A dominant ridge of high pressure situated over the southern portion of the eastern prairies will produce a long duration heat event that has prompted several weather advisories – including orange and yellow-level heat warnings and a special weather statement. According to Environment and Climate Change Canada (ECCC), daytime highs in southeastern Alberta will range from 33 C to 35 C – with lows around 16 C – and last until early next week. Wildfire smoke in southern British Columbia, the territories and the northern portion of the eastern prairies has prompted the national weather agency to issue both orange and yellow-level air quality warnings in those areas. The air quality health index (AQHI) rating in Calgary as of 8 a.m. Friday was a two, or low risk, with the AQHI expected to reach a four, or moderate risk later in the day. The hot and (mostly) dry weather forecast for the next seven to 10 days will likely enhance the wildfire risk within some of those the heat-affected areas – despite the vast amount of rain that fell in some regions during the month of June. Wet conditions in the late spring/early summer can often be a detriment to wildfire risk since that moisture encourages vegetation growth, and that plant material can turn into fuel if there is a heat event in the following months. Conditions should remain calm and clear in the Calgary area for most of the next few days, with the city catching the western edge of the eastern ridge. However, along the axis between that ridge and a low-pressure system in the northwest corner of Alberta (that is cutting into east-central B.C.), there is a risk of active weather – including some potentially large and damaging storms on Saturday night northeast of Edmonton. Calgary has a 30 per cent chance of showers or thunderstorms on Friday – mostly heat-initiated – so potential storm cells could form quickly but should be short-lived. The rest of the weekend will likely be dry in Calgary as well as the communities south and east.
