(WVVA): Our local National Weather Service Forecast Offices in Charleston & Blacksburg issue Winter Weather Advisories “when winter weather conditions are expected to cause significant inconveniences and may be hazardous“. This is usually the case with an expected wintry mix- like a combination of rain/snow/ice/sleet that would make for tricky travel and some slick spots on roads. Though accidents DO HAPPEN, weather that accompanies advisories usually isn’t deemed life-threatening, but instead as an event that simply “warrants extra caution”. For an advisory to be issued, the NWS has to be forecasting a snowfall total of 2-4 inches within a 12 hour period, or any ice accumulation, even if only just a trace.
What to do: Simply bundling up to keep yourself safe & dry, or following winter weather driving procedures will greatly reduce the risk of accidents in ” advisoried” winter weather.
What makes Winter weather “severe”, or defined as a “winter storm” at all? For most of our viewing area, this would mean that 4-6+ inches of snow would have to be forecasted to fall in a 12-hour period, or 6-8+ inches would have to be forecasted to fall within a 24-hour period. For ice- 1/4 inch of more would have to be expected to accumulate on surfaces.
Winter Storm Watches are issued when severe winter weather conditions (matching the criteria above) are possible within the next three days. These are almost always issued before a Winter Storm Warning would be issued. As more model runs come in, and more weather data is analyzed- the the NWS would subsequently decide to update the “Watch” to a “Warning”.
What to do: Until a Warning is issued, viewers need to literally keep “watch” of the situation, and stay tuned to broadcast media/NOAA Weather Alerts, etc.
A Winter Storm Warning is issued when “life-threatening severe weather conditions have begun, or will begin within the next 24-hours. For many, the aforementioned snow or ice amounts would not only cause travel dangers, but widespread power outages as well.
What to do: In these instances, immediate action is required- from completely postponing travel to utilizing a survival kit if caught stranded. Follow us throughout the Week for more know-how and tips on these situations!
IMPORTANT CHANGES THIS YEAR:
After collecting feedback from users, and with the backing of social and behavioral scientists, the National Weather Service has consolidated the following watches, warnings, and advisories listed below. The new "hazard simplification" will be used this coming Winter (2017-2018).
-Freezing Rain Advisory
-Lake Effect Snow Watch
-Lake Effect Snow Advisory
All of the above hazards will no longer be "stand-alone" statements, but will instead be included in the new "condensed" statements listed below:
-Winter Storm Watch
-Winter Storm Warning
-Winter Weather Advisory
-Ice Storm Warning
-Lake Effect Snow Warning (issued at selected offices only).
For more info on Hazard Simplification, CLICK HERE