The jet stream pattern across North America will have a high degree of amplitude through the weekend, which usually means that there can be extended periods of extremes from one coast to the other.
This high pressure ridge over western Canada will also trap more smoke and haze through the weekend, leading to poor air quality in some valley locations, especially in BC.
With the block in place, most of the Pacific storms are directed into Alaska with wind and heavy rainfall.
Between the two high pressure ridges, we have a tough, or dip in the jet stream, which is directed into Ontario and the Midwest U.S. The eastern half of this trough will be dominated by showers this weekend, while the western side will turn chilly. There may even be some wet snow over northwestern Ontario, eastern Manitoba and northern Minnesota this weekend.
It looks like this pattern finally breaks down in about a week, leading to a more typical west to east flow of the jet stream which should bring back the cooler and wetter weather into BC.
