530 on Your AM Dial!

[NealRasmussen]

Pardon me if this has been posted recently, but it's always worth repeating I hope.

Spherics! (also sferic, though I'm not sure which is proper.)

Spherics are the signals in the atmosphere, and in this setting, due to lightning. Lightning emits a lot of radio wave energy in a wide range of frequencies. An AM Radio can pick these up quite well. Just tune your AM radio to a low frequency around 530 that doesn't have a commercial station. A "white noise" area. In these areas between stations is where you can here the storms. Literally.

Most AM radios, or all?, use a di-pole antenna, and to my knowledge, this means the things are quite bi-directional. If you hear a burst of static, a pop to a hiss-like sound, that's a lightning strike. But if the radio is facing west let's say, you won't know if that strike was W or E of you. Unless of course you saw it!

Listening for Spherics on the AM radio is an excellent way to tell when the first cell has fired. I would bet the first strike shows up when it's 55dbz aloft and 35dbz at 0.5 degrees, because the first updraft plume hasn't fallen back out. When it first becomes a 'thunder' storm.

Some say they can audibly discern the difference from a negative and positive strike. I'm not sure about that, but the staccato CG that come out east of the wall cloud sure sound distinct and nasty.

Any titles of books on Spherics, or links to such, please feel free.

And no, this won't work with XFM radio. Though it'd be nice to mix an SFM station with the live AM Radio feed, as the white noise does get old fast.

And lastly. If the low AM band is just static noise from being near an MCS or nasty meso, try tuning up higher to a dead area. This tends to screen out more of the distant strikes.

 

[Dan Robinson]

Before I had mobile data in my car in 2004, I used AM radio on just about every chase. It was essentially free lightning data. With enough observation, you could tell how far away each strike was depending on the volume and 'sharpness' of each sferic, as well as telling apart CGs from intracloud flashes. Of course you didn't have directional information, but if you knew where storms were, you could gauge their intensity by the sferics alone.

Sferics saved me gas money on many late-night lightning chases in West Virginia, where I didn't have direct visual on distant storms due to the terrain. When the lightning on the radio slowed down or stopped, I knew I could go home early and not miss anything.

In fact, I would probably still employ sferics today as a backup lighting detection method if it weren't for the fact that my inverter produces too much AM interference.

 

[Shane Adams]

Yep, an old school method that still works as well as any modern tech. Sometimes simple is best.

 

[rdale]

Ehh - simple is good, but I can't imagine how your 530 AM radio is going to give you more info than lightning strikes plotted on your phone?

 

[Joshua Nall]

As a kid, I would tune to a dead spot on the am dial hoping the crackles of distant lightning would wake me up ahead of an approaching storm. Usually set the volume pretty low wanting to sleep soundly until the storms were close. Pretty neat to wake up to a crackle on the radio then a bit later hear a faint distant rumble of thunder.

 

[John Farley]

Rob, if you lived in southern CO or northern NM you would know. There are huge areas with no cell signal, so I fall back on that fairly often. Particularly when hunting thundersnow in the winter when there are lots of convective snow squalls in the mountains and I want to know if any thundersnow is going on.

 

[NealRasmussen]

Ehh - simple is good, but I can't imagine how your 530 AM radio is going to give you more info than lightning strikes plotted on your phone?

Oh, since it doesn't give azimuth, or range, I don't think it would give you more info than LightningMaps.org, but it's a lot more fun.
Also it has a much faster ping time.

 

[chrisbray]

Isnt AM 530 the station that every sign post on the interstate tells you tune in to for tourist info?

 

[James Hammett]

When I was a kid I built a circuit that interfaced an AM radio tuned to 540 to my TRS-80 Color Computer through the joystick port. A program on the computer plotted the smoothed result on the screen. I set a threshold that kicked on a relay that powered a buzzer when storms were close enough. Needless to say it got a bit busy (and annoying) in the warm season.

 

[BK Noonan]

It also works with a CB radio. I typically have it on when chasing anyhow to listen to trucker chatter about storms. Or to switch to NOAA weather radio to get updates on warnings.

 

[Drew Terril]

It also works with a CB radio. I typically have it on when chasing anyhow to listen to trucker chatter about storms. Or to switch to NOAA weather radio to get updates on warnings.

I used to do this as well. It's been a while since I've had a CB in one of my vehicles but I've contemplated putting an old one I have in my truck. Break up the monotony a bit on road trips. I just need to decide where I'm going to put it.

 

[Michael Snyder]

I used this recently also on the Big Island of Hawaii. No Cell reception across the saddle road, big Cu's going up to the west, nice and sunny still at the top, evening was coming, and as I was searching on the radio for any signal I heard the good old AM radio Lightning signature. I left it on for a while, and by the time I got the Hilo it was pouring like I rarely have seen it, with some close thunder.
Sometimes you forget just how hard it can rain until you get to the tropics.