A High Wind Warning is issued by the National Weather Service (NWS) to communicate the immediate threat of non-thunderstorm winds strong enough to cause significant property damage and hazardous conditions. This alert serves as a clear directive for the public to take action, indicating that dangerous winds are either imminent or currently occurring in the forecast area. The warning signifies that the wind event is expected to be forceful enough to threaten infrastructure, separate from severe weather like hurricanes or tornadoes.
Defining the Criteria
The issuance of a High Wind Warning is triggered by specific, measurable wind speed thresholds that indicate the potential for widespread damage. The standard criteria require either sustained wind speeds of 40 miles per hour (mph) or greater lasting for one hour or longer, or wind gusts reaching 58 mph or higher for any duration. Winds at the 58 mph gust threshold are capable of causing substantial harm, such as snapping large tree limbs, damaging unanchored structures, and blowing debris at dangerous velocities. The requirement for sustained winds of 40 mph over an extended period ensures the warning is reserved for truly persistent and hazardous wind events. These speeds exert continuous pressure on buildings, power lines, and trees, leading to structural fatigue and eventual failure.
Distinguishing Alert Levels
High Wind Warnings represent the highest level of alert for non-convective wind events, indicating that the danger is immediate or currently underway. The difference between a Warning and other alerts, like a Watch or an Advisory, centers on the severity and the timing of the expected weather conditions. A High Wind Watch is a lower-level alert issued when the potential for high winds exists, typically 12 to 48 hours in advance, intended to give the public time to prepare. A Wind Advisory is issued for less severe conditions that still warrant caution but do not meet the criteria for a full warning. Advisory conditions usually involve sustained winds of 31 to 39 mph or gusts ranging from 46 to 57 mph, which can cause minor inconveniences but are generally not expected to cause widespread property damage.
Necessary Safety Measures
When a High Wind Warning is in effect, the most important action is to seek shelter inside a sturdy building and remain there until the warning expires. Stay away from windows and glass doors, as they can break due to flying debris or wind pressure. Outdoor objects should be secured immediately, including patio furniture, trash cans, and anything else that could become a dangerous projectile. Driving during a High Wind Warning should be avoided, especially for operators of high-profile vehicles such as large vans, trucks, and recreational vehicles. Strong side gusts can easily push these vehicles out of their lane or even cause them to overturn. The strong winds frequently lead to downed trees and power lines, making it necessary to be vigilant for debris on roadways and to never approach or touch a downed power line. Power outages are common during these events, so having a battery-powered radio, fresh batteries, and flashlights readily available is a practical preparedness step.