Step 1: on the page called "Important Notices" click "Page Layouts", click "insert" beside "Weather button"

Step 2: edit copy as needed on the "General" tab then click the "Mobile" tab and make it a non-reference page and "Save Changes"

Step 3: Publish

Step 4: When the alert is no longer needed, erase all the copy/coding on the "Important Notices" page on the "General" tab, then click the "Mobile" tab and make it a reference page, click "Save Changes" and Publish