Thunderstorm day

The only thunderstorm statistics which are readily available is the thunderstorm day. A day is defined meteorologically as a thunderstorm day if thunder is heard this implies the oc currence of lightning within about 15 km of the observing site. 

No account is taken in the thunderstorm day statistic of the number of times thunder is heard, nor the number of discrete thunderstorm events per thunderstorm day. Figure 16 illustrates the number of thunderstorm days recorded in the USA, and showing an excess of 100 such days in the St. Petersburg to Orlando region of Florida with a value of about 80 at Cape Canaveral. 

Figure 6.12 shows statistical data for the number of damaged home electric appliances (HEAs) from a Japanese utility company from 1987 to 1991 and 1996 to 2006 [8,9]. The data were based on information from more than 2,000 monitors. There were 21-34 thunderstorm days per year from 1987-1991 (included in Figure 6.12a), 15-23 thunderstorm days per year in 1996-1997, and 24 thunderstorm days in 2004-2005 (included in Figure 6.12b). 

A rain barrel contained 4 gallons of water just before a thunderstorm. It rained steadily for 8 hours, filling the barrel at a rate of 6 gallons per day. How many gallons of water did the barrel have after the thunderstorm ... 

In 1972, Day Zimmermann engineers started a test program. One of the first steps was to select the type of sensor or detector. Consideration was given to infra-red, ultraviolet, and audio signals. After careful study of the alternatives, the ultraviolet was chosen, primarily because of available components and that it would not be affected by sunlight. Audio was discarded because of frequent thunderstorms during the rainy season. 

Among climate phenomena we should mention mists, dust storms, thunderstorms, and hail. Mists are most often observed over the Aral Sea in winter, lasting, on the average, 6 days a month. They are connected with the activity of the Asian anticyclone that facilitates formation of inversions under which the condensation products accumulate. In summer practically no mists occur. Dust storms are recorded, on the average, about 10 days a year [4]. They usually originate at wind velocities of 10-14 ms The visibility in this case may become nearly zero, although more often it drops to 3 km. Thunderstorms and hails are rare events in the Aral region, their number decreases from north to south. 

In the troposphere, the production of ozone results from the day-time oxidation of methane, nonmethane hydrocarbons, and carbon monoxide in the presence of nitrogen oxides. Under natural conditions, methane, produced in oxygen-deficient environments, is released primarily by wetlands, lakes, and rivers. Nonmethane hydrocarbons, such as isoprene and terpenes, are emitted by various types of trees. Nitric oxide is released by soils as a result of microbial activity and is produced in the atmosphere by lightning in thunderstorm systems. 

El Nino refers to a sequence of changes in the ocean and atmospheric circulation across the Pacific Ocean. The water around the equator is unusually hot every two to seven years. Trade winds normally blowing east to west across the equatorial latitudes, piling warm water into the western Pacific. A huge mass of heavy thunderstorms usually forms in the area and produce vast currents of rising air that displace heat poleward. This helps create the strong mid-latitude jet streams. The world s climate patterns are disrupted by this change in location of the massive cluster of thunderstorms. The West coast of America experienced a wet winter. Sacramento, California recorded 103 days of rain. 

Floods are the most common and widespread of all natural disasters. Most communities in the United States can experience some degree of Hooding after spring rains, heavy thunderstorms, or winter snow thaws. Most Hoods develop slowly over a period of days. Flash floods, however, are like walls of water that develop in a matter of minutes. Flash floods can be caused by intense storms or dam failure. Stay tuned to NOAA Radio and prepare to evacuate. Tune to local radio and television stations for additional information. 

Consider the thunderstorms that become organized into long squall lines. These lines can propagate as an apparent entity for a number of hours or for a few days in extreme cases. Most of the individual elements of a squall line are... 

A pilot study of shoulder belt usage is nearly unique because it isolates a benefit change. A survey of belt use was done on a trip from Baltimore to Pittsburgh on Labor Day 1981. During the trip a severe thunderstorm was encountered, which raised the perceived risk of accidental mjury. Of the 125 drivers observed only 13 percent wore belts before the storm, but after the storm use more than doubled. 

In the formation of the puffy, fair-weather clouds known as cumulus clouds, solar heating of the ground warms the adjacent air, and bubbles of this warmed air rise due to buoyancy, their temperature decreasing with altitude according to the dry adiabatic lapse rate (Fig. 4.8). At the altitude where the dew point is reached and condensation begins, a cloud forms, and the stability of the air decreases as the air begins to follow a wet adiabat. Instability can lead to extensive vertical development of the cloud and strong upward air currents within the cloud. On hot summer days, this can lead to the production of a late-afternoon thunderstorm. 

Figure 5.5 Mixing ratios of isoprene (m/z 69) and total terpenes measured at Bago State Forest in November 2006. The sharp rise in the terpene concentration at day 317.3 is a result of leaf damage caused by a thunderstorm. Reprinted from [176], with permission from...

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