Wind vs Wind Gusts and Beaufort scale

Posted by Mehfisto666@reddit | sailing | View on Reddit | 7 comments

Hello,

after 3 years working on passenger vessels and one year of costal sailing I still have a bit of trouble understanding the weather / weather forecast.

I'm located in North Norway, and if I learn something in this last year of sailing, is that whenever the forecast shows wind(wind gusts) for example: 5m/s wind (10m/s gusts) I should completely disregard whatever the wind forecast says and just look at gusts cause that's what i'll be consistently sailing in.

It honestly feels like the opposite, that it will be full on 10m/s winds with some brief relieves down to 5m/s

Now, on thursday there is quite the storm coming and I was looking up windy out of curiosity and it's calling for 40kts wind with 65kts wind gusts.

On the Beaufort scale that makes quite a difference ofcourse as it goes from gale / strong gale all the way up to hurricane-force.

So how should I read this? is it considered hurricane as soon as it's gusting up to 64+ or would that still be considered "only" a gale?

or should it be looked at in conjunction with other factors?

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ppitm@reddit

5m/s wind (10m/s gusts) I should completely disregard whatever the wind forecast says and just look at gusts cause that's what i'll be consistently sailing in.

5 m/s is the most "consistent" windspeed, but of course you still need to contend with the gusts. You need to reef a keelboat for the gusts, generally speaking.

Sustained winds are what determine hurricane-force storms. Gusts to 60+ kts are not at all uncommon in winter storms with no hint of tropical weather.

LameBMX@reddit

I wish this was always the case. round these parts, it seems to be more a min/max. often went out 14 knots gusting 20 knots. only to put a reef in because it's really 20 knots lulling to 14 here and there.

nomadicSailor@reddit

This totally depends on the boat. In a displacement, ballasted boat, reef to the consistent speed and let the boat heel in the gusts. Feather up, and climb to windward going uphill, head down and let 'er rip if going down.

In a catamaran, reef for the anticipated gusts unless ya like swimming....

it literally only dropped to 14 for about 5 seconds every half an hour. I'm agreeing with a previous comment, the consistent speed forecast isn't always the consistent speed you get on the water.

FlickrPaul@reddit

Other factor:

Being in a Northern climate you must also consider the air temp, as colder air is more dense and as such 20Knots at 25C is very different to 20Knots at 5C.

IvorTheEngine@reddit

Air density changes in proportion to the temperature in Kelvin, so that 20 degree change only causes about an 8% difference in density.

so 8% more lift on the sails... thats pretty significant. even though it's a small portion of that lift, some is going to have very high leverage aloft.

People be tweaking and tuning things for far less than an 8% increase in power.