The Cloud from Hell

The cloud is at least 20 Km away and
conditions are almost soarable as
the tandem pilots get ready

Today's forecasts varied but all seemed to show XCs as possible but probably unspectacular. Up on launch everything seemed fine with cycles slowly building. But far out to the NW was a strange wall of cloud with some embedded cumuli. It wasn't like anything I'd seen before - it looked more like a front than a cloud - and I was a bit wary.

After a while, people started launching and were getting above launch easily. Just as I was ready to go, I noticed a big flush cycle. I waited a couple of minutes, and the wind dropped and then, a couple of minutes later, started coming over the back. The cloud was now nearer and was reversing the wind direction - it still looked strange but not threatening in a cu-nim way. A whole group of pilots were stranded on launch.

The cloud is causing a flush cycle and will
soon reverse the wind flow

After about 45 minutes of this the cloud passed over and the wind slowly started coming up the hill again. 5 minutes later it was clearly blown out. Launch conditions after 1 pm are typically strong and the added cloud suck put things over the top.

Frustrating but also interesting...