|Introduction||Products||Definitions||Wind Chill||Safety Kit||Safety Links|
The National Weather Service is changing the watches, warnings and advisories we issue for winter weather. We hope the changes will help make the information we provide simpler and easier to understand.
We'll still be issuing watches, warnings and advisories to let you know about the possibility of snow, sleet, freezing rain and extreme cold. The difference will be in the number of different message types you'll be seeing.
Here's a table showing the different message types you can expect to see beginning this winter season. All other message types will no longer be issued.
|Winter Storm||Winter Storm||Winter Weather|
|Ice Storm||Wind Chill|
The products listed above have specific criteria for issuance, which are summarized in the table below. When we issue an advisory or warning, it means at least one of the criteria is forecast to be met. So, for example, a forecast for 6" of snow accumulation will trigger a Winter Storm Warning -- even if no sleet is expected.
Note that a Wind Chill Watch or Warning indicates that the wind chill is forecast to drop below -20°F.
|Winter Weather Advisory||up to 3"||enough to make walking/driving hazardous||enough to make walking/driving hazardous|
|Winter Storm||≥4" in a 12-hr. period or ≥6" in a 24-hr. period||≥0.5"|
|Blizzard||enough to blow and drift||≥35 mph sustained or frequent gusts|
For the bottom three product types (Winter Storm, Ice Storm, and Blizzard), either a watch or warning may be issued, depending on the timeframe during which precipitation is expected. If conditions are expected to deteriorate between 24 and 48 hours from now, a watch will be issued. If the winter weather is imminent within the next 24 hours, a warning will be issued.
For example, suppose today is Monday and a winter storm is expected Friday. If the forecast holds, a Winter Storm Watch will likely be issued on or around Wednesday to give residents an early heads-up; then, if things are still on track by Thursday, a Winter Storm Warning will be issued to indicate more immediate action is warranted.