ROCKFORD (WREX) — Snow! Sleet! Freezing rain. Northern Illinois is no stranger to extreme winter weather. In the days and hours ahead of severe winter weather, advisories and warnings may be issued.
Knowing what each headline means can help you stay better prepared in the days and hours before a storm moves in.
Winter storm watch:
On occasion, a winter storm watch gets put in place ahead of winter weather. Usually in the 24 to 36 hours ahead of the first snowflakes or sleet pellets, this serves as the heads-up that winter weather is possible. To put it simply, a winter storm watch lets you know to "watch" for winter weather in the hours or days ahead.
A watch typically goes one of two ways in the 12 to 18 hours ahead of wintry weather. A winter storm watch can occasionally be switched to a winter weather advisory. Be aware that if this happens, the advisory is NOT a downgrade.
Winter weather advisories:
A winter weather advisory is issued typically between 12 to 24 hours before winter weather starts. It can also be issued if winter weather is already occurring. Winter weather advisories are also sometimes issued if winter weather could fall during busy travel times, like during the morning commute or busy holiday travel. In general, advisories are put in place for lighter totals of snow, sleet, freezing rain, or some combination.
Winter storm warnings:
There are other occasions where a winter storm watch can be upgraded to a winter storm warning. A winter storm warning is issued 12 to 24 hours ahead of a winter storm and is a call to take action and prepare for potentially dangerous winter weather. These are typically put into place for heavier totals and or longer duration events. Winter storm warnings generally mean tough travel is ahead, but blizzard warnings are an even bigger hazard, especially for folks traveling.
A blizzard warning means extremely dangerous weather conditions are likely within 12 to 24 hours. In order to qualify as a 'blizzard', winds must meet or exceed 35 miles per hour and visibility must be under a quarter a mile or less for three consecutive hours or more. Much like a winter storm warning, a blizzard warning serves as a call to action to avoid any unnecessary travel while winds whip and visibility is reduced.