Contributed by Sim Aberson

A variety of hurricane track forecast models are run operationally for the Atlantic hurricane basin:

1. The basic model that is used as a "no-skill" forecast to compare other models against is CLIPER (CLImatology and PERsistence), which is a multiple regression statistical model that best utilizes the persistence of the current motion and also incorporates climatological track information (Aberson 1998). Surprisingly, CLIPER was difficult to beat with numerical model forecasts until the 1980s.
2. The Beta and Advection Model (BAM), follows a trajectory in the pressure-weighted vertically-averaged horizontal wind from the Aviation model beginning at the current storm location, with a correction that accounts for the beta effect (Marks 1992). Three versions of this model, one with a shallow-layer (BAMS), one with a medium-layer (BAMM), and one with a deep-layer (BAMD), are run. BAMS runs using the 850-700 mb layer, BAMM with the 850-400 mb layer, and BAMD with the 850-200 mb layer. The deep-layer version was run operationally for primary synoptic times in 1989; all three versions have been run four times per day since 1990.
3. A barotropic hurricane track forecast model LBAR, for Limited-Area Barotropic Model, is being run operationally every 6 hours.
4. The NOAA Global Forecast System (GFS), formerly known as the Aviation and MRF models (Lord 1993) has been used for track forecasting since the 1992 hurricane season. An ensemble of low-resolution runs is available four times daily.
5. A triply-nested movable mesh primitive equation model developed at the Geophysical Fluid Dynamics Laboratory (Bender et al 1993), known as the GFDL model, has provided forecasts since the 1992 hurricane season. One version (GFDL0 uses GFS fields for boundary conditions; a second version (GFDN) uses NOGAPS fields for boundary conditions.
6. A doubly-nested movable mesh primitive equation non-hydrostatic model known as H-WRF (for the Hurricane Weather Research and Forecast Model), has provided forecasts since 2006. It uses GFS fields for boundary conditions.
7. The United Kingdom Meterological Office's global model (UKMET) is utilized for forecasting the tracks of tropical cyclones around the world (Radford 1994). NHC starting receiving these operationally in 1996.
8. The United States Navy Operational Global Atmospheric Prediction Systems (NOGAPS) is also a global numerical model that shows skill in forecasting tropical cyclone track (Fiorino et al. 1993). This model was also first received operationally at the National Hurricane Center during 1996. An ensemble of low-resolution runs is available twice daily.
9. The Canadian Meteorological Center's Global Model (CMC) provides forecasts twice per day. An ensemble of low-resolution runs is available twice daily.
10. The European Centre for Medium-Range Weather Forecasts's Global Model (ECMWF) provides forecasts twice per day. It has proven to be the best model for track forecasting, and is the highest resolution global model available. An ensemble of low-resolution runs is available twice daily.
11. The Japanese Meteorological Agency's (JMA) Global Spectral Model provides forecasts, both in high-resolution deterministic runs and low-resolution ensemble runs.

Various types of consensus models (ensemble means) are available from these models

Despite the variety of hurricane track forecast models, there are only a few models that forecast intensity change for the Atlantic basin:

1. Similar to the CLIPER track model, the SHIFOR (Statistical Hurricane Intensity Forecast model) is used as a "no-skill" intensity change forecast. It is a multiple regression statistical model that best utilizes the persistence of the intensity trends and also incorporates climatological intensity change information (Jarvinen and Neumann 1979). SHIFOR has been difficult to exceed until recent years.
2. A statistical-synoptic model, SHIPS (Statistical Hurricane Intensity Prediction Scheme ), has been available since the mid-1990s (DeMaria and Kaplan 1994). It takes current and forecasted information on the synoptic scale on the sea surface temperatures, vertical shear, moist stability, etc. with an optimal combination of the trends in the cyclone intensity.
3. The GFDL and H-WRF models, described above in the track forecasting models, also issue forecasts of intensity change.
4. A statistical scheme for estimating the probability of rapid intensification has been developed (Kaplan and DeMaria 2002) and is now being used operationally. The RI scheme employs synoptic and persistence information from the SHIPS model to estimate the probability of rapid intensification (24 h increase in maximum wind of 35 mph or greater) every 6 hours.

Information on the performance of these models is available after each season here.