Turning completely off for the duration should work. Quote: If a phone is off before the test alert is sent and not turned back on until after the WEA Test exp

Turning completely off for the duration should work. Quote: If a phone is off before the test alert is sent and not turned back on until after the WEA Test expires (approximately 30 minutes), the phone should not get the test message. Unquote Late notice, though I saw the same concern mentioned yesterday or earlier, but not in widespread media.