Under emergency hall lighting, Ed Arnold, Rick Grubin, Jon Wolfe, Greg McArthur, and Lana Stillwell emerge from their offices after violent winds took out power to NCAR's Mesa Lab.

Heavy gusts blew out the windows of at least eight cars in the NCAR parking lot, as well as a large window on the third floor of the Mesa Lab's Tower A.

In the spooky atmosphere of the darkened SCD hall, NCL consultant Mary Haley demonstrates some special effects with a flashlight.

Photos and story: Lynda Lester, NCAR/SCD

High winds knock out power

SCD staff congregate in the hall after a power hit caused by high winds knocked out power to the Mesa Lab on 11 November 2003. SCD safely brought down the NCAR supercomputers, keeping them offline for 16 hours while winds gusting to more than 75 miles per hours howled outside.

SCD helps NCAR researchers study wind patterns by supporting NCAR supercomputers and software packages for scientific visualization—two of which are the SCD-developed NCAR Graphics and the NCAR Command Language (NCL).

Greg Thompson, an associate scientist with NCAR's Research Applications Program, used NCAR Graphics and NCL to produce the first and second image below, respectively. These images show wind speeds and directions at 8 p.m. Mountain Standard Time on 11 November.

The first image is a plot using observational data from surface weather stations. The second image is an analysis of these data from the National Oceanic and Atmospheric Administration's Rapid Update Cycle (RUC) numerical forecast model. This RUC analysis, done at a resolution of 20 kilometers, shows a bull's-eye of high winds right over Boulder. (Click on thumbnail for a full-size image.)

Windy city

Raging winds toppled power lines and trees throughout town, causing a loss of power to the Mesa Lab at 2:15 p.m. In addition to impacting computational facilities, the outage affected critical safety and security systems at the Mesa Lab, which in turn affected all UCAR sites. A window imploded on the third floor of the Mesa Lab, car windows burst in the parking lot, and a Port-a-Potty went flying down the mesa.

Gusts at NCAR's Foothills Lab were clocked at 75 miles per hour, while 80-mph winds were recorded about 25 miles north of Boulder. Some NCAR employees who were blown across the parking lot or observed windows shaking in the Mesa Lab estimate that gusts on the mesa might have been as high as 100 mph.

These downslope winds, which usually come in fall, winter, and early spring, are called "Chinooks" (a Native American term meaning "snow eater") because they are warm and often melt the snow. Chinooks are caused by air masses that drop moisture over Colorado's western slope, rapidly heating up and accelerating as they descend the eastern side of the mountains.

Power to the Mesa Lab was restored about 6:15 a.m. on 12 November.

For more information

• Wind speed symbols
• NCAR Graphics
• NCL
• NCL wind barbs utility
• Downslope wind
• Real-time weather data from NCAR's Research Applications Program
• Real-time weather plots from NCAR's Atmospheric Technology Division