As a result of an effort on our part to restructure the SW+ Alerts subscriptions, only monthly subscriptions of SW+ Alerts in the StormWatch+ apps are currently available for purchase. If you previously purchased an annual subscription and you have received a notice that the subscription cannot be renewed, that is because the annual option does not currently exist.
However, please note that your access to SW+ Alerts will continue and alerts will still be delivered, even without an "active" subscription. We are planning to restore the SW+ Alerts annual subscription option in the near future, which will also correlate with the need for an active subscription (monthly or annual) in order to receive weather alerts. More details, including the timing of these changes, will be communicated in advance via this Help Center article, which is accessible in the app under the main menu > Help Center.