As winter approaches, significant changes are coming to how extreme cold is communicated to the public. Starting this season, the National Weather Service (NWS) will replace wind chill watches, warnings, and advisories with extreme cold watches, warnings, and advisories. This shift aims to enhance understanding of cold weather hazards and ensure that the dangers of low temperatures are effectively conveyed.
What’s Changing?
Previously, wind chill alerts were issued only when wind speeds exceeded 10 mph, focusing solely on the combined effect of wind and low temperatures. However, under the new system, alerts will be based on the apparent temperature, which is the lower value of air temperature or wind chill. This adjustment acknowledges that dangerous cold can occur even in calm conditions.
For example, if the air temperature drops to life-threatening levels but winds remain light, the new extreme cold warning would still be issued—something the prior system didn’t account for.
Why the Change?
The updated system reflects a growing understanding of how cold weather impacts people and communities. By removing the 10 mph wind threshold, the change aims to streamline cold weather alerts and emphasize that frigid temperatures can be dangerous with or without wind.
Wind chill, however, is not disappearing—it will still be forecasted and reported as a key factor in winter weather conditions. The new terminology is designed to simplify messaging for the public while accounting for broader climatological and health impacts.
New Guidelines for Alerts
The thresholds for issuing extreme cold watches, warnings, and advisories have been refined to align with historical climate patterns and their potential impacts. These changes also incorporate insights from recent winters, where dangerously low temperatures have posed threats even in the absence of strong winds.
- Cold Weather Advisory: Issued for conditions that could cause discomfort or mild health impacts for vulnerable populations.
- Extreme Cold Watch: Used to signal the potential for dangerous cold weather conditions within a few days.
- Extreme Cold Warning: Issued when life-threatening cold is imminent or occurring.
A Clearer Message for Safety
By simplifying the criteria and expanding the scope of dangerous cold conditions, the new system seeks to reduce confusion and encourage timely action during winter weather events. Whether it’s protecting yourself from frostbite and hypothermia or ensuring pets and pipes are safe, these changes emphasize preparedness for all cold weather scenarios.