Tuesday, September 25, 2007

Storm-Based Warning System - October 1, 2007

Next week, the National Weather Service will roll out a new way to warn the public about severe weather. The new "Storm-Based Warning" system will begin on October 1st, 2007. The linked article above describes it well. There is also an FAQ document available.

What this means is that when a warning is issued, it won't necessarily be issued for an entire county, but instead, for the areas the storm may track. So it will not be uncommon to hear that Northwestern Christian and Southwestern Greene are under a warning. This has been used already in some degree by the fine folks at the National Weather Service in the description of a warning.

The big change will be the graphical interpretation of the warning. In the image from NOAA, you can see how the old system looks compared to the new one. In this example, it shows how 3 tornado warnings issued in the two different systems results in 70% less area and ~600,000 less people warned. In this example, that's quite a big difference.

For those with weather alert radios that alert by county, that should all continue to work as it has been. According to the FAQ, down the road, extended codes may be released to allow radios to alert by storm, and not by whole county.

My take: When it comes to the text of the actual warning, our local NWS office in Springfield, MO has been very good about listing specific parts of counties when appropriate. However, this will be a pretty big deal when it comes to looking at warnings on a screen and automated systems.


Sniderman said...

Unfortunately, most -- maybe all-- tv stations won't be able to show the polygonal warnings yet as the technology (last I heard) wasn't available.

However, polygonal warnings have been issued for a while if you've been stormtracking with the Gibson Ridge Level 3 Radar Tool. Highly recommend it.

JMo said...

I love GRLevel3. It rocks the house. You answered a big question I had about the TV graphics, thanks for the info.

Weather Underground uses that technology too. You get pager based warnings by the location of your city, not what county you are in. For example (for those who aren't Sniderman and may not follow what I mean), if Greene county mainly falls in the polygon, and Christian isn't listed as a warned county, I get alerted for Nixa if it fits in the polygon. Pretty cool.

Max said...

I've become a big fan of Weather Underground and love some of the use of storm movement. I'd love to have GR3 but it is just to much for my budget.

Anyway, the new warning system will definitely be interesting. I'd like to see how it might impact some counties skywarn groups.