Winter Forecasts

Lets start with the basics. In the cool season the North Pole is pointed away from the sun. As the polar regions lose solar heating and the days shorten, the atmosphere cools significantly, and we see a huge semi-permanent polar air mass covering much of Canada and northern Russia. Parts of it break off regularly as frontal systems and polar highs. The large expansion of the cold air mass boots the jet stream out of Canada, pushing it down into the United States.

Tim Vasquez

Saturday, October 20, 2018 at 12:00 AM ET

Verified

Key Takeaways:

Winter weather is characterized by the expansion of polar air masses, the jet stream shifting into the U.S., and continental cooling, which reverses seasonal wind patterns and can lead to moisture-rich events like the Pineapple Express.
Pilots need a strong understanding of fundamental meteorological principles, such as interpreting wind direction and temperature, as rapidly changing winter conditions can challenge even sophisticated models due to limited upper-air observations.
Icing is a critical winter concern, with various types (clear, rime, and dangerous supercooled large droplets or SLD) influenced by factors like cloud depth, precipitation, terrain, and frontal systems, necessitating careful planning and escape strategies.
Winter also brings an increase in both mechanical and clear-air turbulence, driven by stronger winds, wind shear, and atmospheric instability, requiring pilots to be vigilant about conditions that enhance these risks.

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In WX SMARTS, rather than teaching weather safety, we put you at the forecast counter and immerse you in the preparation of TAFs, area forecasts, and advisories. In addition to knowledge gained, this allows you to select the tricks and techniques applying most to your flying. With November approaching, it’s a good time to review what changes we can expect.

Cooling Things Down

Let’s start with the basics. In the cool season the North Pole is pointed away from the sun. As the polar regions lose solar heating and the days shorten, the atmosphere cools significantly, and we see a huge semi-permanent polar air mass covering much of Canada and northern Russia. Parts of it break off regularly as frontal systems and polar highs. The large expansion of the cold air mass boots the jet stream out of Canada, pushing it down into the United States.