A new text message alert system, called Wireless Emergency Alert (WEA), was launched Thursday, June 28, by the National Weather Service (NWS) in coordination with the Federal Emergency Management Agency. The alert system, which sends text messages to people in areas threatened by severe weather, has been in testing and limited use since 2010, but will now begin to see widespread use.

"At 2 p.m. today we open[ed] the pipes, so our warnings will flow through the system," NWS spokeswoman Susan Buchanan said Thursday, reported InformationWeek. "Ultimately, though, it's the wireless carriers that are implementing it; it's happening on a rolling basis across the country."

Participation in the alert service is voluntary for wireless carriers. Sprint and Verizon are ready for the system, and hundreds of smaller mom and pop carriers have agreed to ready their networks for the service as well. AT&T has the WEA service available in several cities with tentative plans for wider coverage, but iPhone compatibility with the service is limited.

In fact, many older cellphones are not compatible with the alert service, Buchanan said, but all new cellphones on the market by the end of 2014 are expected to have WEA compatibility. A list of compatible models is available on the CTIA-The Wireless Association website.

The severe weather text alerts will be sent within seconds said Mike Gerber, NWS program leader. The alerts do not use GPS to locate users, but are rather sent by cell-tower region. A cellphone user from California vacationing in New York, for example, would receive alerts from only the tower in New York from which he or she currently receives a signal.

The WEAs are intended for warnings only and will not include severe weather watches. In addition, they only include certain weather conditions: blizzards, ice storms, dust storms, extreme winds, flash floods, hurricanes, typhoons, tornadoes and tsunamis.

The WEAs are issued through the Commercial Mobile Alert System, which went live in early April. In addition to alerts from the National Weather Service, presidential alerts will be issued using the system, and state and local agencies also will be able to use it to send emergency alerts and Amber Alerts.

The system was developed through a partnership between the Federal Emergency Management Agency, the FCC and wireless phone carriers to increase public safety nationwide.

Alerts can be a maximum of 90 characters, and in most cases, will only contain basic information such as the type of emergency, when the alert will expire and a recommended course of action. Cellphone users can opt out of receiving all but the presidential alerts.