Watches, Warnings & Advisories for Sunflower Co.

Tuesday, February 22, 2011

Severe Weather Awareness Week - Tornadoes

What is a Tornado?

A tornado is a violently rotating column of air that extends from the base of a storm cloud to the ground.
Some conditions that are conducive for tornado formation include warm, moist, unstable air, strong atmospheric winds that increase in speed and change direction with height, and a forcing mechanism to lift the
air. When a combination of these factors comes together just right, tornadoes form. The most common time of year for tornado formation in Mississippi is during the spring months of March, April, and May, with a
Tornado - Robertson Co.- January 2010 secondary tornado season in November. Additionally, the afternoon and evening hours are the times of day at which most tornadoes occur, as they are the times at which the maximum heating takes place. However, tornadoes can occur at any time of day, and at any point during the year, given the right environment. Many tornadoes occur at night in Mississippi.

Nighttime Tornadoes Pose Greater Danger

The NWS would like to draw attention to nighttime tornadoes. These tornadoes pose a greater danger than those that occur during the daylight because once most people go to bed, they are no longer connected to the watches or warnings issued by the NWS. Also at night, visibility is reduced and observing a tornado is more difficult. This is elevated during the winter months because it is not the traditional tornado season. Research by Gagan et al. 2010 compared tornado statistics from the Great Plains in the classic “Tornado Alley” to tornadoes in the Deep South or “Dixie Alley.” Researchers found that Dixie Alley had far greater amounts of Killer Strong/Violent Tornadoes between 9pm-9am timeframe. Dixie Alley had nearly twice the number of strong/violent tornadoes from Midnight-Noon timeframe than Tornado Alley from 1950-2007.

Having an properly programmed All Hazards NOAA Weather Radio with S.A.M.E. County Coding technology will alarm individuals anytime of day when a severe thunderstorm warning or tornado warning is issued for their county. This device has been credited for saving numerous lives during nocturnal tornado events.

**Source: National Weather Service - Jackson, MS Forecast Office, Mississippi Severe Weather Awareness Week 2011 Brochure which can be viewed/downloaded by clicking the link. 

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