A broad ridge of high pressure covering western Canada will drive temperatures into the low 20s across most of central and southern Alberta on Wednesday. Wednesday began with calm conditions, including very light wind and almost no cloud cover. A weak disturbance will track across the province from the northwest to the southeast throughout the day, forcing cooler air to interact with that warmer air under the ridge. This will produce a brief period of instability, including increasing cloud and stronger wind—especially along the northern foothills. Scattered showers and weak thunderstorms are possible in central and southern Alberta in the late afternoon and early evening Wednesday, including through the City of Calgary. This synoptic setup will lack the ingredients to produce intense periods of rain and/or severe thunderstorms—so where rain does fall, it will be short-lived and accumulations will be minimal. The daytime highs and lows in Calgary will remain above seasonal for the next 7 to 10 days, peaking at 23 C for a high on Wednesday with lows ranging from 4 C to 9 C. The normal high in Calgary this time of year is 15 C with an average low of 2 C. Most of the region will sit under some cloud cover this week with a chance of more persistent and widespread rain to start the weekend. Calgary is likely to see between two and four millimetres of rain from Friday night to Saturday.
