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:
Westwide 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:
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
Short Term: (4/21)
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 April 21 2015:
Much needed moisture fell over much of the region over the past week, but was not enough to greatly improve snowpack or streamflow conditions. East of the divide also received much needed moisture over the past week and improvements are warranted for the shorter term drought over NE Colorado. Another area in Cheyenne county has received 2-3" month to date, and that area is also warranting improvements.
UCRB: The highlighted area is being watched for improvements. Forecasts are for showers across that area for the next week. If that pans out, the area will warrant improvements.
Eastern CO: Removal of much of the D0 over NE Colorado where 1-3" has fallen since the beginning of the month. This D0 is fairly short lived, so improvements are suggested at this time. There is a drier pocket near Akron, CO. That area will be monitored in upcoming weeks if precipitation shuts off and temperatures heat up.
A one category improvement is suggested over eastern Cheyenne county where 2-3" has fallen since the beginning of the month. Conditions quickly dry out west and south of this area where winter wheat is struggling and subsoil moisture has not yet recovered after several years of drought.