Currently in Boston — August 18th, 2022

The nor'easter which had the potential to bring us some rain today stayed too far offshore to give the area any meaningful precipitation. It will be comfortably cool overnight with a nice sleeping atmosphere, followed by a beautiful start to your Thursday. In the afternoon will reach between 75°F and 80°F warmest away from the coastline. It turns hotter and more humid starting Friday with temperatures 85°F to 90°F and humidity levels will continue to increase through the weekend as reading stay in the 80s and lower 90s. The next chance of any precipitation comes early next week but it's only a chance, not a guarantee.

—Dave Epstein

What you need know, currently.

Every winter, atmospheric rivers flow off the Pacific ocean towards California, many of them carrying more suspended water through the air than the largest terrestrial rivers on earth. In 1862 a series of atmospheric rivers proved disastrous for the Western United States, bringing catastrophic and unprecedented flooding to Oregon, California, and Nevada.

In 2010, scientists began a study they called the ArkStorm Scenario, named for the biblical flood, to account for the effect of climate change on these worst case scenarios floods.

According to the geologic record, these floods — caused by a quick succession of atmospheric rivers — occur every 150 to 200 years in California. A new study in Science Advances suggests that climate change has doubled the chances of this kind of catastrophic flooding occurring within the next four decades.

“The last time government agencies studied a hypothetical California megaflood, more than a decade ago, they estimated it could cause $725 billion in property damage and economic disruption,”  writes Raymond Zhong in the New York Times. “That was three times the projected fallout from a severe San Andreas Fault earthquake, and five times the economic damage from Hurricane Katrina, which left much of New Orleans underwater for weeks in 2005.”