COAMPS-TC Real-time Forecast Support for the 2022 Atlantic Hurricane Season

The 2022 Atlantic Hurricane season is just around the corner, officially beginning on June 1.   New for this season, NRL-Monterey will provide deterministic COAMPS-TC® (Coupled Ocean Atmosphere Mesoscale Prediction System – Tropical Cyclone) forecast fields in real-time to NOPP Hurricane Coastal Impacts project partners, for the purpose of forcing surge/inundation/wave model forecasts for landfalling Atlantic tropical cyclones (TCs).

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COAMPS-TC is a regional dynamical tropical cyclone prediction model, developed by the NRL-Monterey and run operationally by Fleet Numerical Meteorology and Oceanography Center since 2013.   With yearly model updates since the original operational implementation, we have developed COAMPS-TC into one of the world’s best-performing models for prediction of TC intensity (include rapid intensification events), structure, and track.   COAMPS-TC forecast are used for guidance by operational forecasters at the Joint Typhoon Warning Center, National Hurricane Center, and Central Pacific Hurricane Center.

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As COAMPS-TC is a regional model, lateral boundary forcing must be provided from a global prediction model.   For the real-time forecast data provided to NOPP partners we will use NOAA GFS (Global Forecast System) as the “parent” global model.   The COAMPS-TC grid configuration consists of a large fixed domain at 36 km horizontal resolution (covering the entirety of a TC basin such as the Atlantic), as well as two storm-following storm-centered inner grids at 12 km and 4 km resolution, respectively.   This grid configuration facilitates high-resolution prediction of the TC and it surrounding environment while providing a computational-efficient simulation of features at the synoptic scale.   The figure below shows the three model grids, using the COAMPS-TC 42 h forecast of Hurricane Ida from the 0000 UTC 28 Aug. 2021 initial time.   The main panel shows the extent of the fixed Atlantic basin outer domain, with black boxes indicating the edges of the inner grids.  The inset panels show the simulation of Ida on the higher-resolution inner grids.

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For the 2022 deterministic COAMPS-TC real-time forecast demonstration, NRL-Monterey will run the model for all Atlantic TCs and INVEST areas (disturbances that could develop into TCs), with forecast initial times every 6 h.  Forecasts will extend to the 126 h lead time.   Forecast data from the 36 km fixed outer grid and also the 12 km and 4 km moving nested grids will be shared with the NOPP partners.   Given data on the three aforementioned grids, the highest-resolution COAMPS-TC forecast data available at any given location can be utilized in initialization/forcing of ocean, wave and storm surge models.  The COAMPS-TC forecast data includes the following fields: 10-m u & v, u & v surface wind stress, 2-m relative humidity, 2-m air temperature, surface pressure, surface longwave/shortwave/net radiation, surface fluxes of latent & sensible heat, and hourly accumulated precipitation.   

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