NOAA/WDS Paleoclimatology - Gray 2003 Northeastern Utah Palmer Drought Severity Index Reconstruction

These data are reconstructed Palmer Drought Severity Index (PDSI) values for the Uinta Basin region (Utah Climate Division 6) of northeastern Utah from 1405-2000 AD. Estimates for PDSI values prior to the instrumental period (1895-Present) were derived from the measurement of pinyon pine (Pinus edulis) tree-rings at four sites in the Uinta Basin. Samples from 144 trees (both living and dead) are included in the reconstruction. Comparison of the instrumental and estimated values shows that the reconstruction provides a good estimate of both single-year drought events and multi-year wet/dry trends. Droughts in the 1950s, 1930s and around the beginning of the 20th century are well represented. While these 20th Century dry events were quite severe, at least two droughts prior to instrumental period (e.g. mid 1400s and ~1735-1755) likely equaled or exceeded their duration. Several pre-instrumental droughts, particularly those in the 1500s through mid 1600s, were of greater magnitude or severity than any dry events after the early 1900s. Overall, this reconstruction suggests that severe, long-duration (>10 year) droughts are a common feature of northeastern Utah's climate.