Concerns developing over potential drought as Pocatello snowfall levels are well below average
Published at | Updated at
POCATELLO — The calendar flip from December 2020 to January 2021 has come and gone, but the normal December snowpacks never arrived in the Gate City.
Pocatello did get some snow last month. Residents woke up on Dec. 14 to nearly 2 inches of powder, but at no point did the snow get any deeper than that, and much of that snow melted away within days.
The city of Pocatello receives an average of 10.7 inches of snowfall in December, according to the National Weather Service (NWS). Last month, Pocatello saw just 2.7 inches, marking it the 14th-least snowiest month on record for the city, according to the NWS. Through the first week-and-a-half in January, a month that sees, on average, nine inches of snowfall in the city, Pocatello has gotten less than two inches.
The concern is not the snowfall at the city level but on the surrounding mountain peaks, which feed the rivers and reservoirs that supply the area’s water throughout the year. Those numbers have been low as well, according to Department of Water Resources District 1 Watermaster Tony Olenichak, who told EastIdahoNews.com that higher-elevation snowfall in the Portneuf Basin is well below average.
The current value of higher-elevation snowfall in the area, Olenichak said, is at 78% of average, creating worry over a potential spring and summer drought.
“There’s always that concern when we have a below-average snowpack, and that’s certainly the case [this year],” Olenichak said.
Olenichak compared this winter so far to last winter up to this point and said that until January, the weather had followed a similar pattern. But, as he discovered in reviewing numbers at this time last year, the area’s snowfall was at 92% of average — 14% above current rates.
Southern winds are to blame for the drier weather pattern, NWS spokesman John Keyes said.
These winds push snow and storms north to Washington, Montana, Canada and Alaska. The byproduct: Montana, Washington and Alaska have seen an increase in precipitation, while states south of those have seen drier-than-normal climates.
Although he acknowledges human involvement in ongoing climate trends, Idaho State University climate expert Professor Bruce Finney is not ready to call this a product of global warming.
“We know that as carbon dioxide in the atmosphere increases, that’s going to make the climate warmer overall,” Finney said. “But we don’t have a very good understanding about how that’s going to affect things on a more short-term nature.”
Finney agreed with Keyes’ assessment regarding the southern winds’ involvement in Pocatello’s dry December. Finney pointed to the National Oceanographic and Atmospheric Administration’s declaration of a La Nina pattern in September as clear forecasting, adding that a “ridge of pressure” in the Pacific Ocean has compounded the issue.
Neither Finney nor Keyes is ready to sound any type of alarm in dealing with the uncommonly warm and dry winter thus far but both have concerns moving forward.
“You know how important water is, for Southern Idaho in particular,” Finney said. “There are some concerns that people should have, because of the effects of how warm climate is. It’s going to affect how that precipitation is distributed. … The snow line is going to be going up the mountain, less (snow) will be stored on the ground, and that is going to affect things like streamflows and reservoirs.”
Pocatello got a downpour of rain the night of Jan. 4, but that is not what the area needs. A shortage of snow now could lead to a shortage of water reserve in the spring and summer months, in turn affecting crops.
Keyes’ worries go one step further.
“A lot of the concerns that we get come later on,” he said. “(Like) snowpack – when it melts off later in the year and how fast it melts off … If we melt the snow off really quick, that is less moisture available to keep the fire season at bay.”
Olenichak, who couldn’t remember the last time higher-elevation snowfall up to this point of the year was so low, added that this is the time of year that concerns over potential drought begin to get significant.
“I’m not too concerned when we’re below average up until about the first of January,” Olenichak said. “But once we get into January and certainly February, if we’re not close to average, then we could experience some shortfalls.”