I was fishing Indiana a month or so ago, it was dark and big storm was rolling in. neither of the 2 radar apps would work. Luckily one of the people onboard had a app that would work but worked VERY slowly. We were only a mile offshore so it’s not like we had bad signal.

 

So I got to reading about radar apps on my phone for a few reasons. First why is there a difference in the size of the storm from one app to another, second why sometimes the apps are very slow or don’t work at all and third they are 10 to 15 minutes behind.

 

I figured I would share as this I think is really going to help me on the water.

 

Short version is the professional storm chasers use the apps PYKL3 and RadarScope. Both cost about $10 but both provide images that are only a minute or two old. Also both much faster than normal apps so will likely work better when you are offshore with low signal.

 

 

Longer answers to my 3 questions for those that are interested in reading more. Now I may be wrong on some of this as I am learning but so far all seems to be true. Please correct me if anything is wrong.

 

Why the size difference. Well that’s because there are 4 angles a radar looks at a storm. From the ground and 4 levels up. Apps can choose to use any of these angles or a Composite that is all the angles together in one picture. So the view of the rain hitting the ground may be much smaller than the view of the entire storm. This called Reflectivity Tilt 1 to 4 and composite reflectivity is all 4 combined

 

Why are some slow or don’t work at all. So the way each of these apps work is there is a server for the app. The server first downloads small files then processes them to make them look nicer and then sends that new processed image out to the phone apps as it is requested. This file is very large so takes time to transfer plus when there are a lot of storms and a ton of users are all trying to access the same area it can slow down the apps server to the point where it stops working or close to it.

 

Why are they 10 to 15 minutes behind. This is because of this processing that is done on the server before it is sent out to the app. The server first grabs the Radar Data file from a nexrad radar then processes the radar image look smooth so it’s easier to read I guess. Nicer looking yes but not easier I don’t think. But this processed image is actually a very large file that takes more time and data to download

 

The Storm Chasers solution. The 2 apps PYKL3 and RadarScope are both paid apps. Rather than processing the image and sending it to your phone these apps (and there are probably more apps that do the same) send over the raw file directly from the Nexrad radar stations which is a very small file and the processing is done on your phone which is very fast and is also images that are only 1 or 2 minutes old.  These apps also let you see all sorts of radar data from wind speeds and direction to radar as different levels to god knows what else. Way more than I ever care to see. I look at 3 things.

Reflectivity Tilt1 which is rain at ground level

Composite Reflectivity which is the rain in the entire storm. This helps to see the front as that can be several miles infront of the rain.

Velocity Tilt 1 which is wind direction and speeds at the ground. Im still figuring this one out.

 

Food for thought.