Model:

CFS: The NCEP Climate Forecast System (CFS)

Updated:
1 times per day, at 17:00 UTC
Greenwich Mean Time:
12:00 UTC = 13:00 CET
Resolution:
1.0° x 1.0°
Parameter:
Geopotential height (tens of m) at 925 hPa (solid line) and Temperature (°C) at 925 hPa (coloured, dashed line)
Description:
This chart helps to identify areas of densely packed isotherms (lines of equal temperature) indicating a front. Aside from this you can use the modeled temperature in 925 hPa (2000 ft a.s.l.) to make a rough estimate on the expected maximum temperature in 2m above the ground. However, this method does not apply to (winter) inversions.
Spaghetti plots:
are a method of viewing data from an ensemble forecast.
A meteorological variable e.g. pressure, temperature is drawn on a chart for a number of slightly different model runs from an ensemble. The model can then be stepped forward in time and the results compared and be used to gauge the amount of uncertainty in the forecast.
If there is good agreement and the contours follow a recognisable pattern through the sequence then the confidence in the forecast can be high, conversely if the pattern is chaotic i.e resembling a plate of spaghetti then confidence will be low. Ensemble members will generally diverge over time and spaghetti plots are quick way to see when this happens.

Spaghetti plot. (2009, July 7). In Wikipedia, The Free Encyclopedia. Retrieved 20:22, February 9, 2010, from http://en.wikipedia.org/w/index.php?title=Spaghetti_plot&oldid=300824682
CFS:
The CFS model is different to any other operational weather forecasting model you will see on Weatheronline.
Developed at the Environmental Modelling Center at NCEP (National Centers for Environment Prediction) in the USA, the CFS became operational in August 2004.
The systems works by taking reanalysis data (NCEP Reanalysis 2) and ocean conditions from GODAS (Global Ocean data Assimilation). Both of these data sets are for the previous day, and so you should be aware that before initialisation the data is already one day old.
Four runs of the model are then made, each with slightly differing starting conditions, and from these a prediction is made.
Caution should be employed when using the forecasts made by the CFS. However, it is useful when monitored daily in assessing forecasts for the coming months, the confidence levels in these forecasts and in an assessment of how such long range models perform.
A description of the CFS is given in the following manuscript.
S. Saha, S. Nadiga, C. Thiaw, J. Wang, W. Wang, Q. Zhang, H. M. van den Dool, H.-L. Pan, S. Moorthi, D. Behringer, D. Stokes, M. Pena, S. Lord, G. White, W. Ebisuzaki, P. Peng, P. Xie , 2006 : The NCEP Climate Forecast System. Journal of Climate, Vol. 19, No. 15, pages 3483.3517.
http://cfs.ncep.noaa.gov/
NWP:
Numerical weather prediction uses current weather conditions as input into mathematical models of the atmosphere to predict the weather. Although the first efforts to accomplish this were done in the 1920s, it wasn't until the advent of the computer and computer simulation that it was feasible to do in real-time. Manipulating the huge datasets and performing the complex calculations necessary to do this on a resolution fine enough to make the results useful requires the use of some of the most powerful supercomputers in the world. A number of forecast models, both global and regional in scale, are run to help create forecasts for nations worldwide. Use of model ensemble forecasts helps to define the forecast uncertainty and extend weather forecasting farther into the future than would otherwise be possible.

Wikipedia, Numerical weather prediction, http://en.wikipedia.org/wiki/Numerical_weather_prediction(as of Feb. 9, 2010, 20:50 UTC).