Introduction

This website presents experimental, real-time hydrologic and streamflow forecasts developed using a macroscale hydrologic simulation model at the University of Washington. The forecasts are initialized on the first day of the month, and the website is updated during the following 3-5 days, although a more rapid update cycle will be implemented in Fall 2006. This research effort is currently funded primarily by NOAA Climate Program Office (through the CPPA program), and was developed earlier under support from the NOA/OGP CDEP program, the IRI/ARCS Regional Applications Project, and the NASA Seasonal-to-Interannual Prediction Project (NSIPP). Hydrologic forecasts are currently initialized once monthly, and are based on two sources:

• the Ensemble Streamflow Prediction (ESP) method; and the ESP method conditioned on ENSO and PDO states
• ensemble forecasts downscaled from the CPC official seasonal outlooks.

In 2003-04, ensemble forecasts were also downscaled from several climate models (NCEP CFS, NASA NSIPP1), and this line of research is being continued in a sister project at Princeton University, which focuses on the Eastern U.S. By fall 2007, the Princeton University and UW forecasting domains will merge, spanning the entire continental US.
In addition to streamflow forecasts, spatial analyses of the initial hydrologic state (i.e., "current conditions") at the forecast date, and of future snow water equivalent (SWE), soil moisture and runoff, are also provided. Similar hydrologic analyses are also under development for more focused, target regions; and at a larger scale, a hydrologic monitoring simulation provides daily real-time updates of snow, soil moisture and runoff conditions for the continental US.

Streamflow Forecasts & Spatial Analyses

Western U.S. Streamflow Forecasts

Western U.S. Spatial Analyses

Western U.S. SWE Observations

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