NIDIS Intermountain West Drought Early Warning System January 16, 2018

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NIDIS Drought and Water Assessment NIDIS Intermountain West Drought Early Warning System January 16, 2018 Precipitation The images above use daily precipitation statistics from NWS COOP, CoCoRaHS,

1 NIDIS Drought and Water Assessment NIDIS Intermountain West Drought Early Warning System January 16, 2018 Precipitation 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. Standardized Precipitation Index Page 1 of 13

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.

2 Standardized Precipitation Index standardizes precipitation accumulations for a specified time period into percentile rankings to -1.5 is equivalent to a D1 to D to -2.0 is equivalent to a D2 to D and worse is equivalent to a D3 to D 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. Snotel and Snowpack Page 2 of 13

3 The above 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). Streamflow Page 3 of 13

4 Page 4 of 13

The top left image shows 7-day averaged streamflows as a percentile ranking across the UCRB.

Colorado River at the CO-UT state line; the Green River at Green River, UT; and the San Juan River near

Surface Water The top left image shows VIC modeled soil moisture as a percentile ranking.

The graphs shown below are plots of reservoir volumes over the past full year and current year to date

5 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. Surface Water The top left image shows VIC modeled soil moisture as a percentile ranking. The top right image shows satellite-derived vegetation from the VegDRI product (which updates on Mondays). The graphs shown below are plots of reservoir volumes over the past full year and current year to date (black). The dashed line at the top of each graphic indicates the reservoir's capacity, and the background color-coded shading provides context for the range of reservoir Page 5 of 13

6 levels observed over the past 30 years. The data are obtained from the Bureau of Reclamation. Some of the reservoir percentiles don't line up at the new year due to differences in reservoir levels at the beginning of 1985 and the end of Dead storage has been subtracted. Note: Lake Granby data are obtained from the Colorado Division of Water Resources, and only goes back to the year Evaporative Demand Page 6 of 13

7 The above images are available courtesy of NOAA s Evaporative Demand Drought Index (EDDI). Drought classification listed is a function of the depth of reference evapotranspiration accumulated over a given period of record with respect to a climatology of The drought categories displayed are in line with the US Drought Monitor's Percentile Ranking Scheme. Data used to generate these maps come from the North American Land Data Assimilation System Phase-2 (NLDAS-2) project, which assimilates observations of temperature, wind speed, radiation, and vapor pressure deficit. The date indicates the last day of the period of record, and the week number indicates the window size for the period of record. Temperature 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. Page 7 of 13

Condition Monitoring and Impacts Map of current condition monitoring reports submitted to CoCoRaHS in the last week overlaid on the current U.S. Drought Monitor depiction.

8 Condition Monitoring and Impacts Map of current condition monitoring reports submitted to CoCoRaHS in the last week overlaid on the current U.S. Drought Monitor depiction. Specific impacts reports from local experts listed below. Rocky Ford, southeast CO All of southeast Colorado has been extremely dry. People got very excited about heavy frost that accumulated Page 8 of 13

last week because it was more moisture than what had happened in awhile. Surface moisture is gone. On a trip to Santa Fe, conditions looked extremely dry.

9 last week because it was more moisture than what had happened in awhile. Surface moisture is gone. On a trip to Santa Fe, conditions looked extremely dry. Days have been unusually warm, while nights have still been cold. This has resulted in sick calves. Wheat in Kiowa County is at a tipping point, showing signs of stress, and already seeing losses. - Chuck Hanagan (USDA-FSA) - webinar input Huerfano County, CO Experiencing warmer nights in the higher elevations compared to the river valleys, but still very dry. Not too much moisture from the recent events, and yet January has had more moisture than most of the rest of the season. Streams are holding up really well for this time of year. But changes need to happen soon. If current pattern continues into March, it could get scary. - Tony Arnhold (USDA-FSA) - webinar input Southwest WY It's January, so sometimes hang with status quo until a bit further into the season. However, putting in a warning conditions (i.e. D0), might be better in order to start the process and give a heads up. - Tony Bergantino (WY State Climate Office) - Outlook Page 9 of 13

The top two images show Climate Prediction Center's Precipitation and

The middle image shows the Weather Prediction Center's Quantitative

The bottom left image shows the 3-month precipitation outlook from Climate

10 The top two images show Climate Prediction Center's Precipitation and Temperature outlooks for 8-14 days. The middle image shows the Weather Prediction Center's Quantitative Precipitation Forecast accumulation for seven days. The bottom left image shows the 3-month precipitation outlook from Climate Prediction Center, and the bottom right image shows the Climate Prediction Center's most recent release of the U.S. Seasonal Drought Outlook. > Summary and Recommendations Page 10 of 13

11 NIDIS Drought and Water Assessment 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. Page 11 of 13

12 NIDIS Drought and Water Assessment Summary: January 16, 2018 While warmer than average conditions still dominated the Intermountain West last week, the high elevation regions of the Upper Colorado River Basin received a healthy bump in snowpack. Basin snowpack values increased between 5% and 10% over the past week. Even with these increases, snowpack is still below average and conditions worsen toward the south. The basins of WY are all near-to-above average, while the northern CO mountains are slightly below average, and UT and southern CO basins are much below average. Across the IMW, precipitation over the past week ranged from 1-2 inches in the higher elevations to quarter to half inch across the lower elevations. These recent precipitation accumulations have resulted in 30-day Standardized Precipitation Index (SPIs) in the 0 to -1 range. The 90-day SPIs highlight the extreme dryness that most of the region has been experiencing. The active weather pattern looks to continue over the next couple of weeks. Page 12 of 13

13 CPC shows an increased chance of below average temperatures for week 2. This is good news for further improving snowpack conditions during this critical time of year, when large accumulations of snow are typical. At this time of year, it is extremely unlikely that the southern and central Rockies (south of Wyoming) will fully recover from the extreme deficits that have been experienced since the beginning of the snow season. Several healthy snow accumulating events in the next couple of months can help minimize some of the impacts to future water supply, but it is likely many of the sub-basins of the Colorado River will not reach their average peak snow water equivalent for the water year. Along the eastern plains, warm daytime temperatures and windy conditions have likely been sucking moisture away from the soils and vegetation. Very cold overnight temperatures and lack of conistent snow have had a damaging effect on livestock, and winter wheat crops are starting to show signs of stress. It's still too soon to tell how the winter dryness and temperature anomalies will impact the crops and land in the spring, but the situation is being monitored. Recommendations UCRB: Although the higher elevations received decent precipitation last week, areas in central UT are still show extremely large precipitation and snowpack deficits. Following the precipitation and snowpack at SNOTEL sites that are below the 10th percentile, an expansion of D2 (maroon shape) is recommended. A further northward expansion of the D1 (orange shape) and D0 (black shape) into southwest WY are also recommended based on the SNOTEL numbers. Eastern Colorado: The U.S. Drought Monitor has proposed a slight introduction of D2 into the far southeastern corner of the state (in Baca County) to match up with deteriorating conditions in the Oklahoma panhandle. Other than this change, status quo is recommended following the large changes made to the region last week. Page 13 of 13

NIDIS Intermountain West Drought Early Warning System November 14, 2017

NIDIS Intermountain West Drought Early Warning System November 14, 2017 Precipitation The images above use daily precipitation statistics from NWS COOP, CoCoRaHS, and CoAgMet stations. From top to bottom,