National Weather Service Weather Forecast Office

Sun spot activity generally follows an 11 year cycle. The peak of the current solar cycle occurred during the year 2000. Remarkably, during the week of October 19-25, 2003, sun spot activity increased dramatically. Sun spot groups 484 and 486 became very large, and where characterized by complicated magnetic fields.

During the morning hours of October 28 (1110 UTC) 486 produced a very intense solar flare. This released high energy particles into space almost directly towards earth. X-rays traveling near the speed of light arrived in the near-earth environment within about 8 minutes of the explosion. Measurements of the x-ray flux indicated that the flare was the third most powerful solar flare on record (records began in 1976). Using images of the sun taken at multiple wavelengths from ground-based and satellite-based equipment, scientists estimated the shockwave from the blast was traveling towards earth at approximately 2100 km/sec (nearly 5 million mph), and would impact earth during the very early morning hours of October 29. At 1157 CST the National Weather Service office in Midland issued a Public Information Statement which discussed the possibility of an aurora occurring in the West Texas and southeast New Mexico skies after midnight.

Shortly after midnight CST (0612 UTC) the shockfront impacted the earth's atmosphere. As a result charged particles traveling in the fast solar winds excited atoms and molecules in the earth's upper atmosphere, causing them to emitt brilliant light in the form of an aurora. Although this process is not unusual, the magnitude of energy associated with the flare resulted in the aurora display to be very widespread and visible well south into the middle and lower latitudes.

National Weather Service meteorologist Todd Lindley photographed the aurora from just outside of Midland. A very intense display, or substorm, became visible around 0240 CST (0840 UTC) and persisted until 0305 CST (0905 UTC). The northern lights appeared as a brilliant red color in the northern sky with pillars and rays
extending vertically above the horizon. The color of the northern lights were a result of ionized oxygen atoms over 200 km above the ground. A much fainter and diffuse display persisted through most of the remainder of the pre-dawn hours.