a warm front pushing eastwards across the southern Prairies. Temperatures will climb to a high near -1°C with a brisk southeasterly wind at 20-30 km/h. Expect fairly cloudy skies with a chance of some light snow on Sunday night with a low near -4°C.

Back To Normal

As mentioned up top, while these cooler temperatures are a shock to the system, we’re simply in a rapid adjustment back towards seasonal temperatures.

November has been a phenomenally warm month so far, with an average high of 11.3°C, a whopping 9.8°C warmer than the typical average high of 1.4°C through the same 17-day period. Including overnight lows, mean temperatures have been over 6°C above normal, more typical of mid-October than November, and November 2016 has taken the crown with the warmest first half1 of November on record.

Top 6 warmest first halves of November in Winnipeg on record. Credit: Rob's Obs
Top 6 warmest first halves of November in Winnipeg on record. Credit: Rob’s Obs

And, while a brief seasonal snap is on the way, models indicate that by next weekend above-normal temperatures will be back in full force, which could enter the month into the competition for warmest November on record!

Long Range

The system pushing the warm front eastwards across the Prairies on Sunday will continue to push eastwards and bring another chance for snow to the region on Tuesday. After that, it appears that a series of low pressure systems will track to our north and begin building warmer air back into the Prairies.

Winnipeg’s seasonal daytime high is currently -3°C while the seasonal overnight low is -11°C.

  1. First half of November is November 1-15, inclusive. ↩