(Bloomberg) – Heavy rains in China, a body of warm water stretching across the North Pacific and folds in the jet stream combine to cause an unusual heat wave that will set records in the northwest of the Pacific.
Seattle and Portland could post their hottest June days in history, while heat warnings are posted in Canada as far north as the Arctic Circle. Dangerously hot temperatures increase the risk of forest fires, can worsen air pollution and pose a threat to public health in an area where many lack air conditioning.
The heat rises under a so-called thermal dome which has likely been exacerbated by climate change. It’s similar to the weather pattern earlier this month that led to a heat wave in California, according to Jeff Masters, a meteorologist with Yale Climate Connections. Wrinkles in the jet stream brought summer weather to a standstill, resulting in prolonged heat waves and droughts, as well as storms and flooding.
“The unusual ripple in the jet stream was associated with a pattern we see more often in summer, which has been linked to man-made climate change,” Masters said.
The current heat wave over the northwest began with torrential rains across China on June 23, Masters said. This fed the jet stream across the North Pacific, making it stronger than usual, triggering a chain reaction of weather conditions that led to the formation of high pressure ridges over western North America. North and rising temperatures in the United States and Canada.
The heat, along with the conditions that caused widespread drought in the western United States, may have been made worse by the warm water spreading over the North Pacific, as well as parts of the seas. Bering and Chukchi near Alaska, said Jennifer Francis, a senior scientist at the Woodwell Climate Center. This trend may have been exacerbated by the decrease in sea ice in the Arctic this year, a situation made worse in recent decades by climate change.
The worst heat will concentrate over the northwest, then seep east into Idaho by Monday, although California also experiences oppressive conditions. Golden State’s power grid manager said he was monitoring the situation closely. Excessive heat monitors cover areas east of Los Angeles, where temperatures could reach 110 degrees Fahrenheit (43 Celsius) on Sunday and Monday, and other parts of the state.
Seattle on Sunday could hit 103 degrees, matching its all-time hottest reading and crossing the 96-degree mark for its hottest June day, said Bob Oravec, senior forecaster at the US Weather Prediction Center. Portland could also tie its all-time high of 107 on Saturday, with other parts of the region reaching all-time highs.
“For the entire northwest throughout the week, temperatures are 25 to 30 degrees above average in some places,” Oravec said. “It’s pretty amazing.”
Extreme weather conditions just days after the official start of summer indicate that threats may intensify during the season and challenge authorities to deal with the growing risks of heat, drought and fire in forest. Western power grids are expected to be strained over the next few months as hot weather increases demand for electricity and drought leaves less water in hydropower reservoirs. California has already seen its first threat of a supply shortage, less than a year after the first continuous blackouts in two decades.
Read more: Drought indicators in western US warn of ‘Big One’
Drought across the west will make this weekend’s heat even hotter as the sun’s energy will primarily be used to raise temperatures rather than evaporate moisture from the soil, said Bob Henson, meteorologist and author of The Thinking Person’s Guide to Climate Change. Overnight lows are expected to remain in the 70s in Seattle, also a record.
“The heat is really going to build up in people’s homes,” Henson said.
Adding to Seattle’s discomfort, only 44% of homes there have air conditioning, the least among the top 15 metropolitan areas in the United States, according to data from the 2019 Census Bureau American Housing Survey.
Peaks in the northwest could strain California’s supplies as states often exchange electricity across borders. Drought in the West is also testing its dependence on hydropower.
Portland General Electric Co., which supplies electricity to Oregon’s largest city and surrounding area, encourages customers to save even though they expect sufficient supply to meet higher demand. , according to spokesperson Andrea Platt.
The Columbia nuclear power plant in Washington, which provides enough electricity for about 1 million homes, is back on line after being shut down for a scheduled refueling shutdown. And hydroelectric facilities are at higher summer production levels after a spring dumping operation to help fish migrate, according to the Bonneville Power Administration.
Meanwhile, U.S. natural gas futures headed for their strongest weekly advance since February on Friday as warm weather in the northwestern states is expected to boost cooling demand.
California power supplies will be tight for most of the summer, said Barbara Clemenhagen, vice president of market intelligence at consulting firm Customized Energy Solutions and a former board member of the Electric Reliability Council. of Texas, the network operator for that state.
“If these temperatures persist throughout the summer, conditions are going to be very tight,” she said.
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