Lightning Detection - Newb Question

Hey guys, just set up my Tempest which has been working brilliantly so far. I have one question regarding lightning detection. This morning I woke up to several lightning alerts from the Tempest. All happened within 2 hours of each other. Then I got another one early this morning with sunny skies and not a cloud in sight. So I checked the radar and no storms had come through. I also checked data from other Tempest units in the area. Not a single detection. Any thoughts? Thanks!

That sounds like electrical interference. It could coincide with turning on a LED lamp or air conditioner compressor startup, etc. It sounds like you need to do some sleuthing to find the culprit.

Thanks, I have it mounted on the roof of my house and there is an AC in a second story window around 10 feet away. That runs constantly this time of year. But it was running yesterday and again today and I haven’t received any additional notifications yet. We’ll see what happens, I’ll keep monitoring it. Thanks.

The AC compressor most likely does not run continuously, (*) only the fan. Since it happened overnight, the thermostat was probably cycling the compressor on/off when it was cooler outdoors.

(*) I don’t know if anyone is selling inverter-type window AC units yet, but those do run the compressor continuously and “distort” the power frequency to control the compressor motor speed. Sounds like a recipe for RF interference, but my inverter-type central AC unit has not caused any false strikes on either my WF equipment or Blitzortung receiver…

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Earlier today, I noticed there was a lighting icon on the main Data Summary Page on the Web Interface, but now its gone even though both stations are reporting Lighting as I’m posting this.
Station ID: 15419 and 24352.

I actually have 3 AC united on the second floor. All have had the compressors cycle on and off repeatedly during the day today. I only received one lightning alert this afternoon, around 3pm. Still not sure what’s going on.

Just a quick update, only one lighting alert last night, around midnight. Still no lightning was detected by area Tempest systems. The AC’s cycles on and off all night.

Still not 100% sure what is causing the issue but I’ll keep watching to see if it gets any worse. Thanks.

Location makes a difference as well. I have two Airs, one horizontal and one vertical, next to each other.

The horizontal one only detects a few strikes, usually legitimate ones. The vertical one detects many, many more on a daily basis, all false, just electrical interference from other sources (lights, compressors etc). I realise you can’t very well mount the Tempest horizontally, but I thought I’d share anyway :slight_smile:

It sounds like your A/C is not causing the false lightning. Time to start checking other sources in your home.

I received 14 false strikes around 10:40 yesterday the 21st and 38 at around 12:20am this morning the 22nd. I’ve checked radar and nothing within a few hundred miles. It’s been great until this so could it have been something affecting the Tempest or a sensor error? I’ll keep watching it but thought I’d better post.

Thanks for these reports, folks. We’ve confirmed those are definitely false strikes. As others have pointed out, the lightning sensor is prone to false strikes from nearby electrical interference - so that’s definitely something to check out.

However, our lightning QC system would normally have suppressed those false strikes - and we’re looking into why that didn’t happen in your case. It may be related to yesterday’s hiccup, though the timing doesn’t line up, so it’s probably unrelated. Either way, we’re looking into it. Stay tuned.


Thanks for the reply. I’ll keep watching and waiting for further response on the issue from Weatherflow. I’ll report any more erroneous lightning strike indications here. Thanks again.

Hey all, a little good news. Just got a lighting notification, 20 miles away. A minute or so later I got a notification from another lightning tracker app showing a thunderstorm around 20 miles away. Good sign!


No false alerts last night, storm came through and it reported very accurately based on comparison with other known lightning tracker services. Every time I saw a flash out the window I would get an alert approx 5 seconds later. Reported accurately on strikes 30 miles away as well. So far so good!