Year's best weekend ahead, what to expect across Ontario
Meteorologist
Thursday, April 14, 2016, 7:17 AM - Congratulations, Ontario: You’ve made it through yet another winter.
With the early April snowfall melted into a distant memory, temperatures will be on the up and up once more across the province through this weekend, resulting in a return to double-digit temperatures and those sunny blue skies that we all love.
Ontario-wide, daytime high temperatures are forecast to be in the 10-20oC range Friday, Saturday, and Sunday, with abundant sunshine and generally light winds – a stark contrast to the first two weekends of the month.
Much like last week in B.C. and Alberta, a strong ridge in the jet stream will be steadily building over Ontario and Quebec as the week progresses, peaking in its amplitude by the weekend.
Under this ridge, winds are forecast to be generally quite light – with one exception, described below – and a higher solar angle combined with clear skies will allow temperatures to climb to the teens in many locations.
Beware the lake-breeze!
If you find yourself close to one of the Great Lakes this weekend, you may find it significantly cooler than you’d expect, with a brisk wind coming off the lake during the day. This phenomenon is known as a lake-breeze, and is particularly common in springtime and early summer.
Because the land heats up faster than the lake, a pressure gradient is created during the day, forcing cooler air to blow across the lake onto the shore. This creates significant temperature differences between the lake shore and areas further inland that can often catch people unawares.
As an example, take the present forecast highs for London and Toronto on Saturday: a balmy 17oC in London, while only 10oC in downtown Toronto.
This is a direct result of a lake-breeze off Lake Ontario, and is expected to make the Golden Horseshoe one of the coolest places in the province this weekend – temperature-wise, of course.
Temperatures on Sunday and Monday are expected to be a few degrees warmer across the province, however, with many northern cities – like Timmins or Kapuskasing – getting into the high teens.
Choose your forecast location wisely!
It is important that you pay close attention to which city you have selected for your weekend’s forecast: a difference of 20 km closer to or farther away from a large body of water can have a huge impact on the forecast high temperature.
If you presently use The Weather Network App, one of the best ways to ensure you get the most accurate forecast specific to your region is to have the “Follow Me” feature enabled. This will automatically tailor the forecast to your specific location – to within 1 km – and will adjust the temperature accordingly depending on where you are. Especially in springtime, there can be significant differences in temperature even within the same city!
It is also important to remember that a Weather Network forecast for Toronto is for a downtown location, and not at Pearson Airport (YYZ). The difference in temperature between these two locations can be surprising, even though they are only 25 km away.
So whether or not you’ll have to deal with a lake-breeze this weekend, it’s already shaping up to be significantly more spring-like than the prior weekends of this season. Hopefully you are able to get out there and enjoy it, and not be too sad that you’ll have to wait at least another 6-8 months before you can build another snowman.
Watch more: Stunning timelapse of Aurora Borealis in Timmins, Ont.
