The extreme heat events of June 8-9 and July 22-23 2011 that have occurred over the urbanized coastal region of New York City (NYC) are examined using the Navy's Coupled Ocean Atmosphere Mesoscale Prediction System (COAMPS) 24 hr weather forecasts on a 1km resolution grid. The model employs an urban canopy parameterization to account for the impact of the city on the atmosphere. The accuracy of the forecasts is evaluated using in-situ observations, and regional land- and ocean-based sensor networks. Forecasts are also compared with the National Weather Service's 12km resolution North American Mesoscale (NAM) implementation of the WRF Model. The study demonstrates how NYC urban heat island (UHI) evolves in time and intensity across NYC's immediate surroundings, Long Island's rural neighborhoods, coastlines and water bodies.

Inland locations have a wide diurnal temperature range while the ocean and large estuarine waterways have a more moderate temperature range. Temperatures reached 39 degrees Celsius at central urban sites over several days and remained high in the evening due to the UHI effect. The UHI evolution varied between the two events both in spatial intensity and duration on account of wind speed and direction. Statistics on coastal temperature and wind variation improved based on COAMPS' 1km resolution capabilities that are not seen using the 12km resolution NAM model. The influence of the coastline on the wind is evident on a 1km resolution allowing the model to capture local meteorological behaviors such as sea breeze effects common to Long Island's South Shore. During the early summer June heat event, the South Shore coastline experienced a pronounced sea breeze effect that was substantially weaker during the late July heat event.

Additional efforts will be made to utilize the COAMPS model for different applications and multi-use projects within the NYC metropolitan area to further understand the behavior of local meteorology.