downslope winds | downslope winds occur when air is forced to flow over a high mountain ridge with a steep lee slope.
Especially during the spring, all parts of the Flagstaff area tend to be windy during the day. The picture changes at night, however, when areas on the lee (downwind) side of the San Francisco Peaks are often very windy while the rest of the area is relatively calm.
Prevailing winds in the Flagstaff area come from the southwest, making overnight and early-morning winds common north and east of the San Francisco Peaks. When the atmosphere aloft is stable and winds aloft are strong, downslope winds can create windy conditions in the lee of the mountain. Overnight and early morning winds regularly occur east of Flagstaff; gusts can reach 45 to 50 miles per hour.
The maps below are based on 24 data collection sites; some of the sites are short-term or seasonal.
- January
- February
- March
- April
- May
- June
- July
- August
- September
- October
- November
- December
- Animated Monthly Wind (allow several seconds for this animation to buffer)
— wind maps created by Dan Stewart.
Note: Maps are framed by the boundaries of the Flagstaff Metropolitan Planning Organization. FMPO is the federal designation for cooperative transportation planning by the City of Flagstaff, Coconino County, and the State of Arizona.
Conditions can change quickly when the wind shifts direction. At 3 am on November 24, 2014, the wind was from the east/northeast at 5 mph with a temperature of 13° at the Flagstaff Pulliam Airport. When the wind shifted to blow from the north/northwest, the temperature rose to 26°. (Click on image to see it larger on a separate page.)
Wind is affected by topography, in other words by the surface of the landscape. When air flowing horizontally encounters the San Francisco Peaks, it is forced upward. As the air rises and cools, the moisture in it may condense into a lenticular cloud. These clouds indicate that windy conditions may be in store for areas on the leeward side of the Peaks.
—Andrew Taylor, Science and Operations Officer, National Weather Service, Flagstaff.
Thank you for this site and your explanation of the wind. I lived in Flagstaff for 28 years. I cycled from Doney Park to NAU for 10 years and very much remember the wind kicking the shit out of me for 12 miles every morning and hurtling me home late afternoon. The wind in Doney is simply amazing and sometimes downright awful. I obsessed over the weather, always looking at wind forecasts, hoping for that calm day which rarely came.
Thanks for the funny description of your experience with local winds! Some people think the official standard of measurement for wind should be called the “Doney.”