Chris_Dunn's Blog

Here is a question from viewer Judy White:

I have never known the difference between a storm warning, watch and advisory.  I never know which one means take cover. J

Little help?

If you had a “weather for dummies” graphic on the news the way they list the terror alerts, I would get it.

Thanks for your help Chris!

Judy-

     The difference between watches, warnings and advisories have to do with timing and intensity.  When it comes to winter storms, a watch is issued when a significant snow is expected to begin beyond 24-36 hours.  12-24 hours out if the threat is still there a watch is upgraded to a warning.  National weather service criteria for a warning depends on the area, with higher amounts required for a warning in the mountains.  A snow advisory is issued when snow is expected to have an adverse impact on travel or outdoor activities, but the amount of snow is less than required for a warning.

When talking about spring and summer severe weather, a watch is issued when conditions are favorable for severe storms or tornadoes to form. A watch is in effect until the threat of severe weather has passed. Think of it as a "heads up!"  A warning is issued when a severe thunderstorm, tornado or flash flooding is actually occuring.  Think of this as "take action, now!"