Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

General Cycling Discussion Have a cycling related question or comment that doesn't fit in one of the other specialty forums? Drop on in and post in here! When possible, please select the forum above that most fits your post!

User Tag List

Reply
 
Thread Tools Search this Thread
Old 06-03-09, 08:22 PM   #1
duke_of_hazard
Senior Member
Thread Starter
 
Join Date: Jul 2007
Location: Peoria, Illinois
Bikes:
Posts: 529
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
How come wind direction does not match storm direction?

In a rainstorm, I often notice the Doppler radar shows the storm moving in one direction but the wind direction is different. How can that be? Shouldn't the wind direction always be the same as the overall direction the storm is heading?
duke_of_hazard is offline   Reply With Quote
Old 06-03-09, 08:27 PM   #2
nahh
on your left.
 
Join Date: Nov 2007
Location: Blacksburg, VA
Bikes: Scott SUB 30, Backtrax MTB
Posts: 1,802
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
There's always a headwind, weather is irrelevant.
nahh is offline   Reply With Quote
Old 06-03-09, 08:33 PM   #3
norwood
GO BIG RED
 
norwood's Avatar
 
Join Date: Nov 2008
Location: Hastings,NE
Bikes: 1996 Bianchi Veloce 1993 Bridgestone MB-3 1992 Trek 700 1992 Trek 820
Posts: 678
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I'm not a meteorologist nor did I stay in a Holiday Inn Express last night, but I believe it has something to do with storm cells being typically low pressure areas. That is they tend to pull air currents (wind) into them. I could be wrong however.
norwood is offline   Reply With Quote
Old 06-03-09, 09:09 PM   #4
surfrider
Guest
 
Bikes:
Posts: n/a
Mentioned: Post(s)
Tagged: Thread(s)
Quoted: Post(s)
A little amatuer meteorology:

Storms (low pressure cells) generally travel from west to east across the USA/North America. However, the storm cell itself tends to spin internally, with the low pressure ones spinning counterclockwise (?) and the high pressure (clear days) cells spinning clockwise. Which way the wind is blowing depends on what part of the storm is passing over you. Example is a hurricane, which is a severe low pressure storm. If you are going to get directly hit by it,you'll experience high winds blowing in one direction, then calm (the 'eye') then high winds blowing in the opposite direction. it you're at its edge, you'll only get wind in one direction.

BTW: The high and low pressure 'cells' spin in the opposite direction in the Southern Hemisphere.
  Reply With Quote
Old 06-04-09, 08:34 AM   #5
Cyclaholic
CRIKEY!!!!!!!
 
Cyclaholic's Avatar
 
Join Date: May 2005
Location: Sydney, Australia
Bikes: several
Posts: 4,270
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 68 Post(s)
"if everything appears to be going OK then you've overlooked the one thing that is going wrong" It's a corollary of Murphy's law.

It means that you can either enjoy the tailwind and ride into a rainstorm or you can ride away from the rain and into a tailwind. Simultaneously riding with a tailwind and away from a storm would contravene the fundamental laws of nature and cause the end of the universe.
Cyclaholic is offline   Reply With Quote
Old 06-04-09, 01:13 PM   #6
ghettocruiser
Former Member
 
Join Date: Feb 2005
Location: dropmachine.com
Bikes:
Posts: 4,062
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
As mentioned, most storms are convective, meaning air rises within them. In order the replace this rising air, wind blows in towards the storm at ground level from all directions.

The actual path of the storm is determined by high-level winds, which are often different from those felt at ground level.
ghettocruiser is offline   Reply With Quote
Old 06-04-09, 01:53 PM   #7
BarracksSi
Bike ≠ Car ≠ Ped.
 
BarracksSi's Avatar
 
Join Date: Jul 2007
Location: Washington, DC
Bikes: Some bikes. Hell, they're all the same, ain't they?
Posts: 13,858
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by norwood View Post
I'm not a meteorologist nor did I stay in a Holiday Inn Express last night, but I believe it has something to do with storm cells being typically low pressure areas. That is they tend to pull air currents (wind) into them. I could be wrong however.
Quote:
Originally Posted by ghettocruiser View Post
As mentioned, most storms are convective, meaning air rises within them. In order the replace this rising air, wind blows in towards the storm at ground level from all directions.

The actual path of the storm is determined by high-level winds, which are often different from those felt at ground level.
Yup, yup. A good storm can be drawing ground-level air into its base from quite a ways outside its cloud boundaries, especially while it's in its forming stages.

Most, if not all, visible clouds are from warmer, more moist air being pushed or lifted into cooler, drier upper air layers. Storms are just big, fast versions, and they're taking in a lot of low-lying air to build up like they do.
BarracksSi is offline   Reply With Quote
Old 06-04-09, 03:18 PM   #8
StephenH
Uber Goober
 
StephenH's Avatar
 
Join Date: Sep 2007
Location: Dallas area, Texas
Bikes:
Posts: 11,231
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
You tend to think of storms as big balloon-like objects that float along with the breeze. But they're not. They're caused by the interactions of different air currents, and that air can be moving while the storm is stopped. So two big air masses can move into each other, and the storm is the collision, which can stay in one place, even though the air masses are moving.

An analogy: You can have a waterfall in a river. The waterfall stays in one place, even though the the water is moving right along.
__________________
"be careful this rando stuff is addictive and dan's the 'pusher'."
StephenH is offline   Reply With Quote
Old 06-04-09, 03:33 PM   #9
BarracksSi
Bike ≠ Car ≠ Ped.
 
BarracksSi's Avatar
 
Join Date: Jul 2007
Location: Washington, DC
Bikes: Some bikes. Hell, they're all the same, ain't they?
Posts: 13,858
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by StephenH View Post
An analogy: You can have a waterfall in a river. The waterfall stays in one place, even though the the water is moving right along.
Interesting analogy. To apply it to a building thunderstorm, reverse it -- imagine the waterfall "falling upwards", which means that it'll have to suck water from the river beneath it. Near the "waterfall" (which might be called a waterspout at this point ), the flow of water is towards the "storm".
BarracksSi is offline   Reply With Quote
Old 06-04-09, 06:29 PM   #10
spinnaker
Every day a winding road
 
spinnaker's Avatar
 
Join Date: Mar 2005
Location: Pittsburgh, PA
Bikes: 2005 Cannondale SR500, 2008 Trek 7.3 FX, Jamis Aurora
Posts: 4,654
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Ground level winds will often change direction right before a storm. If it is windy and the wind suddenly drops, then picks up 180 degrees from where it was, it is time to run for cover.
spinnaker is offline   Reply With Quote
Old 06-04-09, 06:30 PM   #11
spinnaker
Every day a winding road
 
spinnaker's Avatar
 
Join Date: Mar 2005
Location: Pittsburgh, PA
Bikes: 2005 Cannondale SR500, 2008 Trek 7.3 FX, Jamis Aurora
Posts: 4,654
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Quote:
Originally Posted by BarracksSi View Post
Near the "waterfall" (which might be called a waterspout at this point ), the flow of water is towards the "storm".
Waterspouts are a really cool phenomena, I have had the pleasure of several in my life at a very save distance.
spinnaker is offline   Reply With Quote
Old 06-04-09, 07:08 PM   #12
Doug5150
Senior Member
 
Join Date: May 2005
Location: IL-USA
Bikes:
Posts: 1,661
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
In addition to the different wind directions at different altitudes, storms can push "waves" ahead of themselves, and the wind direction changes as these waves pass--the wind is forward (same direction the wave is moving in) in front of the wave, and reverses when the wave passes over and you're behind it.

http://science.nasa.gov/headlines/y2...ndularbore.htm
~
Doug5150 is offline   Reply With Quote
Old 06-04-09, 07:23 PM   #13
StanSeven
Senior Member
 
Join Date: Feb 2005
Location: No Va but ride also in So Md
Bikes: Cervelo SLC-SL, Guru Photon, Waterford, Specialized CX
Posts: 11,776
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 43 Post(s)
The short answer is highs and lows involve rotating movements from different directions. When they pass through an area, visualize what a counter-wise circular motion does.
StanSeven is offline   Reply With Quote
Old 06-04-09, 08:13 PM   #14
BarracksSi
Bike ≠ Car ≠ Ped.
 
BarracksSi's Avatar
 
Join Date: Jul 2007
Location: Washington, DC
Bikes: Some bikes. Hell, they're all the same, ain't they?
Posts: 13,858
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by spinnaker View Post
Ground level winds will often change direction right before a storm. If it is windy and the wind suddenly drops, then picks up 180 degrees from where it was, it is time to run for cover.
It's even cooler when your ears pop.

You'd think that my growing up on the Plains would expose me to more tornadoes, though. However, we knew that when the sirens sounded, it's time not to go looking for danger, but to the basement instead. I did catch one on video with a meteorologist-to-be college friend on a storm chase -- followed it 'till it roped out, too.
BarracksSi is offline   Reply With Quote
Old 06-04-09, 08:30 PM   #15
StephenH
Uber Goober
 
StephenH's Avatar
 
Join Date: Sep 2007
Location: Dallas area, Texas
Bikes:
Posts: 11,231
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Here's my graphical explanation. Warm moving one way, cold air the other, the storm is where they're colliding, and in this case is getting moved north like a zipper. Of course, real life is more complicated.
__________________
"be careful this rando stuff is addictive and dan's the 'pusher'."
StephenH is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 10:49 AM.