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5/17/2016 6:41 am  #1


Predict wind GRIBs

i'm a newbie - 
i have a predict wind account - but cannot seem to sort out how to get Expedition to get GRIB files from Predict wind
i click the Precinct wind icon in weather... but nothing happens (laptop is connected to i/net via wireless)

thx and sorry for being thick

Ross

 

5/17/2016 7:45 am  #2


Re: Predict wind GRIBs

Ross, don't worry you're just going through the same learning curve we all did.  

After you have clicked on (selected) Predictwind on the menu bar, select an area of your chart by clicking and dragging (forms a rectangle)  when you release a dialog box will appear where you can enter your Predictwind credentials.  You can monitor the progress of the download in the menu bar.  When it is complete, click on the ->| Now button.  It will then display the latest weather as downloaded from Predictwind.

 

5/17/2016 8:19 am  #3


Re: Predict wind GRIBs

Great - many thanks -
im sure i'll be back with more stupid questions -

Ross
i'm Irish and male (my wife tells me its my genetics causing the stupidiness)

     Thread Starter
 

5/17/2016 9:30 am  #4


Re: Predict wind GRIBs

I'm also Irish and male and I resent that comment !!  http://cdn.boardhost.com/emoticons/wink.png


I may have to have a word with your wife!

 

5/17/2016 10:09 am  #5


Re: Predict wind GRIBs

On a related note, I have a source of local wind/current GRIBS for SF BAY I want to import. 

Looking at the MyGrib.csv file format, 
the notes for "hours" and "delay" fields  are somewhat terse.!! hours - eg 24 for once a day! delay - hour period until available!

If I wanted to upload daily wind & tide forecasts at around noon local how would I enter that? (UTC is default?) 

I assume that resolution is specified in degrees? (my file grid is specified at 200 meters..) how accurately does this have to be entered? 
 
 


Semiconductor Development Engineer, Retired Viticulturalist, Occasional sailor
"Lioness" 1962 Hinckley Bermuda 40 Custom Yawl
 

5/17/2016 12:34 pm  #6


Re: Predict wind GRIBs

The mygrib is just for various other grib files we have found on the internet.

Everything in it is just information relating to the data. Editing it won't change the files at the other end.

 

5/17/2016 12:36 pm  #7


Re: Predict wind GRIBs

Nick,

If I want to add lines. Do the delay & hour parameters matter?

 

5/17/2016 2:54 pm  #8


Re: Predict wind GRIBs

Ross, the way you describe is OK, but not the best way to download, depending on your personal when/where/bandwidth.
PW make a downloadable app available, Offshore App, a combination of GRIB chopper, GRIB reader and router.  There is a tutorial on their website, but in essence you use that to specify your journey and download the GRIBS you want (days and range).  You then load those into Expedition and away you go.
Why do it that way?  PW have 1 km (24 hrs), 8 km and 60 km models.  If you use method 1, you only get 8 km and 60 km models, not the 1 km models.  If you are 200 km offshore, that doesn't matter, but along the coast, it does.
Incidentally, with PW (PRO I think) you get free access to TideTech.  In my part of the world, the TT Combined Current and Tide (again, coastally important) is 36 MBs,
Cheers

 

5/17/2016 4:46 pm  #9


Re: Predict wind GRIBs

Sheldon - 

Probably not - you could set them all to zero. It doesn't affect most data linked in there.

You can also right-click to get the data.

If you have useful data sources, I can add to the file distributed with Exp. 

 

5/18/2016 6:17 am  #10


Re: Predict wind GRIBs

Thanks, Nick.  

The source I found was very specific to SF Bay, sailtactics.com, and offered a high resolution (200m) daily format based on a morning Weather balloon to assess the marine layer thickness, which given the wind & current patterns in the Bay made sense. 

Unfortunately it doesn't actually extend far enough to where we race beer cans on Wednesday's up the Alameda- Oakland Estuary, so I've gone with PredictWind for now. I'll see if the developer will extend forecast for the 4 hours a night we would need it, at a fine resolution. Since the Estuary is only 100-200 m wide at some points, a grid that got down to that scale would potentially allow some level of "local knowledge". One of our Skippers has been racing this area since 1954, and recently got cataract surgery, so now he can see the weather mark again, I am trying to compensate via technology.
 
I am separately working on mapping the bottom to get precise bathymetry and will try to run my own offline current forecasts using SELFE in the longer run, as well as having a good idea where faster/slower currents & eddies are likely.
 


Semiconductor Development Engineer, Retired Viticulturalist, Occasional sailor
"Lioness" 1962 Hinckley Bermuda 40 Custom Yawl
 

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