View source for Climate Forecast System

{{Short description|Weather prediction and a climate model}}
__NOTOC__
The '''Climate Forecast System''' or '''coupled forecast system''' ('''CFS''') is a medium to long range [[numerical weather prediction]] and a [[climate model]] run by the [[National Centers for Environmental Prediction]] (NCEP) to bridge weather and climate timescales.<ref>[http://www.nws.noaa.gov/om/csd/pds/PCU3/CFS/purpose.htm Climate Forecast System Introduction]</ref> Version 2 became operational as CFSv2 in 2011.<ref name="CFSv2">{{cite journal |last = Saha |first = Suranjana |title = The NCEP Climate Forecast System Version 2 |journal = J. Climate |volume = 27 |issue = 6 |pages = 2185–208 |date = 2014 |doi = 10.1175/JCLI-D-12-00823.1 |display-authors=etal|bibcode = 2014JCli...27.2185S |hdl = 2027.42/113112 |hdl-access = free }}</ref>

==Overview==
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 average]]s out some nine months. The shorter scale has some overlap with the [[Global Forecast System]], [[Navy Global Environmental Model|NAVGEM]] and [[Flow-following, finite-volume Icosahedral Model|FIM]] models (among several other medium-range models) that the US government runs for operational forecast purposes.

"Coupled" refers to the fact that the model couples [[Atmospheric model|atmospheric]] to oceanic modeling. Its forecasts are derived from a 16-member [[ensemble forecasting|ensemble]], with each member initialized on a lead of several days of conditions. The CFSv2 offers output that can be masked to suppress forecasts made with insufficient skill.{{Clarify|date = August 2015}}

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 [[Pascal (unit)|hectopascals]] (hPa), and heights at 500 hPa (all of which are available only at the global or hemispheric scale). Output is rendered as deviation from normal.

==See also==
* [[Model for prediction across scales]] (MPAS)
* [[Community Earth System Model]] (CESM)

==References==
{{reflist}}

==External links==
* [http://cfs.ncep.noaa.gov/ CFS homepage]
 [http://origin.cpc.ncep.noaa.gov/products/people/sweaver/cfs_fcst/ CFS weekly forecast output]
* [http://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2seasonal.shtml CPC seasonal forecasts] <!-- http://origin.cpc.ncep.noaa.gov/products/people/wwang/cfsv2fcst/ -->
* [https://www.ncdc.noaa.gov/data-access/model-data/model-datasets/climate-forecast-system-version2-cfsv2 NCDC data]
 [http://nomads.ncdc.noaa.gov/data.php?name=access NOMADS data access]

{{Atmospheric, Oceanographic and Climate Models|state=expanded}}
{{Computer modeling}}

[[Category:National Weather Service numerical models]]
[[Category:Systems]]