Notifications should be used sparingly and only for timely events. You should never have more then one on your website a time. 

A notification is a message you can display at the top of your home page. Notifications appear below the navigation but above your Spotlight News zone ("ALERT: SCHOOL IS OPEN TODAY"):

You should always include information that helps your parents understand why this notification is so important. We see schools post one sentence that doesn't provide the end user any details. Like any news story this should answer the 5 W's. Who, What, When, Where and Why. If you cannot include that, then you should ask yourself, is it really notification worthy?

Don't Be That Guy

Like crying "wolf", notifications on your site are most effective when used sparingly. If you (and your parents) get used to having regular news items pushed into the Notification zone, it prevents the really important messages from standing out, like at times when your house is about to be blown in.

Three Severity Levels

Notifications come in three severity levels, and use colour to indicate how critical they are. 

Notification

Used as a general notices, items you want your users to know about. 

Alert

This is the middle level notification. 

Emergency

The the most critical; emergency level.

When You Have Multiple Notifications Active At One Time

On a desktop device this may not appear to be an issue. However, what you may not be aware of is how your mobile users experience your website. Notifications are large on mobile devices and take over your entire site when there is more then one. It is very important when you use notifications that they are for limited or short periods of time - such as a couple days, but no longer then one week. If longer there should be extenuating circumstances.