Open letter regarding Flash Flood Warnings and the WEA

Wireless Emergency Alerts (WEA)

My concern is over warning of the Flash Flood Warning (FFW) via the WEA system.  I acknowledge flooding causes the greatest threat to life and property. However, despite the FEMA media campaigns, not everyone lives in a flood prone area.  Large areas of a FFW area (aka polygon) are not affected by running water.

I understand there are limitations to hydrological warnings issued by the Local National Weather Service Forecast Offices (NWSFO), and that it is not practical (or even possible?) to issue a FFW on a stream-by-steam basis, activating only those mobile phones within a predetermined distance of a threatening stream.

Additionally, my understanding is that each mobile carrier (AT&T, Verizon, etc.) uses different methods to notify its mobile subscribers. Unless some standard is agreed upon, how can we verify which users are getting the warnings?

According to the WEA FAQ: “Your cell phone will pick up the warning alert since it was issued for a part of the county you are located in (only county code is used – all or nothing). The current (2012) software program isn’t capable of narrowing down the alert for just those cell phones located within the polygon warning.

For example, if a polygon covers only eastern Montgomery County, all of the carrier’s towers in Montgomery County will send the alert tone to its users.  So, the alert goes out to a large population of people who are not at risk. In turn, this sows the seeds of warning fatigue:  The users will perceive too many false alarms and disable the WEA. Consequently, when it is actually needed, the WEA signal will not be received.

Plus, if the carrier’s towers are close to a county line, will all towers in the adjacent county be notified?  If so, this means even more people are alerted who are not at risk.

Even if/when the technology exists to send an alert only to a phone in a polygon via the phone’s GPS signal, many people disable GPS because it tends to drain battery life.

I respect the argument that people should be alerted to flooding conditions that are nearby, so that they do not travel into flooded areas, but I am concerned that repeated warnings to people not residing in flood-prone areas, in time, will only encourage people to disable WEA.

Additionally, the terminology is not standardized. For example, on my phone, WEA settings allow me to toggle on/off an “Extreme Alert” and a “Severe Alert,” and I do not know how these are coded with NWS.  Is a Tornado Warning (TOR) an Extreme Alert?  Is a FFW a Severe Alert?

There is something in WEA listed as an Extreme Wind Warning. Is that same as a High Wind Warning issued by the local NWSFO?

I do not have a philosophical invasion of privacy issue with the WEA system.  For example, given the intense damage risk that comes with a tornado, and the infrequency of a TOR being issued, I believe that in the current system, the benefits outweigh the drawbacks regarding the TOR.  At least for now.

A more immediate solution may be to set the default for a FFW as an opt-out… requiring the user to opt-in.

I would argue that to keep this current WEA system as is, a new class of product be issued when exceptionally high damage threats have been established, such as ground confirmation of a tornado or an extremely rapid water rise (i.e. greater than 1 foot an hour for a river, 1 foot every 30 minutes for a smaller tributary).  These would be classified as a Tornado or Flash Flood Emergency by the NWS, and would be even more urgent than a traditional Severe Weather Warning.  These would be the events that trigger the WEA.

As a secondary benefit, this allows the NWS to use stronger language when highly anomalous events, like the June 29, 2012 derecho are observed.  This would carry an analogous product called a Severe Thunderstorm Emergency.

About seansublette

Meteorologist at Climate Central. Broadcast meteorologist in Virginia from 1995 to 2015. Born and raised in Richmond, VA. Penn State alumnus. Loves baseball and the rock band Rush. Views are independent of my employer. Past performance does not guarantee future results.
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