Blog Fiasco

July 23, 2012

Disseminating storm-based warnings

Filed under: Musings,Weather — Tags: , , — bcotton @ 10:54 pm

Earlier this month, I wrote about the format and wording of severe weather warnings, and how to effectively shape those warnings. In those previous posts, we came to the conclusion that county sections are pretty lousy ways to define warnings. Defining warnings based on counties leads to over-warning, and using county subsections are ambiguous to the public. Storm-based polygon warnings are the most accurate way to define warnings, but they come with their own problems. First, as I previously discussed, there’s the issue of having to shape around county boundaries. Secondly, they present some challenges in dissemination.

Storm-based warnings are easily transmitted visually (though they still require a basic level of geographical knowledge that I’m not sure we can assume), so they work well on TV, Internet images, and smartphone apps. They are really poor in text or audio formats. Warnings disseminated through audio or text must still reference vaguely-defined county regions. As a result, storm-based warnings lose some of their benefit immediately.

NOAA All-Hazards Radio’s Specific Area Message Encoding (SAME), which is used to selectively activate weather radio receivers, works on a county basis. As a result, the NWS obsoleted its own technology when it switched to storm-based warnings in 2007. On the other hand, county-based warning distribution like SAME has one distinct advantage: the ability to pre-warn. A common recommendation when programming weather radios is to have the radio activate for warnings for your own county and also the surrounding counties. This allows additional lead time in some events. The current warning paradigm does not allow for such a setup.

The future of warning dissemination will be hitting people in the pocket. Mobile phones are the best way to reach a large (and growing) portion of the population. The Wireless Emergency Alert system is a good start. WEA will automatically send warnings to cell phones in affected areas (this also helps to address the issue of people driving, especially through areas they wouldn’t normally be), but it has some room for improvement. The character limit of WEA messages is 90, which is just over half the length of a traditional text message, resulting in a very information-sparse alert. In addition, it will be based on the tower‘s location, not the phone’s. This means that people will receive warnings that do not include them (or worse, will not receive warnings that do include them). Of course, it also requires that people have a WEA-capable device.

In the end, a multi-layered approach is required. Broadcast media must continue to remain a valuable partner. WEA and third-party smartphone apps should continue to get warnings to people’s phones. Weather radio technology should either be upgraded to support location-based alerting or be gracefully retired. Warning siren systems should be upgraded so that they can be sounded selectively (most systems still sound county-wide), or better yet scrapped entirely.

1 Comment »

  1. Sirens fill a place that is not filled by other warning systems. They can be location-specific: if you hear the siren, is applies to you (if all sirens are NOT controlled by the same button).
    WEA looks good, and even a short message could include a link to a NOAA (or another) web site with more infomation, useful on a growing number of phones.

    What we mainly need these days is….more storms!

    Comment by Wallace Hubbard — July 25, 2012 @ 1:18 pm

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