So we’ve all just enjoyed the 4-day weekend, and for once the weather was very nice. For sun-bathing and barbecuing that is. For gliding, it wasn’t so great.
For the non-glider pilots, you must be thinking, surely a sunny day is a good thing?
Unfortunately, although there was plenty of heat in the sun, the problem was caused mainly by the high-pressure weather system, which put in place an inversion. This in turn meant that thermals took a long time to develop as a critical temperature had to be reached before they could break through the inversion. And even when they did, many of them were ‘blue’ (invisible) and/or weak and broken.
Again for non-glider pilots, we generally get inversions when there are established high-pressure weather systems. In summer, you’ll see this on the ground as hot, hazy weather with Easterly, or South-Easterly winds. The longer the HP system is in place, the stronger the inversion gets, and the visibility becomes hazier. The inversion traps airborne pollutants and dust beneath it, giving rise to the smog warnings that some of the UK had over the weekend.
If you went up in an aircraft, you would be able to see the inversion at certain heights. It usually looks like a pale cream-to-yellow stain on the horizon, above which the air is usually a lot less hazy.
Why is it called an inversion? Because it does the reverse of the normal situation – instead of the temperature decreasing with height, it increases. Quite why this happens, I don’t know – you need to ask someone whose meteorological knowledge is much better than mine!
Anyway, the net effect is that the conditions are not good for gliding. Weak, scrappy thermals in a sky with no clouds leads to a very hot and sweaty cockpit, not to mention the pilot! At least normally when there are clouds, if you fly under them you can hide from the sun and cool off a bit!
Despite the weather, we managed to set tasks for the Inter-Club League on two days – Sunday and Monday. These days showed improved conditions, but they still weren’t perfect.
Still, there’s hope for next weekend.
For me, one highlight of this weekend was that I finally persuaded my Dad to fly with me. I’ve been flying for 17 years, and an instructor for 5 years and this was the first time he’d agree to fly with me. I think he even enjoyed it too!
Well done – Glad your Dad finally flew with you. I remember when my parents used to come with me when I was having my PPL flying lessons (I hired a Cessna 172 instead of the 2 seat Cessna 152 + instructor)- I think they were really proud, especially when I was solo, both power and when I got my gliding instructor rating.
Really glad you have got back to flying now you are a MUM!
By: Sue A on April 28, 2011
at 2:15 pm