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Post by renard80 on Mar 21, 2012 12:04:27 GMT 1
I was taught that wide isobars on weather charts indicated gentle winds. This week's charts for southern UK showed high pressure well in charge, with very widely spaced isobars. Great for flying, I thought. However, the winds have been quite strong and blustery - indeed, today's local forecast showed those wide isobars alongside anticipated wind speeds of 10 - 11. I know I live near the coast, where winds are often stronger. But it seems odd that they are not lighter during the present settled high pressure. Just expressing my annoyance and puzzlement, that's all.  |
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Post by geoff2474 on Mar 21, 2012 12:27:07 GMT 1
Sorry to hear that Renard.
Wind speed in South Lincolnshire at the moment is zero with gusts of zero, and is expected to stay that way most of the day.
That means only one thing, the Radian takes to the air, closely followed by the SC and a couple of home builds.
Now how fast can I recharge those Lipos??
Geoff
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Post by flydiver on Mar 21, 2012 18:05:37 GMT 1
You need to know both the overlying weather pattern + pressures, AND the local influences on them.
Where I live (Seattle, Washington) we have a thing called the convergence zone. Stormy weather comes in off the ocean from the SW for the most part. It hits the Olympic Mtns. splits and comes out of the SSW up Puget Sound and then out of the NNW from the Straits of Juan de Fuca.
Where the 2 wind masses collide is the convergence zone. North or south of that spot it can be blowing 20-40 mph and be just about dead calm in the middle.
Any time you live in a coastal area the divergent heating of the land mass and water will affect wind. I've been windsurfing for years so have learned to figure out local phenomenon as well as I can. It saves a lot of driving and frustration. Turns out to be useful for planes also.
Anywhere near you with a nice long steep hill or cliff facing the oncoming wind? That's a good opportunity for taking up sloping. No more stupid motors or lipos - fly like a gull! It's a lot of fun and almost a different sport.
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Post by geoff2474 on Mar 21, 2012 18:42:37 GMT 1
Hi Guys
Just realised I may have confused some of our foreign friends with my wind speed report. I omitted to say if they were in Km/m, Ft/sec, Knots or Mph.
So to clear up any confusion, the wind speed today was zero mph, with gusts of zero mph.
You will find plenty of conversion web sites via Google!!!!!!!!!
Geoff
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Post by renard80 on Mar 22, 2012 0:27:55 GMT 1
Geoff, while you were enjoying your zero wind speed, down here in Southampton I went against my better judgment and flew my SC an hour before sunset, when we can often expect a period of calm. She battled against the wind, got blown across the sky, nearly had a fly-away on more than one occasion. Eventually I had to bring her down to avoid problems.  And still those very wide isobars are on the weather chart! Fly, I'm sure you are correct about localised weather conditions. The weather chart on TV this evening showed anticipated wind speeds of between 4 and 6 mph for this area - except for just one marker showing 11mph, more or less where we are. Also, there is a shallow valley near us, in line with the sea. In the valley is an ancient preserved windmill, formerly used for grinding corn. Those old millers knew a thing or two about wind, they had to because it was their livelihood, and so they would choose the site which got maximum wind most of the time. Personally, I blame the Government . . . |
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And still those very wide isobars are on the weather chart!