Summer warmth on the horizon for Montreal

Like a mountain range in the sky, dark clouds loom on the western horizon Wednesday morning, as an upper level low over Ontario moves into southern Québec. So far most of the chilly weather and heavy rain has remained in eastern and central Ontario. (Valley Weather Photo)

I must admit, I was wrong on the chilly weather forecast so far, as temperatures this week have over performed to this point. Montreal recorded a high of 24C (76F) on Tuesday, as skies cleared from morning rain, and the bulk of the afternoon thunderstorm activity remained to our west over Ontario. An upper level low, part of a larger omega block, has been stuck over the Great Lakes all week. Areas that have been receiving rain, have received quite a bit, in the order of 50mm. Here in Montreal, close to 15mm fell, but it was less than I expected, and temperatures have been warmer.

Radar Wednesday morning showing heavy precipitation from an upper level low spinning over parts of southern Ontario. The bulk of the rain has missed Montreal so far, with only 15.4mm falling so far this month, most of that occurring in the pre-dawn hours Tuesday morning.

As I write, the clouds are playing with the sun, in advance of the low pulling across southern Quebec and dragging a cold front along. Showers, with perhaps a rumble of thunder are likely Wednesday afternoon, before precipitation ends this evening and temperatures fall.

Thursday through Saturday will be partly to mostly cloudy, but fairly dry for southern Quebec. There is a risk of a few spotty showers and temperatures will be much cooler. Morning lows Thursday will drop into the upper single digits, with highs struggling to reach 13C (55F).

The good news is that much warmer, more summer-like weather is on the immediate horizon. High pressure will slowly drift across the region starting Sunday into next week. Highs will be in the lower 20s, Sunday but warming up to 28C (83F) for Monday and Tuesday. Some much needed sunshine is expected.

First Quebec Tornado for 2025

The Northern Tornadoes Project from Western University in London, Ontario finished their survey of damage caused by severe weather on April 29. They determined that outside of straight line winds here in the Montreal region, the first tornado of the season in Quebec occurred north of the St. Lawrence Valley at Saint-Zénon. The EF-1 tornado, capable of winds of up to 165km/h, moved along a 600 metre-wide path for 6.74 kilometres. The storm flattened trees, damaged barns and tore the roof from a home. It was the third tornado reported in Canada so far during this very young severe weather season. Thankfully there have been no injuries reported.