Toronto is in for a brief warm spring teaser this week, with temperatures expected to rise to 18 C on Thursday — the warmest day in a cooler, rain-soaked week ahead.
Warning Preparedness Meteorologist at Environment Canada, Geoff Coulson, says the jump in temperature is due to the Colorado low-pressure system tracking through Ontario mid-week.
“Thursday is the day we tap into the warmest air mass of the week, because the Colorado low that’s going to move through on Wednesday,” Coulson told Now Toronto.
WHAT IS THE COLORADO LOW-SYSTEM?
According to Environment Canada, the Colorado low is a low-pressure system that forms on the eastern side of the Rocky Mountains. These systems typically draw in moisture from the Gulf of Mexico, which helps fuel the rainy weather as they move northeast toward Ontario.
Colorado lows are known for bringing significant precipitation, whether that’s rain, snow, or a mix, and they may also influence temperature swings.
For this week’s weather, the system is responsible for bringing in a brief but noticeable spike in warmth on Thursday for Southern Ontario.
WEATHER FORECAST FOR THIS UPCOMING WEEK
Toronto’s long-term average high for early April is 8 C, making Thursday’s expected high of 18 C an outlier. But Coulson said it won’t last long as a cold front following Thursday’s warmth will bring temperatures back down to more seasonal levels by Friday.
“It’s going to go to northeastern Ontario and up into western Quebec, and that leaves us in what we call the warm sector of that system, a part of the system where temperatures are usually on the warm side, above normal in this particular case, and then once a cold front sweeps through late in the day on Thursday, we go right back to more seasonal temperatures for Friday.”
The rest of the week will feel like a typical early spring in Toronto: wet conditions and temperatures hovering around single digits.
Monday is set to have rainy conditions with a high of 9 C and a low of -3 C, Tuesday is forecasted to have clear conditions with a high of 4 C and a low of -3 C, while Wednesday is set to be a rainy day.
“We’re expecting rain from that [Colorado] system to move into the Toronto area on Wednesday afternoon, and will likely transition to more showers Wednesday evening and into the early morning hours of Thursday, where there’s a chance of thunderstorm activity,” Coulson warns.
Environment Canada is also watching potential rainfalls closely, with a possibility of a special weather statement being issued later today, Coulson said.
Looking ahead to the weekend, expect mostly cloudy skies on Friday and Saturday, with periods of rain moving in by Sunday. Temperatures will be in the single digits, with a high of 9 C on Friday and a high of 7 C on both Saturday, and Sunday.
“For the most part, we’re going to be seeing more single-digit temperatures for those daytime highs,” Coulson said.
“Not to say that as we get further into next week, we won’t see more high temperatures getting into what we see on Thursday, but the overall trend at this point looks to be temperature staying around the seasonal average.”
