Twin States Weather Blog

Polygon Warning Update

The Newscenter 11 Weather team traveled over to Brandon today for the Emergency Managers/Media Workshop. This is a workshop hosted each year by the National Weather Service, and it is really a great opportunity to communicate. All three of those groups (media, emergency managers, and the NWS) are key cogs in the weather wheel. There were some really great speakers, including an update on the polygon warnings. We discussed those in this space a few weeks ago.

The basic premise it to issue warnings based on where the storm is as opposed to county boundaries. This will allow us to more precisely warn those who are really going to be impacted by a storm. Warnings will be smaller, because if a storm is only going to affect part of a county, the warning will only be issued for that part of the county -- not the entire county.

We learned today that the NWS in Jackson and Mobile will be a test site for the new polygon warnings from March 1 - October 1. Some interesting numbers were brought up comparing the old system -- warnings by county -- versus the polygon system:

In 2004, tornado warnings were issued that covered 31,990 square miles and 494 towns. Obviously, tornadoes did not strike that large of an area. So, we can safely say that many of the tornado warnings were for areas not affected by a tornado.

Using the polygon system, those warnings would have only covered 9500 square miles and 152 towns. So, we would have reduced the area where a "false alarm" occurred by 70%!!

I believe that polygon warnings are a great step towards warning ONLY those affected by the storm at hand. But, we are still years away from fully implementing this system. Once the NWS begins issuing these warnings on a full-time basis, we will still have to adapt our weather radios, emergency outdoor sirens, and our warning display software to accurately depict the warnings.

We live in a changing world, and its great to see our NWS taking proactive steps to better serve the public!

posted by WTOK Weather Staff @ 10:18 PM