This week is National Severe Weather Awareness Week. It is a good time to think about how severe weather might impact your family or your farm. 

Severe weather often occurs in March with dew point temperatures in the 50s or 60s. Duane Friend, University of Illinois Extension natural resources educator, explains the impact of dew point on weather.

Water vapor is the gas form of water. Air can only hold so much water vapor. When air reaches a temperature where it is holding as much water vapor as it can hold, the air is said to be saturated. The temperature at which this occurs is called the dew point temperature.

“A more common way of talking about dew point is when relatively humidity is at 100%,” Friend says. “Warmer air can hold more water vapor; cold air can’t hold as much.”

When dew point temperatures are low, the air is not holding much water vapor. Higher dew points mean more water vapor is present. 

“Water vapor heats the surrounding air when it condenses,” Friend says. “High dew points can increase the chances of thunderstorms.”

March is a big transition month from winter to spring. Warm air masses from the Gulf of Mexico start pushing into the state, raising the dew point temperature. 

“That, by itself, doesn’t cause thunderstorms, but if there is a strong cold air mass that moves in and wants to move to higher elevations, that warm air will quickly cool to the dew point temperature as it moves upward, condense to liquid water, release heat and have an even greater tendency to move upward.”

Thunderstorms often form under these conditions, Friend says.

“If you see dew points in March in the 50 to 60 degree range, which indicates a lot of moisture in the air. In turn, the chances for thunderstorms are pretty high.”

These storms often include lightning. Exceeded only by floods, lightning is the second largest killer associated with storms. According to the National Oceanic and Atmospheric Administration, over 25 million cloud-to-ground lightning flashes occur each year.

There are several considerations for avoiding being hit by lightning. As a storm approaches, move indoors before the rain begins. 

“If you can hear thunder, lightning is close enough that it could strike your location at any moment,” Friend says. “Lightning originating near the top of a storm can reach as far as 10 to 15 miles away.”

Do not stand under or next to trees. “If you cannot get to an indoor location, crouch in the open space, keeping twice as far from a tree as it is tall,” Friend says. If there is a group of people outdoors, keep several yards distance from each other.

Swimming, wading, and other water sports are not safe during a storm since lightning striking the water can travel long distances. If a lightning storm begins while boating, crouch in the center of the boat, away from metal.

Ungrounded, open span buildings, such as ball dugouts and picnic shelters, are not always a good option. If no sturdy buildings are close, a hard top vehicle is the next best choice. Avoid touching metal while the storm is in progress.

 As prime tornado season approaches, know what a tornado warning means and what to do.

The National Weather Service issues a tornado warning under two conditions, says Friend: rotation is indicated by weather radar, or rotation has been observed by trained spotters. If a warning is issued for the area, it means residents in the warning area are in the projected path. Bulletins often discuss the potential impact damage from the tornado.

“First thing to do when a tornado warning is issued for your area is to take cover immediately,” Friend says. “Do not go outside to look for the tornado; it may approach quickly with little time to get to safety.”

Preparation for any emergency or disaster is key. When developing an emergency plan, think about all members of your family, including pets. For each type of emergency or disaster, identify a safe place, whether inside or out, and where the family will go in the event of that type of emergency.

• Stay Alert: When there is a chance for bad weather, it is always good to tune in to local radio, television, or online information. A battery-powered NOAA weather radio may be a good item to keep in the home. Change the batteries in twice a year when you change your fire alarm batteries.

• Supply Kit: Have enough food and water for up to three days for each member of your family along with some basic first aid supplies. Don’t forget special needs, such as baby formula or medication. Include records, such as names, phone numbers, and information you need following some type of disaster. 

• Escape routes: Discuss and practice escape routes with children so they know how to get to that location.