The images above use daily precipitation statistics from NWS COOP, CoCoRaHS, and CoAgMet stations. From
top to bottom, and left to right: most recent 7-days of accumulated precipitation in inches; current month-to-date
accumulated precipitation in inches; last month's precipitation as a percent of average;
water-year-to-date precipitation as a percent of average.
Last Week Precipitation:
Water Year 2015 Precipitation:
SNOTEL AND SNOWPACK
The top left image shows the Natural Resources Conservation Service's SNOTEL water-year-to-date
precipitation percentile rankings. The top right image shows sub-basin averaged snow water
equivalent accumulations as a percent of average. The images below show accumulated snow water
equivalent in inches (green) compared to average (blue) and last year (red) for several different sub-basins
across the UCRB (and were created by the Colorado Basin River Forecast Center).
SNOTEL Precipitation Percentiles:
Basin-wide Snow Water Equivalent (SWE) Percent of Normal:
SWE Timeseries Graphs:
STANDARDIZED PRECIPITATION INDEX
Standardized Precipitation Index standardizes precipitation accumulations for a specified time period
into percentile rankings. -1.0 to -1.5 is
equivalent to a D1 to D2. -1.5 to -2.0 is equivalent to a D2 to D3. -2.0 and worse is equivalent to a D3 to
D4. 30- and 60-day SPIs focus on short-term conditions while 6- and 9-month SPIs focus on long-term
conditions. SPI data provided by High Plains Regional Climate Center.
Short Term (30-day):
Long Term (6-month):
The top left image shows 7-day averaged streamflows as a percentile ranking across the UCRB. The top
right image shows 7-day averaged discharge over time at three key sites around the UCRB: The Colorado
River at the CO-UT state line; the Green River at Green River, UT; and the San Juan River near Bluff,
UT. All streamflow data provided by United States Geological Survey.
The top left image shows VIC modeled soil moisture as a percentile ranking. The top right image shows
VIC plus SWE total soil moisture storage.
The above image shows last month's and this month's current volumes of the major reservoirs in
the UCRB, with percent of average and percent of capacity.
All images show temperature departures from average over different time periods (last 7 days on top
left; month-to-date on top right; last full month on bottom). Temperature departure
maps provided by HPRCC ACIS.
Last Week Temperatures:
Last Month Temperatures:
FORECAST AND OUTLOOK
The top two images show Climate Prediction Center's Precipitation and Temperature outlooks for 8 - 14 days. The middle image shows the 3 months Precipitation outlook. The bottom left image shows the Hydrologic Prediction Center's Quantitative
Precipitation Forecast accumulation for the five days between Tuesday 12Z and ending Sunday 12Z. The
bottom right image shows the Climate Prediction Center's most recent release of the U.S. Seasonal
Above is the most recent release of the U.S. Drought Monitor map for the UCRB region. Below shows
the proposed changes for this week, with supporting text.
Summary for January 27, 2015:
Eastern Colorado and the Upper Colorado River basin are currently basking under an unseasonal subtropical high pressure system that arrived out of the southwest. While the warm air does feel like a very nice reprieve from winter it is a bit disconcerting in the context of drought. The challenge in the Upper Colorado River Basin (UCRB) this week appears to be weighing short-term warmth and dryness against lucrative August and September rains, and above average December snowfall in many regions.
UCRB: The warm, dry conditions over the past couple weeks have had a large impact on basin-wide snowpack for the Duchesne, Yampa, White, Gunnison, and San Juan River Basins. Snowpack in these basins have now fallen anywhere from 10-18% with respect to the median over the last two weeks. On longer timescales SPI's are still wet across much of western Colorado, and streamflows are above average in many areas, so it's not a dire drought scenario at this point. It will take a couple moisture-packed systems to catch up on snowpack though, so the classification of "abnormally dry" is justified.
D0 is being recommended for the following area:
Eastern Plains: Status quo is recommended as this region is in their dry season. Huerfano and Pueblo Counties were on our radar for degradations last week, but the area received some beneficial moisture this week and experienced near average temperatures, so this is not the week to make degradations.