March-April 2018

Hydrologic condition
Condition period start
Condition period end

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

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.

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.

Hydrologic Conditions Calculation
(0.120 * 0.513) + (0.662 * 0.456) + (0.198 * 0.971) - 0.011
Hydrologic Conditions Index

For this period, the threshold index value is 0.25 for "normal" conditions. The current index value is less than this and constitutes "NORMAL" conditions.
Note that for the March-April period, there are only "dry" and "normal" designations because "wet" targets are the same as "normal" targets for this period.