Marine Weather Forecasting

[zeehag]

i use passageweather.com, stormpulse, wunderground and sailflow.....sometimes thee national hurricane center--not often----wunderground's models are wonderful for predicting what is coming at me-----i find no need for extra programming stuff -- i have enough to play with as it is..>LOL

[barnakiel]

Re - weather underground OK, but the pre-prediction from NOAA still better as they track every potential tropical and sub-... disturbance and draw tracks for it as if it could become a TD, TS, etcetera. Way cool! (esp. if you have a boat mid-Atlantic, mid-November and you are supposed to route them thru the whole thing ;-)

b.

[sinbad7]

If you send a mail to shipreports@starpath.com with your position a mail with ship reports for the last 6 hours within a radius of 300 miles will be sent back to you.
Quote:To receive instructions on using this service, send an email to shipreports@starpath.com with 'help' in the subject line

Why not display this in OpenCPN??
A few lines of code converted the received mail into a gpx file, which I then imported into OpenCPN.

Below is the result for Latitude: 46.5 N Longitude: 15.5 W
at about 1000UTC. The format for each wpt is "Wind direction, wind speed , time UTC".
I think this could easily become a standard feature in OpenCPN, maybe using a different source than email. A nice reality check on gribfiles!

Thomas

Interesting,and good for additional security checkups,but, I would far prefer to use the saildocs e-mail service for a more compehensive GRIB report which is saved on your HD and best accessible with the free ExpeditionLT with a built-in c-map interface. Dave could include a simple input panel as attached below in order to generate the maps co-ordinates. The e-mail request could either be incorporated in OpenCPN or dispatched separately.

Now I have a feeling Dave has a surprise for us,so perhaps we'd better hold on for a while to see what he conjures up...

[sinbad7]

I tested the shipreports@starpath.com a few minutes ago and still have no reply.
The saildocs reply usually arrives within one minute..

[Wester]

For us living here in the cold North yr.no - Været for Norge og verden fra Meteorologisk institutt og NRK have some GRIB files

Leif

[sinbad7]

As suggested by Wester,#35, here are the links to GRIB files in Scandinavia and Europe: (Click links to download GRIB files)

Oslo fjord-Currents:
Skagerrak-currents:
Skagerrak-curr,weath,wav.:
Centr.Europe-Weath.:
N.Europe-Weath.:
North Sea-Weath,wav.:
Norwegian Sea-Weath,wav.:
Skagerrak-Weath,wav.:

[sinbad7]

Here is an example showing combined weather info from the Skagerrak GRIB file.

OpenCPN does not display data other than the pressure ridges?

[sinbad7]

Same Scandinavian GRIB file displayed in MaxSea. All weather data showing plus currents and tides.

[bdbcat]

Sinbad7....

Please provide some translation/interpretation for the Maxsea display.

1. Wind barbs and isobars are obvious.
2. What parameter/data is represented by the colored background?
3. Small blue arrows?
4. Filled yellow arrows?
5. Color bar scale in lower left is for??

Thanks
Dave

[sinbad7]

Sinbad7....

Please provide some translation/interpretation for the Maxsea display.

1. Wind barbs and isobars are obvious.
2. What parameter/data is represented by the colored background?
3. Small blue arrows?
4. Filled yellow arrows?
5. Color bar scale in lower left is for??

Thanks
Dave

2. and 5. The coloured background represents wave height in m. The color bar is wave height.
3. Small blue arrows? (please explain)
4. Yellow arrows represents currents

Five point menu selects different overlays for wind,current,waves,sea temperature and pressure

[bdbcat]

Sinbad7

Now I'm confused. How can there be wave heights and currents on land, as in the north of the chart?

Little blue arrows: You can see them at the "base" of the wind barbs in the northern part of the chart.

Maybe the GRIB is somehow offset from true position?

Wondering
Dave

[sinbad7]

Dave..
The little blue arrows are indicators of the wave direction.
I agree,looks strange that wave dir and height are also shown over land.

Tore

[LeaseOnLife]

I am glad to see a discussion about displaying other grib data than just wind and barometric pressure!

Maxsea, Expedition LT, B&G Deckman... as well as the Viewfax portion of the latest beta airmail program let the user select the types of values to be displayed and their graphical interpretation. Expedition and B&G allow the selection of more than one grib file.

Here is an example of possible selections in Viewfax. Viewfax can display 5 types:

1. Windbarbs ( used for wind strength and direction)
2. Arrows (arrows show direction, color of arrows show strength. This could be for current/stream, wave direction and height, swell direction and height)
3. Contour lines. Mostly used for barometric pressure, but one can select wave height or other values.
4. Color gradient. By default Viewfax uses this for water temperature, but one can select other values like waveheight.
5. Shading (white, gray to black). By default Viewfax uses this to show rain

Viewfax doesn't handle collisions well (same type of display selected for more than one type of grib data). I believe Maxsea gives an error message.

Maybe sindbad could dig into the Maxsea selection dialog, does Maxsea have more than 5 types it can display at the same time?

[sinbad7]

re # 43..

MaxSea can display the following simultaneously:

Barometric air pressure reduced to sea level
Wind direction
Wind velocity
Water temperature
Wave direction
Wave height
Wave period
Current direction
Current velocity
Tidal information

[LeaseOnLife]

Not sure about the simultaneously: I was more trying to find out the methods/styles to display the data so Dave can develop a few more methods to display grib data.

Here is what I can gather from an older version of MS, version 10:
It can display

1. wind feathers
2. lines
3. colors
4. arrows
5. bubbles

The tides don't come from the gribs, I believe, and opencpn deals with them already. With this version of MS I only see to display 5 grib values at one time.


Maybe a newer versions of MS can show more?? Would be great to get a a screenshot of the selector tool in the latest Maxsea.