What is a High Wind Warning?

The National Weather Service issues various wind warnings to warn the public of dangerous wind conditions. Wind warnings are issued when sustained wind speeds are expected to reach or exceed a certain speed for a certain amount of time. There are three common wind warnings: high wind watches and warnings and the wind advisory.

There is also the much less common extreme wind warning, which we’ll also describe below. Wind warnings are issued frequently across the country, so it’s a good idea to know what each wind warning means and how to prepare for high winds.

The Dangers of High Winds

While wind is a normal part of the weather, high winds are not and can become dangerous to life and property. Wind can be dangerous because it can knock people down, blow things around, make travel difficult, and cause other dangers. Wind can also cause problems with electrical equipment and power lines.

It only takes a windspeed of about 20mph or so to lift small objects and snap smaller tree branches. Winds are also hazardous to air travel, so you see “windsocks” at airports like the one pictured below.

These specially designed fabric tubes are an easy way to judge wind speed. Each colored portion will extend outward every three knots (or about 3.5 mph). A fully extended windsock like the one pictured above would indicate a surface windspeed of at least 15 knots or about 17 mph. The windsock also can turn with the wind, offering pilots a way to judge how winds are blowing across the runway.

Most of us consider a day with 17mph winds pretty windy, but when a wind warning is required, the winds will be far stronger. We’ve ordered the warnings below in order of severity and describe the conditions you can expect if one of these warnings is issued for your area.

What is a Wind Advisory?

A Wind Advisory is issued by the National Weather Service when sustained winds of between 30-40 mph are expected for an hour more, or gusts between 45-55mph are expected for any duration. This advisory may be issued when windy conditions are either expected or imminent. Your local National Weather Service office will detail when the conditions are expected.

While these winds are pretty strong, they aren’t necessarily destructive if some simple preparations are taken. Any loose outdoor objects should either be secured or brought inside. Walking is possible, but it won’t be a pleasant experience. Driving in these winds can also be challenging if the wind blows across the road — the same concept also makes landing a plane in these winds equally tricky.

What is a High Wind Warning?

When powerful winds and gusts are expected, the National Weather Service issues a High Wind Watch or High Wind Warning. This is issued when sustained winds over 40 mph are expected for an hour or more or gusts over 55mph of any duration are expected. A high wind watch is issued when high winds are possible, typically well ahead of the event. On the other hand, a high wind warning is issued when such conditions become likely, typically within 24 hours of an event.

As opposed to a Wind Advisory, a High Wind Warning should be taken much more seriously. Winds of these speeds make walking outside difficult, if not dangerous, and small, and some lighter medium-sized objects will become airborne in gustier winds. Driving will also be equally challenging, especially when driving larger vehicles in crosswinds. In some locations, trucks and large cars may be restricted from traveling in certain areas during a high wind warning.

What is an Extreme Wind Warning?

An Extreme Wind Warning is an especially rare wind warning for the most severe wind events. For an extreme wind warning to be issued, sustained winds of hurricane force with gusts over 115mph must be likely within the next hour. These winds cannot be associated with a tornado, but an extreme wind warning can be issued for hurricanes, Derechos, and other non-thunderstorm wind events.

These warnings are most commonly issued during either Derechos or for areas that will experience the eyewall of a hurricane. If an extreme wind warning is issued for your location, you must take the warning seriously. Head immediately for an interior location of your home, preferably one not susceptible to flooding from heavy rain. If you are outside or driving, find shelter immediately.

Preparing for Strong Winds

What you should do to prepare for windy weather depends significantly on the strength of the expected winds. Windy days are common, especially in the winter and spring, so the wind is not something you’ll need to worry about. However, when winds are strong enough to trigger a warning, follow the below tips to protect yourself and your property.

• Secure any loose objects around your home or property. This includes lawn furniture, trash cans, and anything else that could be blown around in the wind.
• Close all windows and doors, and make sure all screens are secured.
• If you have a generator, ensure it is properly secured and fueled up.
• Fill up any containers with fresh water in case of a power outage.
• Make sure you have a supply of non-perishable food items on hand.
• Check batteries in flashlights and radios, and plan where you will go if there is a severe weather event.