El Niño hiatus: Tahoe’s unseasonably warm temperatures not yet a snowpack concern
While temperatures around the Tahoe Basin are forecast to reach close to 15 degrees above average this week — with no precipitation expected — meteorologists and water resource officials say it’s not yet a cause for concern when it comes to the snowpack.
“February is climatologically our best month for accumulation,” Reno National Weather Service meteorologist Justin Norman said, adding, however, “it’s not uncommon to have a dry spell.”
As to what the unseasonable temperatures could mean for the snowpack, Weather Service senior hydrologist Tim Bardsley said, “We’re in a good spot because we were considerably above average.”
Even with the dry spell continuing, he said, “We’d be right on normal conditions,” although above average would be preferred due to drought.
He further explained that with the low solar angle and shorter days this time of year, the melting impact won’t be as dramatic as it would later in the winter.
“In general, the sun — solar gain — is the most significant,” he said. “People have the perception that it’s temperature.”
While the snow will melt significantly at lower elevations, the deep snowpack at higher elevations is less of an issue, he said, and is less affected by warmer temperatures.
Explaining the process, California Department of Water Resources spokesman Doug Carlson added, “This time of year, the sun is still low, so melt is usually not much — even with a day or two of above normal temps.”
And while snowpack depth may change substantially, water content likely will not see as dramatic of a loss. The snowpack becomes more dense rather than fully melting.
“I don’t think we should be particularly concerned,” Bardsley said regarding the snowpack and dry spell. “Surface conditions impact skiers more than the water supply.”
Should the dry spell stretch into March, however, he said that would be potentially “very detrimental” to the snowpack.
Current forecast models are calling for the high pressure system, which is keeping unseasonable temperatures and clear skies in the region, to potentially dissipate next week — allowing for storms to return.
“There’s a reasonable chance of a wet end of the month,” Bardsley said. “That might save the month.”
Even if it remains dry, Bardsley suggested that the snowpack water content could simply drop back to average.
As of Wednesday, Feb. 9, statewide snowpack water content was at 104 percent — down from 114 percent from Feb. 2 — according to the California Department of Water Resources.
The Lake Tahoe Basin remained substantially higher than the state average, however, with U.S. Department of Agriculture SNOTEL sites still reporting around 125 percent of average snow water content.
According to Weather Channel data, the Lake Tahoe region’s February average high temperature is around 44 degrees, with a record high of 62 reached in 1977.
Temperatures this week are expected to reach the mid to high 50s.