Amateur radio operators are very familiar with atmospheric ducting or “skip” as we call it, which (with the help of the ionosphere when the sun is cooperative) enables some very long distance radio communications well beyond line of sight. The same sometimes holds true for loud audio, such as thunder or sonic booms. See my descriptive graphic below the “continue reading” line.
TheTempestSpark writes in Tips and Notes:
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Is this “ducting”?? the Tallahassee National Weather Service office addressed it in a special statement.
“We had a lot of calls early Wednesday evening, primarily from the area from Woodville to Crawfordville, about rumbling sounds that sounded like a freight train, with residents fearing it was a tornado. But, it was NOT. The leading edge of thunderstorms was well to the south by that time, and while there were still rumbles of thunder, the severe weather was over.
It was certainly unusual, and for those residents – a bit scary, but it was not a funnel cloud or tornado. It was likely a phenomena called “ducting”, and the Tallahassee National Weather Service office addressed it in the special statement below. (Thanks Tallahassee NWS!)
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WWUS82 KTAE 100018
SPSTAE
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TALLAHASSEE FL
718 PM EST WED MAR 9 2011
FLZ011-013>018-026-027-114-115-118-127-GAZ155>158-100230-
JACKSON-CALHOUN-INLAND GULF-INLAND FRANKLIN-GADSDEN-LEON- INLAND JEFFERSON-LIBERTY-INLAND WAKULLA-COASTAL GULF-COASTAL FRANKLIN-COASTAL JEFFERSON-COASTAL WAKULLA-SEMINOLE-DECATUR-GRADY-THOMAS
718 PM EST WED MAR 9 2011 /618 PM CST WED MAR 9 2011/
…STRANGE SOUNDS BEING REPORTED ACROSS THE FLORIDA BIG BEND…
THERE HAVE BEEN SEVERAL REPORTS OF VERY STRANGE SOUNDS FROM THE WOODVILLE AREA SINCE ABOUT 645 PM EST. THE NATIONAL WEATHER SERVICE BELIEVES THIS PHENOMENON IS BEING CAUSED BY THUNDER FROM DISTANT LIGHTNING STROKES… BOUNCING OFF A VERY STABLE LAYER ABOVE THE GROUND. THIS IS CALLED DUCTING…AND CAN ALLOW SOUND TO TRAVEL UNUSUALLY LONG DISTANCES. THIS SOUND HAS BEEN MISTAKENLY ATTRIBUTED TO POSSIBLE TORNADOES…BUT WE AT THE NATIONAL WEATHER SERVICE WANT TO BE VERY CLEAR THAT THERE ARE NO TORNADOES … AND NONE ARE EXPECTED.“
SOURCE: http://www.wctv.tv/home/headlines/Tornado-like_Sounds_Worried_A_Few_Residents_Wednesday_Evening_117711483.html?storySection=story
I’d like to know Before someone attributes this phenomena to man made climate change.
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Here’s the basic idea:
Anyone heard of the Whispering Gallery in Grand Central Station in NYC? I’ve tried it out many years ago and it’s really bizarre. Two people maybe sixty feet apart and facing away from each other can carry on a conversation in a whisper; The sound travels up and over the arched ceiling.
I can hear Yamal from my back yard. It too sounds like a freight train only this one sounds like it’s derailing…
Reddish light reflecting off of inside wall in a few frames, sounds like a spoof, with a kerosene jet heater running behind the camera. Sounds just like one.
I live in a village in Surrey on the North Downs. There is a local story that when the British Army exploded the mines at Messines ridge in June 1917, hundreds of miles away in Flanders, the sound of the 500 tons of explosive was heard on the local heath. If this is true, I suppose the sound was bent downwards by the warmer air in the stratosphere (sound travels slower in cold air, not faster as Bryan Leipper says) and could make the distance in one jump.
It sounds just like the furnace at a Waste-to-Energy cogeneration plant. We have one at Islip MacArthur Airport. It can be heard at 5 or more miles when conditions are right. It typically runs for 10 to 20 minutes per fuel cycle.
Nice recording – mind if I call it a “duct tape”?
re: “(sound travels slower in cold air, not faster as Bryan Leipper says)” — thanks for catching this. I do that too often where input and output don’t quite line up …
I have heard of ducting in sound underwater, but not in the atmosphere. I haven’t see the sounding profile that would indicate ducting potential, either. Refraction plus dispersion, on the other hand, are quite common and can create some unusual effects.
CAPE CANAVERAL, Fla. — Discovery ended its career as the world’s most flown spaceship Wednesday (March 9, 2011), returning from orbit for the last time and taking off in a new direction as a museum piece…When it landed three minutes before noon EST, Discovery ceased being a reusable rocketship. Coincidence?
The noise apparently started about 6:45 pm EST. The shuttle landing was about noon, EST, that day., a difference of 6.8 hours. At 740 miles an hour speed of sound, and assuming the landing and the noise are related, the corresponding distance would have been 5000 miles. That’s quite a tunnel.
Sounds like a well test to me… blowing or flaring gas to atmosphere makes a “jet engine/freight train” sound. Unless you can see the gas/flare, you might not be able to place direction. And 20min would be a short test. Or it could be an ESD at a gas plant or compressor station… don’t know where it is or how proximal it might be to some such plant or well, but that would be my guess.
Being a spotter I’m reading this article and all comments with interest. I have heard this nose during times when the jet stream was active over head both in Huntsville, AL and up in the foothills of east TN. Also when in TN, I notice many a time when sounds would be thrown a good distance even to the point of hearing normal speech of people out side their homes.
As to the question how does a a tornado sound, I was at the Nov. 15, 1989 EF 4 which hit Huntsville, AL. The sound is quite close to what you hear if you witness a rocket engine test, both the water fall to cool the test pad and the blast with a very high pitch which is painful to the inter ear. This sound gets pushed ahead of the tornado and ends once the tornado has passed you. In cases of funnels you do hear a high pitch wail, like it’s carrying it’s own warning system. That roar is usually a sign it’s on the ground.
I couldn’t help but notice the voices, clearly they were afraid. If any of the NWS folks are monitoring this post, you need to use this for spotter classes. While it wasn’t a tornado, pretty darn close!
On May 18, 1980 I was outside pruning by vineyard when Mt. St. Helens erupted over 300 great-circle miles away. — heard it loud clear — no ducting necessary!
I’m living about five miles from the ocean, at an elevation of about 800 feet. The sound from the coast (waves and the local foghorn) gets strongly ducted by the fog. The fog wanders in from the coast, and the sound often comes in with the fog. I’ve always figured that the sound was bouncing off of the earth and the top of the fog, to travel that far and be so clear.
When I was fishing commercially on the Pacific Coast, we’d get what we used to call “tunnel ducting” on the VHF radio, typically when a cold front was passing, and we’d hear VHF calls from a couple hundred miles away.
As to whether what we’re hearing in the tape is ducting of a thunderstorm … seems doubtful to me, but there is a strong cold front involved, so it seems possible. The world is a mysterious place.
w.
In 1970, I lived on a Naval Air Base where we had all manor of jet aircraft A-4 Skyhawks, A-5 Vigilantes, F-4 Phantoms, etc. coming and going, and where we had stationary jet engine testbeds (engine only on an outdoor stationary platform where they turn them > 110% power). This reminds very much of the sounds of distant stationary jet engine testing. The 911 caller said something about an airport some 3-4 miles distant from their location. The flash of light and resolution of the sound agree with that rough distant. Not sure how there would be a flash of light without the sound of a jet engine explosion. Maybe some kind of engine shutdown with subsequent excess fuel flash burnoff?
That’s a real pretty cartoon but it doesn’t prove anything.
Had a similar thing but visually across Scapa Flow in the Orkney Islands off the north of Scotland, in the early morning when it was very still from the beach you could see across to the other side of the flow which was below the horizon, it looked like it was reflecting off the sky onto the water and lasted for some time till the sun rose higher into the sky. It was not very clear but you could identify some landmarks and features.
James Bull.
“Tropospheric bounce” is my theory. It is used to connect North Sea oil rigs into an ISDN network on the UK mainland. It takes a lot of energy, though, to pump out enough signal to get a reliable bounce.
That will be two cents please.
BTW – Glenn said it sounds just like a kerosene jet heater running behind the camera.
That was my first thought too.
At one point the woman said the ground was shaking. One of the titles also mentioned that.
While operating radar over various oceans I have experienced ducting. You could get contacts that were hundreds of miles outside your radar range limit. Also we used to tune in civilian radio from around the world while flying missions over the Indian Ocean. Usually associated with an inversion layer if I remember correctly.
This sounds like an effect similar to a first hand account in Thunder Below, written by Eugene Flukey, the most decorated living Admiral in the U.S. Navy, who commanded the most successful submarine in WWII.
He recalls being on his submarine in the Sea of Okhotsk, watching a convoy that was apparently very close. With their binoculars they could see smoke from the funnels and activity on board. After about 10 minutes, the entire convoy suddenly shimmered and disappeared. It appears that atmospheric ducting made the convoy appear from hundreds of miles away.
same thing occurs in the ocean with sonar and sounds waves … it allows for some long range tracking but also short range dead zones …
I believe it was a jet engine on a test stand ,that was ducted some how from some airbase or airport close by. not uncommon for the time period of this sound. I have heard them run many times while in the Air Force.
I live nearby where this happened and can provide a small amount of info. There are no nearby industrial facilities. This area is very rural with almost nothing for many miles to the E, W, and S. Tallahassee is about 10-20 miles north. No oil or gas wells in the area to be tested (I know this being a former DSTer). Very flat terrain so with all the vegetation it is difficult to see anything lower than 45 degrees in the sky. Nearest airport is near Tallahassee about 10 miles NW of there. Nearest train track is at least 30 miles away. This area gets very few tornadoes but many severe thunderstorms. After/during passage of a TS or landfalling hurricane, the area does get tornadoes. I’d say that based on my experience living here that I’d be somewhat afraid too if I had heard that. I did not hear it (am about 10 miles away).
I was working a music festival back in the late ’80s at the Atlanta Int’l Speedway infield. It had been a rainy weekend, but it quit raining in time for the evening headliners, though the clouds hung in there low and thick. We got shut down that night because a local judge that reportedly lived a couple of miles away couldn’t go to sleep. 🙂
My question after seeing/hearing that video is whether there’s a racetrack anywhere nearby. That’s what it sounded like to me.
What David Ohara said,
I live in Tally, and didn’t hear it. But there isn’t anything of the industrial nature around here to cause this kind of sound, and certianly no rocket/jet testing. Our Airport is nothing to speak of and I doubt any test like that would happen without making the local news, as getting our airport upgraded and commercially attractive has been a political goal for a few years now.
Kerosene Jet heaters aren’t exactly common in these parts either……..I don’t know why though, I mean, it’s not like we go decades at a time without recorded snowfall or anything.