Blizzard happening but thermals still popping.

[T.D.]

We are having a very unusual heavy snowstorm here in Vancouver, 40cm down and still falling. Of course everything is covered in white..except for the main street near our house.

This morning I went for a walk to pick up a few things for Christmas Eve, I was walking on partially cleared black top street because the sidewalks are impassable when I felt the temperature jump a bit and then it warmed up several degrees and a wind came up. Then Boom! Air swirling huge amounts of dry powder snow off of the trees around me and whipping snow off of the nearby lawns. Tree branches whipping around like crazy etc. while 20 metres away things were perfectly calm and the snow was still lazily falling.

The thermal must have busted loose right over me because it was like being inside a mini cyclone, I am sure everyone knows the feeling but this was extremely cool because it happened during a blizzard in a deep freeze.

I've seen winter thermals before but nothing like this classic trash mover, very cool.


T.D.

[tbushell]

I'm continually amazed by the conditions that can generate thermals...

Many, many years ago, we were towing up hang gliders over a frozen lake in Nova Scotia. Much to everyone's surprise, there were thermals over the ice.

I speculate that the water under the ice was warmer than the air above the ice, which provided the energy to form the thermals.

When flying at coastal sites, "sea thermals" have also been widely reported.

Yesterday, a DLG pilot at our local field in Long Island, NY, reported widespread lift over a snow covered field early in the morning. But when I got there around noon, there was almost none.

Story of my life... :(

-Tom Bushell

[Kenny Sharp]

I find lift in Winter, but I think it helps if its a little windy....somewhere around 4-8 mph. is good for me.

[lincoln]

Have found lift on frozen lake on breezy evening just after sunset.

Have also seen thermals, or at least "dust devils" while walking across same lake in breezy snowstorm. Pretty narrow, though.

[seanpcola]

I gotta hand it to you guys. I can't even imagine cold like that.

I really do believe that the body adapts over time. In my area, for example, there is seldom a day in the '30s. No snow or ice, or at least very little. I do not think my bod would take sub-zero temps, much less wet snow.

OTOH, I'm 52, average condition. I work outside most days, all day. Summers are high 90s plus. HIGH humidity. Glaring sun. No problem. A buddy moved down from Vermont. In his 40's, used to working HARD all day, built like a tank. I had to pick him up off the ground more than once his first summer down here. Any doctor would say he was in much better condition than I. His usual operating temp was 70's down to negative numbers. He's good now but it was rough for him the first two years. If I had to move up there all bets would be off. I can't see my old joints working in that environment.

You guys get my respect.

[scaflock]

I know of what you speak Sean. My first year or two out here was ROUGH. I grew up in S. California and heat don't bother me at all. Humidity on the other hand.... Where I was working at we also had three huge ovens for baking paint and powder coating. Avg temp in the shop was about 115 degrees on a good day in the summer. I'm 51 and that took some getting used to.

Cold isn't a problem as you can always put more clothes on. In the heat you can only take so much off and not get arrested. ;)

Jeff

[Viso]

Ill second that. I moved to GA from Sydney and for July and August you just need to stay inside and fly the sim in the cool AC, I cant function in that humidity.

[Kenny Sharp]

Weather changes never bothered me any more than it did anyone else.

When it turns humid, everyone needs a few days to adjust. Usually, it simply requires a different ensemble. Sometimes it can be hard to transition from shorts to long pants, and vice-versa....or from dark clothes, to light colored clothes.

Still though, humidity is terrible for both the pilot and plane.
I'd much rather fly in colder, denser air.
60- 80 deg. F is my favorite.:)

[lincoln]

You're not kidding about the adaptation thing. That first hot day in June can be pretty terrible for cycling, for instance. Especially when you get to the top of the hill and want a rest. Plus if you stop working out as hard and get older, you can't adapt as far. In my late teens and early 20's, I could run a few miles when it was 90 degrees out. That was a long time ago. I can still take a fair amount of cold if properly dressed, but I don't have the same attitude about it if it gets really nasty.
I gotta hand it to you guys. I can't even imagine cold like that.

I really do believe that the body adapts over time. In my area, for example, there is seldom a day in the '30s. No snow or ice, or at least very little. I do not think my bod would take sub-zero temps, much less wet snow.

OTOH, I'm 52, average condition. I work outside most days, all day. Summers are high 90s plus. HIGH humidity. Glaring sun. No problem. A buddy moved down from Vermont. In his 40's, used to working HARD all day, built like a tank. I had to pick him up off the ground more than once his first summer down here. Any doctor would say he was in much better condition than I. His usual operating temp was 70's down to negative numbers. He's good now but it was rough for him the first two years. If I had to move up there all bets would be off. I can't see my old joints working in that environment.

You guys get my respect.

[Kenny Sharp]

Have also seen thermals, or at least "dust devils" while walking across same lake in breezy snowstorm. Pretty narrow, though.

I fly my DLG exclusively in Winter.

Lately, I've been wondering a lot about what particular type of lift I seem to be getting.

If it's 30 deg F. or below, I only get good lift if it is slightly, or moderately, windy (which I define as 4-12 mph.).

Would this lift be classified as thermals? Or something else?

Whatever it is, it seems to behave the same as it does on Summer days, it just indicates differently.
I have to watch the plane more than I have to watch my surroundings.

Sometimes the lift that I get seems to come from nowhere...it just races by the plane and lifts a wing.
And if you want to catch it, you must be on your toes.
Keeping it is tougher too...it seems small and concentrated.

I wonder what's going on here...
Are these thermals, whirlwinds, dust devils...or what?

[tbushell]

If it's 30 deg F. or below, I only get good lift if it is slightly, or moderately, windy (which I define as 4-12 mph.).

Maybe the wind is required to blow thermals from their generating sites to your flying field? In lighter winds, maybe they rise above the launch height of your DLG, so you don't detect them?


I wonder what's going on here...
Are these thermals, whirlwinds, dust devils...or what?

These are all considered thermals - i.e. a rising bubble or column of warmer air. It's just a matter of intensity and visibility that makes it a dust devil (or snow devil).

I'd like to hear more about how winter thermals differ from summer thermals.

-Tom

[gizzo]

I think in colder weather the bubble of warmer air sticks to the ground better. With a bit of breeze, it can blow along until it hits a trigger piont, and up it goes. With no wind, it's too stable and just sits there. If you find yourself flying through an area of zeros ie, no lift, no sink, stick with it until it hits a trigger. Or get the kids to run around under it, drive a car through it. HG and PG pilots often look for a car or tractor when they need that low save, these often trigger a thermal.

[nuevo]

Long ago, when I lived in Longmont, Colorado, I saw a bird circling and climbing in a thermal. All while it was snowing fairly heavy. Fascinating.

[Libelle201B]

The ultimate cold weather thermaling bird may be the penguine. If you see a bunch of them walking in a circle, they are in lift :)

[atmosteve]

:D Libelle201B, I will never look at another penguin in the same way again.

It gets so humid here, you just know we are in for big storms during summer, I'd rather the dry heat of the desert any day to the heavy coastal funk of humidity.
My local park offers interesting thermal hunting as its right on the great sandy straits across from Fraser Island, Qld. At low tide the dark muddy bottom is exposed for Km and it really does create lift that drifts inland during a seabreeze, even more so do the open mangrove flats behind the waterline, the thermals they create aren't huge, but they really pack a punch! When the tide is in the temp differential between the water and the mangrove flats is a good place to hunt.

What TD describes sounds fascinating, like a small pocket of super active lift that snapped up and was squeezed out by the dense cold air around it.
A fella could be excused for carrying a little DLG everywhere he walks around the streets of Vacouver. :D

[mred3]

Thermals are around all year long. It doesn't matter what the temp is outside, thermals happen. It may be 32 degs outside, but if the air is warmed to 34 in one area, you get a thermal. From what I have seen, MOST of the time, cold air has smaller thermals then warm air, but that is not true all the time. You can get dust devils in the winter as well as the summer and if you get a cold day (20 deg.) you still have the potential for thermals. Some are weaker then others, but they are there none the less. I have had just as many thermals on a cold winters day as I had in the summer. The only difference is I suffer more in the winter then in the summer. That's because I like warm more then cold. In fact, I hate cold. After growing up in Indiana and moving to Southern California, I swore I would never live in cold country again by choice. Georgia sutes me just fine and I get great flying days in the winter with lots of thermals and I get bad days with no or very few thermals just like I do in the summer. All you need for a thermal is a difference in temps and off you go.

Ed

[mred3]

Thermals are around all year long. It doesn't matter what the temp is outside, thermals happen. It may be 32 degs outside, but if the air is warmed to 34 in one area, you get a thermal. From what I have seen, MOST of the time, cold air has smaller thermals then warm air, but that is not true all the time. You can get dust devils in the winter as well as the summer and if you get a cold day (20 deg.) you still have the potential for thermals. Some are weaker then others, but they are there none the less. I have had just as many thermals on a cold winters day as I had in the summer. The only difference is I suffer more in the winter then in the summer. That's because I like warm more then cold. In fact, I hate cold. After growing up in Indiana and moving to Southern California, I swore I would never live in cold country again by choice. Georgia sutes me just fine and I get great flying days in the winter with lots of thermals and I get bad days with no or very few thermals just like I do in the summer. All you need for a thermal is a difference in temps and off you go.

Ed