FLYING Magazine News Pilot Proficiency Weather

How to Decipher Flight-Level Weather

Here are some tips for finding the smoothest air to fly in.

Friday, November 01, 2024 at 09:32 AM ET

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Most pilots have access to a ton of weather guidance, but if you are routinely flying in the flight levels, here’s one more product to add to your list—constant pressure charts. [iStock]

Key Takeaways:

Constant pressure charts (upper-air charts) offer crucial "big picture" weather insights for pilots at flight levels, providing details on wind, turbulence, and weather system evolution that surface charts lack.
These charts depict lines of constant *height* for a specific pressure level (e.g., 500 mb), where lower heights (troughs) indicate colder, denser air and adverse weather, while higher heights (ridges) signify warmer, less dense air and typically fairer conditions.
The 500 mb chart is particularly valuable for diagnosing weather system intensity, evolution, and extended-range forecasts, helping pilots identify specific flow patterns (e.g., split-flow, sharp V-shaped meridional flow) indicative of moderate to severe clear air turbulence.
Pilots can access these advanced weather charts, which are often unavailable in typical aviation apps, through the National Center for Environmental Prediction (NCEP) website.

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Understanding the big weather picture is key to making good operational decisions. Most pilots have access to a ton of weather guidance, but if you are routinely flying in the flight levels, here’s one more product to add to your list—constant pressure charts.

Constant pressure charts not only help you with the quantitative aspects of your flight, such as finding the best altitude to minimize your headwind component, but they also help you with a few qualitative aspects, such as minimizing your exposure to uncomfortable clear air turbulence if you know what to look for.

Scott Dennstaedt, Ph.D

Scott resides in Charlotte, North Carolina, and flies regularly throughout the Mid-Atlantic and Southeast U.S. He is a CFI and former NWS meteorologist. Scott is the author of "The Skew-T log (p) and Me: A Primer for Pilots" and the founder of EZWxBrief.