Understanding Winter Weather Advisories & Warnings...

I know there has been some confusion on the watches, warnings, & advisories from the National Weather Service. It does vary from office to office which also adds to the confusion. For Indianapolis, the criteria for a Winter Storm Warning is 6” in 12 hours or 8” in 24 hours. For a Winter Weather Advisory, it is 3-5” in 12 hours.

For a Wind Chill Advisory, it is -15 to -24 and a Wind Chill Warning it is -25 of colder.

A watch is just that and usually an advisory or warning follows. Watches for winter weather are usually issued 36 hours or more in advance.

When the advisory or warning criteria is not met, then a Special Weather Statement is issued.

This information and much more detail can be found in this NWS Directive.