Drought news: So far 2012 is the second dryest year on record, statewide snowpack = 39% of avg #CODrought

snowpackcoloradobasinhighlow11272012.jpg

Click on the thumbnail for the current Statewide Basin High/Low ogive. The NRCS statewide map that I usually show is out of sync with the graph. They are working on it, according to Mage Hultstrand. She told me via email:

The High Low graph is using the “old” 1971-2000 averages and includes all the SNOTEL sites in the basin (with averages).

The statewide update map has already been switched over to the “new” 1981-2010 normals. We have not yet completed the calculations of these new normals for all of our sites; as a result this map does not include all the sites across the state or in the South Platte basin yet. That’s why I showed the high low graph instead of the map at the [Water Availability Task Force] meeting. For right now it is the more accurate representation of conditions across the state.

We plan to have all the new calculations done by January 1 and then the two products will both be updated with the new averages and should match.

Here’s the recap of the November 20, 2012 Water Availability Task Force Meeting from the Colorado Water Conservation Board.

With ten consecutive months of below average precipitation, the 2012 water year, which ended on September 30th, saw just 75% of normal precipitation. November has continued on a below average trend; although a storm around Veteran’s day brought beneficial moisture to the mountains, slightly boosting statewide precipitation from 54% on November 1st to 58% as of the 19th. At this early stage in the snow accumulation seasons, snowpack is at 45% of average. Despite a cooler October, November temperatures are above seasonal averages. Currently, this calendar year ranks as the 2nd warmest on record (1895-2012) with a statewide average temperature of 51.7 degrees Fahrenheit.

 As of the November 20, 2012 US Drought Monitor, 100% of Colorado is experiencing some level of drought classification. D2 (severe) and D3 (extreme) cover nearly 79% of the state, while 13% of the state is experiencing exceptional drought (D4), isolated to the eastern plains. This is a slight decrease in D4 classification since the start of the water year on October 1, 2012.

 Many municipalities that had implemented both voluntary and mandatory watering restrictions earlier in the year will keep these in place throughout the winter. Through the irrigation season Colorado Springs Utilities (CSU) saw consumption increase to the highest levels since 2002; consequently reservoir levels are the lowest since 2002. Other communities are closely watching the situation and have some concern should the drought conditions persist for another year.

 Statewide reservoir storage is at 66% of average and 37% of capacity. The highest storage levels are in the Yampa/ White River Basin, at 96% of average while the lowest storage in the state is the Rio Grande River basin at 47% of average. All other basins range from 61% to 73% of average and 17% to 52% of total capacity.

 Many basins that were able to rebound following the 2002 drought are reporting reservoir levels that have not been seen in nearly a decade; while others that were not able to fully rebound to normal levels post the 2002drought continue to report below average reservoir levels.

 Surface Water Supply Index values have improved in some areas (Huerfano, Cache La Poudre & Big Thompson) and deteriorated in others. The central portions of the state as well as the southwestern corner have seen the largest decline. This is largely due to decreased stream flows and decreased storage levels. During this time of the year the SWSI is calculated using observed, rather than forecasted, stream flow volumes.

 For the first time in nine years ENSO-neutral conditions are likely to dominate through the winter months. Without El Nino or La Nina influencing weather patterns, it is difficult to determine when the current drought regime will be broken in Colorado. The latest long term experimental forecast, issued November 19th, shows below-normal chances of moisture from January to March throughout much of Colorado. This is based largely on other factors such as a cold north Pacific (PDO) and a warm North Atlantic (AMO).

From The Pueblo Chieftain (Chris Woodka):

Colorado snowpack through November is only 43 percent of normal, raising concerns that a statewide drought may be entering its second year.

The statewide water availability task force, meeting last week in Denver, pointed to several indicators that drought is continuing. The most extreme drought is in the Lower Arkansas Valley — Crowley, Otero, Kiowa, Bent, Las Animas and Prowers counties — where the drought could be entering its third year. Despite a widespread storm on Veterans Day, snowpack is at 43 percent of normal statewide. The Arkansas River basin is in the worst shape at 26 percent, while the Colorado River basin, which supplies supplemental water to this basin, is at 44 percent.

The Rio Grande basin snowpack is at 43 percent.

Early snow levels are not a good indicator of water availability for 2013, since most of the snow in Colorado falls in March and April. Coupled with last year’s subpar snowpack, however, a dry winter could spell trouble.

Statewide reservoir storage is at two­thirds of average and just 37 percent of capacity. were able to rebound following the 2002 drought are reporting reservoir levels that have not been seen in nearly a decade,” said Taryn Finnessey, of the Colorado Water Conservation Board and co­chair of the task force.

Some cities are extending outdoor water restrictions into winter months.

Pueblo did not put restrictions in place, but was forced to draw down water held in storage to meet increased demand.

The task force also noted that temperatures in November were again above normal, as 2012 has been the second warmest year on record. The warmest was 1934.

Long­term forecasts call for drier than normal conditions through March.

From the Vail Daily (Lauren Glendenning):

In recent memory, the 2007-08 season started off dry and ended up wet. Last season — one of the worst snow years on record — started out snowy. You can never tell what December and the rest of the season will bring based on November weather, but that doesn’t help local hotels waiting for December bookings to fill up.

The sunny skies are unsettling, said Meteorologist Joel Gratz, who runs the powder forecasting site www.opensnow.com.

Gratz points out that weather, or storm tracks, often gets stuck in a pattern. Over the last decade or so, he said those patterns have tended to persist for 2 to 4 weeks and then they change. Last season, however, the pattern never really flipped, Gratz said.

“That was the first time I had seen that in a long, long time,” he said. “We were on the wrong side of the storm track and nothing really shifted, and the last few weeks we’ve been on the wrong side of the storm track and nothing has really shifted. … It’s unsettling to see this now. I don’t know if it’s going to change or not. I have no clue.”[...]

Sites like www.accuweather.com predict weather a month in advance. That site shows the Vail area turning to a colder, snowier pattern around mid-December, but Gratz said you just can’t scientifically predict weather that far in advance.

He does see a storm heading toward Colorado around Monday, but he only expects 2-4 inches out of that storm, if that.

It’s still a bit too early to pin down the exact timing or amounts, but the models are somewhat consistent with this storm hitting Colorado, so I’ll jump on the band wagon,” Gratz wrote in his Tuesday forecast. “At this point I wouldn’t expect much more than a 2-4 inch event, but maybe if we get lucky there could be talk of six inches.”

Gratz has looked at some historical data over the last 30 years and said there have been maybe 2 to 4 seasons that had an equally slow start like this season. Half of those seasons turned out about average, and half turned out below average, he said.

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