The SuperNova Early Warning System (SNEWS): https://snews2.org/

brings together the fantastic [1] Super-Kamiokande, the [2] IceCube, and other global detectors, to provide early warning of Supernovas.

You can subscribe... https://snews2.org//alert-signup/

[1] https://en.wikipedia.org/wiki/Super-Kamiokande

[2] https://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory