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Computer Models

Computer Model Definitions

About TWC Mesocast

The TWC Mesocast model is run by The Weather Company using input data from the GFS model. It is run at a higher resolution than GFS, so will pick up coastal showers and smaller-scale weather systems far better than the global model. However, due to its initial and boundary conditions being set by GFS, its overall pattern will often bear a lot of similarity to that of GFS. TWC Mesocast is run twice daily (00Z and 12Z) and is available on the website within 3 hours of the initialisation time.

About LAPS

LAPS stands for Limited Area Prediction System. It is one of the regional numerical forecast models operated by the Bureau of Meteorology. It is run twice daily (00Z and 12Z) and gives forecasts out to 72 hours at 3 hourly intervals. It has an operational horizontal resolution of around 35km and 29 vertical levels. It does have the capability to be operated at around 5km resolution, but this is over much smaller domains and largely only for research purposes.
About MesoLAPS

MesoLAPS is a high resolution version of LAPS. MesoLAPS (or MLAPS) has a resolution of 12.5km and a smaller domain than LAPS. MesoLAPS runs out to 48 hours at 3 hourly time intervals.
About GFS

GFS stands for Global Forecast System. It is the operational numerical weather forecasting model run by NCEP. The GFS superseded the AVN and MRF models, on which it is largely based. Forecast data from the GFS is available out to 180 hours at full resolution (with a 6 hour time-step) and 16 days at a reduced resolution.

About GASP

GASP stands for Global AnalysiS and Prediction. The medium range global numerical forecast model operated by the Bureau of Meteorology. GASP is run twice daily, with model output available around six hours after each run out to 7 days. GASP has a horizontal resolution of around 85 km and 29 vertical levels.

ECMWF stands for the organisation which runs the model the European Centre for Medium-Range Weather Forecasts. It is an operational numerical forecasting model. ECMWF is run twice daily with model output available in 24 hour time steps. Forecast data from the ECMWF is available out to 168 hours.


COLA stands for Centre of Ocean-Land-Atmosphere Studies. GFS stands for Global Forecast System. The COLA GFS precipitation forecast charts show accumulated precipitation in 7 day blocks from the GFS forecast data. There is also a percent of normal chart, which shows the forecasted rain in the first 7 day period as a percent of the average amount of rainfall for the corresponding period.

Significant Wave Height (WWIII HSIG)

WW3 stands for WaveWatch III. It is a wave model developed by NOAA/NCEP. The model displays SIgnificant wave Height (HSIG) and wave direction at 3 hour intervals out to 180 hours. Significant wave height is the average crest to trough height of the highest 33% of waves in a given sample period (typically 20 to 30 minutes). The maximum wave height can be up to twice the HSIG.

Peak Wave Period (WW3 PPER)

WW3 stands for Wavewatch III. It is a wave model developed by NOAA/NCEP. The model displays the Peak Wave Period (PPER) and wave direction at 3 hour intervals out to 180 hours. The PPER is estimated as the period, time taken for consecutive wave crests or wave troughs to pass a given point, corresponding to the waves producing the most energy.

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Southwest WA heats up before a soaking

16:39 EST The mercury soared in the nation's southwest today with Perth recording its hottest September day on record, however heavy rain and cooler temperatures will arrive on Sunday.

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