Spring is just about here, if you go by its official start date, on the equinox. But in the American West, it feels like we skipped right to summer. A record-smashing heat dome has settled over a huge swath of the United States, from California to Montana and down to Texas. At my house in Colorado Springs, where we are 6,700 feet in elevation, highs could hit 90 degrees Fahrenheit this Saturday. The usual high temperature should be around 55 this time of year. Just outside Phoenix, a baseball spring-training matchup between the Chicago Cubs and Cincinnati Reds was rescheduled to 6:05 p.m. Friday, rather than a typical afternoon start time. Highs around Phoenix are expected to hit 106 Friday and Saturday, about 30 degrees above normal for mid-March. We are roasting out here.
This is not normal. Or at least it wasn’t normal in the past. The heat wave is happening because of a bizarrely strong ridge of high pressure in Earth’s atmosphere. The ridge suppresses cloud formation and brings in warmer air. Such atmospheric ridges are more common in the summer, but this one would be unusually intense even for that season. It is the strongest ridge ever observed in March, Kaitlyn Trudeau, a senior researcher at the science nonprofit group Climate Central, told me. The group’s researchers have developed a prediction model that assesses how much a warming trend or record high can be attributed to human-caused climate change. According to the model, climate change is making this week’s western high temps five times more likely.
More subjectively, this heat dome is “otherworldly,” “genuinely startling,” and “absurd,” depending on which meteorologist you ask. The spread of March temperatures on Colorado’s Front Range is typically wide, but not so wide that the Denver metro area should be expecting highs in the 80s—even inching up to 90. March is also, famously, the state’s snowiest month. Peak snowpack usually falls around April 9. This year, we passed peak snowpack a couple of weeks ago, and the heat wave means that by mid-April, much of the snow will probably be gone for the season…