@article{d11073f08f1145528c2e1c000b510199,
title = "Forecasting the Hydroclimatic Signature of the 2015/16 El Ni{\~n}o Event on the Western United States",
abstract = "Dry conditions in 2013-16 in much of the western United States were responsible for severe drought and led to an exceptional fire season in the Pacific Northwest in 2015. Winter 2015/16 was forecasted to relieve drought in the southern portion of the region as a result of increased precipitation due to a very strong El Ni{\~n}o signal. A student forecasting challenge is summarized in which forecasts of winter hydroclimate across the western United States were made on 1 January 2016 for the winter hydroclimate using several dynamical and statistical forecast methods. They show that the precipitation forecasts had a large spread and none were skillful, while anomalously high observed temperatures were forecasted with a higher skill and precision. The poor forecast performance, particularly for precipitation, is traceable to high uncertainty in the North American Multi-Model Ensemble (NMME) forecast, which appears to be related to the inability of the models to predict an atmospheric blocking pattern over the region. It is found that strong El Ni{\~n}o sensitivities in dynamical models resulted in an overprediction of precipitation in the southern part of the domain. The results suggest the need for a more detailed attribution study of the anomalous meteorological patterns of the 2015/16 El Ni{\~n}o event compared to previous major events.",
keywords = "Drought, ENSO, North America, Precipitation, Seasonal forecasting, Temperature",
author = "N. Wanders and A. Bachas and He, {X. G.} and H. Huang and A. Koppa and Mekonnen, {Z. T.} and Pag{\'a}n, {B. R.} and Peng, {L. Q.} and N. Vergopolan and Wang, {K. J.} and M. Xiao and S. Zhan and Lettenmaier, {D. P.} and Wood, {Eric F.}",
note = "Funding Information: N.W. was supported by the Netherlands Organisation for Scientific Research (NOW) Rubicon Fellowship 825.15.003 (Forecasting to Reduce Socio-Economic Effects of Droughts). E.F.W. was supported by the NOAA Climate Program Office under grant NA15OAR4310075. D.P.L. was supported by the NOAA Climate Program Office under grant NA14OAR4310293. E.F.W. and D.P.L. designed the forecast experiment and initiated the experiment.X.G.H. and K.J.W. collected and aggregated the Princeton University and UCLA student forecasts. M.X. collected all the observations and made them available.A.B., X.G.H., H.H., A.K., Z.T.M., B.R.P., L.Q.P., N.V., K.J.W., M.X., S.Z., andN.W. produced the forecasts.N.W., E.F.W., and D.P.L. contributed to the design of the figures and all contributed to the writing of the manuscript. The station observations for this study can be obtained at http://www.wcc. nrcs.usda.gov/. The gridded SWMobservations are available at http://hydro.washington.edu/forecast/monitor_cali/index. shtml. The NMME forecasts are available at https://iridl. ldeo.columbia.edu/SOURCES/.Models/.NMME/#info. The student forecast can be obtained by contacting the authors responsible for the forecast of interest (see the supplemental material). Publisher Copyright: {\textcopyright} 2017 American Meteorological Society.",
year = "2017",
doi = "10.1175/JHM-D-16-0230.1",
language = "English (US)",
volume = "18",
pages = "177--186",
journal = "Journal of Hydrometeorology",
issn = "1525-755X",
publisher = "American Meteorological Society",
number = "1",
}