Observation and Modeling of Hurricane Maria for Damage Assessment

During the month of September 2017 Hurricanes Irma and Maria passed throughout the Caribbean and dealt damage to the various islands in their wake. Hurricane Irma, a category 5 Hurricane, passed 50 nautical miles North of Puerto Rico and caused 10-15 inches of rain, wind gusts of 75 mph, and widespread blackouts throughout the island along with a total near loss of electricity and water supply for a few days. Hurricane Maria arrived shortly thereafter as a high-end category 4 hurricane with maximum sustained wind speed of approximately 155 mph with the eye of the storm passing through the center of the island. Hurricane Maria, at the time of landfall, had a wind speed of 155 mph and a total storm rainfall of 38 inches, making it the stronger storm in the last 75 years. Both Hurricanes Maria and Irma were powerful storms that battered Puerto Rico, however Hurricane Maria turned in the most catastrophic event that left a lasting impact on the island of Puerto Rico as it brought to full collapse the electrical power grid rendering the island completely out of power for more than ten months. The human loss was quantified in more than 2,000 casualties, making it the most devastating storm in US history. In order to use these experiences as learning events for damage assessment on the society and the infrastructure reliable metrological variables are required at high temporal and spatial scales across the islands. This by itself is a challenging task as the National Weather Service (NWS) collapsed in the first hours of the storm. In this research we use the Weather Research and Forecast (WRF) model to recreate the events and the outputs are compared and validated with the limited observational records for storm track, rainfall and wind speed. The synoptic conditions of the storm indicate that it was fueled by average Sea Surface Temperatures of 30⁰C which represented anomaly of 0.5⁰C. It is simulated that the storm landed at south east of the island with a wind speed of 135 mph and left the island at northwest at 116 mph. Simulated time series of wind speed are in close resemblance as compared ocean buoys data with simulated peak wind speed of 120 mph in the northern coast. The total rainfall for the event was simulated to peak at 30 inches at the center of the islands and was validated with post-hurricane National Weather Service (NWS) rainfall with a normalized Root Mean Square Error (RSME) of 0.2. The orographic effects are simulated enhancing the rainfall at high altitudes in the central mountains of the island. An example of damage assessment, the risk of failure of the electrical power towers as a function of wind speed is simulated for the entire island which simulates higher risks of failure at Northwest of the island. This validated results can also be used as an input to other models for example hydrological models in order to geo-locate regions for risk due to flooding.