Currently in Philadelphia — May 20th, 2022

Sunny and warm then record-setting heat over the weekend

The weather, currently.

The weather forecast for Friday is for sunny skies and very warm temperatures. Morning temperatures will start off in the lower 60s and afternoon high temperatures will reach the upper 80s. Winds will be light and out of the south. No precipitation is expected. This is another day where sunscreen will be needed if you are spending anytime outdoors.

The outlook for the weekend is for record-setting and potentially dangerous excessive heat. High temperatures on Saturday will reach the mid 90s, and Heat Index values will top out around 100°F. This is the first big heat event of the season. Take extra precautions if you are outdoors.  Drink plenty of non-alcoholic beverages and have a shady or air-conditioned location available if you need to rest. Sunday's high temperatures will reach the lower 90s and high humidity levels will continue. This excessive heat event will break when a cold front moves through the region late Sunday night.

Gary Szatkowski

What you need to know, currently.

As a heatwave sweeps across the nation, Denver is set to see some significant snowfall this weekend, with temperatures dropping from the 90s to the low 30s. Snow in late-May is unusual, but not alarming — nothing compared to 1816, which is known as the Year Without a Summer.

In April of 1815, Mount Tambora — a volcano in present-day Indonesia, that had been dormant for 200 years — erupted, sending a plume of ash the size of Australia into the sky and causing a volcanic winter. The ground froze in July and August, snow fell in June, crops and livestock died off — causing widespread famine. According to the New England Historical Society, farmers, who had already shorn their sheep for the summer, tried to tie their wool back onto them, to no avail.

Allegedly, the founder of the Old Farmer’s Almanac, Robert Thomas, had mistakenly printed copies predicting a cold, snowy July that year. Upon discovering his mistake, he had the copies destroyed — only to be vindicated by the volcanic winter.

The basic principles behind volcanic winters are what have inspired researchers to look into certain kinds of geoengineering—namely shooting aerosols into the atmosphere, that would block the sun and effectively mimic the effects of a volcanic eruption.

The risks to geoengineering are manifold, however. Although it may succeed in cooling the climate temporarily, geoengineering is not an argument against reducing emissions and could very well end up worsening the situation.

Alan Robock, a climatologist at Rutgers University outlined some of the risks in a 2016 paper, including ocean acidification, widespread drought and famine, and rapid warming if stopped (once you stop shooting aerosols into the atmosphere, the planet warms faster than if you’d done nothing at all.)

“So far geoengineering research concludes that there is no safe Plan B,” Robock writes. “And provides enhanced support for mitigation and adaptation.”

—Rebecca McCarthy