Hooray for less snow this winter. But will your water be rationed?

What a difference a year makes.

By this time last winter, about two feet of snow had fallen on the Tri-Cities.

This winter, just four inches have been recorded so far, according to the National Weather Service.

That’s been nice for Tri-City residents who don’t like driving on icy roads or shoveling snowy driveways.

However, a good snow pack still is needed in the East Cascade Mountains to ensure a gradual snow melt to feed the Yakima River for the irrigation season.

The snow pack for the upper and lower Yakima Basin is “certainly decent,” if not at the 100 percent of normal that irrigation district leaders like to see, said Tyler Roberts, watermaster for the Washington Department of Ecology’s Office of Columbia River.

Ecology’s Water Supply Availability Committee will make the official determination.

A La Niña system was predicted for this winter, which can bring colder and snowier weather than usual to the Northwest.

But it doesn’t always do that, as this winter so far has shown, despite typical ocean temperature patterns for a La Niña.

Above normal temperatures have been recorded in parts of the state, with temperatures in the Tri-Cities at least through December around average.

January in the Tri-Cities has seen mostly air moving in from the west rather than continual cold air from Canada, according to the National Weather Service.

In the Washington Cascade Mountains, particularly for the lower Yakima Basin, temperatures have been warmer and precipitation has been lighter than normal this winter through mid-January.

La Niña weather conditions can show up later than usual, Roberts said.

While it is too soon to say if that will be the case, “weather over the last week has been favorable to a more typical La Niña,” he said.

A series of storms that have moved across Washington over the last week have improved the snow pack for much of the state.

As of Wednesday, the upper Yakima Basin snow pack was at 86 percent of normal and the lower Yakima Basin snow pack was at 87 percent of normal, both up 5 percentage points from earlier in the month.

The Washington Cascade Mountains have significantly more snow than the Oregon Cascade Mountains, where until the last week a persistent high pressure ridge blocked precipitation there and sent it into Washington and British Columbia, Roberts said.

As of Wednesday, most of Oregon still had 50 percent or less of normal snow pack.

Much can still happen before it’s time to start irrigating vineyards, orchards and urban lawns from the Yakima River this year.

Traditionally, February and March are the months with the greatest snow accumulation, according to Roberts.

But crucial to the irrigation season is keeping temperatures cool enough to allow a snow melt to steadily supply the Yakima River.

“An early melt is the biggest threat,” Roberts said.

Daytime temperatures remain higher than usual in the Yakima Basin, despite some colder recent nights.

The big question is whether this is going to be another 2015, Roberts said.

During the summer drought of 2015, the Kennewick Irrigation District restricted when and for how long district residents could water their lawns.

KID relies on the Yakima River for water.

So far this winter, the snow pack appears to be mimicking 2017, Roberts said, despite the different weather in the Tri-Cities this winter compared with last winter.

Coincidentally, storms are even arriving on the same weeks of the winter.

There should be no shortage of water for irrigators who rely on the Columbia River. The upper Columbia Basin is at 121 percent of normal snow pack.

The lower Snake River Basin has 97 percent of normal snow pack.

This story was originally published January 24, 2018 at 6:56 PM with the headline "Hooray for less snow this winter. But will your water be rationed?."