West Weather Research and Forecasting (West-WRF) Ensemble Model Forecasts

The West-WRF Ensemble is not currently running in real-time in an effort to improve the forecast skill through validation and verification. CW3E will resume real-time forecasting using the West-WRF Ensemble prior to the next cool season.

The products are provided “as is” and are intended for research purposes only (disclaimer).

West-WRF is an ongoing effort at CW3E to develop a regional weather prediction system tailored to western U.S. weather and hydrological extremes, including heavy rainfall and extended dry periods. The model is based upon the open-source WRF-ARW, version 4.4.1, under version control at NCAR: http://wrf-model.org.

The West-WRF ensemble consists of 200 members generated using NOAA’s 0.5o Global Ensemble Forecast System (GEFS) (80 members) and the 0.1o European Centre for Medium-Range Weather Forecasts (ECMWF) Ensemble Prediction System (120 members) forecasts as initial and boundary conditions. Forecasts will be updated once daily based upon 00 UTC (4 PM PST) duty cycles during the wet season: October through March. The ensemble uses a 9-km domain with 60 vertical levels and is run to 168 hours lead time with output every 3 hours for all variables and 15 minutes for select variables. Some products below use a subset of the spatial and temporal ranges.

Atmospheric River (AR), Integrated Water Vapor Transport (IVT), and AR Scale Products

Percentile Maps

Probability Maps

Hourly QPF

15-Minute QPF

Probability of Blizzard Conditions

Probability of Fire Weather Conditions


During the rest of the year, CW3E scientists, with the help of collaborators, are using West-WRF as a platform to conduct research into physical process studies, probabilistic forecasting techniques, and the sources of forecast error using data assimilation and forecast verification. If you have encountered this page during the time of year when we are primarily focused on research activities, the images displayed show an interesting forecast from the previous wet season.

Model domain configuration, physics, I/O, and tailored diagnostics have been developed by CW3E personnel. Inquiries should be directed to Daniel Steinhoff or Luca Delle Monache. Forecast products displayed here are intended for educational purposes only, and should not be used to inform decisions that carry risk to property or health.