Can Autonomous Weather-Observation Sailboats Improve Forecasts over the U.S.?

Imagine an unmanned sailboat that can collect highly accurate weather and upper-ocean observations.

A sailboat that could stay offshore for months or more and can handle the most severe weather.

A sailboat with real-time satellite communication and capable of either staying at one location or following a pre-programmed path.

A sailboat observation platform that is not only more capable than current weather buoys far less expensive to deploy and maintain.

Now imagine a line of such sailboats stationed off the entire U.S. West Coast, providing a "picket fence" of weather/ocean observations that would help warn the U.S. West Coast of approaching weather systems.  Observations that might improve weather forecasting over the entire nation.

Too good to be true?  Science fiction?   The product of too many meteorological happy hours?

No, this is now reality.    The observing sailboat is called a Saildrone, produced by the eponymously named company and the brain child of its visionary founder and CEO Ricard Jenkins. 

A line of Saildrones is now off the West Coast as part of a joint Saildrone/ University of Washington project:  The Saildrone Pacific Sentinel Experiment.   And the implications of this new observing platform are potentially revolutionary.

The Saildrone

   The figure below illustrates the standard observing systems of a Saildrone.  For the atmosphere, all the old favorites:  wind speed and direction, temperature, humidity, barometric pressure, solar radiation. For the ocean, everything from ocean temperature below the surface, the temperature of the sea surface, wave heights, and near-surface ocean currents--to name only a few.    Plus, the Saildrones have multiple cams, so one can view the sky and sea surface. Amazing.

The "Competition"

            NOAA/NWS (National Weather Service) runs a major buoy program, with the weather/ocean buoys off the U.S. West Coast shown below. The blue squares are the fixed weather/ocean buoys.  There are five of them offshore.  Three of them have either failed or have 3 or more critical sensors broken.   The other two, not so well placed, have one important sensor gone.   Not good.  The red stars are tsunami buoys. The density of the fixed buoy network is relatively sparse, and the buoys tend to break or get loose from their moorings after major storms. 
            The other problem with the NOAA fixed buoy program is its costs: hundreds of millions of dollars a year, including the need for very expensive ship time to service, retrieve, and deploy buoys.

The offshore buoys are important for West Coast forecasting, particularly the buoys at 130W.  They tell us how well our forecast models are doing as storms approach the coast and whether the forecasts need to be updated or amended.  They supply data that can be assimilated into models to improve downstream forecasts.  Unfortunately, NOAA does not have a functional line of buoys offshore.

The Saildrone Sentinel "Last Line of Weather Defense" for the US West Coast

As someone who has spent his life working to improve weather forecasts along the U.S. West Coast, I have often been frustrated by the unfortunate state of the offshore NOAA buoy network.  My colleagues in the National Weather Service feel the same way. Although West Coast weather forecasts have improved, with better models and more satellite observations, some major forecast busts have occurred, such as the (in)famous Ides of October storm of 2016;  we have lacked sufficient surface observations offshore to view the failure mode of this storm and other in a timely way.

I had heard about Saildrones and was intrigued by their potential to improve weather forecasting.  So intrigued I contacted, Richard Jenkins, CEO of Saildrone.   Graciously, he invited me down to his impressive facility in Oakland, where I saw a dozen or so boats being constructed and talked about their use as a data source for numerical weather prediction.

I was excited enough about Saildrones that I wrote a white paper describing a project in which a line of Saildrones was positioned off the West Coast, about 300-400 miles offshore.  A "picket fence" dense enough to get a piece of any major system approaching from the west.   The graphic below shows what I proposed to Mr. Jenkins:  six Saildrones (for a start), indicated by the yellow pins, with the red ones indicating currently operational NOAA buoys (but with some sensors broken).

Richard Jenkins was enthusiastic about the project and during the summer his company prepared the boats and some moved into position during September and early October.  Five of the boats are now in place as I write this and providing us with real-time atmospheric and ocean information.  The last boat will head out to sea this week.  A UW team is now in place for evaluating the potential for this new observing platform (including my colleague Greg Hakim, who specializes in data assimilation, research scientists Jeff Baars and Rick Steed, who have built the data acquisition and display infrastructure and will work on modeling experiments, and  UW scientists David Ovens and Robert Tardif who will help with modeling.

To allow you to view the Saildrone data in real time, members of the team have created a project web site (https://sailnet.uw.edu/).  You can view the new observations, how the observations differ from what NOAA/NWS thought was out there, and much more.

A sample of the cams on one Saildrone

An Adaptive Observing System?

Saildrones obviously can move (as much as 50 miles per day, depending on the wind).  Could we take advantage of this capability to improve observations of important storms?    Weather forecasts are now quite good 4-5 days out.  Let's say a storm is going to approach the central California coast, but there is some uncertainly of exactly where.  With that much time we could move "picket fence" of Saildrones to greatly increase their density in the area of uncertainty, and thus hopefully, lock down the storm characteristics, improving downstream forecasts.  Or perhaps a hurricane is forecast to threaten the East Coast, but with great uncertainty in location (such as with Dorian).  In such case, the source of the uncertainty is often off the West Coast of the U.S.  We have techniques for determining the key areas that observations are need and could move the Saildrones into position.

A Replacement for the NOAA Buoys System?

Currently, NOAA fields a little over 100 fixed buoys.   Many have stopped working, are adrift, or have major sensor failures (current status here).  Winter storms cause major damage to these buoys.  The only way to fix or retrieve them is through very expensive ship operations.   But now imagine replacing them with Saildrones.   Problems with a Saildrone?  Just sail a replacement out there!  And Saildrones could be adaptive, moving around for optimal positioning.   I suspect that this approach would save millions or tens of millions of dollars.

Sunday afternoon Saildrone Observations

The Project

Here are some of the big questions we would like to answer this winter:

1.   Can Saildrone observations offshore delineate deficiencies in the NWS atmospheric analysis over the eastern Pacific?
2.   Can we improve numerical weather prediction by using the Saildrone observations?
3.   Can we secure a better picture of approaching major storms (e.g., Pacific cyclones, atmospheric rivers, etc.) using this new platform?
4.  Can Saildrones be shown to be a robust observing system for the very stormy northeast Pacific?
5.  Can we learn about offshore weather and ocean features using this new platform?
6.  Might we might be able to adjust the position of Saildrones based on forecasts to better observe important storms?

The first stage is now done:  building the software infrastructure to access and display the Saildrone observations and to compare them to NWS analyses.   The next step will be to complete numerical weather prediction experiments for a limited number or cases (particularly ones in which the Saildrones were suggesting that the NWS model analysis were problematic.

This is going be very exciting.   Not only the science, but the potential to improve U.S. weather prediction for major weather events.  Much of the U.S. is downwind of the Saildrones and potentially we could improve forecasts for the lower 48 states.  And the use of Saildrones might be able to save NOAA millions of dollars per year by replacing the pre-existing buoy network.