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Old 02-11-19, 04:22 PM
Jim from Boston
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Originally Posted by noglider View Post
@Jim from Boston, where do you get wind speed and direction? I haven't found an accurate web site.

Maybe it's hard to do here, as the wind speed and direction varies from one spot to another because of how the terrain shapes the wind. There are some spots that normally have wind in reverse direction at almost all times, so I'm observing eddies.
Since I commute in a relatively straight Southwest direction, if the wind direction seems constant along the route, I record the speed from at the beginning of the ride.

More relevant to me is my 1 – 6 scale:
Originally Posted by Jim from Boston View Post
On my Excell spreadsheet I track:...

Wind speed and direction: Either as recorded on a weather station, or on a personal 1 to 6 scale (headwind / tailwind) based on flying flags; to explain variations in average speed......
Originally Posted by Jim from Boston View Post
Here in Boston, wind speeds of 4 of 6 on my scale are rare, less than once a year, and gusts do have the force to push me laterally. I don't conscientiously think about falling tree limbs, but such usually occur with rainstorms that dissuade riding.

It's useful to assess wind speed and direction because on good and bad riding days, sometimes it's hard to know if it's me and my energy levels or the wind that's responsible.

My most dangerous wind riding was along the South Rim of the Grand Canyon, with gusts that vigorously pushed us laterally to the left; about a 5 of 6, graded retrospectively.

Originally Posted by Jim from Boston View Post
My idea of a 1 to 6 scale of wind phenomena (waving flags) to guage wind force (speed) is based on the formalized Beaufort Wind Force Scale.

The Beaufort scale is from 1 (calm) to 12 (hurricane force) and the determination of the scale number is based on defined observations of phenomena such as rising smoke; papers, dust and debris on the ground; wave heights; flags; umbrellas unfurling, etc
Originally Posted by Wikipedia
The Beaufort scale is an empirical measure that relates windspeed to observed conditions at sea or on land. Its full name is the Beaufort wind force scale

Today, many countries have abandoned the scale and use the metric system based units, m/s or km/h, instead,but the severe weather warnings given to the public are still approximately the same as when using the Beaufort scale.
Originally Posted by Jim from Boston View Post
On review of the Beaufort scale descriptions, I would estimate my determination of 4 of 6 equivalent to the Beaufort number of about 5 of 13 (“fresh breeze” ;wind speed of 19-24 mph/29-38 km/hr).

One standard for assessing wind speed with a weather vane or flag, is that it should be unobstructed, and about 20 feet above ground. I make my determination on flags of at least a few feet in length.

The Beaufort number of 3 (“gentle breeze,” 8-12 mph) is identified when “Leaves and small twigs in constant motion; light flags extended.”

My personal 1 to 6 scale is a handy way to make that assessment en route. BTW, I have found a semi-quantitative scale of 1 to 6 a pretty suitable estimation for wind speed; I also use such a scale to evaluate my levels of dress by temperature increments.

I picked it up on a whitewater rafting trip when I learned the difficulty of rivers is determined as 1 to 6.

Originally Posted by kbarch View Post
Jim's 1-6 scale reminded me of the Beaufort scale, which goes to 12 (for hurricanes) - and I suspect the numbers are fairly close, seeing how a 6 on the Beaufort scale is a "strong breeze" of 25-31 mph.

It isn't until you get to an 8 or a gale that twigs get snapped off and progress gets generally impeded.

I always liked the description of 5 on the Beaufort scale: Fresh Breeze. Sounds nice, but at 19-24 mph, above most cyclists' comfort range.

Seems like many cyclists start to be dissuaded when there's anything more than a Gentle Breeze.

Last edited by Jim from Boston; 02-11-19 at 06:56 PM.
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