St. Louis to Phoenix Turbulence Forecast

STL → PHX · 1,259 miles · ~3h 1m

What to Expect

The St. Louis to Phoenix route, heading west over 1259 miles, definitely has some unique turbulence considerations. Crossing the Mississippi Valley means you might encounter convective turbulence, those bouncy, localized bumps caused by rising warm air. Next up is Tornado Alley, notorious for severe convective turbulence, especially during certain times of the year. As you move into the Great Plains, be prepared for clear-air turbulence (CAT), which can happen even on a seemingly clear day due to wind shear. Approaching Phoenix, the Southern Rockies can bring mountain wave turbulence, and the Mojave and Sonoran Deserts often see thermal turbulence as the hot ground heats the air. Remember that pilots are highly skilled at monitoring and navigating these well-understood weather patterns.

The St. Louis to Phoenix route passes over the Southern Rockies in New Mexico and southern Colorado. While somewhat lower than the peaks to the north, these mountains still produce notable mountain wave turbulence, particularly when strong southwesterly winds aloft align perpendicular to the ridgeline.

Turbulence Factors on This Route

• Convective Turbulence: The Mississippi Valley is a breeding ground for squall lines and mesoscale convective systems that produce widespread turbulence.
• Clear-Air Turbulence (CAT): The jet stream frequently meanders over the Great Plains, producing wind shear and clear-air turbulence at cruising altitudes.
• Mountain Wave Turbulence: The Southern Rockies produce lee waves when southwesterly upper-level winds flow across the terrain.
• Thermal Turbulence: Extreme desert heating generates strong thermal updrafts that cause low-to-mid-level turbulence, especially in summer afternoons.

When Is This Route Bumpiest?

For the smoothest possible ride, aim to fly this route in the fall, and also in winter and summer. Spring and early summer are often bumpier, because the Mississippi Valley and Tornado Alley are prone to more intense convective activity. Late winter and early spring can also see more turbulence as weather patterns shift. The Southern Rockies have mountain wave turbulence in winter. Even summer can experience turbulence from thermal activity over the deserts. Pilots are always watching the weather and adjust course as needed, but booking during a calmer season can help minimize your chances of encountering significant turbulence.

Tips for This Flight

If possible, booking a morning flight will often provide a smoother experience, as thermal activity and storm development tend to increase later in the day. Any turbulence you encounter on this route will likely feel like driving on a bumpy, unpaved road, with some occasional moderate jolts. For extra comfort, choose a seat over the wing, which is typically the most stable part of the plane. Staying well-hydrated can also help you feel more relaxed during the flight, and remember that the flight attendants are there to assist you and answer any questions you may have.

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Forecasts based on NOAA HRRR and GFS atmospheric model data.