How Much Wind Would It Take?

[Backtrack]

Just out of curiosity, how much wind would be needed for it to literally sweep you off your feet and throw you?

80mph last night was very hard to walk in.

[Thunder Snow]

I think that would be enough to bring a child off its feet, not sure for a adult though. Although it was VERY hard to walk in last night.

[Coast]

Weight?

Surface area presented to the wind source?

Frictional qualities of footwear?

Gust or sustained wind?

Remember Hurricane Ike and this reporter?

http://www.youtube.com/watch?v=2Hfz60ccR7s

[Backtrack]

Weight?

Surface area presented to the wind source?

Frictional qualities of footwear?

Gust or sustained wind?

Remember Hurricane Ike and this reporter?

http://www.youtube.com/watch?v=2Hfz60ccR7s

9 stone

open field

gust

good trainers

:lol: That video is hilarious!

Edited November 12, 2010 by Backtrack

[Osbourne One-Nil]

You were having 80mph gusts in Runcorn?

[TonyH]

80mph last night was very hard to walk in.

Show us your graph we don't believe you

[Coast]

9 stone

open field

gust

good trainers

Oh god don't ask me about maths or physics, I'm useless!! Somewhere in these lies the answer I'm sure:

http://encyclopedia.farlex.com/force

http://www.mayq.com/Best_european_trips/Cycling_speed_math.htm

http://en.wikipedia.org/wiki/Drag_(physics)

You need Newton and Galileo!

[helen of the north]

I find when it gets into the 80's i can walk with great difficulty against or cross wind but, as soon as i start walking with the wind i'm going to be forced to run and eventually cowp. anything past this one naturally gets or (should get) into the crawl position. lol

[Osbourne One-Nil]

I never thought I'd read that it had got into the 80s in Caithness, but I'd forgotten about wind speed.

[egret]

Just out of curiosity, how much wind would be needed for it to literally sweep you off your feet and throw you?

80mph last night was very hard to walk in.

I suspect the answer will relate in some way to the terminal velocity of someone falling through the atmosphere (120mph) where body friction with the air equals force of gravity upon body mass.

There would have to be a vertical component (upward movement) to make you take off rather than slide along and that would be a combination of a gust bouncing off the ground and the body pivoting around your feet (fisrt you would lean at an angle and then rotate around your foothold). Best guess 130mph to take off and go a few yards?

In a tornado scenario it would be a case of air rising at more than 120mph to take you (or a cow as in certain film clips) aloft.

Edited November 12, 2010 by egret

[Backtrack]

Thanks all.

My WS shows 36mph was the max gust, but it's enclosed. I found it hard to walk last night, planes were struggling to fly. The wind was easily 80 mph.

One gust actually went off the chart of my WS and dazed it for a few mins before it started to transmitt data again!

120 mph sounds impossible. Anyone want to move to the USA?

Thanks coast and everyone else.

I suspect the answer will relate in some way to the terminal velocity of someone falling through the atmosphere (120mph) where body friction with the air equals force of gravity upon body mass.

There would have to be a vertical component (upward movement) to make you take off rather than slide along and that would be a combination of a gust bouncing off the ground and the body pivoting around your feet (fisrt you would lean at an angle and then rotate around your foothold). Best guess 130mph to take off and go a few yards?

In a tornado scenario it would be a case of air rising at more than 120mph to take you (or a cow as in certain film clips) aloft.

Wow thanks.

Edited November 12, 2010 by Backtrack

[Cookie]

my dad fell over the garden fence in 2005 going to check the roof, gusting 90 mph at the time.

[helen of the north]

I never thought I'd read that it had got into the 80s in Caithness, but I'd forgotten about wind speed.

it didn't. it was very calm here cept for a few hour breezy stint in the morning. i'm speaking generally not about yesterday.

[Soaring Hawk]

it didn't. it was very calm here cept for a few hour breezy stint in the morning. i'm speaking generally not about yesterday.

I rather think OON was speaking generally too.........the naughty boy.

(You'll get used to his sense of humour)

[Osbourne One-Nil]

The wind was easily 80 mph.

You can't possibly say that! an 80mph gust is an extraordinarily strong powerful thing and, well, I'm not saying it didn't happen so much as saying it's almost impossible to guess wind speed.

it didn't. it was very calm here cept for a few hour breezy stint in the morning. i'm speaking generally not about yesterday.

I was actually making a witty observation about Caithness's temperatures....in the 80s....see what I did? I had a holiday in Caithness many years ago and I'll never forget the talk of Thurso being how it had reached 70º!

Nice to see Soaring Hawk post. I guess the sheltered accommodation warden fixed her internet.

[Terminal Moraine]

Thanks all.

My WS shows 36mph was the max gust, but it's enclosed. I found it hard to walk last night, planes were struggling to fly. The wind was easily 80 mph.

I'd bet a large sum of money that the wind was nowhere near 80 mph in Runcorn last night, if you don't believe me get a hand held anemometer and, next time there's a good gale, go up to around 1500' on an exposed moor. It becomes difficult to walk when the wind is around 40 mph, at 60 mph you'd be walking bent double and 80 mph is more than enough to knock you off your feet.

If the wind was a perfectly steady 80 mph then standing upright would be just about possible if you weigh more than about 11 stones; but the wind is never perfectly steady.

When the mean speed reaches around 60 mph it's a huge effort to stand upright as you try to compensate for the lulls and gusts. You have to lean into the wind and brace yourself which means you tend to topple forward in the lulls and be thrown backwards in the gusts.

The highest speeds I've recorded with my trusty hand held anemometer are means of 68 mph, gusting to around 95mph.

On each occasion I was blown over several times and the only way it was possible to read the anemometer was to hold it tightly with two hands and half stand, half crouch; even then it was shaking so much it was difficult to read it.

I reckon the highest gusts in your area last night would have been around 60 mph.

[PersianPaladin]

I've been brought down to the earth by a 20mph gust before...

mind you...I think that was down to a door being slammed in my face.

[rossco89]

now, heres one. Slightly off topic. How strong a wind would it take to blow every chimney stack (not just the chimney pot, the stack too) for every house in a street?

[Jan]

Highest gust in the Mersey area was recorded by Crosby coastguard at 68mph and that was on the coast.

[Bluebreezer54]

' Planes were struggling to fly ' ?? Are you sure ?? Im still trying to work out how Bactracks weather station recorded an actual w/speed of 36 mph yet that somehow equates to 80 mph.

[full_frontal_occlusion]

I suspect the answer will relate in some way to the terminal velocity of someone falling through the atmosphere (120mph) where body friction with the air equals force of gravity upon body mass.

There would have to be a vertical component (upward movement) to make you take off rather than slide along and that would be a combination of a gust bouncing off the ground and the body pivoting around your feet (fisrt you would lean at an angle and then rotate around your foothold). Best guess 130mph to take off and go a few yards?

In a tornado scenario it would be a case of air rising at more than 120mph to take you (or a cow as in certain film clips) aloft.

Very much less than 120 mph. Probably half that.

Once you are unsettled by the gust (quite easy) and moving, then to gain stabiity again, you will not only need to overcome the force of the wind, but also negate the momentum of your own body relative to the ground. Moreover, once unseated, there is now no friction to stop your acceleration.

Which is why as Helen of the North observes going with the wind is more difficult to control. Get low down on all fours to lower your C of G, generate more friction with the ground and present less surface area to the wind.

If you come into contact with a stationary object, then the lower that contact is with your body, the greater the leverage force of the wind. i.e. The object acts as a fulcrum and leverages you to fall over.

You also need to consider the type of clothes you are wearing as they will act like a parachute.

ffO

Edited November 12, 2010 by full_frontal_occlusion

[milkmaid]

i've been,out in 90 mph ,it was difficult found breathing is difficult ,it tends to hurt to breath or that might just be me ,with keeping your feet is the main problem is you brace against the wind gust dies down you relax a bit and next gust catches you off guard meaning you land on your but or face ,staying low is good ,and using whatever shelter you can against walls ,but you have to way that up against stuff falling although it tends to fly a few feet away if it's coming off the building you are using a shelter

just what i can remember

i don't enjoy being out in that sort of speed

[Osbourne One-Nil]

I've been brought down to the earth by a 20mph gust before...

mind you...I think that was down to a door being slammed in my face.

I can't believe that!

It would mean someone actually had actually opened the door.

[Backtrack]

' Planes were struggling to fly ' ?? Are you sure ?? Im still trying to work out how Bactracks weather station recorded an actual w/speed of 36 mph yet that somehow equates to 80 mph.

Yep. My station is VERY enclosed, and by that I mean it's behind the house surrounded by lots of other houses.

The planes were rocking side to side violently, and they were crawling along. They normally absolutley fly over here (No pun intended) :lol:

I'd bet a large sum of money that the wind was nowhere near 80 mph in Runcorn last night, if you don't believe me get a hand held anemometer and, next time there's a good gale, go up to around 1500' on an exposed moor. It becomes difficult to walk when the wind is around 40 mph, at 60 mph you'd be walking bent double and 80 mph is more than enough to knock you off your feet.

If the wind was a perfectly steady 80 mph then standing upright would be just about possible if you weigh more than about 11 stones; but the wind is never perfectly steady.

When the mean speed reaches around 60 mph it's a huge effort to stand upright as you try to compensate for the lulls and gusts. You have to lean into the wind and brace yourself which means you tend to topple forward in the lulls and be thrown backwards in the gusts.

The highest speeds I've recorded with my trusty hand held anemometer are means of 68 mph, gusting to around 95mph.

On each occasion I was blown over several times and the only way it was possible to read the anemometer was to hold it tightly with two hands and half stand, half crouch; even then it was shaking so much it was difficult to read it.

I reckon the highest gusts in your area last night would have been around 60 mph.

It was getting to the point where I had to brace myself for the gust.

It got too much, I was almost being pushed over, but not quite. I was having to turn my back to stand up properly!

I'll buy this.

http://cgi.ebay.co.uk/HANDHELD-ANEMOMETER-WIND-SPEED-METER-Sailing-Surfing-/140357932622?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item20adfc164e

Edited November 12, 2010 by Backtrack

[Coast]

I'll buy this.

I've got one, nice little gadget to keep in your pocket for when you're out and about.