It’s all in the spread.

Bob’s on vacation and I had a solo flight booked. I’m finally cleared to do those power on stalls solo and I was determined I was going to kill this particular demon once and for all and have another bash at the forced approaches. Always good to keep them fresh and clear in my mind, as well as the other airwork that I need to practice.

As usual the weather had other ideas. The day before I woke to a completely white vista, fog so thick you couldn’t tell there was an outside world. It’s been a feature of our summer this year. Temperatures have been a lot cooler than usual but the air is still as humid as ever.

One lesson I managed to retain from my painful attempts to hack my way through the required knowledge for the meteorology exam was the conditions that are conducive to fog formation. Temperature and dewpoint close together and light winds usually equal fog. Because the temperatures have been low, fog has been common.

Sure enough on the day of my lesson I woke up to low ceilings and IFR reports at the airport. This is the METAR/TAF from about an hour before I needed to leave. Even though the ceilings were predicted to lift, it wasn’t going to be enough to do any upper airwork.

More worringly was the view out to the west. Barely visible in the photo but painfully obvious to me was a bank of fog sitting just over the Humber Bay.

Having lived here long enough now, I know that the situation could change very quickly. Or stay static. It was so hard to predict. If the temperatures warmed up, the spread would increase and the fog burn off (that happened the day before) but equally possible was the fog staying around or getting worse.

So I cancelled. Quelle surprise.

As it turned out the ceilings varied between 800 and 3800ft for the entire morning. The fog waited until later.

Maybe I could have flown. I certainly couldn’t have done the upper airwork that I wanted to.

Sure enough, later that evening, as the temperature dropped I looked out the window and saw that the airport was gone.

This photo shows that the fog bank starts off as a thin layer.

And then creeps over the buildings.

It is very very eerie to watch, but fascinating none the less. But you don't want to fly in it.