Final answer:
GEFS produces output 4 times a day with weather forecasts going out to 16 days.
Step-by-step explanation:
GEFS stands for Global Ensemble Forecast System, which is a computer model used by the National Centers for Environmental Prediction (NCEP) to provide weather forecasts. The model uses an ensemble approach, which means it runs multiple simulations with slightly different initial conditions to provide a range of possible outcomes. This helps to increase the accuracy and reliability of the forecasts.
The output of GEFS is produced 4 times a day, at 00Z, 06Z, 12Z, and 18Z. The 'Z' stands for Zulu time, also known as Coordinated Universal Time (UTC), which is the standard time used in meteorology. This means that the output is produced at midnight, 6 AM, 12 PM, and 6 PM UTC.
The output includes weather forecasts for a period of 16 days. This is because the model runs for a total of 16 days, with each run being 6 hours apart. This is known as a 'timestep,' and it is the interval at which the model makes calculations and produces output. Therefore, the output includes weather forecasts for the current day, plus the next 15 days.
It is important to note that the accuracy of the forecasts decreases as the lead time increases. This means that the forecasts for the first few days are more reliable compared to the forecasts for the later days. This is due to the chaotic nature of the atmosphere, which makes it difficult to predict with certainty beyond a certain timeframe.
Overall, GEFS produces output 4 times a day with weather forecasts going out to 16 days. This frequent and extensive output allows meteorologists to make more informed and accurate weather predictions, helping to keep people safe and informed about potential weather hazards.