AI cracks cyclone forecasting, Jeff Dean leaves Google, and Wall Street's $500B AI debt machine

Hurricane season is peaking, and this year the best forecaster on the planet is a model. DeepMind's WeatherNext posted a genuine breakthrough in predicting cyclone tracks and intensity, beating the physics-based systems that meteorologists have refined for decades. Weather is my favorite kind of AI story: no benchmark drama, no vibes, just a hard prediction problem where being right is worth billions in insurance, shipping, and lives. AI for science keeps promising results like this. This week it delivered one.

The strange part is what else happened at Google the same week. Jeff Dean, the engineer who built the infrastructure Google runs on and has steered its AI for a decade, left after 25 years to start an AI-for-science company with a group of senior researchers. Demis Hassabis stepped back from running DeepMind to a chair role, and Gemini co-lead Oriol Vinyals is out too. Google's AI just proved it can out-forecast the weather service, and the people who made that possible are heading for the exits to compete with it.

Follow the money and the week gets even more interesting. The FT pulled apart the $200 billion machine of private credit, chip leases, and data center guarantees that Google built to finance Anthropic. Alphabet sold $25 billion of bonds into $115 billion of orders. Banks are offloading $15 billion of Anthropic data center debt, and JPMorgan now expects tech bond sales to clear half a trillion dollars this year. The AI buildout used to be funded by the richest balance sheets on earth. Now it is funded by IOUs. Capability had a great week. The credit markets are the ones holding the receipt.