It's about time someone studied the 'Halfway Grade Effect'

By Jayson Jacoby January 29, 2010 10:05 am

As great divides go, the Rocky Mountains get a lot of press, but I think the Halfway Grade puts the Rockies in the shade.

Not literally, of course.

In terms of topography, the Halfway Grade (and its shadow) would seem pitifully diminutive compared to the most inconspicuous foothill in the Front Range.

Even measured against our more modest local standards the Halfway Grade — the sagebrush ridge that separates the Eagle and Pine valleys in eastern Baker County — is hardly imposing. The summit where Highway 86 crests the grade is a meager 3,653 feet above sea level. That’s barely 200 feet higher than Baker Valley.

But in meteorological matters, I know of few eminences as mighty as the Grade.

I drove over it on Sunday.

There was no snow in Richland, on the Eagle Valley side.

In Halfway, the Pine Valley town a mere eight miles away as the chukar flies, the snow was about belly high on a mule deer.

But this vast discrepancy was not the product of some rare confluence of weather phenomena, akin to a tornado that destroys one home but disturbs not a single shingle next door.

What I’ve described is in fact the normal state of things, snow-wise, for mid-winter in this part of Baker County’s Panhandle.

If you live in Richland you can in most winters handle your snow-moving needs by means of a simple shovel.

But if you live in Halfway you’d do well to enlist the assistance of some implement powered by an internal combustion engine. And most people there do. Taking on a typical Pine Valley winter with just a shovel is akin to running a farm with a pair of oxen and a walk-behind plow.

Blisters, is what I’m talking about.

According to the National Climatic Data Center (a place I’d happily get locked in overnight), Halfway’s average yearly snowfall, from 1971-2000, was 73.5 inches.

Richland’s average during that period was a paltry 17.8 inches.

This is why every other road sign in Pine Valley shows a snowmobile.

If you see a snowmobile in Eagle Valley it’s like as not lashed to a trailer that’s either going toward, or just leaving, Pine Valley.

Halfway Grade affords the most compelling view of this disparate scene. From the ridgetop you look east and see a land cloaked in white, while to the west the dominant color is the dull brown of pastures in winter fallow.

The dramatic difference between the two valleys intrigues me in large part because it defies the general principles of weather.

Take, for instance, elevation.

Since the temperature, with occasional exceptions, falls as elevation rises, as a rule the higher you climb the deeper the snow.

Halfway is higher than Richland but the difference — about 450 feet — is far too slight to account for why Halfway accumulates more than four times as much snow.

To cite another nearby example, Baker City is almost 700 feet higher than La Grande, yet Baker City’s average annual snowfall barely beats La Grande’s — 26.6 inches to 20.4 inches.

Their relative proximities to the Wallowa Mountains certainly plays a role too in making Halfway infamous for the depth of its snowdrifts, while Richland basks in its reputation as the county’s banana belt.

(I don’t think you can actually grow bananas in Richland, but its peaches are luscious and its apples fine.)

Pine Valley rubs right up against the Wallowas’ granitic shoulder; it looks like what we think of when we say “mountain valley.”

Eagle Valley, by contrast, has more the appearance of a river delta, lying as it does where the Powder River reaches the emasculating sluggishness of Brownlee Reservoir.

From Richland you can’t even see the high peaks of the Wallowas.

Yet neither elevation, nor distance from the Wallowas, seems to me a satisfactory explanation for why blizzards bypass Richland but barge into Halfway and hang around for days.

For one thing, this situation is precisely opposite of the rain shadow effect that usually prevails in the West.

Examples abound in Oregon, the most obvious being the rain shadow created by the Cascades.

In general, the windward side of a mountain or ridge is wetter (and snowier) than the leeward.

Yet Richland, despite being on the windward side of the Halfway Grade, is quite arid compared with Halfway, which is on the leeward.

The solution here ultimately requires the attention of someone who’s a lot smarter than I am.

I’ve long thought that this matter — what I call the “Halfway Grade Effect” — is an ideal topic for a master’s thesis or doctoral dissertation in meteorology or climatology.

I’ve never actually read such a document but it seems to me this is just the sort of mystery that would entice a budding scientist.

And with the way the federal government is throwing money around these days a student wouldn’t have to plead too hard to get a grant.

I’d do it myself except I’m terrible at math and probably would fail the entry-level courses.

Although I kind of understand Doppler radar.

Jayson Jacoby is editor of the Baker City Herald.