‘Hot, any way you cut it.’ Excessive heat predicted for the weekend, including a 108 day

This time last year, Fresno was in the midst of a record-breaking heatwave.

So, while the current trend of triple-digit temperatures feels a bit excessive, it’s fairly normal for the season.

“We’ve been relatively lucky this year,” said Jim Andersen, a forecaster/meteorologist with the National Weather Service in Hanford. We did have an abnormally wet May and any heat we’ve had so this summer has been short lived, he added.

This wave of heat is expected to last through the weekend, at least. The weather service has issued a heat advisory starting at 1 p.m. Thursday through 8 p.m. Friday, when temperatures are expected to reach 104.

That’s your reminder to drink water, find shade and limit outdoor activity. Also, Fresno will open its four cooling centers — at Frank H. Ball park, Ted C. Wills Community Center, Mosqueda Community Center and Pinedale Community Center — when temperatures are predicted to be 105 and higher.

There is an excessive heat watch in place through Sunday, when temperatures are expected to peak at 108 (that’s two degrees shy of the record high for that day, set in 1980).

“We start to trend downward on Monday,” Andersen said.

By mid-week, temperatures will return to the season norm — around 99 degrees. The high Wednesday is expected to be 100.

“We’re still going to be hot any way you cut it,” Andersen said.

Along with the heat, there is some moisture coming out of a ridge of high pressure. That means humidity for Fresno and thunderstorms in the Sierra and across parts of the Kern County mountains and desert. Indeed, a flash flood warning was issued for those areas through 11 p.m. Thursday. Heavy rains, up to two inches an hour, were possible in some area, according to the weather service.

So, this is not the dry thunderstorms and lightning that’s expected north in the Bay Area, Andersen says, but it’s still being watched as lightning can cause fire.

Those fires mean bad air.

The heatwave also coincides with a change in air quality in the Valley. We can expect a rise in bad air days over the next few months, after what had been a relatively clean summer. From June 1 to July 16 of this year, Fresno had a 10 percent rise in the number of days that ranked as “good” on the air quality index, according to the Valley Air District.

“It’s been a great year so far. We’ve had a lot of good visibility days,” said Jon Klassen, the district’s director of air quality forecasting.

Of course, we typically see the highest levels of ozone concentrations (those bad air days) in August and September, due to the increase of forest fires.

Klassen expects ozone levels to spike once fire season kicks in.

“Even though it’s been a good start to this year, we don’t want to jump to conclusions.”

This story was originally published July 25, 2019 at 12:28 PM.