Spann began his broadcast career in Tuscaloosa in 1973 at WTBC radio.[3] There, in high school, he worked the night shift, while former ABC 33/40 anchor Dave Baird worked mornings. Spann volunteered many hours following the 1974 Alabama tornadoes in Jasper. He began his television career in the summer of 1978 at 33/40 predecessor WCFT in Tuscaloosa, the "33" in 33/40. In fall 1978, Spann moved to WSFA in Montgomery as weekend sports anchor and part-time weatherman. After spending the summer of 1979 as afternoon-drive announcer at Top 40 station WHHY-FM ("Y102") in Montgomery, he was hired at WAPI-TV in Birmingham as chief weatherman, despite having no formal weather education. At the age of 23, he was one of the youngest chief weathermen in the country.

Channel 13 was sold to Times Mirror in 1980 and renamed WVTM-TV, and Spann impressed his new bosses enough that they moved him to sister station KDFW in Dallas in 1984. In 1985, he was named the best weathercaster in the Metroplex by the Dallas Press Club, defeating such competition as KXAS-TV's Harold Taft and WFAA-TV's Troy Dungan. After only two years, he returned to Alabama as part owner of a small AM-FM radio station combo in Demopolis with Dave Baird. He returned to television in October 1989 as chief weatherman at Birmingham's WBRC-TV. At the same time, he enrolled in Mississippi State University's meteorology program, earning the NWA and AMS seals of approval upon his graduation.

Spann left WBRC in 1996 in a move that made local headlines. WBRC had just been purchased by News Corporation and was dropping its longtime affiliation with ABC in favor of Fox. Spann, a devout Southern Baptist, was unhappy with Fox's then-steady diet of reality shows and other programming. Spann followed several of his former WBRC colleagues to the newly formed ABC 33/40, which had merged WCFT with WJSU-TV in Anniston and a new low-power repeater in Birmingham, and had replaced WBRC as Birmingham's ABC affiliate. He has been at ABC 33/40 ever since.

Spann is the founder of The Weather Factory (formerly The Weather Company) which provides broadcast weather forecasts for a number of radio stations and weather data for industrial and business clients. Spann was the 33rd person in America to receive the AMS distinction as a Certified Broadcast Meteorologist. Spann remained on television for ten hours during a tornado warning for western Jefferson County on April 8, 1998. An F5 tornado struck Oak Grove High School before 8:00 that evening. The next day, Spann spoke from a helicopter about the warning and the high school's damage.

Beginning in 2007, Spann could be heard by listeners of the Rick and Bubba Show, a popular syndicated radio show based in Birmingham but heard across the country, mainly in the Southeast. Spann's tenure began when the show switched flagship stations in Birmingham to WZZK-FM, where Spann's forecasts had been heard for some time beforehand. He is also the chairman and one of the founders of AllWorship.com, a non-profit organization webcasting three streaming radio stations which feature worship music in English and Spanish. The organization grew out of WRRS/Reality Radio, a commercial FM radio station that broadcast Contemporary Christian music in the Birmingham market from 2000 to 2001.

In 2004, Spann hosted a television special about severe weather safety. He interviewed Goshen United Methodist Church's F4 tornado survivors of March 27, 1994 including the former pastor, Kelly Clem and her husband, Dale. Later, he spoke about the tragedy and safety instructions to Brian E. Peters, Warning Coordination Meteorologist from the National Weather Service Forecast Office in Calera's Shelby County Airport. He is also the host of WeatherBrains, a weekly weather podcast and board chairman of the Children's Hospital of Alabama.

Formerly a longtime member of Hunter Street Baptist Church, Spann is the children's Sunday School teacher at Double Oak Community Church outside Birmingham.

Some of the notable events covered by Spann include:

• Hurricane Frederic (one week after he signed on in September 1979)