Winter Weather Warning Terms

The following terms WARN the public of more serious winter weather situations that may cause impossible traveling conditions and could pose a threat to life and property.

PRODUCT Description
WINTER STORM WATCH Issued when conditions are favorable for the development of hazardous weather elements, such as heavy snow or sleet, blizzard conditions, significant accumulations of freezing rain or drizzle, or any combination thereof. Watches are usually issued 12 to 48 hours in advance of an event.
WINTER STORM WARNING Issued when hazardous winter weather conditions are imminent or very likely, including any occurrence or combination of heavy snow, wind-driven snow, sleet, and/or freezing rain/drizzle. Winter Storm Warnings are usually issued for up to a 12-hour duration, but can be extended out to 24 hours if the situation warrants. The term "near-blizzard" may be incorporated into the "winter storm warning" for serious situations which fall just short of official blizzard conditions.
BLIZZARD WARNING Issued for winter storms with sustained winds or frequent gusts of 35 miles per hour or greater and considerable falling and/or blowing snow reducing visibility to less than 1/4 mile. These conditions are expected to last at least 3 hours.
HEAVY SNOW WARNING Issued for expected snowfall amounts of 4 inches or more in 12 hours or 6 inches or more in 24 hours. Snow is the only precipitation type expected.
ICE STORM WARNING Issued when damaging ice accumulations are expected during freezing rain situations; walking and driving becomes extremely dangerous. Ice accumulations are usually 1/4 inch or greater.
SLEET WARNING Issued when accumulations of sleet covering the ground to a depth of 1/2 inch or more are expected. This is a relatively rare event.
SHORT TERM FORECAST (NOWCAST) A short term forecast designed to give specific, detailed forecast information for the next 1 to 6 hours on a county-by-county basis. Non-severe watch and warning information are contained in these forecasts which are routinely issued several times per day, and more often during busy weather periods. is the U.S. government's official web portal to all federal, state and local government web resources and services.