Weather Alerts: Watches and Warnings
What they mean and what to know
Severe weather can strike at any time. Having a plan is imperative before the weather turns active. Review it with your family. A few things to think of as you review your plan. What if severe weather strikes while your at home, at work, the kids are in school, or while you’re out running errands?
Thunderstorms can occur in every season in the United States, even in the winter. An average of 300 people are injured and 50 killed yearly from lightning strikes. However, lightning does not determine whether a storm is severe. A severe thunderstorm is one that contains large hail, or damaging wind threats.
Have at least two ways to receive alerts. Your phone can be a great way but there are times when cell phone lines fail. A NOAA weather radio is a fantastic resource and will still work with phone lines go down and electricity goes out (with batteries). The only problem is that there are some areas in our region where the NOAA weather radio signal isn’t strong enough to work. There is more information on this at the bottom of this page.
WATCH VS. WARNING
A watch means conditions are favorable, or the ingredients are in place. A watch will be issued typically for several hours ahead of the potential for severe weather. A watch may not be issued if the threat is isolated.
A warning means take action. This means the threat is imminent or is occurring now.
Watch and warning areas: A watch is typically issued several hours in advance
A watch will be issued for a larger area, multiple counties and will be issued to the entire county if the threat is expected to be across a broad area.
A warning will be issued for a smaller area, what we call a polygon. This can be a smaller part of one, two or even three counties and is going to be concentrated in the threat area. This will issued for a smaller part of the county.
NEW WARNINGS AS OF 2021
The National Weather Service now has new wording when it comes to severe thunderstorm warnings. This will be the first full year of these being implemented as they arrived last August. This is to heighten the alert when a storm goes from a ‘typical’ severe thunderstorm with large hail and damaging winds to a ‘really bad’ severe storm with stronger winds or larger hail.
Think of it this way: we get severe thunderstorms each year that produce damage. The derecho of 2012 is a severe thunderstorm of very extreme nature but when it comes to a warning, it falls in the severe thunderstorm category. So how can we best communicate a warning with a ‘typical’ severe thunderstorm with damaging winds of 60mph and a derecho with winds of 70-80 mph?
This is the way to do that. This is to let you know when a severe storm becomes more than just a severe storm.
Any severe thunderstorm warning that is issued for your area in the category of “destructive” will now alert you on your phone like flash flood and tornado warnings.
WHAT TO DO DURING A SEVERE THUNDERSTORM OR TORANDO WARNING
CREATING YOUR SEVERE WEATHER PLAN
FACT VS. MYTH
TRUE OR FALSE:
1. A watch will always come before a warning
- FALSE! There will be times when a warning is issued without a watch preceding it.
2. I heard there was a tornado warning (in a nearby town) but I didn’t receive the warning! Something must be wrong with my alerts.
- FALSE! Only those within a warning like a tornado, severe thunderstorm, or flash flood will receive the alerts. These types of “hyperlocal” warnings are based on location within a county, the entire county will not be alerted. Only the small area in the threat will get the warning.
3. It’s not raining so that means I’m safe from lightning
- FALSE! Lightning can strike out many miles away from the storm. This is usually the most deadly kind of lightning strike, also called a ‘bolt from the blue.’ Lightning can strike out 10-15 miles away from a storm, in any direction.
4. Tornadoes or storms can move in any direction, not just west to east.
- TRUE! Tornadoes tend to move from southwest to northeast but this is not always the case. In some instances a tornadic storm can have erratic movement. Many storms do move from east to west but storm cells can split and can move in different directions. Atmospheric conditions determine how fast storms move and in what direction.
WHERE TO SIGN UP FOR WEATHER ALERTS
- The WHSV weather app. It’s free and customizable. You can choose the sound or make it silent. You can select which alerts you want to receive
- NOAA weather radio, there are several to choose from. There’s a map of the NOAA weather radio coverage area at the bottom.
- You can also sign up per your locality. All the links for the Virginia counties we cover are listed below:
NOAA Weather Radio Coverage Map
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