Wednesday, December 23, 2009

HEAT WAVE OF 1980 .... USA!!

The 1980 United States Heat Wave was a period of intense heat and drought that wreaked havoc on much of the midwestern United States throughout the summer of 1980. It is among the most devastating natural disasters in terms of deaths and destruction in U.S. history, claiming at least 1,700 lives[1] and because of the massive drought, agricultural damage reached US$20.0 billion (US$55.4 billion in 2007 dollars, adjusted for the GNP inflation index).[2] It is among the billion-dollar weather disasters listed by the National Oceanic and Atmospheric Administration.


 Causes

The heat wave began in June when a strong high pressure ridge began to build in the central and southern United States allowing temperatures to soar to 90 °F (32 °C) almost every day from June to September. The high pressure system also acted as a cap on the atmosphere inhibiting the development of thunderstorm activity leading to exceptionally severe drought conditions.

Effects

The drought and heat wave conditions led many midwestern cities to experience record heat. In Kansas City, Missouri, the high temperature was below 90 only twice and soared above the century mark (100 °F/38 °C) for 17 days straight and in Memphis, Tennessee, the temperature reached an all-time high of 108 °F (42 °C) on July 13, 1980, part of a 15-day stretch of temperatures above 100 °F (38 °C) that lasted from July 6–20, 1980.

In Dallas/Fort Worth, Texas, high temperatures exceeded 100 °F (38 °C) a total of 69 times, including a record 42 consecutive days from June 23 to August 3. Dallas/Fort Worth reached an all-time high on June 26 and 27, when the temperature reached 113 °F (45 °C) on both days. In all the Dallas/Fort Worth area saw 29 days in which the previous record high temperature was either broken or tied. Wichita Falls, Texas would hit 117 °F (47 °C), the highest temperature ever recorded in that city to date.

On the northern rim of the high pressure ridge, several severe long-lived windstorms called derechos formed. The most notable was the "More Trees Down" Derecho that occurred on July 5. It raced from eastern Nebraska to Virginia in 15 hours, killing 6 and injuring about 70. The Western Wisconsin Derecho of July 15 caused extensive property damage.

Posted via email from Enviromenment

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