North American Ensemble Forecast System (NAEFS)
The North American Ensemble Forecast System (NAEFS) is a joint project involving the Meteorological Service of Canada (MSC), the United States National Weather Service (NWS) and the National Meteorological Service of Mexico (NMSM). NAEFS was officially launched in November 2004 in presence of representatives of the three countries.
NAEFS combines the state-of-the-art ensemble forecasts run by the MSC's Global Environmental Multiscale Model and the NCEP Global Spectral Model. When combined, the grand ensemble provides weather forecast guidance for the 0-384 hours that is of higher quality than the currently available operational guidance based on either set of ensembles alone. It allows the generation of a set of forecast products that are seamless across the national boundaries between Canada, the United States and Mexico. The research/development and operational costs of the NAEFS system are shared by the three organizations (MSC, NWS, and NMSM), which make it more cost effective and result in higher quality and more extensive weather forecast products.
NAEFS forecast graphics and information can be found at:
|Models||NWS Global Forecasting System (GFS) and
MSC Global Environmental Multiscale Model (GEM)
|Daily Frequency||0000 UTC and 1200 UTC|
|Forecast Length||16 days|
|Initial Condition Uncertainty||Ensemble Kalman Filter (EnKF)|
|Control||1 NWS + 1 MSC|
|Ensemble Members||40 (20 NWS + 20 MSC) for each cycle|
|mean, mode, standard deviation,
and probabilities (10%, 50%, 90%)
|NWS/MSC: 1 deg x 1 deg global products
NWS: downscaled CONUS 2.5 km, Alaska 3 km
References for GEFS, NAEFS and post processing:
Cui, B., Z. Toth, Y. Zhu and D. Hou, 2012: Bias Correction For Global Ensemble Forecast, Weather and Forecasting, 27, 396-410
Cui, B., Y. Zhu, Z. Toth and D. Hou, 2018: Development of Statistical Post-processor for NAEFS. To be submitted to Weather and Forecasting
Guan, H., B. Cui, Y. Zhu, 2015: Improvement of Statistical Postprocessing Using GEFS Reforecast Information, Weather and Forecasting, Vol. 30, 841-854
Hou, D., Z. Toth, Y. Zhu, W. Yang and R. Wobus, 2012: "A Stochastic Total Tendency Perturbation Scheme Representing Model- Related Uncertainties in the NCEP Global Ensemble Forecast System" Submitted to Tellus-A)
Hou, D., M. Charles, Y. Luo, Z. Toth, Y. Zhu, R. Krzysztofowicz, Y. Lin, P. Xie, D-J. Seo, M. Pena and B. Cui, 2012: Climatology-Calibrated Precipitation Analysis at Fine Scales: Statistical Adjustment of STAGE IV towards CPC Gauge-Based Analysis, Jaurnal of Hydrometeorology Vol. 15 2542-2557
Liu, Q., S. J. Lord, N. Surgi, Y. Zhu, R. Wobus, Z. Toth and T. Marchok, 2006: Hurricane Relocation in Global Ensemble Forecast System, Preprints, 27th Conf. on Hurricanes and Tropical Meteorology, Monterey, CA, Amer. Meteor. Soc., P5.13.
Ma, J., Y. Zhu, D. Wobus and P. Wang, 2012: An Effective Configuration of Ensemble Size and Horizontal Resolution for the NCEP GEFS, Advance in Atmospheric Sciences, Vol. 29, No. 4, 782-794
Ma, J., Y. Zhu, D. Hou, X. Zhou and M. Pena, 2014: Ensemble Transform with 3D Rescaling Initialization Method, Monthly Weather Review, Vol. 142, 4053-4073
Palmer, T. N., R. Buizza, F. Doblas-Reyes, T. Jung, M. Leutbecher, G. Shutts, M. Steinheimer, and A. Weisheimer, 2009: Stochastic Parametrization and Model Uncertainty. ECMWF Tech. Memo. 598, 44.
Shutts, G., 2005: A kinetic energy backscatter algorithm for use in ensemble prediction systems. Quart. J. Roy. Meteor. Soc., 131, 3079-3102.
Toth, Z., and E. Kalnay, 1997: Ensemble forecasting at NCEP and the breeding method. Mon. Wea. Rev., 125, 3297-3319.
Wei, M., Z. Toth, R. Wobus, and Y. Zhu, 2008: Initial Perturbations Based on the Ensemble Transform (ET) Technique in the NCEP Global Operational Forecast System, Tellus 59A, 62-79
Whitaker, Jeffrey S., Thomas M. Hamill, Xue Wei, Yucheng Song, Zoltan Toth, 2008: Ensemble Data Assimilation with the NCEP Global Forecast System. Mon. Wea. Rev., 136, 463-482.
Zhou, X., Y. Zhu, D. Hou, Y. Luo, J. Peng and R. Wobus, 2017: The NCEP Global Ensemble Forecast System with the EnKF Initialization. Wea. Forecasting, 32, 1989-2004.
Zhu Y., and Y. Luo, 2014: Precipitation Calibration Based on Frequency Matching Method (FMM), Weather and Forecasting, Vol. 30, 1109-1124