FPS staff report
December 31, 2012
The Ohio Committee for Severe Weather Awareness is helping the public understand weather advisory terms in an event the national Weather Service (NWS) issues a winter storm Watch, Warning or Advisory.
Advisory - A less severe winter weather event that is imminent.
Watch - The potential exists for significant or dangerous weather event.
Warning - A significant or dangerous weather event that is imminent.
Advisories, usually issued 6-18 hours prior to the event, highlight hazardous weather conditions, which could lead to life-threatening situations if caution is not exercised.
A winter weather advisory is issued for any combination of accumulations of snow, freezing rain, freezing drizzle or sleet that will cause significant inconvenience and moderately dangerous conditions. An advisory is issued when: visibilities from a combination of snow and blowing snow will be reduced to 1/4 mile or less or when snow is expected to accumulate 3-5 inches in 12 hours in Northern Ohio.
A watch is usually issued between 12 and 48 hours before a weather event. Watches are issued for blizzard conditions, high winds or wind chill temperatures, or lake effect snow fall. A winter storm watch alerts the public to the potential for heavy snow, significant icing or a combination of these events.
A warning is usually issued 6-18 hours before the weather event and could include:
Blizzard - Sustained or gusty winds of 35 miles per hour (mph) or more and falling and blowing snow creating visibilities below 1/4 mile. These conditions usually persist at least three hours.
High Wind - Sustained winds will be 40 mph or greater for at least one hour or any gust of wind expected to be 58 mph or more.
Ice storm - Issued when the event will be entirely ice accrual with an accumulation of a quarter-inch or more from freezing rain and damage expected.
Lake Effect Snow - For the snowbelt area of Northeast Ohio, when lake effect snow is expected to accumulate to six inches or more in 12 hours or less, or eight inches of snow in 24 hours or less.
Wind Chill - Dangerous, life threatening wind chills less than or equal to -25 degrees Fahrenheit.
Freezing Rain - Rain that freezes upon contact with a cold surface. Freezing rain creates a glaze of ice.
Sleet - Solid grains of ice formed from rain that freezes before reaching the ground. These pellets of ice tend to bounce upon contact and may accumulate enough to cover the ground, even to a depth of several inches.
Snow Squall - An intense fall of accumulating snow, reducing visibility significantly and often accompanied by increased winds.