It’s a record dry spell. Implications? Is global warming here?

        If it seems as if grass turned golden brown astonishingly early this young summer, you’re not imagining things. Western Washington’s long dry spell has broken a record: The 46 days since the last significant rain (May 19) were the driest on record for those dates at four Western Washington weather stations.

       And if it keeps up, it’ll become the area’s driest entire summer on record, which not only is troublesome for lawns, but also for a regional symbol – salmon.

        “Essentially summer started abruptly in Western Washington on May 20,” said state climatologist Phil Mote, a research scientist with the University of Washington’s Climate Impacts Group. He and another UW research scientist, Karin Bumbaco, asked the National Weather Service to compare prior years with this year’s precipitation from May 20 to Independence Day.

       “I didn’t think it would come out that extreme,” Mote said by e-mail. “We’re still very early in the summer, and if it stays dry, we could see a lot of impacts, like record-low flows, fish kills, forest fires.”

      It’s not just a tad drier.

      “It’s drier than even the driest summer that we know in Western Washington,” Bumbaco told the PostGlobe.

      At Seattle-Tacoma International Airport, only 0.18 inches of rain fell during the 46-day stretch examined, which was May 20 to July 4. That’s down from the previous record for that time span – 0.64 inches in 1965. And it’s less than the 0.79 inches that fell in 2003, which turned out to be the driest full summer on record. See statistics for the other three weather stations in Olympia, Hoquiam and Quillayute here. Although there are exceptions (such as North Bend, which endured more than an inch of rain June 19), overall it has been dry in most places.

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      Although researchers say it is impossible to tie any one weather event to the ongoing changes in the climate, they say that warmer, drier summers are likely in a globally warmed future.

      Implications of the current spell?

      Brown lawns, for one. “People can actually see this effect on their lawns: The lawns went dormant much earlier than normal this year,” UW hydrologist Alan Hamlet told the PostGlobe.

      “If I were a salmon in a creek, I think I would be worried if I knew what was coming,” Hamlet said. “For cold-water fish and other things that depend on cold water – yeah, it might be a problem.”

      Salmon need cool waters. Once streams reach about 72 degrees, salmon get into trouble – they become stressed, they become vulnerable to disease and they’ll stop migrating, UW climate/salmon researcher Nate Mantua said.

      Spring chinook and summer steelhead are either in the rivers already or going to be entering the rivers over the next few weeks, Mantua said.

      Right this minute, salmon are OK. But if the rest of the summer stays dry, streams will become shallower. If we have really hot weather, then those stream temperatures can start heading toward stressful.

       “The stage is set for a relative squeeze on the supply of cold stream flow,” Mantua says. Those cold streams serve as homes to both rearing juveniles and migrating adults of many salmon populations that come in during late summer and early fall.

      Another implication: The Northwest River Forecast Center has alerted river users to expect stream flows to be 50 percent to 75 percent lower than usual through Sept. 1 at such places as the Okanogan River near Tonasket and the Methow River near Pateros, according to UW. Other rivers of concern include the Dungeness River near Sequim and the Skagit River near Concrete, the water flows of which are expected to be 75 percent to 90 percent of normal.

     “We’re particularly concerned about the northern Cascades and Olympic mountains, because those areas were already dealing with lower-than-normal snowpack before this dry spell,” Mote said in a news release. As of April 1, snowpack there was 67 percent to 77 percent of normal.

      Should we be alarmed? Maybe if your vacation home sits east of the mountains in fire territory. “I think if I were vulnerable to fire, I would be concerned,” Hamlet said. “But I think for people as a whole, it isn’t much of a water-supply issue this year. ... It is not an alarming thing for people in their everyday lives. Water supply is pretty abundant this year.”

      A dry summer is consistent with what’s expected to come to the Pacific Northwest because of global warming, and 2003 and 2004 brought very dry summers, too, Mote said. 

     Mote and other scientists are quick to say that no particular weather event can ever be blamed on climate change, so this dry spell cannot be blamed on global warming. “I don’t think this dry spell has anything to do with the regional impacts of global warming (or more precisely, human-caused climate change),” Mantua said Sunday by e-mail. “I think it’s just one of those things that happens with our variable climate.”

   As mentioned in past articles, however, the overwhelming majority of scientists say that global warming is real and that some of its effects are felt already, as evidenced by shrinking glaciers in the North Cascades.