Some help interpreting some radar images?? Part One

[Christopher Madairy]

Where exactly is the hook? I am pretty sure I can see where the cool out-flow air and rain are wrapping around the in-flow slot at the rear of the rotating thunderstorm - so where exactly is the hook? Also, this images are not as smooth looking as the one I see on the tele with the weather - are they different types of systems that produce clearer images?


[Broken External Image]:http://www.skywarn.ampr.org/hook3.gif

[Broken External Image]:http://www.skywarn.ampr.org/hook2.gif

[Broken External Image]:http://www.skywarn.ampr.org/hook1.gif



Thanks to all &73.

Christohper, N3QXX[/code]

 

[Jeff Snyder]

The "hook echo" is essentially a storm feature as-seen-on-radar which signifies precipitation "wrapping" around the back side of the mesocyclone. They come in all sorts of sizes and shapes, but many look like the hooks on the two images below. The hook is something to look for when looking for the tornadic potential of a supercell, but it doesn't mean that a tornado will form; it's just something to keep an eye out for. Remember, an awesome hook doesn't mean much in terms of tornado potential if the supercell is not entirely surface-based (e.g is elevated to whatever degree), such as the 4-5-03 supercell(s) across nothern TX that dropped massive hail and had very nice hook echo displays, but didn't really produce (save for a tornado early in the first supercell's lifecycle).

[Broken External Image]:http://www.tornadocentral.com/now/hobartsupercell.png

[Broken External Image]:http://www.tornadocentral.com/now/okcsupercell2.png

As for TV radar displays... Many TV stations use NEXRAD radar data, but run the data through a smoothing filter, which makes the reflectivity pattern quite smooth (though you can lose important features in the process). Other TV stations have their own radars, but most still apply some sort of smoothing to make the storm look "prettier' to the average viewer.