An abundance of celestial pyrotechnics and a serious paucity of precipitation marked the Walla Walla Valley’s latest dalliance with a Pacific low pressure system this past week, as thunderstorms skirted the local area while dropping copious amounts of rain on neighboring portions of the Evergreen State.
The low, which moved haltingly up the California coast late last week, pumped loads of moisture into Washington and Oregon on the stiff southerly winds that circulated around its center. This moisture, when combined with daytime heating and aided by a series of small vortices embedded in the flow that provided some added lift, resulted in several days of afternoon and evening thundershowers over much of the two-state region. These prompted multiple fire watches and warnings and the occasional severe storm that featured brief heavy downpours, nickel-sized hail and winds gusting to 60 miles per hour — such as the one on Sunday afternoon, near Bluewood, that rattled a good slice of Columbia County as it plowed its way from south to north.
Although cumulonimbus clouds (thunderheads) practically surrounded Walla Walla at any given time over the period, only a few desultory drops of rain fell from above — despite the vivid lightning displays that rent the sky and the brilliant flashes that lit the horizon, giving the appearance of some epic World War II naval battle raging in the distance.
Ultimately, it was a case of much ado about nothing — a meteorological instance of a lot of sound and fury signifying nothing — at least in our immediate vicinity. The close proximity of a cell Friday night did supply a small measure of excitement, as outflow winds from a nearby storm gusted to 35 miles per hour at the airport and knocked over the screen at Three Rivers Winery, much to the chagrin of patrons immersed in an outdoor movie there.
As the responsible low meandered up the coast, the inflowing moisture diminished. By Sunday night clearing skies and slightly cooler air allowed for excellent viewing of the Perseid meteor shower that annually provides an August spectacle featuring numerous bright fireballs in the night sky. Your weatherperson, with a couple of friends from Back East in tow, ventured out into the blackness of a wheat field not too far from town to escape the lights of our bustling burg, which might interfere with our appreciation of the event. Thirty minutes, two meteors and four very sore necks later, we piled back into the car — well-chilled and somewhat disappointed in the relative lack of atmospheric action and the absence of a truly “wow” moment, although the level of activity almost certainly increased markedly as soon as we gave up and went home.
The low will migrate into British Columbia, resulting in a transition to a drier, more westerly flow. The lack of clouds and lessening moisture will mean an increase in our afternoon maximum temperatures here in the Valley over the next couple of days, with highs generally in the low to mid-90s under mostly sunny skies. By week’s end, another approaching area of low pressure may lead to the development of more thundershowers as moisture and instability increase. Weekend readings should be near normal — which for mid-August means upper 80s.
For those seeking something more fall-like, the 16-day outlook indicates that the weekend of Aug. 24-25 could be precisely what the doctor ordered, with temperatures perhaps struggling to make it out of the 70s following the passage of a dry Pacific cold front. In the meantime, our local grapevines are ripening nicely in the August sun, which means that it is time to cover them in netting to prevent the grapes from being gobbled up by hungry birds — a task that for your weatherperson has all the appeal of a second knee replacement, but one which cannot be ignored without serious consequences.
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 firstname.lastname@example.org.