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Severe Weather Awareness Week – Day 2: Warning Reception

| by Henry Luker

By National Weather Service Des Moines

Governor Terry Branstad, the Iowa Homeland Security and Emergency Management Division, and the National Weather Service have designated the week of March 24 to March 28 as severe weather awareness week in Iowa. Each morning this week, the National Weather Service in Des Moines will issue a Public Information Statement focusing on a different item each day. Topics this year includes the following:

  • Monday: Flash Flooding
  • Tuesday: Warning Reception
  • Wednesday: Tornadoes
  • Thursday: Severe Thunderstorms
  • Friday: Family Preparedness

Today’s Topic is Warning Reception

One of the most important precautions you can take to protect yourself and your family from severe weather is to remain weather aware. Being weather aware means you are informed of the weather forecast and alerts to the potential hazards. Knowing what to do and where to go when watches and warnings are issued is key to your safety, but a watch or warning is only helpful if you are aware of them. How do you receive information about watches and warnings – with today’s technology there are many different ways to receive this information, including the internet, commercial TV and radio, and NOAA Weather Radio. However, all these technologies have one thing in common, it is up to you to remain weather aware and actively listen for watches and warnings.

What to Listen For

A watch is issued to give advance notice when conditions are favorable for the development of severe weather, whether it is severe thunderstorms, tornadoes, or flash flooding. When a watch is issued for your area, it is time to take precautions and make sure you are prepared should bad weather strike.

Warnings are issued when severe weather is occuring or imminent. When a warning is issued for your area, you should take action immediately to protect your life and your property.

Broadcast Media

The National Weather Service has a strong relationship with the broadcast media. The NWS relies on the broadcast media to help broadcast NWS warnings to the public. This is a very important relationship since most Iowans get severe weather warnings from commercial media.

Television meteorologists and broadcasters transmit NWS warnings to the public. In addition, they usually add value to the warnings with radar displays and visually explain where the threat is. Studies have discovered that local commercial TV is the primary source of warning information (Wolf, 2009) reaching the majority of people. Warning information is supplied through reading NWS warnings on the air, or by occasional scrolls providing the information. During high-end events, television stations will often go wall-to-wall weather coverage interrupting normal broadcasts. Warning reception from television stations is maximized during significant events in metro areas during the daytime or evening hour and it is minimized during marginal severe events in rural areas at night.

Radio media is another important way Iowans get severe weather warnings. The radio media varies from large AM station with a very large coverage area to smaller stations scattered across central Iowa. Several stations will provide wall-to-wall severe weather coverage during high-end events with a focus on their local area. The Emergency Alert System (EAS) is used to broadcast severe weather warnings. When stations are closed, they use the EAS to transmit severe weather warnings directly from the NWS to the public.

NOAA Weather Radio

Known as the “voice of the National Weather Service,” NOAA All-Hazards Weather Radio (NWR) is provided as a public service by the National Oceanic and Atmospheric Administration (NOAA), part of the US Department of Commerce. NWR includes more than 900 transmitters, covering all 50 states, adjacent coastal waters, Puerto Rico, the U.S. Virgin Islands, and the U.S. pacific territories. NWR requires a special radio receiver or scanner capable of picking up the signal. Broadcasts are found in the public service band at these seven frequencies (Mhz):

  • 162.400
  • 162.425
  • 162.450
  • 162.475
  • 162.500
  • 162.525
  • 162.550.

Modern NWR receivers are often SAME (Specific Area Message Encoding) capable, meaning they can be setup to only alert or turn on for specific areas (usually counties in the midwest) by programming them via a small keypad on the receiver. In this manner, you won’t be awakened at 3 AM for a warning which is not of interest to you.

All Iowans should benefit from NWR since a NWR transmitter is likely within range. It is a great way to get a warning in the middle of the night when you may be asleep, or in remote locations.

NOAA Weather Radio is on of the best indoor warning systems available. Unfortunately, studies have shown that only five to ten percent of the population owns a weather radio (Wolf, 2009).

All-Hazards Messaging

NWS forecast offices have pre-arranged agreements with emergency managers to facilitate the receipt and transmission of emergency non-weather related messages. These messages can be broadcast over the NWR and may interrupt the regular broadcast using special alerts tones and SAME codes. Examples of these non-weather events include:

  • Toxic Chemical Incidents
  • Nuclear Power Plant Accidents
  • Amber Alert

Outdoor Warning Systems

When it comes to severe weather, outdoor warning systems (known as sirens) have one purpose and one purpose only – to alert people who are outdoors that something is dangerous is happening and they should go inside. Depending on local policy, sirens may be sounded for a variety of life-threatening hazards, but always with the intent that people outdoors should seek shelter.

Across Iowa, local siren activation policies vary widely. The city or county government is usually in charge of siren activation polic. The National Weather Service does not have the authority to activate siren systems, but the NWS works closely with communites with the severe weather warning system including storm sirens.

For severe weather, most communities sound sirens anytime a Tornado Warning is in effect for their area. Other communities have stricter policies and only activate the outdoor warning system for actual tornado sightings, while a few activate sirens for both Severe Thunderstorm and Tornado Warnings. The NWS encourages communities to activate outdoor warning sirens for high-end Severe Thunderstorms (Wind speeds above 70 MPH and/or hail of two inches or greater). To find out your community’s siren policy, check with your local emergency management agency.

Cell Phones and Mobile Devices

People can have cell phone notification of NWS warnings. Services vary from carrier to carrier. There are several providers who offer emergency alert notification, including severe weather warnings for a small fee. Since most people carry a cell phone, or other mobile device, receiving severe weather warnings through text message is an excellent way to keep informed.

Wireless Emergency Alerts

Select high-impact NWS warnings are sent to cell phones as a Wireless Emergency Alert (WEA). Additional alerts from other government agencies, such as FEMA or other civil authorities, may also be sent to your phone.

Here is how it works, if you are at home, or traveling in an area where a warning has been issued, your phone will receive alerts broadcast by nearby cell towers. If your phone is enabled to receive alerts, your phone will receive an alerts that resembles a text message – the message will be no longer than 90 characters. The alert will have a special tone and vibration, repeated twice, so that you will be able to tell it apart from a regular message. If you receive an alert, you should follow any action advised by the emergency message and seek additional details.

The service is free of charge and messages will not count towards texting limits on your wireless plan. It comes enabled on newer cell phones depending on the carrier. Click here for some frequently asked questions and answers concerning wireless emergency alerts. 

The Internet

In recent years, many people receive severe weather warnings over the internet. Most people still use desktop or laptop PC’s to gain access to the internet. Internet access is expanding rapidly and now many people have internet access on their cellular phones and smartphones.

People use various websites which have access to NWS warnings. The direct way to access NWS warnings is at it’s website or the NWS Des Moines website. 

One major advantage in using the internet is viewing warnings graphically. Since NWS warnings are issued based on the storm and not the county, modern severe weather warnings are best viewed graphically to see exactly where the warning is in effect.

Social media websites are gaining in popularity. Warnings may be received on these sites as well.

The number of people receiving warnings over the internet, mobile devices, and social media will likely continue to increase. For more severe weather preparedness information online, go to the NWS Des Moines website.