Variables and Values

1. The mean July Palmer Drought Severity Index for two climate stations in Nebraska (NCDC Nebraska Divisions 5 and 8) was 1.32 equivalent to 45.3% of the 1947-1994 July conditions.

2. The July end-of-month content in Lake McConaughy as a percent of total capacity was 83.1%, equivalent to the 44.5% level of July end-of-month content over the 1947-1994 period.

Variables and Values

1. To set the hydrologic condition for June, an index of conditions is computed using four Platte basin variables. These variables and their corresponding values were as follows:

   1. The mean May streamflow in the Platte River at Grand Island was 1,883 cfs (provisional USGS data), or at the 62.6 percentile level of 1947-1994 April flows.
   2. The mean May Palmer Drought Severity Index for four zones (NCDC climate divisions Colorado #1, Wyoming #8, and Nebraska #1 and #7) was 2.13* equivalent to the 81.7 percentile level of 1947-1994 May conditions.
   3. The mean May streamflow in the South Platte River at Julesburg (CO-NE stateline) was 412 cfs (provisional data), equivalent to 59.9 percentile of 1947-1994 May flows.
   4. The April 1 percent-of-normal snowpack in the North Platte Basin of Wyoming* (seven specific NRCS locations) was 101.4% of normal, equivalent to the 58.3 percentile level of 1947-1994 conditions. 

Variables and Values

1. The mean April streamflow in the Platte River at Grand Island was 2,055 cfs (provisional USGS data), or at the 62.9 percentile level of 1947-1994 April flows.

2. The April end-of-month content of Lake McConaughy was 1,467,900 acre-feet, equivalent to 84.2% of maximum capacity and 25.7 percentile level of the 1947-1994 April percent-of-capacity.

3. The April end-of-month content of three upper South Platte reservoirs (Antero, Eleven-Mile, and Cheesman) was 186,525 acre-feet, equivalent to the 68.7 percentile level of their 1947-1994 April contents.

4. The April 1 percent-of-normal snowpack in the North Platte Basin of Wyoming* (seven specific NRCS locations) was 101.4% of normal, equivalent to the 62.2 percentile level of 1947-1994 conditions.

Variables and Values

1. The mean February streamflow for the Platte River near Grand Island gage (provisional USGS data) was 1,710* cubic feet per second, equivalent to the 51.3 percentile level of 1947-1994 February conditions. (*The USGS streamflow gage at Grand Island reported "ICE" conditions for the entirety of February.  Data from the Overton gage was used as a surrogate)

2. The mean February Palmer Drought Severity Index for four climate zones in three states (NCDC divisions Colorado #4, Wyoming #8, and Nebraska #1 and #7) was -0.52, equivalent to the 45.6 percentile level of 1947-1994 February conditions.

3. The February end-of-month content of seven North Platte reservoirs (Alcova, Glendo, Gray Reef, Guernsey, Kortes, Pathfinder, and Seminoe) was approximately 2,125,352 acre-feet, equivalent to the 97.1 percentile level of 1947-1994 end-of-month February conditions.