Snowpack news: A week of warm weather sends snowpack downward

From The Pueblo Chieftain (Chris Woodka):

A warm week of weather left the state with a decreased snowpack of just 84 percent of median in terms of moisture content. A cold front is expected to move into the state today, bringing with it some additional moisture later in the week. March and April are traditionally the snowiest months, providing much of the water supply for later in the year.

But for now, the snowpack is below average throughout the state, with the exception of higher elevations in the central mountains. The South Platte and Arkansas River basins are near normal, overall, while the Upper Colorado River basin is at just 91 percent.

The flow in the Arkansas River below Pueblo Dam doubled Sunday to about 330 cubic feet per second after the end of the winter water storage program. Area ditches began taking water, rather than keeping it in storage at Lake Pueblo and other reservoirs in the Lower Arkansas Valley.

Water use by Puebloans began to increase over the weekend as well, but not dramatically, said Seth Clayton, director of administrative services for the Pueblo Board of Water Works. Water use increased by about 500,000 gallons Sunday, as temperatures hit 79 degrees.

“I think people are still nervous and haven’t kicked up their sprinkler systems yet,” Clayton said. “It really starts to go up at the end of March.”

Still, Pueblo water use has averaged just over 12 million gallons per day through Sunday, up a bit from the five-year average. By the end of March, it should be around 18-19 million gallons per day.

Following record snow in February, Pueblo is still above average with 1.43 inches of precipitation since Jan. 1.

From the Leadville Herald:

Two weeks of wet weather through the end of February and beginning of March have provided a significant increase in snowpack statewide and an even greater boost to those southern Colorado basins that are still ailing after several consecutive years of below-normal snowpack.

Despite substantial accumulations statewide, snowpack has not quite returned to normal; it was 87 percent as of March 1.

Further investigation of SNOTEL data indicates that during the nine-day period of Feb. 20 through March 1, the state of Colorado received two inches of snow water equivalent, 181 percent of the normal for that time frame. That is a 9 percent increase in snowpack percent of median. Preliminary numbers into March indicate an additional 7 percent increase between March 1 and March 5. On March 1, with 20 percent of the mountain snowpack accumulation season remaining, time is dwindling to close the gap and reach typical statewide peak snowpack levels.

Brian Domonkos, snow survey supervisor with the U.S. Department of Agriculture Colorado Natural Resources Conservation Service, said, “While not every major watershed in the state saw snowpack improvements this month, precipitation during the latter half of February was a highly beneficial to many water budgets across the state.”

The recent storm patterns were most beneficial to the Rio Grande watershed, receiving 300 percent of normal snowfall in the last nine days of February. The South Platte and the Rio Grande both received a 13 percent gain over the course of February. In the South Platte River basin, snowpack has not reached 2011 or 2014 levels at this point, but conditions are still better than 1988, 1993, 1994 and above normal.
Statewide precipitation for the month of February was right at normal, a drastic change from 45 percent of average received during the month of January. Year-to-date statewide mountain precipitation totals increased 3 percent since last month. Colorado reservoir storage increased as well from Feb. 1 to March 1 from 104 to 105 percent of average. Stream flow forecasts saw marked improvements most particularly for the state’s southern streams.

Domonkos put the recent weather into perspective. “This storm could not have come at a better time,” he said. “Without this storm, if the same weather patterns since Jan. 1 had persisted through spring, mountain snowpack would have narrowly reached only the minimum snowpack peak.”

From the Associated Press (Dan Elliott) via The Denver Post:

Colorado water officials will get an update on mountain snowpack and an early look at potential flooding threats from the spring runoff on Tuesday.

State task forces on water availability and on floods are holding a joint meeting to hear reports on weather forecasts, snow levels and the possibility of flooding when spring arrives in the high country and the snow begins to melt.

Colorado’s snowpack is closely watched because it provides water for four major river systems that originate in the state: The Colorado, the Platte, the Arkansas and the Rio Grande.

The Colorado River is under especially close scrutiny because it helps supply California, which is in the midst of a historic drought. The most recent assessment available showed 40 percent of California was in an exceptional drought, the driest of five categories used by the federal government’s U.S. Drought Monitor. Nearly 28 percent was in an extreme drought, the second-driest category.

In Colorado, the snowpack in the mountains and valleys that directly feed the Colorado River was 91 percent of the long-term average Monday. In three other Colorado basins that eventually feed into the Colorado River, the snowpack was 73 to 81 percent of average.

East of the Continental Divide, snowpack in the basin that feeds the South Platte was 104 percent of average, while the North Platte River basin was at 86 percent. The North Platte flows north into Wyoming before turning east into Nebraska, where it joins the South Platte to form the Platte River.

The Arkansas River basin had 96 percent of average snowpack, and the Upper Rio Grande basin had 80 percent.

Rain or extended warm spells in springtime can hasten the spring runoff and trigger floods by putting more snowmelt into Colorado’s rivers and streams than they can handle.

From the Vail Daily (Melanie Wong):

Think it’s been unseasonably warm? So do the walkers and runners out on the recreation paths, the fly fishermen in the Eagle River and the skiers cruising down the mountain in short-sleeves.

March weather data shows that this winter has brought stretches of higher-than-average temperatures and that mid-March has had the thermometer at or near all-time record highs for the month. The highest recorded temperatures for Vail in March are in the mid-50s, which are similar to what Eagle County has been seeing the past few days. Typically, average March temperatures are closer to the mid-40s, according to National Weather Service data.

According to SNOTEL information gathered on Vail Mountain, the record mid-March high for the last 30 years was 56 degrees in 1995, with several other very warm Marches in 2011 and 1999. March 15 of this year was very close to those record highs, with a max temperature of 53 degrees. However, Monday could break that record, with the forecast calling for a high of 56.

“Essentially we’re under a ridge of high pressure, meaning there’s a bubble of warm air in the atmosphere over us,” said National Weather Service meteorologist Ben Moyer. “In fact, most of Colorado is seeing high temperatures. On Monday, Denver is at 69, and Pueblo is in the lower 80s.”

However, as National Weather Service data acquisition program manager John Kyle points out, this winter has not only brought warm highs, but also a good number of very cold days.

Dec. 14 was a record warm day, as were a few days in February, Kyle said. However, there was also a record low day recorded around New Year, and the first week of March was colder than the historical average.

“Minus the latter part of December and a couple brief days, it looks like it was a warmer than normal winter, and that was the case for most of the Western Slope,” said Kyle.

SNOWPACK STILL OK

The good news is that snowpack levels are still looking strong, ranging from 83 percent of the average snow water equivalent to 113 percent of average at the Eagle River headwaters at Fremont Pass to 107 percent on Copper Mountain.

“The (snow water equivalent) took a huge hit on Vail Mountain between Sunday and Monday, but Fremont and Copper held tight. Does that cause concern? Yes, but there’s still a good month of winter left,” said Diane Johnson, of the Eagle River Water & Sanitation District.

Snowpack affects reservoir levels, fire danger for later months and river levels. Mountain residents should certainly be concerned about stream flow levels, but Johnson said it’s too early to tell if the local waterways will be normal or suffering come spring.

“A few years ago, we were saved by end-of-winter storms after a very poor snow season,” she said. “Even if we get snow in late April and May like we did in 2013, it can really help our situation here.”

As far as precipitation, the predictions are positive. The outlook from the Colorado Climate Center calls for higher than average chance of precipitation during the next few weeks, although it is also calling for higher than average temperatures.

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