Kalmus meter VS West Dennis meter

[shreddbob]

Iceratz, yes you do have many years experience as indicated by referring to the "Wind Hotline"! I too go way back. You are right on with the WSW, SW at Kalmus and the headlands plus venturi effects. I've seen this boost Kalmus over W. Dennis especially on days where the water is much cooler than the air. As for tides, consider the water cooling affect of a high tide and the water warming at low tide. For humid and warm/hot winds you'll get better coupling of the wind to the water (overcoming the cold layer of temperature inversion at the water) plus best sea breeze enhancement when the water is about 8 - 15 degrees cooler than the air over nearby land away from the beach. This effect is more important, in my opinion, than ingoing vs. outgoing tide. Usually low tide (warmer water) is best for wind to water coupling. Except for perhaps right now when water is around mid 70's and air in low 80's, and we may actually do better with the high tide bringing in cooler water. (In late summer I've seen the wind die during the few hours around low tide at W. Dennis many times.) Of course if the pressure gradient (isobars) are stronger, then the water temperature factor can be negated.

I also agree that W. Dennis loves a SSW or South wind--provided the water's not too cold.

As far as best formed swells (versus nasty chop) I've found incoming tide, 'til about 1 hour or so after high tide, better at W. Dennis and on Buzzard's Bay. Kalmus gives best swells at low tide, on far side of the channel (while dodging nasty boulders).

[iceratz@comcast.net]

[djs789]

Iceratz: , but neither tidal flow nor current contribute in any measurable way to wind strength, either true or apparent.


Yes, Tide will not make a difference in the what a wind meter on land will read, but If the tide is for instance opposite the wind direction, when sailing the wind you experience will be stronger. Here is why: You are not observing the wind from a fixed point on earth. You are in the water moving with the current in the opposite direction as the wind. So you will experience a stronger wind. For instance, if the wind is 18 knots and the current is 2 knots, you will experience 20 kts. Furthermore, you should rig for 20 kts. This is a similar to apparent wind. Draw a vector diagram if you don't beleive me. By the way, the opposite is true if the tide is travelling with the wind you should rig for 16 knots. But again the wind meter doesn't know the difference.

The wind meter would know the difference if it was floating along with the current though.

Whether you travel faster or slower with the incoming or outgoing tide with respect to the earth (GPS) is another story. I don't think you can say in general...it would depend on alot of factors.

Interesting discussion, thanks

[iceratz@comcast.net]

[lasrer]

Trust the experience of the Iceratz.

He knows this area very, very well.

He also saved my life 20 years ago when my rig and board separated in nuclear conditions in the Gorge and he recovered it.

Thanks Iceratz!

ed

[djs789]

Iceratz wanted to know...

[iceratz@comcast.net]

Hey that's a 'cool' review of the facts! Thanks for the calculations.
I have a lot of experience sailing on ice and notice the difference easily on many days with varying temperatures.
The coldest day so far was -11deg F, and it was blowing 20. Wind chills were in the dangerous regions with frostbite.
The sail felt quite powerful that day.