Thursday, April 30, 2009

Radar icons

After about 50+some emails from the discussion Amy and I had about radar icons,I have decided to do a little/fast write up on this topic..I have taken a lot of classes seminars on radar interpretation through out the years...

We have all seen them.those little icon that appear on some radar programs...How accurate are they?
Well for the most part the are just for show...Sometimes they may right on,however most of the time forget them...Lets talk about the lightning icons first....First off if you have a radar program that does display them...9 chances out of ten the icon them self's are going to be 15+ mins late,unless you are paying for a sub to some place....Now if you have a lightning detector and have the ability to over lay that onto the radar you will have the most accurate areas of lightning....Ok lets talk about that tornado icon...First off don't believe them...If you really and truly want to see rotation in a storm learn how to read the Base Velocity scans along with the Storm Relative scans...I have been experimented with this when out storm chasing...There are times when the icons would show up,however the storm was not doing nothing..Cross checked it with the scans above and sure enough nothing going on..There has been times when there a tornado was on the ground no icons were showing up on the radar program,however there was a tornado on the ground.Sometimes if the tornado is strong enough it will show up as a hook on the Base reflectivity scans..Same thing goes for the Meso icon...Us the Base Velocity and SRM scans....Now for he hail icons...Once again don't believe them....Best ways to figure out if hail is falling in a thunderstorm is to looks at the base Reflectivity...The higher the DBZ say 60 + the better chances you may have large hail falling..However that still does not tell you for sure.Here is another way...One has to use the higher tilts of the radar..Without going into a lengthy discussion on that,I will make it short and sweet and to the point...The reason why you will need to use the higher scans is because hail cores are stronger in the higher elevations of thunderstorms.Which makes since..Here you have to understand how a thunderstorm works.If you can use a cross section view of the radar that is the best way to see the hail cores...use 1.5 and higher scans..on the cross sections or base...Hail will produce a 3 body scatter/spike on the radar if one sees this you could have hail up to inch + dim falling...Here is a simple discussion....The 3 body scattering/spike are cause from the radar bean hitting hail scattering to the ground ,then scattering back upwards and them scattering once again by the hail aloft in the storm...Now another way one can see hail and is kind of cheating but good for the non experience people who really don't understand the radar operations,however this way may be 10 mins late..Ok one can use the composite image...Some radars program if not all will tell you the track of the fast it is moving,whether there is hail and what size..Also it will tell you what cells may have meso and tornado signatures to them..So as far as the icons go..I would not put to much faith in them. Do I use them no way!..Radar is not all about the pretty colors that show up, and them little icons there is so much more than that