Teach Me About Radar, Please!

[terra seright]

OK, I followed a link from one of Jason Boggs' sites and it took me to weathertap. I did that because my local news station's radar only reaches so far and I couldn't find anything I like better.......until now. WeatherTap rocks!

The thing is, I don't understand some things about radar in general...for instance, when a system on the radar suddenly shows up cut in half...is that caused by wind?? What causes the little "hole" in a system on radar (wish I could find a picture or two so you can see what I mean), is that wind too? Is the heaviest part of a cell the "hail core"? I've heard of it referred to this way...or is it just the "most intense part"??

Anyway, those are just a couple of questions...I have many more. I think if you're a spotter, you should have some knowledge about radar, at the very least. Some net control operators may not have a vast knowledge of how radar works, and it's really difficult for me to have complete trust in the voice on the radio all of the time.

Can anyone point me in a good direction for learning this art? Or maybe this thread could be used for the edumakation of those of us who need to know?

Question number three--what does a REAL hook echo look like? How can you tell it's not some kind of glitch?

Just a few to get going. Hope I've not re-done a thread here, I searched this forum, and found nothing....and I really think it's something that should be in the spotter forum.

 

[S. Shannon]

Radar etc.

Follow this link http://okfirst.mesonet.org/train/nids/BREFguide.html It will show you some things about radar. Also go to http://www.srh.noaa.gov/srh/jetstream/doppler/doppler_intro.htm. It will give you some good run down about radar.

As for your questions.....Sometimes web based radar get some broken information from the server to your computer, The hail core. Sometimes it is associated with the heaviest part. The VIL (Vertically Integrated Liquid) will give you a better signuerature of the hail core. A Hook Echo. Is best found in the base radial velocity and the storm base velocity. You will look for a couplet of two different colors from the positive and negative MHZ. To see it on radar base velocity means it has already been happening for a few minutes.

Once you learn look at weather all over the country. Don't wait for it to happen near you. Look at other severe events. Watch some youtube chasers (but don't do as some of them.. ahem..Reed Timmer) and look at plenty of pictures. get to know the "looks" of storms.

Also, check out and bookmark everything weather you come across. From ads to what other people are talking about. You can never have too much info.

Finally, READ. I am still learning myself so don't take everything to heart. I have given the most accurate I know.

For a good web based radar go to weatherunderground.com and select NEXRAD radar. Play with the advanced radar types after you look at the jetstream program(first link I gave you)

If you want to spend a little money for faster and more options with radar download grlevel3. It is free to try for a month then I think $80 to own. Best there is.

 

[Rick Schmidt]

Terra:

Something that might be helpful when you are viewing NWS radar sights.....if you are viewing storms close to your area, and/or close to the radar sight, go to the next nearest radars in each direction, and they might give you a different perspective of the storms you want to view. I do that all the time, and I can see features of the storm or storms that don't show up, because they are too close to the 'local' radar sight. Hope that helps without being too confusing! ---Rick

 

[Greg Blumberg]

I helps to learn a bit about radar basics before you actually start thinking about what the display is telling you. For example, the display that you see is NEVER the be-all-end-all. There are multiple issues that can impact what the radar data is displaying.

Are you looking for something intensive, or just a summary in your learning?

Also, the hail core can be detected by the VIL, but I don't recommend it. VIL is vertical, but not all updrafts and storms work straight up and down. I recommend learning the Lemon technique for your first step in reading radar patterns. For me it's usually the first thing I do when targeting storms and watching the evolution of them. If I wasn't going to see a concert today I'd be watching the storms in the IL vicinity. If you get this message before today's event is over with, I'd try applying the Lemon technique to those storms.

http://en.wikipedia.org/wiki/Lemon_technique

If the links on that page don't help you, Google it. There are probably some better pictures out there than what is shown on the link I gave you.

Also, any GR product is great to work with, but if you really want the nitty-gritty of what radar can show you, go with GRLevel2 or GRLevel2 Analyst Edition. Those two versions work with higher resolution data than GRLevel3.

 

[Mike Pohlen]

NWS Paducah also has a science page with 9 audiovisual presentations about various aspects of using Doppler radar. They at times get rather technical, but they can be a big help in learning about it.

http://www.crh.noaa.gov/pah/science/science.php