The National Weather Service issued a heat advisory in North and Central Texas until 7 p.m. Sunday.

“Hot and humid air will remain in place all weekend,” a NWS announcement said. “The high temperatures and humidity will combine to produce heat index values between 105 and 108 degrees through the week.

In addition, winds will be generally less than 10 miles per hour, limiting the cooling ability of those involved in vigorous outdoor activities.”

Locally, vigorous outdoor activities include the Howard and Linda Guerin Memorial Toys for Tots Run starting at 10 a.m. today at the U.S. Marine recruiting office at U.S. Highway 84 and Hewitt Drive.

Organizer Randy Guerin said two rest stops with water for sale will be set up along the route.

The thermometer is expected to reach or exceed 100 degrees today and Sunday, and dip into the mid-70s at night.

Robbyn Brooks of People for the Ethical Treatment of Animals issued a statement warning that extreme temperatures can harm or kill dogs.

She said owners should make sure animals always have a way to get out of direct sunlight when left alone all day and should never have to keep up with people running or riding bicycles because they may suffer a fatal collapse.

Brooks warned against leaving dogs in parked cars even for short periods and said heated asphalt, pavement and sand can burn dogs’ feet.

She asked all persons to be alert to the welfare of any animal left outside, to contact authorities about any dog without shelter from the sun and to provide it water if possible.

NWS meteorologist Joe Harris in Fort Worth said the heat wave is caused by a high pressure system in the middle and upper atmosphere.

“In the summer, these systems are centered over the southern plains, especially Texas,” he said. “Air in high pressure systems is always falling and undergoing compression, which warms the air and makes for very hot temperatures.”

Harris said the high pressure “lives here and migrates. Sometimes it’s centered over the southeast, sometimes over western Texas, but as long as it’s centered over us, it will stay hot. It will probably be this way another three or four days.”

The NWS is forecasting a 20 percent chance of rain next Wednesday through Friday.

dbolding@wacotrib.com

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