We're supposed to go to Rainbow Lake today, but the customer doesn't want to go if we can't get back. Rainbow Lake, despite the lovely name, is a less hospitable place to spend ones free time than Moose Jaw. Before I understood the customer's priority I said cheerfully that it wouldn't kill me to spend the night in Rainbow Lake, and was rewarded with a look of uncertainty. Perhaps vampires roam the streets of Rainbow Lake after nightfall. Popular culture would imply that vampires were a little trendier than that, though. The single eating/drinking establishment there is described to me as having tables made out of cable spools, with cigarette-burned tablecloths stapled to them. I accept their priorities and study the weather forecast.
There is a front moving in from the west that will drop ceilings, visibility and eventually snow. It is forecast to reach Fort Nelson just as I'm scheduled to be returning there, but should remain within VFR limits for a couple of hours afterwards. The progress of the front has not been out of line with the forecast, but that sort of thing is difficult to gauge across the BC mountain ranges. I use my piloty skills and experience to say yes, we can go to Rainbow Lake and return before the weather cuts off our return.
Rainbow Lake, despite the fact that its airport identifier resembles a Russian obscenity, has quite a nice airport. The runway is paved, wide, fairly level, and has a large apron. The trip out there is uneventful and the weather stays good at Zama Lake too.
I use the phone in the fuel shed to all flight services for a weather update while I wait for the on call fueller. The front is still moving pretty much as forecast, so the weather I'm copying down as the briefer reads it over the phone is pretty much what I was expecting. The current weather is better than the earlier forecast and the forecast is almost symbol for symbol identical to the earlier one, but then the briefer continues "... and from 22Z to 24Z a 40 percent probability of freezing rain." It's 2145Z now.
"What?" I say, even though I heard him perfectly. I really should have expected it. The approaching warm air mass is a little warmer than expected, so that instead of snow it might produce rain as it overlaps the cold air mass that is present now. But when rain falls through cold air it turns cold, and can be chilled below zero celsius without turning to ice. That is freezing rain, and when you fly into it, it builds up on the airframe, causing severe icing. I do not want to be flying in freezing rain. I ask the briefer a few more questions to get a picture of speed and direction and options.
"Is there anything else I can do for you?" he asks.
"Make it not be freezing rain?" I suggest, but he can't help me there.
I have the fueler put on enough fuel to get me back here if I have to return, but not ful tanks, to save time and weight. We load quickly and I think there's less than a minute on my watch between engine start and take-off. I'm flying west, conscious that I'm peering intently into the sky ahead as if I could see ahead a hundred miles and forty minutes to know what I will encounter.
The ceiling comes down a bit as I approach destination, but there is no precipitation and then I hear a radio call from a pilot doing a practice hold at Fort Nelson, in the same aircraft type as I am flying. No pilot would be out in one of these in freezing rain if he had a choice, and a training flight is clearly a choice, so I can relax a little. The FSS gives me traffic information that allows me to merge efficiently with other incoming aircraft.
The rain is just starting as I am putting the covers on the wings. They are going to be needed tonight. I'm happy that I came through for my customer with an accurate prediction of our ability to do the work, and I'm happy not to be in Rainbow Lake tonight.