Several states in the western and southwestern United States will experience an unprecedented spring heat wave this week, with temperatures soaring to record levels. Hot summer weather is expected to increase health risks in the coming days.
“Another world?” WFLA-TV chief meteorologist and climate expert Jeff Berardelli posted on social media. “It sounds like an exaggeration, but from a meteorologist’s perspective, this looks unusual. It’s like nothing we’ve seen in March.”
Predicting the pressure in the middle layers of the atmosphere helps meteorologists estimate surface temperatures. Standard sea level pressure is 1013.25 millibars, but at higher altitudes, forecasters typically look at 500 millibars. The altitude at which air pressure drops to 500 mb is a key indicator of air quality. The higher the water level, the warmer the column of air beneath it.
When the height of an area rises by 500 mb, it indicates that the high pressure ridge is strengthening and surface temperatures are usually higher. Meteorologists with the National Weather Service in Phoenix were surprised by the forecast height, a sign of the strength of the southwest ridge that will form there this week.
“This will make this ridge one of the strongest on record in the region, not just in March but also in April,” National Weather Service forecasters noted.
On March 17, more than 45 million people in California, Arizona and Nevada were under heat warnings.
“The extreme heat warning means a period of very hot temperatures, even by local standards,” explained meteorologists at the National Weather Service office in Phoenix. “Actions should be taken to mitigate the effects of the extreme heat.”
Phoenix will rewrite its record books in mid-March. The city has only experienced 100-degree temperatures once in March. Between March 18 and 22, highs will soar above 100 degrees. That means not only is Phoenix likely to break records on consecutive days, but it’s also going to blow those records by 7 to 10 degrees.
The National Weather Service and the Centers for Disease Control and Prevention collaborate to issue heat risk forecasts. Think of it like a heat “threat level” – the higher the category, the greater your risk of heat-related illness if you stay outside for too long.
On March 17, approximately 25 million people in the West were at moderate heat risk (Level 2 of 4). More than 1 million people are at significant heat risk (Level 3 of 4). By the end of the week, millions more people will be in these risk categories. By March 20, nearly 37 million people may experience moderate heat risk, while nearly 3 million people will face severe heat risk.
It’s worth noting that power outages can also occur during these situations. If the power grid goes down, the number of people without air conditioning will increase. Meanwhile, “living spaces can become deadly in the afternoon and evening for those without air conditioning,” according to the National Weather Service’s interpretation of the heat risk category. “Demand on the health system is likely to increase as demand on the health system increases significantly [emergency room] access. “
March through August (meteorologically speaking, spring and summer) was the third warmest period on record in the contiguous United States last year. This week’s historic heat wave means a sweltering start to spring in several states.
Heat has been the leading cause of weather-related deaths in the United States over the past 30 years, killing more people each year on average than floods, lightning, and hurricanes combined. The overheating of the Earth is exacerbating heat waves, making them more intense and widespread.
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