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NOAA's OPC (Ocean Prediction Center) is shifting resources away from some existing graphical products

This is an important notice to Mariners. This is long, somewhat technical, and TIME SENSITIVE. We request you read, perhaps do your own research, and then hope you sign the petition. (from the Seven Seas Cruising Association)

Two respected marine weather forecasters, Lee Chesneau and Chris Parker, have raised concerns about planned changes in NOAA’s OPC. It is the opinion of both Lee and Chris that those changes will have a negative impact on cruisers.

"In late 2017, early 2018, and in the fairly near future, NOAA's OPC (Ocean Prediction Center) is shifting resources away from some existing graphical products (images, such as charts depicting weather features) - and devoting more resources to gridded products plus a new 72-hour image forecast.”

Weather Analysis and Forecasts

Members of SSCA can go to the SSCA website——to view Chris’s full article in which he discusses his (and Lee’s) concerns with two of the changes.

The FIRST MAJOR CHANGE: removes the 72-hour details from the 96-hour products. He concludes that “While these changes simplify the images, there are 2 big problems:

1.       In order to have a reasonable day-to-day forecast, I now need 4 charts, where before I only needed 2 charts. These are image products, which take a long time (and often lots of electricity and/or satellite or HF radio email time) to access.

2.       It is easier to get a sense of weather patterns by analysing on a single image how features evolve over 3 days rather than only 2 days.”

The SECOND MAJOR CHANGE: Upper-air troughs are no longer drawn on 500mb charts. Says Chris, “Removing the depiction of upper-air troughs from the 500mb forecast image means mariners may fail to realize there's an approaching upper-air feature which could influence his/her weather.”

Chris Parker continues: WHAT ABOUT THE IMPROVEMENTS?

“While the new images are easier to read, and there are more images, needing to receive and analyze 4 large images instead of 2 is a drawback - not a benefit.

Additional geographic areas will be covered by NDFD (forecaster verified) GRIB (gridded) forecasts. This is a benefit for those who use NDFD GRIBs, but I'll make 2 observations:

1.       NDFD GRIBs predict only gradient wind speed/direction and height of waves 0 they do not weight in on squalls or many small scale (in time and/or size) events, upper-air/500mb weather, ocean swells, and the direction/interval of the significant wave.

2.       In order to use these raw data products, I must either be connected to the Internet (to use an online viewing tool), or use a combination of a special data delivery tool and special data viewing software (these are readily available at little or no cost, but require mastering the special tools).”

So NDFD GRIBs are good for some mariners, but not for all, and do not include everything a prudent mariner should know about upcoming weather.”

Chris concludes with this: "I agree with Lee Chesneau the changes are on-the-whole bad for Cruisers, and I already signed Lee's petition. Feel free to quote me.”

This could impact all who cruise and who rely on NOAA to provide information that will allow you to make prudent decisions. It’s important. Please read, review, and share this message.

To sign the petition, go to


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