Go or no/go?

Winter flying and its unique challenges

January 2, 2024 By Ian J. Twombly

Flying in the winter can be a major drag.

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Low and overcast ceilings, icing potential, and strong winds can all join forces to make you long for the bumps of summer.

A marginal day in early November in the Northwest mountains is a great example of what late fall and early spring can bring to the area. A low-pressure system spinning off the coast is pulling moisture from the Pacific Ocean and dumping it east along an advancing cold front. You are trying to fly VFR in a Cessna 172 to see a friend, west at 10,500 feet from Pocatello, Idaho, to Burns, Oregon, early in the morning. You wake up to overcast skies and light winds, and about 40 degrees Fahrenheit.

Checking the forecast, it’s clear there is rain along the route. There’s a high-pressure system over southern Idaho, but the cold front that’s pushing east is bound to knock it out of the area. The radar doesn’t look promising with rain to the north of the route, sliding generally east, and heavier stuff to the west of your destination, also heading east.

You check the METARs and are surprised to see overcast ceilings of about 6,500 feet in Pocatello, 8,000 feet in Boise along the route, and 9,000 feet at your destination. Even the worst of the precip is in an area of ceilings at 8,000 feet. However, there are airmets for mountain obscuration, icing at 9,000 feet msl, and IFR along the route. Oh, and the headwind is 20 to 40 knots on the nose.

The forecast looks to be pretty stable, with rain at each of the three stations, and ceilings of 5,000 in Boise and 4,000 in Burns. Surface winds aren’t a concern. The temperature will hover around 50 for your arrival in Burns and be between 46 and 49 in Boise as you transit. Temperatures aloft are between 0 and 5 degrees Celsius at 9,000 feet, with the freezing level around 10,000 feet.

So, are you headed to the airport or back to bed?

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A: What I would do

By Dave Hirschman

This flight looks like it can be done safely in VFR conditions, but it’s likely to be turbulent and slow. And when the pilot eventually gets to Burns, they’re almost certain to be staying there for a few days until the weather clears for a return home.

Visibility looks good along the route, and the colorful composite radar images are almost certainly showing moisture at much higher altitudes than this Cessna 172 pilot intends to fly. The relatively high freezing level also bodes well. As long as the pilot stays in visual conditions, structural ice won’t be a problem. The biggest potential showstopper is turbulence. Strong winds at high altitude colliding with jagged mountains are almost sure to create sharp jolts along much of the route, especially on the lee side of mountain passes.

But adequate ceilings provide sufficient terrain clearance as long as the pilot follows the time-honored mountain-flying practice of sticking to relatively low elevations on the route (basically, following the Snake River to the Idaho/Oregon border, then tracking the Malheur River to Burns).

This is sure to be a challenging flight with the pilot’s seatbelt cinched tightly the entire time. But there is good radio and radar coverage along the route so the pilot can keep informed about changing weather conditions, and there are many diversion airports and ample areas to turn around if necessary.

I say go and enjoy Burns, but expect to stay there for a while.

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Ian J. Twombly

Ian J. Twombly is senior content producer for AOPA Media.

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Go or no/go?

Winter flying and its unique challenges

A: What I would do

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