Last April was the great melt.

This April is the great freeze.

Or at least the extremely sluggish melt.

The two months could hardly have had more disparate effects on Northeastern Oregon’s mountain snowpack.

This discrepancy partially explains why a year ago most of the region was still enduring a drought, while today no part of Oregon is.

Through the first 18 days, this April has been much colder, and somewhat wetter, than the 2016 version.

The average high temperature at the Baker City Airport for that period was 54 degrees this year, compared with 66 degrees last April.

The temperature trends are reflected in the region’s snowpack.

Although this might seem improbable considering how vastly different the past two winters were at low elevations — this past winter was the snowiest in Baker County’s valleys since 1992-93 — the snowpack in the mountains was quite similar, on April 1, this year compared with last.

But after April 1 the trend lines begin to diverge quickly.

Last April a warm spell early in the month, with temperatures more typical of June, rapidly eroded a snowpack that in many places was above average when the month started.

At Eilertson Meadow, for instance, along Rock Creek in the Elkhorns about nine miles west of Haines, the water content in the snowpack on April 1, 2016, was 7.6 inches. That’s 13 percent above average.

But just a week later — during which the temperature at the airport reached 70 or warmer on five days — the water content at Eilertson Meadow had shrunk to 2.6 inches.

By April 11 the snow was gone.

This April, by contrast, with temperatures so far topping out at 64 degrees, the snowpack has melted much more slowly.

At a few higher elevation sites the water content, after dropping slightly earlier in the month, has actually risen since then.

“From about 5,500 feet elevation on up, most of the (snow)pack is still there,” said Wes Morgan, manager of the Burnt River Irrigation District in southern Baker County.

The combination of cool temperatures and frequent rain (or hail, or snow) showers has also delayed the onset of irrigation on most farm and ranch land.

That allows Morgan and other irrigation district officials to store in reservoirs most of the snow that has melted.

Lyle Umpleby of the Powder River Water Control District said Tuesday that he’s “guardedly optimistic” that the district’s two reservoirs, Pilcher Creek and Wolf Creek, both west of North Powder, will fill later this spring.

Umpleby said that when he inspected the Carnes Ditch near Pilcher Creek last week he had to travel in the morning because by afternoon the snow, which still lay deep on the irrigation ditch’s bank, would have been too soft to support the weight of his four-wheeler.

A year ago the ditch was snow-free.

Unlike Umpleby, Morgan needn’t reserve a smidgen of caution when forecasting whether his district’s reservoir, Unity, will fill.

Indeed Morgan could have filled Unity to the brim several weeks ago, when low-elevation snowmelt was pouring into the reservoir along the Burnt River.

Over the past month or so Morgan has kept the reservoir slightly below full — it was at 93 percent of capacity Tuesday afternoon — so there’s room to accommodate the glut of water that would run into the reservoir during a warm spell that melts the snowpack quickly.

See more in the April 19, 2017, issue of the Baker City Herald.