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The Weather Models Information


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  • Location: Dunoon Argyll Scotland
  • Weather Preferences: Snow
  • Location: Dunoon Argyll Scotland



    Founded: 1988.

    Updates Per Day: 4.

    Range: 384 Hours.

    Full Name: Global forecast system.


    Mainly called 'GFS' is a global numerical weather prediction computer model run by NOAA. The model is run four times a day and is only the only one of the three main weather models that updates this many times a day. It also produces forecasts up to 16 days out however it is arguable that only up to day 5 or 7 is accurate.

    How it works

    The model runs from 0 hours to 192 hours at a resolution of 27km. After 192 hours to 384 hours it is run at 70km resolution. The GFS collects weather observations across the world then processes everything into a supercomputer to make a forecast.


    The GFS model was originally called the Aviation Model (AVN) until its name was changed to Global Forecast System (GFS) when the Aviation model was combined with the Medium Range Forecast Model (MRF).

    Extra Information

    It is the only global weather model that is available for free in the public domain. Many weather websites across the world use it's data. It is one of the best medium range models available.

    GFS Supercomputer


    Sources http://en.wikipedia....Forecast_System



    Founded: 1975.

    Updates Per Day: 2.

    Range: 240 Hours.

    Full Name: European Centre for Medium Range.


    Also known as the ECMWF or ECM is an independent intergovernmental organisation supported by 19 European Member States and 15 Co-operating States. At its headquarters in Reading, England, one of the largest supercomputer complexes in Europe is linked by high-speed telecommunication lines to the computer systems of the national weather services of its supporting States. The Centre's computer system contains the world's largest archive of numerical weather prediction data.

    How it works

    ECMWF uses the computer modelling technique of numerical weather prediction (NWP) to forecast the weather from its present measured state. The calculations require a constant input of meteorological data, collected by satellites and earth observation systems such as automatic and manned stations, aircraft, ships and weather balloons. The ECM does the first 10 days at 16km resolution which is why it is generally the most accurate model.

    The data is fed into ECMWF's databases and assimilated into its NWP models to produce:

    1. Medium-range forecasts, predicting the weather up to 15 days ahead. The medium range data can be found on

    websites across the web but they only go to 10 days.

    2. Monthly forecasts, predicting the weather on a weekly basis 30 days ahead.

    3. Seasonal forecasts up to 12 months ahead.

    Both the 30 day and seasonal forecasts are not available to the public for viewing.


    ECMWF delivered its first operational medium-range weather forecast to its Member States on 1 August 1979. It was produced using the CRAY-1A. This used about 5 hours of CPU time to produce a 10 day forecast, which was more than 50 times faster then the CDC6600, thereby making the production of 10-day forecasts a feasible undertaking.

    ECM's Supercomputer


    Sources http://www.ecmwf.int/ http://en.wikipedia....ather_Forecasts



    Founded: 1854 and started computer modelling in 1959.

    Updates Per Day: 2.

    Range: 144 Hours.

    Full Name: Met Office.

    How it works

    It gathers information from weather satellites in space and observations on earth, then processing it using two IBM supercomputers. It has a resolution of 1.25 deg between 0h & 72h and between 96 & 144h 2.5 deg.


    The Met Office embraced the computer age in 1959, when a Ferranti Mercury, nicknamed Meteor, was purchased. Capable of doing 30,000 calculations a second, it was a major step forward in the evolution of making weather forecasts. For the first time, scientists were able to regularly use numerical methods to make their forecasts.

    Extra Information

    The Met Office's Global Model forecast has consistently been in the top 3 for global weather forecast performance over the past few decades in independent verification to WMO standards. Today IBM supercomputer which can do more than 100 trillion calculations a second. Its power allows it to take in hundreds of thousands of weather observations from all over the world.

    Met Office Supercomputer


    Sources http://en.wikipedia....wiki/Met_Office http://www.metoffice.gov.uk/


    Founded: 1982.

    Updates Per Day: 4.

    Range: 180 hours for 00z & 12z. 144 hours for 06z & 18z.

    Full Name: Navy Operational Global Atmospheric Prediction System.

    How it works


    The acronym NOGAPS has been used since 1982 to represent the Navy’s global numerical weather prediction system, which includes components for data quality control, data assimilation, model initialization, and model forecasts. While the nature of the components has changed considerably over the years, NOGAPS has been and remains the central engine that is the heart of the Navy’s environmental prediction capability.


    It has been performing poorly in recent years compared to the other global models, so it has been removed from the consensus models that the National hurricane center uses as of 2011.

    Sources http://www.nrlmry.navy.mil/ http://www.wunderground.com/



    Founded: 1956.

    Updates Per Day: 2.

    Range: 72 hours for 00z. 192 hours for 12z.

    Full Name: Japan Meteorological Agency.

    How it works

    It has a resolution 2.5 deg x 2.5 deg. It like other weather models collects weather observations around the world then processes it using their own supercomputer to produce a forecast.


    In 1968, the World Meteorological Organization designated the JMA as a Regional Specialized Meteorological Centre for Asia. In June 1988, the WMO also assigned the JMA as a RSMC for the Northwestern Pacific under its Tropical Cyclone programme. In July 1989, the RSMC Tokyo - Typhoon Center was established within the headquarters office, which dealt with the forecasting and dissemination of active tropical cyclones, as well as preparing a summary of each year's cyclone activity.

    JMA's Supercomputer


    Sources http://en.wikipedia....ological_Agency http://www.weatheron...ARCHIV=0&ZOOM=0


    Founded: 1991.

    Updates Per Day: 2.

    Range: 240 hours for 00z. 144 hours for 12z.

    Full Name: Global Environmental Multiscale Model.

    How it works

    The operational GEM model dynamics is formulated in terms of the hydrostatic primitive equations with a terrain following pressure vertical coordinate (h). The time discretization is an implicit two-time-level semi-Lagrangian scheme. The spatial discretization is a Galerkin grid-point formulation on an Arakawa C-grid in the horizontal (lat-lon) and an unstaggered vertical discretization. The horizontal mesh can be of uniform or variable resolution, and furthermore can be arbitrarily rotated, the vertical mesh is also variable. The explicit horizontal diffusion is -2 on all prognostic variables.


    The GEM model has been developed to meet the operational weather forecasting needs of Canada for the coming years. These presently include short-range regional forecasting, medium-range global forecasting, and data assimilation. In the future they will include nowcasting at the meso-scales, and dynamic extended-range forecasting on monthly to seasonal timescales.

    The essence of the approach is to develop a single highly efficient model that can be reconfigured at run time to either run globally at uniform-resolution (with possibly degraded resolution in the "other" hemisphere), or to run with variable resolution over a global domain such that high resolution is focused over an area of interest.

    GEM's Supercomputer


    Sources http://en.wikipedia....ultiscale_Model http://collaboration...blic/index.html


    Founded: 2004.

    Updates Per Day: 4.

    Range: 1074 hours.

    Full Name: Climate Forecast System


    The CFS is a long range model, it does 4 updates a day going out to 1074 hours. However it's long range forecast is capable of going out to 6834 hours ahead (9 months).

    How it works

    It has a resolution of 2.5 def x 2.5 deg. 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.


    Developed at the Environmental Modelling Center at NCEP (National Centers for Environment Prediction) in the USA, the CFS became operational in August 2004.

    Sources http://www.weatheron...ARCHIV=0&ZOOM=0


    Founded: 2004.

    Updates Per Day: 2.

    Range: 72 hours.


    Global weather forecast model also known as the GME is from the German Weather Service.

    How it works

    It has a resolution of 0.25 deg x 0.25 deg. GME is the first operational weather forecast model which uses an icosahedral hexagonal grid covering the globe. In comparison to traditional grid structures like latitude-longitude grids the icosahedral-hexagonal grid offers the advantage of a rather small variability of the area of the grid elements. Moreover, the notorious "pole-problem" of the latitude-longitude grid does not exist in the GME grid.

    Sources http://www.weatheron...ARCHIV=0&ZOOM=0


    This guide was made to give an easy, quick understanding of the weather models used across the world - weathermaster.

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  • Location: Dunoon Argyll Scotland
  • Weather Preferences: Snow
  • Location: Dunoon Argyll Scotland

    Thanks Weathermaster - will reference this often. Do you have the run times for each model ?

    Good guide here http://forum.netweat...t-update-times/

    But since you asked for each model here's mine,

    When the models start their runs,

    Winter Time UK

    GFS - 00z 3:30am - 06z 9.30am - 12z 3:30pm - 18z 9:30pm.

    ECM - 00z 6am - 12z 6pm.

    UKMO - 00z 4am - 12z 4pm.

    NOGAPS - 00z 3:30am - 06z 9.30am - 12z 3:30pm - 18z 9:30pm.

    JMA - 00z 6am - 12z 6pm.

    GEM - 00z 4am - 12z 4pm.

    GME - 00z 3am - 12z 3pm.

    Summer Time UK

    GFS - 00z 4:30am - 06z 10.30am - 12z 4:30pm - 18z 10:30pm.

    ECM - 00z 7am - 12z 7pm.

    UKMO - 00z 5am - 12z 5pm.

    NOGAPS - 00z 4:30am - 06z 10.30am - 12z 4:30pm - 18z 10:30pm.

    JMA - 00z 7am - 12z 7pm.

    GEM - 00z 5am - 12z 5pm.

    GME - 00z 4am - 12z 4pm.

    Hope that helps as for the CFS I don't know what time of day it updates but it does go through at least 4 updates every 24 hours.

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