Latest weekend forecast lowers triple-digit sizzle

The latest weather forecast is turning down the sizzle this weekend, but only by a degree or two.

Sunday could still see highs of 102 to 104 degrees across the Spokane and Coeur d’Alene area, the National Weather Service said Wednesday afternoon.

That official forecast predicted a high of 99 on Saturday, 103 on Sunday and 97 on Monday, which was 1 to 2 degrees lower than the morning forecast.

At the same time, a heat advisory was issued Wednesday evening for the Columbia Basin, the Palouse and other areas to the south and west for highs up to 107.

National Weather Service forecasters said the outlook is still uncertain because clouds may arrive to shield the sun.

“That can shave off 5 degrees,” said forecaster Paul Bos.

The weather service forecast may tell a different tale than your cellphone. Forecasts from some commercial weather service companies have shown Sunday temperatures as high as 108.

Hundreds of companies take raw data from the weather service and create forecasts to sell to media, businesses, government agencies and websites. Those forecasts are frequently different than the ones made by local weather service bureaus because of the varying techniques they use to interpret the raw data.

Even so, a reading of 103 degrees in Spokane is somewhat unusual. The last time it occurred was in 2007, and prior to that, in 1998.

The all-time record of 108 degrees was reached twice – on Aug. 4, 1961 and July 26, 1928. Records date back to 1881.

Typically, Spokane hot spells reach the upper 90s to low 100s, but don’t go beyond that. Weather records for the past 20 years show that excessive heat at or near the century mark generally lasts from two to four days.

Many of us likely remember the last four days of July 2014 when the temperature went to 98, then 100 before settling back to 99 for two days.

The most recent stretch of three days with triple-digit highs came in July 2006.

That said, there are many summers when Spokane never sees triple digits.

The summer heat peaked at 99 in 2013 and 98 in 2012.

During the coming heat wave, forecasters are calling for only minor temperature differences between Spokane International Airport – where observations are compiled for official climate records – and downtown Spokane and Coeur d’Alene.

This weekend, downtown Spokane could be 1 degree hotter than the official airport forecast while Coeur d’Alene could be a degree cooler.

If you’re looking for rain, isolated showers may be possible starting over the Cascades, then spreading north and east as the weekend winds down.