Alpine weather forecast

Heat on the horizon

A cold front swept across the Chic-Chocs Tuesday night delivering 5-10 cm of snow and strong winds that abruptly shifted from the south to the northwest. Alpine weather observations were not available but freezing levels appeared to have risen to 400 metres for a few hours Tuesday evening, with rain falling in the valleys and along the coast before switching to snow. Cold fronts are defined as the leading edge of a cold air mass. This front could have been called a “frigid front” as temperatures plummeted by upwards of 12 degrees in just a few hours.

A robust ridge of high pressure will build over southern Quebec on Wednesday supporting ongoing cold northwest winds of 40-60 km/h. Low cloud will give way to increasing sun in the afternoon. The cloud will be shallow with a top near 700 metres such that the alpine will shine in the sun most of the day. Despite the sun, temperatures will remain rather chilly with a high of only -15C and a low flirting with -20C Wednesday night. The ridge will shift east to lie directly overhead on Thursday which will lighten winds to the southwest. Temperatures will be much more comfortable near -6C in the mountains and -2C in the valleys. Despite some thin high cloud, snow surfaces could soften on steep south aspects before refreezing Thursday night possibly creating a new melt-freeze crust. The very southern tip of a trough will clip the region Thursday night generating flurries and possibly a couple of centimetres.

The warming trend begins in earnest Friday as a southwesterly flow develops across eastern Canada. An approaching warm front will keep skies cloudy and could deliver a few wet flurries as temperatures climb near the freezing mark. Moderate southwest winds on Friday will strengthen to 30-50 km/h on Saturday helping the mercury to climb further close to +7C. Skies should be partly sunny such that all aspects will soften with no refreeze expected Saturday night. Looking further out, rain appears inevitable Sunday into Monday as a deep low over northern Quebec drives warm, moist up the east coast. With the spring equinox on March 20^th, spring will arrive a few days ahead of schedule.

Forecast Confidence :

Confidence is good with the overall trend towards warmer and warmer conditions. The amount of cloud cover is somewhat uncertain as Thursday’s ridge could be considered a “dirty ridge” with low cloud trapped beneath it. Both rounds of flurries Thursday night and Friday afternoon should be fairly light or even non-existent so no accumulation is expected. Unfortunately, the warm rain Sunday into Monday seems rather certain so get at the good snow while you can!