Published on July 29, 2025 at 10:07 p.m.
An impressive system stagnates off Alaska and could have effects to Quebec. Explanations.
A weather giant that defies the rules
A gigantic depression system over 1500 km in diameter is currently swirling in the Gulf of Alaska. This altitude depression was formed a few days ago near the sea of the Tchoukche, between Alaska and Siberia north of the Bering Strait, before diving into the Gulf of Alaska, where it is now almost motionless.
Why is he not moving? Because it is stuck between two atmospheric ridges, one in western Canada, the other towards the sea of Béring. Result: a real weather traffic jam generated by a cold drop detached from the polar jet current which stagnates and which amplifies the development of a ridge.
If the cold drop is linked to the jet current, this would create an omega blockage (the shape of air circulation of which looks like the Greek letter Ω) on Canada.
This type of configuration is much more typical of transition seasons, such as fall or spring. In summer, the atmosphere is usually dominated by more stable diets, with a less powerful and less winding jet current and systems that circulate more quickly.
Seeing such depression settle and stagnate for several days in July is therefore out of the ordinary. This is precisely what makes this phenomenon so remarkable: a behavior worthy of October in the heart of summer.
Consequences in the West and to Quebec
This atmospheric blockage amplifies heat on the west of the country. The ridge above the meadows promotes a rise in hot air, which could cause temperatures up to 10 ° C above normal for several days.