How to Read an NWS Winter Storm Warning vs. Winter Weather Advisory

When winter weather threatens, the National Weather Service (NWS) issues official alerts to warn the public. Knowing the difference between an Advisory, a Watch, and a Warning helps families and educators make informed decisions.

The Hierarchy of Winter Weather Alerts

1. Winter Weather Advisory (Be Aware) - **Criteria:** 80%+ confidence that winter weather conditions will cause significant inconvenience, but not severe enough to meet warning criteria. - **Typical Triggers:** 2 to 4 inches of snow, light freezing drizzle, or blowing snow. - **School Impact:** Possible 2-hour delayed openings or selective rural cancellations.

2. Winter Storm Watch (Be Prepared) - **Criteria:** Issued 24 to 72 hours in advance when conditions are favorable for a hazardous storm, but exact track and amounts remain uncertain. - **School Impact:** Administrators monitor forecast models; extracurricular evening sports may be tentatively rescheduled.

3. Winter Storm Warning (Take Action!) - **Criteria:** 80%+ confidence that a high-impact winter weather event is imminent or occurring within 12 to 36 hours. - **Typical Triggers:** 6+ inches of snow in 12 hours (or 8+ inches in 24 hours), or significant sleet accumulation. - **School Impact:** Extremely high likelihood of school cancellation (75% to 95%).

4. Blizzard Warning (Life-Threatening Emergency) - **Criteria:** Sustained winds or frequent gusts of 35 mph or greater, combined with falling or blowing snow reducing visibility to less than 1/4 mile for at least 3 consecutive hours. - **School Impact:** Mandatory complete closures, transit shutdowns, and emergency travel bans.