The Saildrone Pacific Sentinel Experiment

Improving Weather Forecasts over the West With Unmanned Sailboats Collecting Weather Observations

saildrone   Sail Map

Why a Saildrone Experiment Off the West Coast?

The West Coast of North America experiences very active weather during October through March, with major weather systems approaching from the west. Such systems include intense Pacific cyclones that bring strong winds to the coastal zone as well as atmospheric rivers, plumes of moisture that can drop large amounts of precipitation as they ascend the mountainous terrain of the western U.S. NOAA buoys are sparse over the offshore waters and some are not reporting or have problematic sensors. Weather satellites are important but they do not replace measurements in the lower atmosphere and at the surface. Weather observations from commercial ships are often of poor quality, with commercial shipping avoiding the most severe, but important marine weather.

Although weather forecasts have improved greatly, some major weather systems approaching the West Coast have been poorly forecast, such as the Ides of October Storm in 2016. Lack of high-quality weather observations offshore could be part of the problem.

The Saildrone is a new observational system that offers high quality atmospheric and oceanographic observations using unmanned sailboats. Saildrones can remain offshore as long as a year, are autonomous, robust to high seas and strong winds, and have continuous satellite communication. More details about the Saildrone platform is found here.

The essential question to be answered in this experiment is: can the use of Saildrone observations improve short-term (24-hour or less) forecasts along the West Coast and for longer projections to the east?

To help answer this question, a fleet of six Saildrones will be stationed roughly 300 miles offshore in a "picket fence" from due west of the Olympic Peninsula of Washington State to west of Point Conception of southern California (see map above) for the 2019-2020 winter. With boats separated by about 170 miles, this line of Saildrones will provide valuable new information about approaching weather systems.

This project is entirely funded and supported by Saildrone, Inc. and is a joint project with the University of Washington.

Current Project Status (10/13/2019)

Six Saildrones are now positioned in a line along the Coast, with the northern-most boat (SD-1054) now circling NOAA buoy 46005 before moving northward into its final position. We are now developing the project web pages that will provide more detailed information and comparison to model initializations and forecasts.

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For More Information

Please contact Professors Cliff Mass ( or Greg Hakim ( at the University of Washington or Saildrone CEO Richard Jenkins (here)