Storm watcher training takes place
Published 9:34 pm Saturday, April 7, 2012
Between 40 to 50 county residents showed interest in becoming storm spotters by showing up for a training session Thursday evening.
The focus of the training, conducted by National Weather Service Warning Coordination Meteorologist Frank Revitte, was on the types of severe weather that strike southeast Louisiana and south Mississippi.
Identifying tornados and storm types was a large part of the training. Revitte said most tornados that occur in this area are weak and short-lived. The strongest common tornados that occur in this region range from an EF1 (86 to 110 miles per hour) to an EF2 (111 to 135 miles per hour). The scale used to rate tornados by strength is called the Enhanced Fujita scale. The scale tops out at EF5, which is a tornado with wind speeds in excess of 200 miles per hour.
Revitte said a major tornado for this region would be an EF3, ranging from 136 to 165 miles per hour, but those types of tornados are rare this close to the coast. The further north stormy weather occurs in the continental United States, the greater the chance of strong tornados. Tornados along the coast are usually weak, he said.
Warning residents of an impending tornado is not easy, especially with smaller, weaker storms. Revitte said radar usually cannot see tornadic activity, so the National Weather Service relies on damage reports and investigations after a tornado has passed to record their instances. Larger storms, such as supercell storms that include mesocyclone activity, are detectable by radar and such storms typically produce tornados, so those storms prompt the National Weather Service to issue warnings, Revitte said.
“A lot of our tornados are short-lived and they come from storms that don’t scream at us,” Revitte said.
Revitte gave the residents in attendance things to look for before determining if a tornado could occur. He instructed them to look for cyclonic activity, funnel clouds and debris at the bottom of what looks to be a tornado. If the storm appears to have a tornado but there is no debris being strewn about at the bottom, it is most likely just a column of rain. If a funnel cloud extends more than halfway from the cloud base to the ground, he suggested they report such activity, because a tornado is likely to form.
Storm damage can occur due to winds that are not associated with tornados, such as a down burst, or straight line winds. Revitte said he discerns the cause of storm damage by debris patterns. Tornados cause damage within a small fixed path with distinct edges and includes debris strewn in different directions. Damage from straight line winds has no distinct edges and includes debris is strewn in one direction.
Lightning is a part of storms, and can be dangerous for a storm spotter. Revitte said lightning is the second most common weather killer, and weather spotters are usually in prime areas for being struck. A tell tale sign that lightning is about to strike is that one’s hair will begin to stand on end. Revitte said if a person’s hair begins to stand on end, he or she should get inside as fast as possible, or get as low to the ground as possible, to avoid being struck.
The National Weather Service works off of damage reports and information on storms from the community. Some things residents can look for include hail with a diameter the size of a dime or larger, winds faster than 58 miles per hour, tornados, wind damage and widespread flooding, Revitte said.
Storm activity and damage should be reported to the Pearl River County Emergency Management office at 601-795-3058 during operating hours. Emergency Management Director Danny Manley said there are times after hours that the office is staffed if a major storm event is expected.
Manley suggested residents avoid calling 911 unless there is an emergency. He said storm damage that does not pose a threat to others is best reported to his office. Storm damage can be reported to the National Weather Service by way of its website at http://www.srh.noaa.gov/lix/ and clicking on the “submit storm report” icon near the bottom of the page.