March 24-28 is Severe Weather Awareness Week for Nebraska and Iowa. Each day, a different aspect of severe weather will be highlighted, explaining the science behind them, and how you can stay safe when severe weather threatens. Today we will be discussing the difference between a "watch" and a "warning", as well as an explanation of the severe weather threat scale.
THE SEVERE WEATHER THREAT SCALE
The National Weather Service's Storm Prediction Center monitors the severe weather risk for the country, and uses a threat scale ranging from one to five. The higher the number, the greater the risk for severe storms in that region.
On average, we see about 50 severe weather risk days in this part of Nebraska and Iowa, per year.
LEVEL 1 (GREEN) - This is the lowest risk. While thunderstorms are possible, the overall risk of severe weather is low. These can produce damaging winds, large hail, or an isolated tornado, but they would not be widespread.
LEVEL 2 (YELLOW) - The level 2 risk is the "standard" risk for severe weather. A few thunderstorms are expected to become severe with large hail, damaging winds, and a few tornadoes possible. Of the 50 severe weather risks we see in a year, around 35 of them are a level 2 or higher risk.
LEVEL 3 (ORANGE) - A level 3 risk is when severe weather chances increase. In a level 3 risk, numerous storms are expected to become severe with large to very large hail, significant damaging winds, and several tornadoes possible with a few on the stronger side. Of the 50 severe weather risks we see in a year, around 3 of them are in a level 3 or higher risk.
LEVEL 4 (RED) - A level 4 risk is issued when a significant severe weather or tornado outbreak is expected. A level 4 risk is relatively rare for Nebraska and Iowa. In a level 4 risk, you could expect widespread large hail, damaging winds, and numerous tornadoes with a few strong tornadoes possible.
LEVEL 5 (PINK) - A level 5 risk is the highest category that denotes a significant to possibly historic severe weather or tornado outbreak. Level 5 risks are rare anywhere in the US, including Nebraska and Iowa. Since 1987, only 21 level 5 risks have been issued that include Omaha. The last time we saw a level 5 risk was on June 3, 2014.
WATCH VS WARNING: WHAT IS THE DIFFERENCE?
A watch means that conditions are favorable to the development of severe weather, but they are not imminent.
A Severe Thunderstorm Watch means that conditions are favorable for the development of storms mainly capable of producing large hail and damaging winds. However, any severe thunderstorm in Nebraska or Iowa may become capable of producing tornadoes, too.
A Tornado Watch means that conditions are favorable for severe storms, including tornadoes.
Watches are usually issued over a several-hour duration and span over a wider geographical region where conditions are favorable. A watch means pay attention to the weather and know where to go if the weather gets bad, but you do not need to take any urgent action.
A warning means that the threat of severe weather is occurring or imminent to your specific neighborhood and it is time to take action.
A Severe Thunderstorm Warning means that a severe thunderstorm, capable of damaging wind or large hail is occurring or imminent.
A Tornado Warning means that a tornado is occurring or is imminent in a specific location.
A warning lasts less than an hour until the threat is either moved on or weakened. Warnings also cover a smaller geographical area, typically less than the size of a county depending on the storm.
WAYS TO GET SEVERE WEATHER ALERTS
There are many ways to receive weather alerts. It is best to have multiple ways to get alerts in case any one of them fails. The more ways you can be alerted for severe weather, the better likelihood you will get the warning and take action. Here are a few ways to receive alerts:
Weather Radio - You can purchase a weather radio at most stores. These sound an alarm when an alert is issued. You can program them to only sound for specific alerts. Weather radios will alert you of both watches and warnings, and can be battery-powered in the event of power outages during severe weather.
Wireless Emergency Alerts (WEA) - Most phones have this feature pre-installed and turned on. This is the same system that Amber Alerts are transmitted for. Wireless Emergency alerts will only sound in a Tornado Warning or a Severe Thunderstorm Warning where the hazards are baseball-size hail and/or 80+ mph winds. Although your phone automatically has them enabled, make sure you have them enabled by checking the WEA settings.
Television - At the bottom of our screen is a crawl that displays any watches and warnings that are in effect. This should be a secondary way to get alerts, as the TV needs to be on to see the alerts.
Phone Apps - Hundreds of phone apps will alert you when dangerous weather approaches, some more reliable than others. The 3NewsNow app has alerts that will sound in dangerous weather and are customizable.
Outdoor Warning Sirens - While useful, outdoor warning sirens should never be your only way to get alerts as they are meant for outdoor use. Even if you can hear them inside, the chances of hearing them in the middle of the night during a raging thunderstorm are lower. Thus, have multiple ways to receive alerts!
