Four Things You May Not Know About ForeFlight Lightning

The lightning layer now in ForeFlight has been switched to use a much improved lightning source called the Earth Networks Total Lightning Network (ENTLN). This is the world’s largest lightning detection network with over 1200 sensors worldwide. This is the same lightning network that has been used by the NTSB when investigating aircraft accidents. Here are four facts about the lightning displayed in ForeFlight.

#1 – The lightning depicted in ForeFlight is worldwide

It is estimated by research meteorologists that at any given moment in time, there are nearly 2,000 thunderstorms occurring around the world. This includes about 100 strikes for every second that passes. This is important since the presence of lightning is indicative of dangerous convective turbulence and the potential for low-level wind shear. Ground-based radar such as NEXRAD has a limited range and only covers a small portion of the earth. Lightning detectors, on the other hand, can sense strikes from a thunderstorm that is a thousand miles away providing coverage in regions where ground-based radar does not reach.

#2 – All forms of lightning are included

The Earth Networks lightning sensor is a wideband system. This enables the sensor to not only detect strong cloud-to-ground strikes, but detect weak in-cloud pulses as well. With a detection efficiency of nearly 95 percent, the lightning depicted in the distinct ForeFlight layer includes just about all of the natural lightning that is occurring around the world.

#3 – Radar layer includes lightning

While connected to the Internet, there are two ways to display lightning in the ForeFlight Mobile app. By default, lightning is included as part of the radar layer. So tapping on the radar layer in the dropdown menu will also overlay the latest lightning. However, it is important to understand that this lightning depiction overlaid on the radar has not been upgraded to use the new ENTLN as of yet.

To get the higher density lightning, you must tap on the Map mode button and select Lightning from the dropdown menu. This unique lightning layer is useful when also displaying the color-enhanced satellite layer. Areas of thunderstorms typically have very cold (high) cloud tops. Blue, yellow, orange and red colors on the satellite layer depict regions with cold cloud tops. However, not all cold cloud tops indicate an area of deep, moist convection (thunderstorms). So the lightning layer as an overlay is a good way to confirm where the truly nasty convection is occurring.

#4 – Latest 5 minutes of lightning are depicted

Regardless if you are viewing the lightning overlaid on the radar layer or the separate lightning layer, the age of the strikes depicted typically ranges from 3 to 8 minutes. Then, this lightning continues to age as it is cached in the app for the next five minutes. After this five minute period, the app automatically removes the older strikes and refreshes the display to include the latest strikes.