Today’s and Thursday’s Lewiston-Clarkston weather forecasts of mid-90s temperatures raise the question: How many triple-digit days will we have in summer 2019?
Will it be the dozen of 2018, or the 13 of two years ago? Or the skimpy five of 2016? Or the 20 of 2015, which was the most in the past 17 years?
The guesstimate: 11.
That’s close to the 17-year average of 10.4 per year.
The source is reliable Bob Tobin, a meteorologist at Spokane’s regional federal weather bureau. But this guesstimate comes with a caveat: It’s a projection based on data. The science of weather forecasting is, in a word, simply a projection. No guarantee, in other words.
After all, it’s still late spring. Summer (get out your datebook or app) isn’t for another nine days. It will officially be summer on Friday, June 21, at 8:54 a.m. Today and Thursday, in other words, will simply feel like summer.
Tobin said the Lewiston-Clarkston and Inland Northwest forecasts are for close-to-normal temperatures. “Closer to normal, and you might be slightly above normal in 2019,” he said. It would likely be “between your normal of 10.4 triple-digit days and 12, so let’s call it 11.”
For gardeners and farmers, we’ll be “on the edge of the above-normal chances of precipitation,” too. Sure, there’ll be the usual few thunderstorms, but it’s more likely to be plain rain for the most part.
Rain? Keep in mind that slightly more than normal isn’t a considerable amount of Lewiston-Clarkston precipitation. Since 1981, July on average has .66 inches of rain, .69 inches in August and .67 inches in September. After all, Lewiston’s annual precipitation since 1981 is only 12.31 inches.
In this sport of our keeping track of triple-digit days, when might we expect the first 100-degree day to hit? Since 2002, there’s an average of just less than one triple-digit day in June. The most come in July (an average of 6.2 days), followed by an average 3.5 days in August and rarely in September (on average, once every eight years).
A year ago, the first triple-digit day of 102 didn’t arrive until July 13. July had eight days of 100 or more and August had four, including the year’s high of 111 on Aug. 9, a record for the date. The last was 100 on Aug. 16.
What was the record Lewiston year for most triple-digit summer days? It was 27 and in three different years—1942, 1939 and 1938. But we can disregard that. In 1956, the government’s weather station moved from its downtown location in the Hotel Lewis-Clark to the Lewiston-Nez Perce County Regional Airport. That was a change in elevation from 708 feet to 1,437 feet, meaning official temperatures of today are less than in the old days.
Looking back, how was winter of 2018-19? You might remember, it was almost snowless in December and January (first with a half-inch total to close out the year and then just a trace in the first month of 2019). Most of us put away the snow shovel.
Then came the record-setting February onslaught. Lewiston, with an average total snowfall of only 13.7 inches, was deluged by 31.3 inches. March followed with 1.7 inches, making it a total 33 inches for the calendar year.
And that was after this column in mid-October advised you to “not buy a new snow shovel for the winter ahead. Unless, of course, the handle is already broken.” Take February out of the equation, and the advice would have been on target. Last winter had more smiles on the faces of skiers and snowboarders than on residents having to use the snow shovel, not a broom.
And how did our brothers and sisters on the Palouse fare last winter? Moscow, with an average 29.2 inches of annual snowfall, had a total of 43 inches. That included 2.5 inches in January, 36 inches in February and 4.5 inches in March.
Forecasting, all in all, is more sport than science.
Alford is president of TPC Holdings, parent company of the Tribune. He may be contacted at firstname.lastname@example.org or at (208) 848-2250.