Tag Archives: jeff masters

Our Snowpack is INSANE!

Break through: A snow blower from east of Chinook Pass meets a snowblower from the westside. (June 17 photo: WSDOT)

University of Washington meteorologist Cliff Mass is freaking out:

As reported by the U.S. Department of Agriculture’s Natural Resources Conservation Service the Olympic Mt. snowpack (actually the total snow water equivalent–SWE–of the current snowpack) was nearly four hundred times normal.

That’s pure snow! Do you have any idea what the street value of this mountain range is? As Mass explains, the huge numbers are partly because some areas have snow at all in late June.

If you’ve been complaining about the lack of warm weather, you might want to temper your enthusiasm–a strong streak of sun would likely cause substantial flooding at this point. (That leads Mass to a historical digression about the value of dams in regulating meltwater flow, and the great Vanport, Oregon, flood of 1948.)

Over at Jeff Masters’ weather blog, he’s taking a big-picture view of the varieties of meteorological experience: “2010 – 2011: Earth’s most extreme weather since 1816?” It’s been a cool spring here in the Pacific Northwest, but consider Pakistan’s high temperature record in 2010: 128 degrees. Finland reached 99. Finland!

Meantime, someone left the Arctic’s “refrigerator door” open, and “the U.S. had its coldest winter in 25 years. A series of remarkable snow storms pounded the Eastern U.S., with the ‘Snowmageddon’ blizzard dumping more than two feet of snow on Baltimore and Philadelphia.” All in all, a colder, wetter spring–even if it is one for the record books–sounds like we have gotten off lightly so far. I know people who have dealt with local flooding will, with reason, disagree with that.

Seattle’s Cold, Wet Spring Part of National “Extreme Spring”

(Image: United States Global Change Research Program)

Remember Seattle’s cold, wet spring? Well, it wasn’t just us.

The Weather Underground’s meteorologist Jeff Masters has posted a La Niña wrap-up  for you: “U.S. had most extreme spring on record for precipitation.”

While the driest spring on record dessicated Texas, and one of the top-ten driest springs dehydrated New Mexico and Louisiana, northwesterners in Washington and Oregon were grumbling their way through one of the top-five coldest springs the region has seen in the last century or so. Washington was one of nine states deluged by the most precipitation seen in 117 years of record-keeping.

(If you factor in both temperature and precipitation, this was the fifth most extreme spring in the past 102 years, nationally.)

In contrast, our problems (a plethora of potholes, more hydroelectricity than we know what to do with) don’t look that bad:

Nature’s fury reached new extremes in the U.S. during the spring of 2011, as a punishing series of billion-dollar disasters brought the greatest flood in recorded history to the Lower Mississippi River, an astonishingly deadly tornado season, the worst drought in Texas history, and the worst fire season in recorded history.

Even for a La Niña year, this was unusual weather, not least because La Niña just wouldn’t leave. It persisted through spring, and so the “jet stream remained farther south than usual over the Pacific Northwest and Midwest, and blew more strongly, with wind speeds more typical of winter than spring.”

Thus, the South grew cotton-mouthed, while the Midwest saw cataclysmic collisions of cold and warm air, and torrential rains. (“Since global ocean temperatures have warmed about […] 1°F over the past 40 years,” writes Masters,  “there is more moisture in the air to generate record flooding rains.”)

It’s ironic that while this kind of spring makes you suspect climate change is messing with the dials, as the image above illustrates, climate change models (at least) anticipate that the reverse would happen. The trend from from 1970 to 2000, notes Masters, has been for the jet stream to weaken and move northward (270 miles north). This spring’s jet stream, in both strength and position, was an outlier.

That said, Masters points out that this isn’t your father’s global atmospheric system any more: “recent record Arctic sea ice loss” may be causing atmospheric circulation changes in the Arctic Oscillation, pushing the jet stream southward “over Eastern North America and Western Europe during late fall and winter.” And again, it’s the warming temperature of the world’s oceans that helps increase the humidity of the air above them.

So you might call climate change, for better or worse, the wind at the back of what we’ve seen this year.