Another hot dome ready to roast Northern Rockies, Canada
The next in a series of relentless heatwaves is shaping up across parts of the western and northern plains, with temperatures set to climb triple-digit again from Idaho and Montana to northern Alberta and from Saskatchewan.
Why is this important: The West has already been extremely hot so far this summer, with a series of heat waves of unprecedented intensity for some areas.
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Heat waves have combined with drought conditions to give rise to massive forest fires that are spreading rapidly from Washington state to California and east into Idaho. According to the US Drought Monitor, 64% of the West is mired in “extreme” to “exceptional” drought conditions, the two worst categories.
How it works: With extreme drought conditions firmly in place across the West, the region is locked into a positive feedback where drought helps warm the atmosphere, which only dries up the conditions further, thus adding to the heat.
During June and July, a series of strong areas of high altitude high pressure, colloquially known as thermal domes, settled in different positions in the west. First, one of them made their home in the Southwest, pushing temperatures triple-digit in Phoenix and Las Vegas.
Then, from late June to early July, an extraordinarily strong and persistent dome of heat anchored over the Pacific Northwest, slowly drifting through southwestern Canada over time.
This heat event gave highs of 116 ° F in Portland, 108 ° F in Seattle and a Canadian record of 121 ° F in Lytton, BC. The day after this temperature was recorded in Lytton, the small town was destroyed by a forest fire.
One study concluded that the heat wave was “virtually impossible” without man-made global warming, spurred by fossil fuel combustion, deforestation and other factors.
In the meantime, other thermal domes have come and gone across California, maintaining warmer than average temperatures. As river and reservoir levels drop across the state, water temperatures rise, killing species of fish.
The California Department of Fish and Wildlife has said it expects almost all young Chinook salmon in the Sacramento River to die this summer due to unusually warm temperatures.
And after: Over the weekend, the next heat dome is expected to develop over the northern Rockies, extending its influence north into southern Canada.
In Billings, MT, an excessive heat watch is in place for “dangerously hot conditions with temperatures dropping from nearly 100 ° F on Saturday to 103 to 106 ° F on Monday.” Nighttime lows won’t bring much relief either, with temperatures only slipping around 70 ° F.
The typical high temperature for Billings on July 15 is around 88 ° F with a low of near 60 ° F.
Likewise, temperatures in Idaho are expected to climb triple digits, along with Utah and North Dakota.
However, Canada can experience the most extreme temperatures, with highs up to 40 ° F above average for this time of year.
To note : The heat wave could continue in some areas, including British Columbia, Alberta, Saskatchewan and Manitoba, where triple-digit highs could be seen until next weekend.
What they say : “Most of the West is a powder keg right now and if dry lightning or human actions lead to even more fires, the potential for explosive growth is of great concern, ”said Steve Bowen, head of human analysis. disasters at Aon, highlighting the likelihood of the next heat. wave to cause more fires.
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