Coupled Forecast System
The Coupled Forecast System, also known as the Climate Forecast System (both phrases shortened to CFS), is a medium to long range numerical weather prediction and climate model run by the National Centers for Environmental Prediction. The current version of the CFS, version 2, became operational in 2011.
The CFSv2 is run once daily at NCEP, at multiple time scales. The medium-range model forecasts in one-week intervals out to four weeks, while the longer-range scale forecasts on three-month moving averages out approximately nine months. The shorter scale has some overlap with the Global Forecast System, NAVGEM and FIM models (among several foreign medium-range models), which the U.S. government runs for more precise operational forecast purposes.
The "Coupled" in the model's name refers to the fact that the model couples both atmospheric modeling and oceanic modeling into one all-purpose model. Its forecasts are derived from a 16-member ensemble, with each member initialized on a lead of several days worth of conditions. The CFSv2 offers output that can be masked to remove forecasts with insufficient skill.
Among the variables made available to the public include precipitation and surface temperature (both of which are available both on a global spatial scale and a continental one), winds at 200 and 850 hectopascals, and heights at 500 hectopascals (all of which are available only at the global or hemispheric scale). Output is rendered as deviation from normal.
- Suranjana Saha, Shrinivas Moorthi, Xingren Wu, Jiande Wang, Sudhir Nadiga, Patrick Tripp, David Behringer, Yu-Tai Hou, Hui-ya Chuang, Mark Iredell, Michael Ek, Jesse Meng, Rongqian Yang, Malaquias Pena Mendez, Huug van den Dool, Qin Zhang, Wanqiu Wang, Mingyue Chen, Emily Becker, 2013 : "The NCEP Climate Forecast System Version 2." (Journal of Climate, under review, revised.)