HWRF is NOAA’s primary model for tropical cyclone (tropical depressions, tropical storms, and hurricanes) forecast. The distance between places where forecasts are made in the model (the grid resolution) must be small to make accurate forecasts. However, the amount of computer power needed increases as these points get closer together. To save computer power, HWRF runs with a higher resolution only around the tropical cyclone than outside using so-called nesting. The current HWRF can only forecast one tropical cyclone at a time. This paper presents a way to forecast up to four tropical cyclones at a time using movable multi-level nesting (MMLN). The nests
can follow each tropical cyclone. This paper documents the design of the MMLN for the first time. The model is run for four seasons.
- Important Conclusions:
The version of HWRF wth MMLN improved forecasts of where the storm was going.
The version of HWRF with MMLN can better forecast places outside the tropical cyclone (the environment) that controls where the storm will go and how strong it will be than the regular version.
The version of HWRF with MMLN may be used during upcoming hurricane seasons to improve forecasts.
You can find the paper online at http://journals.ametsoc.org/doi/abs/10.1175/WAF-D-16-0087.1.