Alert updates that tell you what changed

The National Weather Service revises an active warning constantly — a tornado threat goes from radar-indicated to observed, hail grows from 1" to 1.75", an expiration gets pushed back. Until now those revisions either passed silently or arrived as a repeat of the original alert. Now every update spells out exactly what changed: "Tornado threat now Observed; Hail 1.00" → 1.75"; Warning extended to 4:45 PM CDT." You'll see it on the alert page, in the history timeline and CSV export, and in the text, email, and Slack update itself.

To keep the signal clean, you control how often updates reach you, per rule: Escalations only (the default) notifies you when a warning gets more dangerous, All updates sends every change, and Off stays quiet until the all-clear. Times are shown in the warning's own local zone, and routine continuations that don't materially change anything no longer ping you at all.