Spring comes up short of normal precipitation
It may have been a different spring than we’ve been used to experiencing the past few years, but expect another typical summer in the Inland Northwest.
That’s the conclusion from Eastern Washington University geography and meteorology professor Dr. Bob Quinn after looking at some of the factors that broke the mold residents have been used to the past few years.
Coming off a series of cool and wet springs where late precipitation boosted snowpack, and subsequently river flows and reservoir pools, the spring of 2013 has left the region wanting for more moisture. And there’s little hope we’ll get what is needed to get things back to normal.
“We’ve of course had a highly up and down spring so far,” Quinn said. “We moved into a fairly dry pattern in late March and April and even early May.”
That meant the area was nearly 2 inches below normal yearly precipitation. “With that hot spell we had in early May, things were getting a little grim in terms of soil moisture,” Quinn said. “You could see that out in the scablands where soils are very shallow the plants were just rushing to make flowers and seed because they sensed that low soil moisture.”
Then with a shift in the weather patterns to close out May, everything changed. It helped close the gap, but still leaves the land in need.
A cold upper-level low that got established along the Oregon-Washington coast just hung around and hung around. Quinn described it like spokes in a wheel that not only spun moisture into the area but delivered cold temperatures as well.
Despite the wet spell, that low only produced about half the moisture that normally might fall during May. In other words a half-inch as compared to an inch, and that’s at the National Weather Service so other locations got more, or less.
“We had a couple of afternoon shower sequences that probably put another quarter of an inch down in our area and the weather bureau got nothing,” Quinn said.
And the cold air threw some curveballs too.
“The mountains have gotten clobbered,” Quinn said. “Where we’ve gotten a quarter-inch, they’ve gotten an inch,” he said. And some of that even fell as snow in elevations above 3,500 feet. The town of Bickleton, which sits at about 3,000 feet elevation above the Columbia Gorge and 10 miles away, got between 6-8 inches of snow May 22 forcing cancellation of school.
Early May’s snowpack totals this year in the Spokane River basin totaled 96 percent of normal, not that much different than in 2012 with 104 percent, but way down from 2011 when May 4 SnoTel readings sat at 161 percent.
The game changer this spring was that span of warm weather mid-month.
May’s hot spell stripped about 70 percent of the snowpack which was largely below normal in many basins. The heat wave, which pushed temps into the mid 80s in many areas, even took higher elevation snow, Quinn said.
The rain that surrounded Memorial Day weekend was what Quinn called “million dollar” precipitation for farmers. Soil moisture got back to normal with the “miracle rains,” as he termed them.
“Had that hot, dry period continued for another 10 days the wheat would have rushed into flower and seed,” Quinn said. “It would have really affected the yields.”
The region is basically about 2.25 inches below normal even with that timely rain. Another trough will settle with us soon and promises another squirt of moisture, “But over the long haul we’re definitely below normal and June is our last chance,” Quinn said.
The aspect of Mother Nature that controls both short and long-term weather in our region are sea surface temperatures in the Pacific Ocean.
“Sea surface temperatures show two things,” Quinn said. “We have a large warm water pool out in the Gulf of Alaska; we have a little bitty cold water pool off of Oregon, Washington and California.”
Generally the last week in June signals the switch to summer patterns where the Pacific high extends northward along the coast, deflects summer storms into Southeast Alaska and gives the Northwest its trademark hot and dry summers. Quinn then sees summer weather hitting right on target, June 20 or 21.
“I’m not looking for a blazing hot summer, but a very normal summer,” Quinn said, adding, with lower moisture levels going in it will create a quicker start to the wildfire season.
While it’s too early to really be sure, Quinn’s also seeing indications that we may be returning to a La Nina pattern for next winter. “I’m not quite ready to jump on board with that quite yet so for now we’re still La Nada.”
Paul Delaney can be reached at email@example.com.