When people think of the “Big One” in California, they imagine a catastrophic earthquake.

But the real Big One will be a megaflood, that could cause over $1 trillion in damage and become the worst natural disaster in world history... (thread) 🧵 160 years ago, California experienced such a flood.

From Dec 1861 to Jan 1862, nearly 40 straight days of relentless rain and snow battered the state.

This became known as the Great Flood of 1862.

The result: apocalyptic flooding across California.

With winds blowing at 60-80+ mph and bone-dry humidity, no amount of water or firefighting could have prevented the tragedies of the Eaton and Palisades fires.

A thread... 🧵
The only way to have prevented these devastating wildfires would have been not to build in these areas to begin with. This was not a true forest fire or wildfire but a full-blown urban conflagration.

A severe marine heatwave near Japan has been ongoing for the last several months, with sea surface temperatures currently up to 8°C (14.4°F) above normal.

This is not just a local issue. Both global ocean heat content and sea surface temperatures have reached their highest levels in Earth's recorded history in 2023.
If you want to track and learn more about marine heatwaves, check out NOAA's Coral Reef Watch: coralreefwatch.noaa.gov/index.php

A ~4,000 mile long stretch of severe marine heatwave conditions extends all the way from the coastal waters off of West Africa to the coastal waters just south of Iceland.

We are witnessing one of the most extreme marine heatwave events ever recorded in modern history. The North Atlantic is 0.6°C warmer today than any other year since at least 1981.

This is astonishing margin considering, water has over 4x the heating capacity of land, meaning it’s takes much more energy to heat water than land. The N. Atl is also over 4x the size of the US.

California in October 2022 versus March 2023.

From being entrenched in a multi-year extreme drought to having one of the deepest snowpacks on planet Earth. The latest drought monitor shows that this winter's storms have completely removed drought across the Central Coast, part of the Sierra Nevada, and the far North Coast.

Over the following weeks, drought removal is likely across SoCal, the Bay Area, and all of the Sierra Nevada.

Europe is experiencing its worst heatwave ever recorded.

The combined intensity and scale of this winter heatwave is unlike anything in European history. Tens if not hundreds of millions of Europeans experienced the hottest January day ever recorded in their respective regions. All on the same day.

https://twitter.com/scottduncanwx/status/1609643109100445701

Taking into account the intensity, duration, and extent of the ongoing heatwave, as well as the exceptionally warm overnight lows and the added humidity (especially in SoCal), we are looking at one of the worst heatwaves in modern history for California. Last night SoCal experienced a brutally hot night with millions not seeing temperatures dip below 80F, and that's combined with brutal humidity.

San Diego only got down to 82F, making it one of the hottest nights in city history. The average daytime high in September is 77F.

China is experiencing the worst heatwave ever recorded in global history.

The combined intensity, duration, scale, and impact of this heatwave is unlike anything humans have ever recorded.

Over 260 locations have seen their hottest days ever during this 70+ day heatwave. @extremetemps has been covering this heatwave for months and has found some truly astounding stats. Many locations have experienced nearly a month (!) of their hottest days ever recorded.

https://twitter.com/extremetemps/status/1561808166337347584?s=20&t=vnf878N05a4V9VtDeyTarA