Weather radio

From Infogalactic: the planetary knowledge core
Jump to: navigation, search
A Gorman-Redlich CRW-S weather radio

A weather radio service is a public broadcast service dedicated to airing continuous weather reports. In most locations, it requires a specially-designed radio capable of receiving "weather band" frequencies - when tuned to one of these channels, it receives a radio station that broadcasts both routine and emergency weather information. Many weather radio receivers are equipped with a standby alerting function - if the radio is off or tuned to another band and a severe weather bulletin is transmitted, it can automatically sound an alarm and/or switch to a pre-tuned weather channel for emergency weather information.

Weather radio services may also broadcast non-weather-related emergency information, such as in the event of a natural disaster, an AMBER alert or a terrorist attack. They generally broadcast in a pre-allocated very high frequency (VHF) range using FM. Usually a dedicated weather radio receiver or radio scanner is needed for listening, although in some locations a weather radio broadcast may be retransmitted on a conventional AM or FM frequency (as well as HD Radio substations), some terrestrial television stations broadcasting in MTS stereo transmit weather radio on their second audio program (SAP) channel as well as on one of its digital subchannels (where news and weather are applicable), on local public, educational, and government access (PEG) cable TV channels or during Emergency Alert System activations for tornado warnings primarily on cable systems.

Weather radio receivers

Two types of weather radio receivers; the common Midland home weather radio (model WR-100) to the right is often the most popular and known unit sold in the United States, while the orange Oregon Scientific model on the left is portable and water-resistant for outdoor use.

Weather radios are widely sold online and in retail stores that specialize in consumer electronics in Canada and the United States. Additionally, they are readily available in many supermarkets and drugstores located in the southern and midwestern U.S., which are particularly susceptible to severe weather - large portions of these regions are commonly referred to as "Tornado Alley". The price of a consumer-grade weather radio varies depending on the model and its extra features.[1]

Weather radios are generally sold in two varieties: home (stationary) or portable use. Portable models commonly offer specialized features that make them more useful in case of an emergency. Some models use crank power, in addition to mains electricity and batteries, in case of a power outage. Some models have a built-in flashlight and can double as a cellphone charger. Some also serve as a more general emergency radio and may include multiband and two-way communication capability. "Scanner" radios designed to continuously monitor the VHF-FM public service band are already able to receive weather channels.

Historically, it was not uncommon to sell portable radios that featured AM, FM, and TV audio (VHF channels 2-13), with the weather band included some distance down the dial from TV channel 7 (after the U.S. digital TV conversion, these types of radios became mostly obsolete).

One of the early consumer weather alert radios (model KH6TY) was designed and manufactured by Howard (Skip) Teller, who was issued a patent on the alerting mechanism[2][3] and was instrumental in the design of the PSK31 Digipan software and hardware,[4] and the Amateur radio NBEMS emergency communications system.

Most receivers from the 2000s and the 2010s, and even some from the mid-1990s, are able to listen silently for weather alerts via the SAME protocol and then sound an alarm to warn the listener of impending severe weather or emergency events. SAME allows listeners to "customize" their radios to only receive alerts issued for specified geographic areas; this technological feature filters out and eliminates "nuisance" alarms for events that do not affect a listener's preset location. In the U.S., SAME locations are defined as counties (and in some instances, parishes, territories, or marine zones) and are set using preassigned six-digit FIPS county codes; in Canada, CLCs are used. Besides SAME alerting capability, modern weather radio receivers may include visual alerting elements (e.g., multicolored LED indicator lights) and allow for the use of external devices (e.g., pillow vibrators, bed shakers, strobe lights, and loud sirens, which attach via an accessory port) to alert those who are deaf or hearing impaired. Since April 2004, radio models marketed as "Public Alert-certified" must include these features and meet certain performance criteria, as specified in electronics industry standard CEA-2009.[5]

Governmental weather radio services

Frequency Official name Marine Channel Public Alert Channel
162.400 MHz WX2 36B 1
162.425 MHz WX4 96B 2
162.450 MHz WX5 37B 3
162.475 MHz WX3 97B 4
162.500 MHz WX6 38B 5
162.525 MHz WX7 98B 6
162.550 MHz WX1 39B 7
161.650 MHz WX8 21B
161.775 MHz WX9 83B
163.275 MHz WX10 113B

The United States, Canada and Bermuda operate their government weather radio stations on the same VHF band, using FM transmitters.

WX1 through WX7 are the standard "weather band" channels, as assigned and implemented by NOAA,[6] and are consistently used across U.S. Government agencies, including the Coast Guard.;[7] WX8 and WX9 are Canadian Continuous marine broadcast channels. WX10 was formerly used by the NWS for coordination during power outages. Most mainstream NWR receivers (and their operating manuals) confuse the WX and seven-channel Public Alert numbering schemes, and apply an inconsistent "channel 1-7" labeling scheme (usually implemented in ascending frequency order).

Notable weather radio services include:

The "official" NOAA WX numbering scheme does not increase in frequency order because the weather channels were created gradually over the years. 162.55 MHz was at first the only frequency (so was thus WX1), then 162.4 (WX2) and 162.475 (WX3) were added later to prevent RF interference. The others mainly came into use in the 1990s in less-populated rural, areas and as fill-in broadcast translators relaying an existing station or sending a separate, more localized broadcast into remote or mountainous areas, or those areas with reception trouble.

Canadian broadcasts are also transmitted on travelers' information stations on FM and AM, especially near national parks.

Bermuda has only one station dedicated purely for weather, on 162.55 MHz from Hamilton, now operated by the Bermuda Weather Service with tropical weather forecasts from NOAA. It has a second station, however, for marine conditions and forecasts, ZBR (operated by the Bermuda Maritime Operations Centre), at 162.4 MHz.[8][9]

Mexico has since launched its own weather radio system, SARMEX (Sistema De Alerta De Riesgos Mexicano, or Mexican Hazard Warning System) for coverage of its cities.[10]

All stations transmit a 1050 Hz tone immediately before issuing a watch or warning, and this alone serves to activate the alarm feature on many older or basic alerting radios. Except for Bermuda, all U.S. and later Canadian stations transmit WRSAME codes a few seconds before the 1050 Hz attention tone that allow more advanced receivers to respond only for certain warnings that carry a specific code for the local area; these receivers usually have an option to sound the alarm only for serious warnings (by default), while allowing the user to either select or block other alert types at their discretion (for example, a flash flood watch could be ignored by a person living on the top of a hill, while a tornado warning is an immediate emergency anywhere) - however, the alert's text scroll will appear on the visual display even if the audible alarm is silenced.

Commercial weather radio services

The weather radio band is reserved for governmental services. However, most standard AM and FM broadcast radio stations provide some sort of private weather forecasting, either through relaying public-domain National Weather Service forecasts, partnering with a meteorologist from a local television station (or using a meteorologist hired by the station, common when a radio station is a sister station of their TV counterpart or has a news and forecast-sharing agreement), affiliating with a commercial weather service company, or (in the most brazen cases) pirating a commercial service's public forecasts without payment or permission. (The first option is not available, or at least legally, in Canada, where Environment Canada's forecasts are under crown copyright.) Accuweather (through United Stations) and The Weather Channel (through Westwood One's NBC Radio Network) both operate large national weather radio networks through standard AM and FM stations.

History of weather radio

The United States Weather Bureau first began broadcasting marine weather information in Chicago and New York City on two VHF radio stations in 1960 as an experiment.[11][12] Proving to be successful, the broadcasts expanded to serve the general public in coastal regions in the 1960s and early 1970s.[13] The U.S. Weather Bureau adopted its current name, National Weather Service (NWS), and was operating 29 VHF-FM weather-radio transmitters under the National Oceanic and Atmospheric Administration (NOAA) in 1970.[11] In 1974, NOAA Weather Radio (NWR), as it was now called, reached about 44 percent of the U.S. population over 66 nationwide transmitters.[13] NWR grew to over 300 stations by the late 1970s.[12] Local NWS staff were the voices heard on NWR stations from its inception until the late 1990s when "Paul" was introduced.[14][15] The messages were recorded on tape, and later by digital means, then placed in the broadcast cycle.[14] "Paul" was a computerized voice using the DECtalk text-to-speech system.[14] "Paul's" voice was dissatisfactory and difficult to understand; thus "Craig", "Tom," "Donna" and later "Javier" were introduced in 2002 using the Speechify text-to-speech system.[14][15] Live human voices are still used occasionally for weekly tests of the Specific Area Message Encoding (SAME) and 1050 Hz tone alerting systems, station IDs, and in the event of system failure or computer upgrades. They will also be used on some stations for updates on the time and radio frequency.

In the 1990s, the National Weather Service adopted plans to implement SAME technology nationwide; the roll-out moved slowly until 1995 when the U.S. government provided the budget needed to develop the SAME technology across the entire radio network. Nationwide implementation occurred in 1997 when the Federal Communications Commission (FCC) adopted the SAME standard as part of its new Emergency Alert System (EAS).[11] NOAA Weather Radio public alerting expanded from weather only to "all hazards" being broadcast.[16]

NWR grew to over 800 radio stations by the end of 2001.[11] As of January 2014, there were 1032 stations covering approximately 97% of the United States, Puerto Rico, the U.S. Virgin Islands, American Samoa, Guam and the Northern Mariana Islands.[11] As of January 2015, there were about 1025 stations in operation, with 95% effective coverage.[17]

See also


  1. url=
  2. Teller, Howard. "Latching detector circuit US 4158148 A". Retrieved 5 July 2015. 
  3. Retrieved 5 July 2015.  Missing or empty |title= (help)
  4. "A Panoramic Transceiving System for PSK31" (PDF). Retrieved 5 July 2015. 
  5. url=
  11. 11.0 11.1 11.2 11.3 11.4 "The History of NOAA Weather Radio". Weather Radios Direct. Retrieved 13 May 2014. 
  12. 12.0 12.1 "History of NOAA Weather Radio". National Oceanic and Atmospheric Administration (NOAA). 
  13. 13.0 13.1 Nelson, W.C. (2002). "American Warning Dissemination and NOAA Weather Radio". 
  14. 14.0 14.1 14.2 14.3 "Voices Used on NOAA Weather Radio". National Weather Service. Retrieved 3 July 2012. 
  15. 15.0 15.1 "Voice Improvement Processor". National Oceanic and Atmospheric Administration (NOAA). 
  16. Kupec, R. J. (July–August 2008). "Tuning in: Weather radios for those most at risk". Journal of Emergency Management. 6 (4). 
  17. NOAA Weather Radio brochure: NOAA/PA 94062 (PDF), January 2015