Snowpack

Recent snowfall over the past week (March 13-15) in northern Montana is contributing to good growing season forecasts, especially for irrigators. Winter is not over yet in this scene from the National Weather Service Great Falls, showing drifting snow from winds on March 16.

All the river basins in Montana have received above normal snowfall this winter.

Lucas Zukiewicz, water supply specialist for the USDA Natural Resources Conservation Service (NRCS), said all the signs point to ag producers having good irrigation this summer.

“Ag producers, especially irrigators, are going to be pleased as we approach spring and summer. So far, it is great news,” said Zukiewicz.

From mid-April to May, the river flows start to come up, he said.

On Jan. 1, there were “dismal” reports of snowfall, and concerns about a dry spring river flow in 2020.

Surprisingly, record snowfalls in the mountain ranges supplying water to regional rivers and streams in January and again in February, changed that forecast.

At this point in the winter, around 75 to 85 percent of the seasonal peak snowpack has typically accumulated at mountain locations. This data gives forecasters clearer insight into what the snowmelt may yield in seasonal water supply during spring and summer.

Snowpack totals in all river basins across Montana are now near to above normal for March 1.

As the transition into spring continues, weather patterns across Montana will change.

“Mountains west of the Divide typically experience lower monthly snow totals through spring. However, spring months can be significant to river basins east of the Divide,” he said.

While spring starts on March 19, there is still typically a lot of winter left to come in the mountains, and some good months may be ahead for our east of the Divide river basins.

However, future snowfall, spring precipitation and temperatures during the next three months will play a critical role in both the timing and volumes experienced during runoff this year.

“These months can make or break our spring and summer stream flows,” Zukiewicz said.

The U.S. Drought monitor effective March 10 is currently showing some abnormally dry areas in south central and a large spot in the northwestern region of the state.

Hopefully, that will change as spring comes on strong.