California and Western Nevada Precipitation Reconstruction for 1571-1977 AD Diaz, H.F.; Wahl, E.R. Diaz, H.F. Wahl, E.R. Precipitation Reconstruction drought earth science/paleoclimate/climate reconstructions|tree ring (precipitation,ring width,one root mean square error lower bound,inch,Oct-Sep,climate reconstructions|tree ring,null,principal component analysis|regression analysis,N,PC spatial regression) earth science/paleoclimate/climate reconstructions|tree ring (age,null,null,year Common Era,null,climate reconstructions|tree ring,null,null,N,null) earth science/paleoclimate/climate reconstructions|tree ring (precipitation,ring width,one root mean square error upper bound,inch,Oct-Sep,climate reconstructions|tree ring,null,principal component analysis|regression analysis,N,PC spatial regression) earth science/paleoclimate/climate reconstructions|tree ring (precipitation,ring width,null,inch,Oct-Sep,climate reconstructions|tree ring,null,principal component analysis|regression analysis,N,PC spatial regression) earth science/paleoclimate/climate reconstructions|tree ring (latitude,null,null,degree north,null,climate reconstructions|tree ring,null,null,N,null) earth science/paleoclimate/climate reconstructions|tree ring (longitude,null,null,degree east,null,climate reconstructions|tree ring,null,null,N,null) earth science/paleoclimate/climate reconstructions|tree ring (precipitation,ring width,null,inch,Oct-Sep,climate reconstructions|tree ring,null,principal component analysis|regression analysis,N,principal components regression) earth science/paleoclimate/reconstructions (California and western Nevada>LATITUDE >LONGITUDE ) An analysis of the October 2013–September 2014 precipitation in the western United States and in particular over the California-Nevada region suggests this anomalously dry season, while extreme, is not unprecedented in comparison with the ~120-year long instrumental record of water year (WY, October–September) totals, and in comparison with a 407-year WY precipitation reconstruction back to 1571. Over this longer period nine other years are known or estimated to have been nearly as dry or drier than WY 2014. The three-year deficit for WY's 2012-2014, which in California exceeded the annual mean precipitation, is more extreme but also not unprecedented, occurring three other times over the past ~ 440 years in the reconstruction. WY precipitation has also been deficient on average for the past 14 years, and such a run of predominantly dry WY’s is also a rare occurrence in our merged reconstructed plus instrumental period record. STUDY NOTES: Water year (October through following September) precipitation for California and western Nevada is reconstructed using existing western United States river flow reconstructions as predictor data. The full 0.5x0.5 degree gridded EV reconstruction for the entire continental United States (CONUS) west of 95 W from which the California and western Nevada reconstruction is extracted is included as a separate ASCII file (values are expressed as standardized anomalies). The rows of this file represent years AD (listed in the first column), starting with the third row; the rest of the columns provide the gridded reconstruction data, organized according to all longitudes for each latitude going from W to E. The first two rows (except for the 0 placeholder values in the first column) give the latitude (first row) and longitude (second row) information for each column. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Diaz, H.F. Investigator : Wahl, E.R. 2015-03-26 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/18295 https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/diaz2015/Main_Gridded_WY_Precip_Reconstruction.txt https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/diaz2015/diaz-wahl2015.txt https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/diaz2015/Main_Gridded_WY_Precip_Reconstruction.txt https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/diaz2015/diaz-wahl2015.txt English https://www.ncdc.noaa.gov/paleo/study/18295 https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/diaz2015/Main_Gridded_WY_Precip_Reconstruction.txt https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/diaz2015/diaz-wahl2015.txt Henry F. Diaz and Eugene R. Wahl2015Recent California Water Year Precipitation Deficits: A 440-year PerspectiveJournal of Climate28124637-465210.1175/JCLI-D-14-00774.1https://journals.ametsoc.org/doi/10.1175/JCLI-D-14-00774.1 START YEAR: 1571 AD * END YEAR: 1977 AD -124.4 32.5 -116.5 42