Tag Archives: understanding weather reports

WINTER WATCH, WARNING AND ADVISORY

Do you know the difference?

During winter, we hear these terms on the weather forecast somewhere in the United States.  Do you really pay attention and understand what they mean?

If your answer is “No”, READ ON:

WATCHES:  According to weather professionals, there is a 50% chance that severe winter weather will materialize:

  • Winter Storm Watch:  Possibility of severe life-threatening winter weather conditions that include: heavy ice and/or near-blizzard conditions, or heavy snow.
  • Blizzard Watch:  Blizzard conditions may happen.
  • Lake-Effect Snow Watch:  Heavy lake effect snow likely.
  • Wind Chill Watch:  Potential of wind chills of -25°F or less, causing risk of hypothermia and rapid frostbite.

WARNINGS:

  • Winter Storm Warning:  Winter weather is expected to cause life-threatening public impact from winter hazards that include ice, near blizzard conditions, heavy snow, drifting snow and dangerous wind chills.
  • Heavy Snow Warning:  When 7 inches or more of snow is expected in 12 hours or less, or 9 inches or more is expected in 24 hours or less.
  • Ice Storm Warning:  Issued for ½ inch or more of ice accumulation, which can cause damage to trees and power lines.
  • Blizzard Warning:  When blizzard conditions are about to happen or expected in the next 12 to 24 hours.  These include frequent gusts of or above 35 mph and falling, blowing and drifting of snow, reducing visibility to ¼ mile.
  • Lake-Effect Snow Warning:  Potential of 7 inches or more of lake effect snow.
  • Wind Chill Warning: Issued when the wind chill is expected to be -25°F or less.  In less than 10 minutes, frostbite can happen.

ADVISORIES:

  • Winter Weather Advisory: Hazardous combination of ice and snow that exceeds warning criteria.  These may be significant and/or life-threatening if proper precautions are disregarded.
  • Snow Advisory: When forecasters are confident that the entire event will be snow and an average of 4-6 inches of snow is expected in 12 hours or less.
  • Freezing Rain Advisory: These advisories are issued only when there is a high probability that the whole event will be freezing rain, resulting in very slippery roads.
  • Snow and Blowing Wind Advisory:  Prediction of frequent gusts or sustained wind of 25 to 34 mph, accompanied by falling and blowing snow, which can occasionally reduce visibility to ¼ mile or less for three hours or more.
  • Wind Chill Advisory: Given for wind chills of -15°F to -24°F.

Source: NYSEMS