Workweek Outlook: Cool and unsettled to begin the week

The Sault region will feel the effects of an area of upper-level low pressure to start the workweek. You may have heard this term used by weather broadcasters before, but what exactly does it mean?

Well, an upper-level low (otherwise known as a cold-core low) is self-explanatory by its name in that it is an area of low pressure that spins several kilometres above the surface. What makes these phenomena unique is that their strength increases with height above the Earth's surface and that they are associated with a pool of cold air at higher altitudes which sometimes works its way down to the surface. Upper-level lows are not uncommon and can occur year-round. They can form by several processes including airflow over a mountain range, due to strongly varying temperatures several kilometres above the surface, or in the presence of strong winds in the upper atmosphere.

So, what does this all mean for our weather you may ask? Upper-level lows are not represented by your typical warm front and cold front structure at the surface. Instead, one should expect cooler temperatures with widespread cloudiness and showery precipitation (in this case, snow showers). Since computerized weather models see better detail in the low levels of the atmosphere, upper-level lows have been known to give weather forecasters grief in their practice.

Although this particular upper-level low is not expected to bring significant weather to the Sault region, upper-level lows have been known to be associated with severe weather in the warm season and can also act as a catalyst to fuel powerful winter storms. As a matter of fact, this upper-level low will aid in the development of a potent winter storm that is forecast to impact the Maritimes early this week.

Weather conditions should gradually improve as low pressure exits the region by the second half of the workweek. Unfortunately, for those that are hoping for a major warm-up, temperatures are likely to remain at or slightly below seasonal.

Cloudy with periods of light snow begin before sunrise on Monday morning. Light snow becomes intermittent snow showers in the afternoon. Snowfall accumulations of 2-5 cm are expected by the afternoon. A northwest wind in the afternoon will make a high temperature of 1°C feel like -3.

Mostly cloudy skies persist into Tuesday with a few lingering flurries. High temperatures climb to be near -1°C in the afternoon, but a gusty northerly wind will make it feel closer to -7.

Cloudy periods will likely continue for Wednesday and Thursday with occasional sunny breaks in the mix. A few isolated flurries cannot be ruled out for Thursday. High temperatures are expected to hover near to the freezing mark for both days as a northwesterly flow persists.

Clouds should give way to sunny periods for Friday, although temperatures struggle to climb above the freezing mark.

The average high temperature for the Sault according to climatology resides right around 0°C for this time of year, while the average low temperature is about -10°C.