Coriolis effect

[TangoWhiskey]

http://en.wikipedia.org/wiki/Coriolis_effect

Pretty good article. The animation at the top is great.

I found this article after looking at a plot of F3-F5 tornados that showed their ground tracks:

http://www.hprcc.unl.edu/nebraska/F3-5tornadoes-us1950-2005.html

Noticing that they all (mostly) tracked NE, I thought "that's probably due to Coriolis effect".

But, is it really? Coriolis effect tends to deflect things to the RIGHT in the Northern Hemisphere. These track lines tend to deflect to the LEFT.

What say you weather gurus?

 

[JasonCT]

Just reminds me of high school physics class Troy!
And the fact I'm getting older lol

 

[tonycondon]

from what i understand, motion of tornadoes is generally random. there is a little science behind it, but you never really know where they are going to turn.

 

[CJones]

from what i understand, motion of tornadoes is generally random. there is a little science behind it, but you never really know where they are going to turn.

If you think about it, you could narrow a tornado track down pretty good -- it's always going to lead to a trailer park.

 

[cherokeeflyboy]

I am NOt a wx guru for sure, but I use the following text to help explain the effect in ground school.
Air starting at rest with respect to the ground will move towards a low pressure center. Such motion in the Northern Hemisphere will deflect to its right. However, the forces which got the air moving towards the low pressure center in the first place are still around, and the result will be a vortex of air spinning counter-clockwise. Air will try to turn to the right, the low pressure system will try to draw the air into itself, and the result is that air is held into a circle that actually turns to the left. Without the Coriolis effect, fluid rushing in towards a point could still form a vortex, but the direction would either be random or depend solely on the initial conditions of the fluid.
The eye of a hurricane is a clear example of fast winds bent into a tight circle, moving so fast that they can't be "pulled in" to the center. The very low pressure at the center of the hurricane means that there is a strong force pulling air towards the center, but the high speed of the wind invokes the Coriolis effect strongly enough that the forces reach a kind of balance. The net force on air at the eye wall is a centripetal force large enough to keep the air out at a given radius determined by its speed.

 

[Everskyward]

I'm not a weather guru either but I thought that tornadoes generally moved from from southwest to northeast because they often develop in thunderstorms located to the south and southeast of low pressure areas and the winds aloft around the low are from the southwest in these locations. This is a complete guess on my part but it sounds logical to me.

 

[flyingcheesehead]

If you think about it, you could narrow a tornado track down pretty good -- it's always going to lead to a trailer park.

*scene: Beavis and Butthead watching a news story about an approaching tornado...*

Butthead: Huh huh... We're there dude!
Beavis: Yeah yeah! Ummmm... Where?
Butthead: Huh huh... The trailer park, dumbass!

 

[Let'sgoflying!]

tornadoes generally moved from from southwest to northeast because they often develop in thunderstorms located to the south and southeast of low pressure areas and the winds aloft around the low are from the southwest in these locations.

I think you are right; the pic attached is a regional area showing such motion SW to NE. I have seen a national depiction as well, it was exactly the same with 00's of parallel tracks, all SW to NE.

I think they tend to develop at the most southerly portion of a line of cells because that is where the greatest source of moisture aka energy is, and they move as noted towards the center of the low which is N/NE of them. I believe that is how Archie Trammell puts it.

 

[tonycondon]

its a matter of resolution i guess. yes they will generally move in the direction of the storm. but they dont just bore down in a straight line. zigging and zagging is fairly standard.

 

[judypilot]

http://en.wikipedia.org/wiki/Coriolis_effect

Pretty good article. The animation at the top is great.

I found this article after looking at a plot of F3-F5 tornados that showed their ground tracks:

http://www.hprcc.unl.edu/nebraska/F3-5tornadoes-us1950-2005.html

Noticing that they all (mostly) tracked NE, I thought "that's probably due to Coriolis effect".

But, is it really? Coriolis effect tends to deflect things to the RIGHT in the Northern Hemisphere. These track lines tend to deflect to the LEFT.

What say you weather gurus?

I'm more of a climatologist than meteorologist, but I would say, as have others, that the Coriolis effect is in play, but kind of indirectly. They move along a front (a boundary between two air masses), and if the northernwestern airmass is a low-pressure area (often the case in the SE US), the flow along the front is to the NE in the northern hemisphere.

The analogy of the balance within a hurricane is a good one. The same kind of balance occurs on a larger scale with any low-pressure area, so you never have air flowing straight into the deepest part of the low, and that IS because of the Coriolis effect.

Judy

 

[Let'sgoflying!]

1st yr college I needed a geography-type course so I figured the Climatology 100 course would be 'fun', I had a small background of weather study from the aviating, new some of the terms. Ha. The 'bird course' (as we used to refer to easy-A courses) was a nightmare. Unbelievably complicated. I don't think anyone got an A, what a struggle. New respect for the topic was gained.

 

[flyingcheesehead]

1st yr college I needed a geography-type course so I figured the Climatology 100 course would be 'fun', I had a small background of weather study from the aviating, new some of the terms. Ha. The 'bird course' (as we used to refer to easy-A courses) was a nightmare.

We used to have names for all of them. Physics for Fools, Rocks for Jocks (Geology 101), etc.