So I managed to get working weather warnings last year, when the UK snow hit. As my wife kept asking.
I cobbled this together from our places and people on the forums, but through i would help my UK friends (and anyone else that needs it)
Please note i only use the normal web interface, not lovelace.
So in my config have this entry.
feedreader:
urls:
- http://metoffice.gov.uk/public/data/PWSCache/WarningsRSS/Region/se
Then i have an automation for alerting me via notification
- alias: 'Alert From Weather RSS Feed'
trigger:
- platform: event
event_type: feedreader
action:
- service: notify.james
data_template:
message: "{{ trigger.event.data.description }}"
title: "{{ trigger.event.data.title }}"
If you have other items in you feed it will alert you to changes in these as well.
To find your location on the go here and use the link listed