WATCHES vs WARNINGS

WATCH

Conditions exist for the formation of the weather phenomenon in the area.

WARNING

The weather phenomenon has been sighted, is occurring or is indicated by weather radar.  Take immediate action to protect yourself.

Storm Ready Community

The National Weather Service designated the city of Coppell as a Storm Ready Community in 2002.  To be eligible for this, a community must meet the following criteria:

• Establish a 24-hour warning point and EOC
• Have multiple ways to receive severe weather warnings and forecasts and alert the public
• Create a system that monitors weather conditions locally
• Promote public readiness through community seminars
• Develop a hazardous weather plan to include training severe weather spotters and holding emergency exercises.

   

Thunderstorm Facts

The typical thunderstorm   15 miles in diameter Lasts an average of 30 minutes   1,800 thunderstorms occur at any moment around the world. That's 16 million a year!  Of the estimated 100,000 thunderstorms that occur in the United States, about 10 percent are classified as SEVERE.   A thunderstorm is classified as SEVERE where it contains one or more of the following criteria:   Hail 3/4" or greater Winds gusting in excess of 58 mph A tornado

Flash Flooding

Flash floods and floods are the number one cause of death associated with thunderstorms...more than 140 fatalities each year.  Most flash flood fatalities occur at night and most victims are people who become trapped in their automobiles.  Six inches of fast moving water can knock you off your feet; a depth of two feet will cause most vehicles to float off. Flash floods can occur with little or no advanced warning.  The following sequence of pictures illustrate how quickly a flash flood can roar through an area. The following pictures were photographed within minutes of each other. 

Lightning

Occurs in all thunderstorms 80 fatalities and 300 injuries each year Each year, strikes the Earth 20 million times   The energy from one lightning flash could light a 100-watt light bulb for more than three months.   Most lightning fatalities and injuries occur when people are caught outdoors in the summer months during the afternoon and evening.

Tornado

On average, 800 tornadoes are reported, resulting in 80 deaths and over 1,500 injuries.   The US leads in tornado touchdowns. Ninety to ninety five percent of all tornadoes worldwide are reported in the US. Second--Australia with 4%.   Most likely to occur between 3:00 and 9:00 p.m.   Moves generally southwest to northeast at an average forward speed of 30 mph.

Environmental Clues

Tornado Protective Actions

Occasionally, tornadoes develop so rapidly that advance warning is not possible. Remain alert for signs of an approaching tornado.

At home or at work, move to a pre-designated shelter or move to an interior room or hallway on the lowest floor and get under a sturdy piece of furniture.  The key is to put as many walls between yourself and the outside as possible.  Once in the hall or room, assume the "Duck and Cover" position with your head against the wall using hands to cover your head.  If unable to get completely down, get down as low as physically possible.

Stay away from windows.  Studies show that opening windows does not alleviate pressure change.  Opening windows only delays you getting to a safe area.

Get out of automobiles.  Do not try to outrun a tornado in your car; instead, leave it immediately for a more secure structure.  In the Wichita Falls tornado of 1979, approximately 90% of the people killed went inside their automobiles trying to flee the storm.

Mobile homes, even if tied down, offer little protection from tornadoes and should be abandoned for a more secure structure.

If you are caught outdoors with no available sturdy structure, lie down in a low-lying area with your hand covering the back of your head and neck.  While in that low-lying area, keep alert for possible flash flooding.

Excessive Heat

From 1936 through 1975, nearly 20,000 people were killed in the United States by the effects of heat and solar radiation.  In the heatwave of 1980, more than 1250 people died.  In a normal year, about 175 Americans succumb to the demands of summer heat.

Excessive Heat Protective Actions