Good to moderate air quality expected

Weather Forecast: Issued on Saturday, April 19, 2014

A high pressure ridge is over most forecast regions Saturday causing partly to mainly clear skies, except for northern and parts of central forecast regions, where partly to mainly cloudy skies are occurring ahead of low pressure trough that is over Manitoba. Precipitation is also expected to develop ahead of the trough in northern and central forecast regions Saturday evening. A north to northeasterly flow is occurring and is expected to continue through the evening across many forecast regions, except for southern Ontario, where a southeasterly flow is occurring and is expected to continue into the evening. Air quality indices are forecast to be in the good to moderate categories in southern Ontario, and generally be in the good category elsewhere.

During Sunday, the high is forecast to move eastward over most forecast regions while the low is expected to move eastward across northern Ontario. Partly cloudy to mainly cloudy skies with scattered precipitation, near to above seasonal temperatures and south to southeasterly winds are forecast. Air quality indices are expected to be in the good to moderate categories in southern Ontario, and generally be in the good category elsewhere.

During Monday, a low pressure trough is forecast to develop over northwestern Ontario and is expected to track eastward across northern Ontario. The trough is forecast to cause partly to mostly cloudy skies with scattered precipitation, near to above seasonal temperatures and a south to southwesterly flow. Air quality indices are expected to be in the good to moderate categories in southern Ontario, and generally be in the good category elsewhere.

In summary, for Saturday, Sunday and Monday, air quality indices are expected to be in the good to moderate categories in southern Ontario, and generally be in the good category elsewhere.

Smog Alert by Email

Sign up now to receive notification of Smog Alerts

Smog, comprised of Ozone (O3) and/or Fine Particulate Matter (PM2.5), is primarily a summer phenomenon, occurring mostly in southern Ontario; however, PM2.5 can elevate smog levels during all months of the year. For this reason, the ministry reports the AQI hourly, seven days a week; and continues to provide air quality forecasts daily.