Severe weather can be an exciting time for meteorologists and storm chasers, but to ordinary citizens, the damage from hail, lightning, high wind speeds, tornadoes, and the hurricanes that can result from these storms can be extremely costly and deadly.
Super storms occur when Northern cool air masses move south meeting warm air masses. A southwestern storm may also move northeast intersecting with the northern cool air and southern warm air. As these air masses intersect, wind speeds can increase frequently causing straight line winds. If the wind speed exceeds 58 miles per hour, the storm is considered to be severe. The NWS, National Weather Service, will then announce that a thunderstorm threat in imminent. These high winds speeds are generally accompanied by heavy rain, lightning, and sometimes hail.
If the intersected masses of air begin to move in a circular motion, the formation of a funnel cloud, or tornado, can result. If a funnel cloud is not actually seen during a storm, but excessive damage has occurred, meteorologists will study the direction of the debris before releasing information stating that the storm was tornado or straight line winds associated with a storm. If trees are bent and debris has been moved in only one direction, the culprit is generally straight line winds; on the other hand, if debris is distributed in all directions, a reasonable assumption is that a tornado has passed through the area.
Tornadoes have formed all over the world, but Tornado Alley, Texas, Kansas, Oklahoma, and Nebraska, in the United States is especially vulnerable to these storms in the spring and fall. These states have suffered up to 500 tornadoes in one storm season, ranging from F-1 to F-5 in strength. The size of a tornado is measured by the damage done by the funnel cloud. Tornadoes with a wind speed of 150 mph are likely to do more damage by picking up and relocating more debris than a tornado with an 70 mph wind speed; thus, categorizing the tornado according to the Fajita scale. When a thunderstorm is approaching an area, meteorologists will report the impending conditions indicated by Doppler radar and broadcast the appropriate information and warnings. A tornado watch indicates that there is a possibility of a tornado forming from a thunderstorm. A tornado warning will be announced when a tornado has actually been spotted on the ground or radar highly suggests that a tornado is likely to occur.
Hurricanes can also form out of super storms over the ocean; but unlike a tornado, there is generally several days warning before the storm reaches landfall. A hurricane is formed when the pressure at the deep center of the storm becomes lower and lower. Rising warm air causes the air masses to begin moving in a circular motion, similar to the movement in a tornado. As the storm moves over the warm, humid ocean air, the circulating air mass increases in speed. When the storm, usually beginning in the cool Atlantic Ocean, moves with the Gulf Stream into the Gulf of Mexico or along the east coastline of the United States, the storm is energized by more warm, humid air. As the storm reaches land, storm surges, lightning, strong winds, and heavy rains can be extremely destructive decimating entire communities.
When the super storm has passed, a rainbow will often appear. As misunderstood as rainbows are, mostly by the myths that surround them, there is a scientific explanation. A rainbow appears differently to different people depending on where the person is standing. A person must be standing with their back to the sun, with the storm in front of them, so that the sun rays can refract off each water droplet. The light rays enter raindrops, refract back toward the sun from another angle and produce the bands of color to be visible. Each light ray is a certain amount of distance from the next one; that distance is called a wavelength. Sunlight appears as white light; however, the light rays the sun produces separate into bands according to their wavelength; each band is called a spectrum. Blue has the shortest wavelength and red, the longest wavelength, thus forming the colorful arc that becomes visible.
Cities that frequently experience severe weather will place tornado sirens strategically around the town to warn the citizens when to take cover; however, these sirens may only give the area a five-minute warning. When a hurricane is bound to occur on land, many areas subject to the storm may be evacuated. Windows and other vulnerable parts of a structure are frequently boarded up with plywood and all outside items removed or stabilized. Each family, living in an area frequently visited by super storms, should establishment a safety plan with meeting places designated and survival kits kept nearby. Purchasing an NOAA (National Oceanic and Atmospheric Administration) weather radio is also recommended, as they will be operable if electrical service is interrupted.
Super storms can bring violent, relentless thunderstorms, tornadoes and hurricanes; however, the appearance of the rainbow always gives hope that the worst is over and rebuilding can begin.