SEVERE  W EATHER...Stats & Facts


  Lightning           Tornadoes        Flash Floods  
Every thunderstorm has lightning. In fact there are more than 40 million lightning strikes every year in the contiguous United States, with more than 100 fatalities due to lightning. Here in Colorado, lightning is the number one life threatening weather hazard. In the past 10 years there have been an average of 3 fatalities and 15 injuries reported each year from lightning. The toll may be worse, as recent studies have shown that many lightning accidents are not reported.

Lightning heats the surrounding air to 50,000 degrees. This causes a rapid expansion of the air which produces thunder. A lightning stroke also contains an enormous amount of electricity, enough to supply power to several homes for a month. The heat and electricity pose the greatest risk to the individual. Most lightning deaths and injuries occur when people are caught outdoors. Lightning also causes many fires in Colorado.
Lightning Data
**1959-1995**

LOCATION NUMBER OF
INJURIES
PERCENT
OPEN FIELDS, BALL PARKS,
AND OPEN SPACES
130 40%
UNDER TREES 32 10%
BOATING, FISHING,
AND WATER RELATED
20 6%
NEAR TRACTORS OR
HEAVY ROAD EQUIPMENT
7 2%
GOLF COURSES 18 5%
AT TELEPHONES 6 2%
VARIOUS UNKNOWN LOCATIONS 115 35%

**1959-1995**

LOCATIONNUMBER OF
**DEATHS**
OPEN FIELDS, BALL PARKS,
AND OPEN SPACES
48
UNDER TREES 19
BOATING, FISHING,
AND WATER RELATED
5
NEAR TRACTORS OR
HEAVY ROAD EQUIPMENT
3
GOLF COURSES 7
AT TELEPHONES 0
VARIOUS UNKNOWN LOCATIONS 17

Colorado ranks 11th in the U.S. in both injuries
and deaths caused by lightning.


Tornado Facts
Tornadoes have been reported 9 months of the year, and the peak season for tornadoes extends from mid May through mid August. June is by far the month with the most recorded tornadoes. Tornadoes have occurred every time of the day, with over half of them developing between 3pm and 6pm, and 88 percent occurring between 1pm an 9pm MDT. They also occur statewide, but by far the largest number develop in eastern Colorado to the east of Interstate 25.

Since 1950 the two counties with the most tornadoes have been Weld and Adams. In fact, Weld county has one of the highest frequencies of tornadoes across the country. It's mainly due to the size of the county. Weld is 2 to 3 times the size of most counties across the nation.

The last tornado death in Colorado occurred on June 27, 1960 in Sedgwick County. The most well known tornado outbreak occurred in metro Denver on June 15, 1988. Five tornadoes resulted in seven injuries and damage in excess of $15 million.




COLORADO TORNADOES
2006



COLORADO TORNADOES
1950-2006

Flash Flood Facts

In the United States, flash floods are responsible for more deaths than any other thunderstorm phenomena. Year to year in Colorado, only lightning is more deadly. Flash flooding usually is the result of very heavy rains in a short period of time over a small area which causes small streams to turn violent. It is hard to understand the destructive potential of moving water, but the result was clear to see after the Big Thompson Flood of July 31, 1976. That flood killed 145 people, destroyed 418 homes and 52 businesses, and resulted in $35 million in damages. Survivors spoke of a wall of water, a very rapid rise in water level, and a loud roar. No wonder flash floods are referred to as the "Awesome Power".

Other flooding here in Colorado occurs in the spring when the mountain snowpack begins to melt. Heavy rainfall coinciding with the runoff will cause some rivers and streams to swell out of their banks.

Sometimes a dam failure will cause a flash flood. The damage resulting from flash flooding in July 1982 following the Long Lake Dam failure is preserved in Rocky Mountain National Park.


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