Can we talk about this prevailing-winds-west-to-east thing?
 

This is, right now, a theoretical discussion, but there seems to be a pretty well-known idea that the winds across America blow from west to east, therefore anybody biking across the country from east to west is going to face lots of headwinds whereas someone going the other direction will have the wind at their back all the time. Whenever someone's asking questions about a cross-country tour, they're inevitably warned against going east to west since they'll be biking into the wind the whole time.

I do have some friends who biked west to east (northern tier) and swear this is true, but as the saying goes, the plural of anecdote is not data. I personally have a hard time believing this, and will until I hear it from a meteorologist or some other evidence-based source rather than hearsay and the accounts of a few cross-country cyclists.

There are others that share my skepticism, who say things about local wind conditions being more relevant and that those aren't consistently in one direction, and of course plenty of personal stories about people who biked west and had no bad experience with wind - or whatever. However, people who do believe in the wind thing swear that its true, not based on any evidence I've seen, just with the insistence of a commonly-known fact, like that you have to watch out for mosquitoes around water in the summer.

What's your take? Do you have any personal experience with this? Any scientific perspective? Googling hasn't shown up much so I'm wondering what people think.

John Meiners toured the TransAm Trail in 2010. He took wind measurements just about everyday at the about the same time of day. Here is the link to his most excellent results:

http://www.crazyguyonabike.com/doc/p...id=132132&v=DY

Jude, The prevailing wind direction in the US is West to East. The wind direction at one particular place and time in the US depends on other factors such as the jet stream and low level high and low systems and your position in relation to them.

For long range weather predictions a friend once told me to buy a Farmer's Almanac.

Brad

NY to LA. Rode this route summer of 2009 June 25 to August 22. Wind was not a problem.

http://i256.photobucket.com/albums/h...ictures010.jpg

I guess this is why I'm skeptical. I keep hearing "prevailing winds" thrown around as a phrase - but what does it actually mean? That, overall, wind is more statistically likely to blow toward the east? That there's some larger system of winds blowing eastward? In any case, it seems the second part of your first paragraph is what's relevant - unless the "prevailing winds" mean that wind is blowing eastward more often, then it's hardly relevant to biking, right?

+1. And a veteran of the Northern Tier west to east (a portion of it I have done twice), I can tell you that I did not constantly have the wind at my back. On the High Line in Montana we generally had west to east winds, and they were often strong. However, in ND we had several days of nasty headwinds and crosswinds. We had headiwnds in MN, IA, IN and OH that I can remember. Climbed Kagamagus into a headwind produced by a storm. Get a summer system of warm, humid air rotating out of the SE and instant headwind if you heading east.

Just this summer I was on part of the Trans Am route heading "east" between Missoula and the "east" side of Big Hole Pass. Headwinds those two + days. The minute we turned roughly NNW on the Pioneer Mountains Scenic Byway we picked up a tailwind. And I had some days of headwinds riding "east" on the Trans Am from Missoula to Fairplay, CO back in '00.

I put east in quotes because you are not always heading east when riding from the west coast to the east coast. MN on the NT route is a good example. Lots of SSE riding. Heading roughly south back into the U.S. from AB was an extremely hard day thanks to a headwind most of the way.

Personally, average temperature and humidity levels would be more of a consideration than wind direction.

uh 10 Wheels... which way did you ride? :D

My experience has been that when you do get a west>east tailwind, it will, on average, be stronger than east>west winds. In the SW, there is no doubt, from several trips, that the prevailing winds are west>east. Conversly, I have experienced many days of light easterly winds on the NT and on a trip from La to Fl. East of the Mississippi, the winds are more likely to be lighter and more variable than west of the Mississippi.

In West Texas, Oklahoma, all you gotta do to see where the prevailing winds come from is look at the direction the short trees are leaning.

From the Great Lakes and northeast, the prevailing wind are definately from the west or southwest (like 70-80% of the time). I've been working as a weather observer in Quebec for 13 years. I've worked in several stations in the province and toured all over eastern Canada. There are also stats about it. The trees are bent towards the east. I always plan with the prevailing wind in mind and never regretted it.

I forgot...I had picked this illistration of July Prevailing winds up somewhere.

Edit. I picked this up in the 1916 Annals of the Association of American Geographers, Vol VI,
"The Prevailing Winds Of The United States", by Robert De C. Ward

Granted it was 1916, but to say it has changed drastically may be reason to agree with the highly contested subject of "Global Warming"...so beware! LOL! :)

NY to LA

I used to fly ultralight aircraft. When you fly these little gems you are expected to learn the fine art of micrometeorology. I do believe cyclists could benefit from same. This myth of west to east winds would not exist if more people understood how the weather is generated...not just from jet streams and high/low pressure cells but also from the nearby terrain.

4 rememberable headwind days going West to East on the Northern Tier. Second week in June start.

4 rememberable tailwind days going South then West to East Starting Cedar City to Phoenix then across. Mid September beginning.

After the trip I learned about two things. Monsoon winds of the SW and http://www.tceq.texas.gov/airquality...windroses.html The texas wind roses were spot on except when the first of the fall storms were blowing through.

The first time down the west coast was all tailwinds on the second try 50/50 due to two weeks of mid-lat cyclones bashing the PNW. The normal high pressure over the interior never had a chance to set up.

Hmm, it's more complicated than I thought.

West winds are more common than east winds here in SW Ohio. However, the fantastic weatherspark.com has a nice local averages page. Scroll all the way down to see average wind speeds and directions.

S, SW, and W winds are the most common here. And windy days drop in the summer, along with very few W winds, and more NE winds.

http://fs.weatherspark.com.s3.amazon...ercent_pct.png


Wind speeds:

http://fs.weatherspark.com.s3.amazon...dSpeed_mph.png





Fraction of time spent with various wind directions, including calm days in white. Note that the graph doesn't go to 100%, the rest is calm, too.

http://fs.weatherspark.com.s3.amazon...ercent_pct.png


~~~~~~~~~~~~~~~~~~~~~~~~~~

Compare with Clinton, Iowa for example:

http://fs.weatherspark.com.s3.amazon...ercent_pct.png

Or Albuquerque, NM:

http://fs.weatherspark.com.s3.amazon...ercent_pct.png

Mechanisms, the planet rotates in its atmosphere.
the temperature draws cold dense, to replace hot rising air..

Mr. Clements, said something like the 'the coldest winter spent was a summer in San Francisco'

the central valley is hot, then. connected by the Carquinez straights, thru the delta,

I've seen it, lived in the fog belt just south of the Park.
the Golden Gate does a fine job of sending a narrow band of fog directly at Berkeley..
Like laying out toothpaste from the tube..

Oregon Coast , summer [july, august], has prevailing wind from the NW,
winter storms Usually from the SW, rather than Arctic off AK.


there are Microclimates even within this town .. vine ripened tomatoes
on the south side , not on the other side of the hill.

I heard the same sort of stuff, and I finally started asking people, "Did you lose any tree limbs when the wind hit 130 mph last weekend?" After "No," then "Huh?" I explain that the prevailing W-E winds are in the jet stream. The fact we may not have had more than a 7 mph breeze then starts to filter into their mind, usually followed by, "Oh! So the winds at ground level aren't always west to east?"

At some wind speed, just the fact that there's a crosswind starts to feel like a headwind. 20 mph SSW feels like it's in your face going west.

Kansas, for instance, felt like one long 15-25 mph headwind going west. (Pete Staehling will tell you it was a worse headwind going east the previous year!) Check out http://www.wcc.nrcs.usda.gov/climate/windrose.html for Wichita, KS, in June, and you'll see the wind's almost always out of the south, +/- 30 degrees.

FWIW, our worst headwind was from Windy Gap through Jeffrey City, WY to Sweetwater Crossing. That was painful, and cost us a day to recuperate. Now THAT was a headwind!

This is great!

Funny story. I had two friends with when I did that segment. It was hell for them, one of the worst days of the ride. If you ask them about headwinds, they'll bring up southern Wyoming. On that day, I was a few hours behind. When I got there, the wind was gone. You really can't count on anything, when it comes to wind...

In Kansas, we had tailwinds most of the time. In Wyoming, it would often be a headwind in the morning and a tailwind in the evening. We quickly learned that while in Kansas it was practical at times to wait until night to ride, in Wyoming the wind doesn't care what time it is. Sometimes it would actually pick up at night.


We traveled west, be the way, and any trouble with the winds was worth it for the fact we didn't have to climb up the rainy side of the bitterroot or cascade mountains. I've heard the eastward climb from Eugene to Mackenzie pass isn't actually that bad, but I don't believe it.

Last year I rode W-E and the wind was mostly NE or SE. This year I rode E-W and the wind was mostly SE. (my wind direction observations are based on my time through the plains, when the wind really matters. last year my plains were Kansas and this year North Dakota)

If I had a preconceived notion that the wind tends to go E-W, I would have confirmed it based on my experiences, but most people assume the opposite direction to be the truth.

I believe that the wind does what it wants, and you should just expect a headwind every day.

Two cyclist meeting on the road, one heading east, the other west, each will be fighting a headwind. Just the way it is.

Here my 2 cents. I answered the "why are you riding against the wind" question so many times prior to the start of my modified Northern Tier ride, I decided to keep track. Here's a cut and paste from my crazy guy journal:

For those of you who skipped to the end and have missed out on this discussion, the decision to ride 'against the wind' by going east to west has been quite a topic of conversation. Enough so that I decided to document the wind direction as we rode in hopes that others might be able to make such decisions based on fact rather than common presumption. This might be a good time to say that I would not attempt to repeat this trip in hopes of doing any better with the weather. We had some cold rain for the first part of the ride but after that, the weather was about as good as I could possibly have hoped. The promised west wind in the Columbia River Gorge was a downer, but it wasn't crippling and would have been much less of an issue had we broken that portion of the ride into smaller segments, or (heaven forbid) taken a day off somewhere during that stretch.

For the purposes of my very informal survey, the following definitions apply:

Headwinds: Strong enough that you would not want to ride without draft partners.

Crosswinds: Strong enough to cause handling problems when passed by trucks.

Tailwinds: Strong enough to easily add 3-4 mph to our average speed.

The day got a mark if the wind was a factor for more than 3-4 hours.

Direction Head Tail Cross
N 0 0 0
NW 2 0 0
W 3 0 1
SW 3 0 2
S 0 1 2
SE 1 2 0
E 0 2 2
NE 0 0 0

You can see the results and draw your own conclusions. As for me, the benefits of riding east to west far out-weigh the hassle of just a couple of extra days of headwind.

Well, i can't seem to get the columns to line up but i trust you get the idea.

I have no doubt there are some very detailed records of wind trends for almost everywhere in North America. I went from Ashland Oregon to West Yellowstone Montana and had massive tail winds for much of it, maybe one day of headwinds the whole way. I left Ashland on Labor Day. When I would motor by a rider struggling east to west at a snail's pace I felt sad for them.

My thought is that, while overall the west/east wind thing is a wash, in certain locales there is a definite prevailing wind. However, on any given day, things can change. The comment about the terrain having a big effect also seems right to me.

I regularly ride Los Osos Valley Road, which starts in the oceanside community of Los Osos, California, and heads east into San Luis Obispo. Typically, in the afternoon, the wind blows in from the ocean and down the valley, all the way into San Luis. If you go that way, it almost blows you into town. Riding back against the wind is tough. This is about 95% of the time. Occasionally, though, the winds will reverse. In the morning the wind usually blows lightly in the opposite direction. A really nice loop is to start in San Luis in the morning, ride out to Los Osos for lunch, then ride back to San Luis in the afternoon. The wind will be at your back for most of the loop.

This is probably useless for most people (although Los Osos Valley Road is on the coast route), but my point is that in certain locales there is a definite prevailing wind direction, and it can make a difference; there might be a good reason to choose one direction over another when riding a certain route.

I rode the Lewis and Clark route from Portland to Missoula a couple years ago. I remembered all the windsurfers/kite boarder on the Columbia River between Oregon and Washington. That affected my decision to go west to east. It turned out to be valid. The wind pushed me hard from behind, day after day, until I left the Columbia. Going the other direction would have been unpleasant.

When I've ridden down the west coast (twice) I've gone north to south. It wasn't as windy as the Columbia Gorge, but there were more days with a tailwind than with a headwind.

The ONLY thing that counts is karma. The fastest way to accumulate bad karma is to apply human reasoning when discussing or second guessing the wind.