Walla Walla’s summer of 2013 chose to leave the stage with some real theatrical flair this past weekend with a blustery exit that was uncannily reminiscent of an event just 10 days earlier. After two days of absolutely crushing, record-breaking heat, dark and ominous-looking clouds once again gathered on the southwestern horizon on Sunday evening, presaging the wild weather that was soon to follow.
Thanks to a very unstable atmosphere provided by weekend temperatures in the upper 90s — breaking and tying records set all the way back in 1930 — combining with the lift associated with a strong Pacific cold front, conditions were ripe for an outbreak of severe thunderstorms as occurred on Sept. 5.
Soon the airwaves were crackling with warnings regarding a line of severe storms packing winds up to 70 miles per hour that had formed in north-central Oregon, racing northeastward through Umatilla, Pendleton and Milton-Freewater toward Walla Walla. This, of course, was your weatherperson’s cue to set up his favorite viewing chair outside so that he might catch all the action, and the spectacle did not disappoint in the least.
Shortly, a roiling, brownish mass of cloud presented itself to the south and southwest, advancing inexorably toward the city. It soon became obvious that this mass was a dust storm generated by the gust front out ahead of the thunderstorms, which were blowing fiercely enough to sweep up tons of dust and dirt from recently harvested and plowed soil. The air was filled with a gritty, brown haze that, upon its arrival, dropped visibility well below a mile.
Driven by winds that gusted to 51 mph at the airport, the scene looked like a tableau drawn directly out of the Dust Bowl days. Once again, trees swayed wildly in the wind, with some further breakage of limbs, causing power to fail in parts of the city. The failures, however, were not nearly as numerous and long-lasting as in the Sept. 5 event. Regrettably, electrical service was restored in time for your disconsolate forecaster to witness the aftermath of another power failure, occurring in Seattle, where his beloved 49ers were being thoroughly throttled by the Seahawks in a game that had been delayed nearly an hour by lightning in that part of the state.
Only a trace of rain fell during the storm here in Walla Walla, with the bulk of the precipitation falling to our north and west, where intense periods of heavy rain were reported — on the order of a couple of 10ths in just 15 or 20 minutes. The lack of rain here was a very favorable development for our local grapes, many of which are nearly ripe and ready for harvest. Thin-skinned whites like sauvignon blanc would be particularly vulnerable to damage now from free moisture lingering on the clusters, so we will gladly trade a bit of dust and dirt on the fruit for a virtually rain-free storm. And no, we do not wash the grapes before they are processed — a question that is asked with surprising frequency.
Temperatures tumbled by nearly 30 degrees in the wake of the storm as cool, marine air behind the front chased the weekend warmth off to the east. This will most certainly be our last bout with summer heat this year, so it is time to stow the SPF 40, drain the kiddie pool and air out those wool sweaters that have been mothballed for the last five or six months. Fall, though officially not arriving until this Sunday, is here — and not a moment too soon for your aged and overweight weatherperson.
Today will bring yet another round of showers and a possible thunderstorm with the passage of another Pacific front, along with afternoon readings that may not get out of the upper 60s. Somewhat warmer weather will follow for the second half of the week under rebuilding high pressure, but yet another front may bring inclement and cooler weather back into our area for the weekend. The models diverge at this point with regard to next week. The Global Forecast System points toward a continuation of the wet and cool regime, while the European Center for Medium Range Weather prefers a drier and somewhat warmer scenario.
As nice as it would be to experience some gentle, cooling rain, the viticulturist in me must insist on a dry pattern in order to keep the grape-harvest ball rolling toward a felicitous conclusion sometime next month. Welcome, fall equinox!
A lifelong fan of both the weather and the Baltimore Orioles, Jeff Popick is an instructor at the Center for Enology and Viticulture at Walla Walla Community College and manages the school’s teaching vineyard. Send your questions and comments to him at email@example.com.