DISCUSSION: Will there be snow in Manitoba this weekend?

This question is not answered by a simple yes or no, we need to dig much deeper into what is going on in the atmosphere to be able to get a glimpse of what the future might hold for the Prairie Provinces. We're sure you have seen a forecast somewhere mentioning snow, so we thought we would throw in our thoughts on this!

Figure 1 - Upper Atmosphere (current)


We are going to go into as much detail as we can without losing anyone (hopefully). Figure 1 above shows what is happening in the upper parts of the atmosphere this morning (12z). This is important to look "upstream" for potential weather systems. You see the cluster of "H" on the bottom left of the chart? Good, now look above that, you see a low "L" and then keep going up, another two "L". These are upper-level low pressures or "troughs". These will move towards the North American continent in the next few days and bring some nasty weather to portions of the Prairie Provinces.

Extra Info: weather systems always move from west to east across the North American continent.

Figure 2 - Upper Atmosphere (forecast)


Now that we know there are some "upper-level low pressure systems" upstream and coming towards us, we can now use a forecast model to look at what the same 500mb chart might look like in the future. Figure 2 above gives a prediction of where that upper-level low might be on Saturday. This is the ECMWF (European model), arguably one of the best forecast model we have at our disposal.

Figure 3 - Surface Depiction (forecast)


Next we can look at the surface, because that is really what we care about (i.e. that is where we live). Figure 3 depicts a forecast depiction at the surface on Sunday morning. What is important to note here is the strong gradient, which I have outlined in yellow, seen between the area of low pressure (blue blob) and area of high pressure (red blobs). This is referred to as baroclinicity in the meteorological world, which is just a fancy way of saying temperature gradients. In this case, we have strong temperature contrast, or a strong baroclinic zone. This baroclinic zone is important, because it is usually the transition zone during cold weather months (i.e. where the snow changes to rain and vice versa). Where this sets up will be important to monitor in determining which areas will receive rain, freezing rain and/or snow.

Extra Info: Since air moves from high (H) pressure to low (L) pressure, in Figure 3, one can see that cold Arctic air is being dragged from the north, towards the low pressure situated in Wyoming. Therefore, a northerly wind (coming from the north) would be expected across the Prairies on Sunday. The closer the lines in the yellow circle are, the tighter the gradient and therefore the stronger the winds.

Figure 4 - Precipitation Type (forecast)


If you made it this far, we applaud you. This is the good stuff and what most people care about. What type of precipitation will I get? Well as you have read before, it is a bit more complicated than simply looking at Figure 4 from one model run and saying "this area might get snow this weekend or next week". While this generates good ad revenue for weather stations, it is far more complex than what Figure 4 depicts. Figure 4 depicts that our transition zone will be somewhere around the Manitoba/Saskatchewan border on Monday, but with very low model confidence.


This leads us to the ultimate question....will we get snow or what?

Figure 5 & 6 - So...will it snow or not?


This leads us to whether or not it will snow. While temperatures (Figure 6) will support possible snowfall on Sunday-Monday for parts of Manitoba and Saskatchewan, it is unlikely that the snowfall will stay on the ground very long due to warm soil temperatures. Figure 5 depicts the soil temperatures across Manitoba, most of which show 10C+ soil temperatures. Therefore, even if a lot of snow falls in areas like Westman, it won't stay on the ground very long!

Conclusion


So ultimately, the answer is possibly yes and then no. Yes, you might see snow fall, but you likely won't see much accumulation across Manitoba. We will give you updates if this changes in the next few days as model data gets refined.