Paper on the impact of dropwindsondes from the Global Hawk on forecasts published in Monthly Weather Review


A drone, what we call an unmanned aircraft system, can collect data in tropical cyclones (TCs) to improve forecasts.  Scientists have used the Global Hawk drone that can fly at an altitude of up to 60,000 feet for over 24 hours at a time since 2010. The Global Hawk releases dropwindsondes that measure wind, temperature, humidity, and pressure four times every second as it falls to the surface and radios that information to scientists on the ground. 

This study looks at the impact of dropwindsonde data from the Global Hawk from 2012-2016 on forecasts from the National Oceanic and Atmospheric Administration operational Hurricane Weather and Forecasting (HWRF) model.  To put the data into the model, we used the Hurricane Research Division’s experimental Hurricane Ensemble Data Assimilation System (HEDAS). 

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  1. Global Hawk dropwindsondes generally improve analyses and forecasts of where the center of the TC is, how strong it is, and its structure.
  2. They have the greatest impact on forecasts of TCs that are changing quickly strengthening or weakening.
  3. They also have the greatest impact on TCs that traditional Hurricane Hunter aircraft cannot reach because they are too far from land.  This shows that the Global Hawk could be an important addition to the aircraft used to gather information during the hurricane season.

You can see the paper at