Model:

CFS: The NCEP Climate Forecast System (CFS)

Ververst:
1 times per day, at 17:00 UTC
Greenwich Mean Time:
12:00 UTC = 13:00 MET
Resolutie:
1.0° x 1.0°
Parameter:
Verticale beweging op 925 hPa in hPa/h
Beschrijving:
De verticale beweging van de lucht bepaald in hoofdlijnen het weer op een bepaalde plaats. Stijgende luchtbeweging (negatieve waardes in de kaart) veroorzaakt meestal bewolking en vaak ook neerslag, terwijl dalende luchtbeweging (positieve waardes in de kaart) voor oplossende bewolking en zonnig weer zorgt. Bij zeer sterke verticale luchtbeweging hoort in principe onweer en zwaar weer. Door de combinatie met vertical 700 kan met zien of ook in hogere lagen forse stijgbeweging optreedt. Bij vermenigvuldiging van de waardes in (hPa/h) met ongeveer 0.25 krijgt met als resultaat de verticale wind in cm/s. De verticale beweging is de som van vorticiteits- en temperatuuradvectie. Deze twee kunnen afzonderlijk groot zijn en elkaar deels of geheel opheffen.
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).