Water Spouts, the cause?

-- Last Updated: Feb-04-05 10:52 AM EST --

Scene: Having lunch, 5 feet up on some rocks off of mid-size lake in Canada. We are on the north side of the lake, facing south, in a small protected bay. Sunny day, 75 degrees, water temp on main lake about 40 degrees, late May, 2002. Little wind, a blue bird day.

The trees start to rustle above our heads, we look up and out towards the water, and we see a water spout rising up to 20 feet in the air, 15 feet from shore. Our baseball caps get sucked off our heads, branches break off of the trees. After 15 seconds it ends, water droplets from the spout drop down on us. After the spout goes away, the lake water continues to churn for two to three minutes as if it is alive.

What caused this? It is the second time I have seen this happen, but the previous time I saw it from two miles away, and I thought my eyes were deceiving me. Six of us witnessed it this time.

Defined plus some awesome pics of spouts
Here you go, dont forget to check out the great pictures below too! Awesome!

n



Observing water spouts

Copyright Anna Foley.

Water spouts are rotating columns of air similar in appearance to that of the tornado. They develop over warm ocean currents during unstable conditions or as cold front boundaries pass over the ocean. These are not very dangerous but can affect boats and yachts. Because they are over the ocean, they do not pick up debri but water spray is observed at the base.



Water spouts can develop over the ocean and move over the land. They are then called tornadoes. It is here where water spouts can be dangerous and has caused extensive damage to trees and buildings as well as over turn caravans in coastal communities. Once on the land, they dissipate fairly quickly. On the ocean however, they can last much longer.



Sometimes, tornadoes form over the land and pass over a lake or the ocean. These are then called water spouts despite the difference in the formation processes and dynamics.



http://www.theweatherprediction.com/humor/4/

http://www.seadoc.net/postimages/waterspout.jpg

http://www.wildweather.com/gallery/images/photo-spout-1.jpg

Not really what I saw.
Those forming over the ocean like on the atached pics look more like traditional tornados like we get here in the midwest-Funnel clouds dropping down from the sky sucking up water. What we saw happened on a calm day, blue sky day, and the water rose up out of the lake. I’ve witnessed tornados, and it certainly wasn’t a tornado, it was much smaller, no clouds. Any other ideas?

They look different bc no dirt

– Last Updated: Feb-04-05 11:19 AM EST –

And they look different because they only have water and water vapor in them as opposed to land vortexes that suck up debris of all kinds.

And the ones you saw don't develop necessarily up high in a rotating cloud, but due to rapidly heating air, (the clear day) and warming air causing turbulence in a micro area. The lifting has a angular force that translates into rotation as was explained to my feeble brain. I await an expert!

sounds like the right direction
key words were “micro” and “turbulence”. When it was over (within 3 minutes)it was like nothing had happened. It was still a blue sky, warm day. I think the difference in water temp and air temp, and warm air maybe getting trapped above the surface of the lake. I just can’t picture the mechanics, or the forces, that would cause it to happen.

Quite a sight, aren’t they
Saw several of them on a trip to Florida several years ago. I had been paddling off Fort Desoto, near St Petersburg, and saw a storm bearing down on me. I beat feet off the water, and went back to Clearwater Beach to hang out in an “establishment” with some friends for the afternoon, since the weather was so crappy.



As we were sitting on the deck of said establishment having some yummy alcoholic refreshments, we watched 3 waterspouts form in the distance ---- right near where I was paddling earlier according to the TV news.



The paddling was cut short, but I got to see a great display of nature, and the beer tasted good, too. Always have a backup plan!



Wayne

Interesting
We have lots of dust devils down here in the arid southwest and that sounds like what you observed with respect to the timing, intensity clear day etc. They seem to be associated with heating at the surface and then a spin from a gust of wind. Doesn’t make sense though over a cold water surface though does it?



Their unpredictability is one of the things that makes them amazing.



Glad you were on shore to experience having your hat snatched off. Might get a little spooky on the water.

Called them ‘Dust Devils’
In Southern California.

Can reach amazing heights, clear blue sky, suck up dirt over dry desert land or water over lakes. Very impressive. Often seen in summer over lakes in the desert areas. I’ve seen them overturn boats on Lake Perris in S. Cal. Remember seeing one traversing the foothills above Fullerton, SoCal, from Fullerton, looking toward the hills looked like it was more than a 100 foot tall! is that possible? Can last for at least a full minute or more.



We used to “play” in the smaller ones, (10-20footers) run out to them and try to disrupt the motion.



No foolin’ as sure as the grunion run in Feb!



Tom


looked like the playful type

– Last Updated: Feb-04-05 1:49 PM EST –

This event looked more playful than dangerous, but given the water temp I wouldn't have wanted to try to disrupt the motion in my canoe. It sort of stunned us, no one even reached for a camera.

Had one come up a river once

– Last Updated: Feb-04-05 2:17 PM EST –

While camping on the shores of the Andorscoggin River (NH) I watched one come up the river, into the campground and yank a large tarp off its' poles and suck it up into the air well above the tree tops before depositing it in the trees on the far shore. It was kind of a combo water/dust devil.

Thermals
Sounds like a thermal. A column of warm rising air. They form due to differntial heating of air near the surface of the land or water. On land they form over things like parking lots, plowed fields, rocky areas. Over water they can form over shallow spots, or large patches of kelp, or exposed rocks.



At strong thermal over land can last for a long time, because the warm area on the ground continues to heat cooler air coming in the replace the warm air that has risen. Over water they don’t last as long because the water getting picked up tends to cool things down.

Not long for the Whirl!
Here is a nice summary:



http://www.mb.ec.gc.ca/air/summersevere/ae00s25.en.html



Never heard of 'em “gustnadoes” – one more thing to worry about :-).

More Interesting Stuff
Another type of less ominous ocean cyclone is the fair-weather waterspout. Much like a dust devil on land, it’s a small, usually harmless vortex of wind that pops up in a superheated pocket of ocean air on a quiet sunny day and plays on the sea surface for a short time, perhaps as little as a few seconds. It’s more common than the tornadic waterspout and much more benign. Tropical latitudes have many more of these than mid-latitudes, but there’s a good chance of spotting a fair-weather funnel cloud during the summer months if you spend a lot of time on the beach or in a boat.



http://www.sentinelpublications.com/waterspouts.htm

Almost got caught in one in NJ
A few years ago, same type of day as you described. Only it formed with the sound of a twin engined big block race boat idiling. It shot up about 30-40 feet and lasted less than a minute. Very impressive. I was less than 30 yards from it forming. This was in the mouth of 2 small rivers with two distinct rows of trees that may have formed a chute.I was about 15 miles inland from the Ocean.



Geoff

What Mint_Julip Said…
The scenario you describe sounds like it has the ingredients for thermal production.



You said: Having lunch, 5 feet up on some rocks off of mid-size lake in Canada. We are on the north side of the lake, facing south, in a small protected bay. Sunny day, 75 degrees, water temp on main lake about 40 degrees, late May, 2002. Little wind, a blue bird day.



Spring in the upper latitudes usually spells instability (change of temp with altitude). Light winds allow more efficient heat transfer from the land to the boundary layer of air. The protected bay offers more protection yet. You are on some rocks with a southern exposure. That gives more direct exposure to the heat of the sun and rocks heat faster than vegitation or water. You didn’t mention which direction the prevailing breeze was from but I would guess that it was from your back. Maybe not but that would have offered a perfect stage for lee-side thermal development.



Rocks heat the air and a small but intense thermal lifts off. Talk to a physicist about the angular momentum thing. If it happened near a farm field you would have seen a dust devil. If the thermal moved back over the land you would have experienced a rapid increase in the wind off the water and the tree tops would have gotten pretty noisy. The thermals movement over the water quickly diluted the warm air with cold and the thermal “died”. Since air really weighs quite a bit any momentum is not overcome immediately. It may not be lifting fast enough to hold the water up but the spin is still there. For a bit, anyway.



That’s my story and I’m sticking to it.

Thermal
Thermal is the right answer here. Thermals start from the ground up. Tornadoes and water spouts begin as a vortex spinning parallel to the earth’s surface before touching down. I’ve had weather classes with my wildland fire training. That’s where I learned about cyclones or dust devils. They can be strong enough to blow a semi over.

Yeah thermals…

– Last Updated: Feb-05-05 4:47 PM EST –

It was just a very strong thermal, much like dust devils. True waterspouts are a much different animal than thermals. Typically thermals are created from solar heating and waterspouts happen with large areas of instability (moisture and pressure differences). I've sat and counted 13 waterspouts out on Lake Michigan one afternoon. The conditions of that Fall day were very extreme (warm water cool air).

As a soaring pilot I have a love and appreciation for thermal activity. The ability to stay aloft depends greatly on guessing, while flying, where your next thermal will be released from earth. It's a free ride in the air and the feeling of being lifted by an unseen force is quite awesome. Reading the terrain for signs of thermals is an art form and misreading them can be very dangerous.

The thermal you witnessed was a very strong version of what the ones that lift off all day long (some days better than others) nearly all year long. I think a contributing factor to the strength of that thermal was the cool air of the lake. The lake was causing a sinking factor to the surrounding air and probably holding down the warm air around the rocks (rocks are great thermal producers, they retain heat very well). We call this a Cold Dome effect. This effect will shield objects from releasing heat until the air is heated to a point and then it just pops. This would account for the strength of it and the short duration. Picture water drops on the roof of your tent. They're just hanging there until they get too heavy or until you touch them, then they run like a faucet. Thermals act the same way and they even drift along the ground like a bubble or drop of warm air and when they touch something they release. Sometimes telephone poles, cars, rock outcroppings, hills or mountains, and even people can release them. They don't have a long life and only some of them reach the height of the dewpoint to deliver the moisture they're carrying to make a cloud. You can visualize them as tall pillars of rising air slightly leaning downwind and rotating counter-clockwise. They are usually only about thirty feet in diameter.

It's not easy to keep a glider in the lift of a thermal given that they are small (my gliders have wingspans of around 30'), moving, and spinning. You even have to approach them from the correct direction to get a good bite into them to make use of the lift. If done incorrectly they will spit you out. The danger in this activity come from the vertical component of the small air mass, it can stall your glider. One other danger comes from being stuck in a very strong thermal and unable to get out. The latter has resulted in deaths from Hypothermia, and hypoxia. Suffering from either of those while flying a weight controlled glider is a bad thing.

I could sit here and write about thermals for hours but I won't show just how dull I am.

But anyway, what you experienced there was an everyday occurrence but in rare power. The strongest thermals I've encountered were a couple thousand feet over the flats of Indiana (in the country farm tractors plowing fields are like the finger that touches the drop of water on the tent roof, they release thermals). I was flying along at about 1500' after being towed up by truck (very interesting, like a reverse bungi jump) looking for lift when I faintly saw corn stalks swirling around ahead of me. When I flew into it the lift was so strong I was sure my glider would be ripped apart, It was awesome.