Thunderstorm Watch: Conditions are right for a severe thunderstorm to occur.

Thunderstorm Warning: A warning means a severe storm is heading toward your area and you need to seek shelter immediately. Expect strong winds, damaging hail, deadly lightning and heavy rainfall.

For facts and tips on thunderstorms, visit The National Weather Service.
Flash floods can occur after heavy rains. Make sure you don't get washed away.

Myth: If it is not raining, then there is no danger from lightning.
Fact: Lightning often strikes outside of heavy rain and may occur as far as 10 miles away from any rainfall.

Myth: The rubber soles of shoes or rubber tires on a car will protect you from being struck by lightning.
Fact: Rubber-soled shoes and rubber tires provide NO protection from lightning. However, the steel frame of a hard-topped vehicle provides increased protection if you are not touching metal. Although you may be injured if lightning strikes your car, you are much safer inside a vehicle than outside.

Myth: People struck by lightning carry an electrical charge and should not be touched.
Fact: Lightning-strike victims carry no electrical charge and should be attended to immediately. Contact your local American Red Cross chapter for information on CPR and first aid classes.

Myth: "Heat lightning" occurs after very hot summer days and poses no threat.
Fact: What is referred to as "heat lightning" is actually lightning from a thunderstorm too far away for thunder to be heard. However, the storm may be moving in your direction!

Previous information from the National Oceanic and Atmospheric Administration National Weather Service.
More lightning safety tips.

Further Reading on Lightning Safety

Fujita Scale:

Enhanced-Fujita Scale: The Enhanced-Fujita Scale is an update to the original F-Scale mentioned above, modified by a team of meteorologists and wind engineers and was implemented for operational use on February 1, 2007. The new scale takes into account quality of construction and standardizes different kinds of structures. The wind speeds on the original scale were deemed by meteorologists and engineers as being too high and engineering studies indicated that slower winds than initially estimated cause the respective degrees of damage. The new scale lists an EF5 as a tornado with winds at or above 200 mph (324 km/h), found to be sufficient to cause the damage previously ascribed to the F5 range of wind speeds. None of the tornadoes recorded on or before January 31, 2007 will be re-categorized.

Tropical storm warning: Winds of 55 to 74 miles.

Hurricane watch: Winds above 74 miles per hour. Hurricane conditions threatening land are a serious possibility.

Hurricane warning: Winds above 74 miles per hour. Hurricane force winds are expected to hit land.

The Saffir/Simpson hurricane scale:
Category One: A hurricane with wind speeds between 74 and 95 m.p.h. or with a storm surge four to five feet above normal.

Category Two: A hurricane with wind speeds between 96 and 110 m.p.h. or with a storm surge six to eight feet above normal.

Category Three: A hurricane with wind speeds between 111 and 130 m.p.h. or with a storm surge nine to 12 feet above normal.

Category Four: A hurricane with wind speeds between 131 and 155 m.p.h. or with a storm surge 13 to 18 feet above normal.

Category Five: A hurricane with wind speeds greater than 155 m.p.h. or with a storm surge greater than 18 feet above normal.

For more information concerning watches and warnings, go to the National Hurricane Center page.
Be sure you're safe! Check out Hurricane Preparedness.

Freezing rain: Rain that freezes when it hits the ground, creating a coating of ice on roads and walkways.

Sleet: Rain that turns to ice pellets before reaching the ground. Sleet also causes roads to freeze and become slippery.

Winter Weather Advisory: Cold, ice and snow are expected.

Winter Storm Watch: Severe winter weather such as heavy snow or ice is possible within the next day or two.

Winter Storm Warning: Severe winter conditions have begun or are about to begin.

Blizzard Warning: Heavy snow and strong winds will produce a blinding snow, near zero visibility, deep drifts and life-threatening wind chill.

Frost/Freeze Warning: Below freezing temperatures are expected.

Though we may not get much snow here, know what to do if you are traveling and get stuck in severe winter weather. Wind Chill Information.

Extreme Heat: Temperatures that hover 10 degrees or more above the average high temperature for the region and last for several weeks.

Before Exposure

During Exposure
After Exposure Previous information from The Weather Channel and American Red Cross.
Heat Stress Information. Your car can also suffer during extreme heat. Know how to react if your car overheats. To learn more about heat waves, visit National Weather Service Safety Tips.

For more information concerning severe weather, visit National Severe Storms Laboratory.