A watch, warning or advisory? What does it all mean when it comes to winter storms? Here's an explanation.
By News 12 Meteorologist Allan Nosoff
Those who use the News 12 app got a push alert this morning with a WINTER STORM WATCH for their area. What does this mean, and how does this differ from a WINTER STORM WARNING or WINTER WEATHER ADVISORY?
All three of these alerts are issued by the National Weather Service (NWS) when accumulating snow or ice is in the forecast. Each of these alerts have a different criteria in the timing and amounts of snow expected.
The first of the alerts, a WINTER STORM WATCH, is issued as soon as 48 hours ahead of the onset of snow or ice. Conditions are favorable for significant snow or ice accumulation, typically the potential for six-or-more inches of snow.
If the snow or ice is expected to be less significant, a WINTER WEATHER ADVISORY is issued as soon as 36 hours ahead of the onset of snow or ice. About three-or-more inches of snow is forecast, but significant snow in-excess of six inches is not expected.
If the snow is expected to be significant, a Winter Storm Watch can be upgraded to a WINTER STORM WARNING. They are also issued as soon as 36 hours ahead of the first flakes. Six-or-more inches of snow is forecast in a 12-hour span.
If the snowstorm is expected to bring significant snow AND wind, a watch can be upgraded to a BLIZZARD WARNING. Wind gusts of 35+ MPH and reduced visibility under ¼ mile is forecast over three consecutive hours.
One recent change made in 2020 was the cancellation of a BLIZZARD WATCH. A Winter Storm Watch will be used instead, and upgraded to a Blizzard Warning if the wind forecast criteria is also met.
The News 12 Storm Watch Team will continue to inform you of any snow and/or high wind that may impact the area. Make sure to tune in to News 12 and download the app, as the nor’easter approaches!