How important is weather to you! Can you help me please!

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Seastream

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As a sailing nut and even worse a software geek I’ve got this bug about writing a programme to animate “The weather” on a PC or to put it another way weather routing. Could I ask anybody who wants to reply the following?

What is the most popular way in which you get your weather forecasts?

Suck it and see!
Navtex box?
Web?

What does everyone do while on board in transit?

I would love to know if it is worth finishing the programme! Then to be totally mad I would like to get the true and the good to test it and tell me I’ve got it all wrong! If it works as it has for me, then I could put it up as shareware.

What would also help is how many people have a PC on board to run a small programme?

Your help would be appreciated
 
Prior to leaving for the boat - Web sites, mainly Synoptic charts. Up to last moment.

On board Navtex and coastguard bulletins (but these are too slow to update, they will read 0500 when 1200 has come out, they only update twice, why?)

If unhappy with Navtex and CG, i.e. conflicting between forecast and reality, will down load charts through SSB, though not too often.

If moored on a cruise by a marina or club will obtain forecasts through them, often meteo fax is it?


How do you intend to update your system while cruising?

Mobile data to laptop is notoriously slow and expensive!
 
grib files (via saildocs) and German forecasts from www.dwd.de via internet when available or via SSB radio and saildocs when no internet. Plus Ch16 forecasts, local information as and when available. Plus weatherfaxes (via SSB) when I feel the need. My navtex is pretty near useless - don't know if it is the kit or what, though most people seem to have probs. Certainly don't get much down in the Gibraltar area via navtex.

I would pay good money for a system that is capable of providing weather forecasts at least 80% reliable. But then the owner of such a system would have the world beating a path to their door!!
 
Thank you very much for taking the time to reply.

Now the set up as I have it now on test.

The problem is a number of things 1st is the bandwidth cost if as you know you use a mobile on board you can use dial up (9.6 bps) or GPRS (42000 bps) both expensive as you say but, if the weather software was on your notebook first (either download from site while at home, CD or Internet café)

This would then allow just the animation file to be transmitted on demand for a 3 day forecast. Right now I can use (with permission) my company servers, I can get a 30gig file from the US Gov’mt web sites (think how big this is by looking to see how big your hard dive is!!) What is then required is JUST 40kb from this massive download for a 3 day animated on demand forecast! Which means it will take 3 mins on dial up via your mobile, or 40 seconds via GPRS. The file then loads into the animation software with some basic contour maps you can then see the wind move and build, temp pressure, cloud cover, more or less like the BBC after the news!

2nd Signal via mobile I use a 12-volt signal Amp bought on a trip to the far east where signal strength can be bad. This plugs into an external aerial on board outside, the net result is just wonderful!! Where you would have 1 bar on your phone you now get 5!! I took a trip from Menorca to Sardinia; before I left the signal of Vodafone ES I had Siptel Italy with the amp going no loos of signal, but if you did you would only be without it for a few hours on a 36-hour crossing.

In summing up a 40kb download Via GPRS would take 40 sec, this would mean 30 3 day on demand downloads would cost £5.97 on Vodafone…………. Now I know how Ms Macarthur did it! With weather routing via Satellite!

If I take this further could I send you a copy to test, or what do you think of the above as it is hard to get anybody to tell me!
 
The weather is very important to me. I live approx 40+ miles inland and have an Oregon weather station which gives me a very good local 12 hour forecast, however experience has shown me that the weather over 40+ miles can be very differant. Many the day I have got home from a days sailing to find the roads local to where I live wet and sometimes flooded after a warm and sunny days sailing, weather can be very local! I used to be a hang glider pilot so wind speed and direction has always been very important to me. I use the internet, navtext and local radio to find if it is worth "going"
Andy
 
Re: Not for me but....

you'll likely have a big market.

I like a look at a synoptic chart if I'm sailing a longway but I'm not bogged down by forecasts and neither do I value them greatly.

If I can check a shipping forecast every couple of days and relate it to my barometer and what used to be called "single observer forecasting" or looking out of the window, I'm happy enough.

Weather routing has it's place but for local area cruising it's overkill.

I am in a minority though.
 
Interesting.

If what you say is possible, a 3 minute call to obtain a forecast which will be graphical would be a hit.

Can you tell us what kind of information you are suggesting, synoptics, wind charts, waves, a text portion?

How many days ahead do you propose, 5 days minimum for longer treks, 48 hr inshore.

Out of interest, are you a meteorologist or IT, I ask as I would also like to know where you propose to gather the data from and who will actually form the forecast? I am not trying to take away from a good and indeed very interesting idea, just asking if you might embellish a little more.

Will happily beta test for you, I have done a few tests for people now and tend to send back reams of suggestions for improvements, though I don't know if that is a good or bad thing! /forums/images/graemlins/grin.gif
 
Well thank you for replying

To answer your questions

The information is a PC map of the world very much like a chart in full colour with contours the reason for using this type of map is it is public domain and does not have a copyright. What we then do is go for weather satellite information the problem here is size. Weather data is supplied in a 30-40 Gig file every 6 hours. This means you need very very big servers and bandwidth to download this file. This is what the BBC uses after the news to animate world weather. The file is also coded to aid transmission only making it as I say 30-40 gig!!! If it were un-coded it would be much bigger! In the file there are the following for about 20 areas around the globe once it has been put through a big sifting process.

Wind speed
Pressure
Cloud cover
Wave height
Air temp
Ocean Current
Surface pressure
Rain
Snow
Relative Humidity
Sea temp
Swell + wind

Once the “sifting” has sorted the data we are then able to “overlay” the weather onto a map/chart and make it move just like the BBC weather overlay, it is now down to about 40kb for 3 day. So 30-40 gig down to 40kb?? We throw away a lot of un-useable data from the download.

I believe that the Met office charges over 200k per year to “sift” and then they supply the finished product “caned” like tomatoes, don’t forget you have to write the animation software with bolt in maps as an overlay.


As I say you need military grade servers to sift! Which right now I have permission to use. The 3-day forecast could be 4,5,6,7 days but the size of the file would jump from about 40kb to 60-70kb then you would be into 6/7 minutes download and much higher mobile phone cost! This is with compression of the “to animate file” we send to the PC onboard. I also believe that the most you “should” download is 3 day, as the weather will change a fair bit as my field tests have shown. I must say seeing the weather animate on your PC is very easy to understand, the way we show the wind is either scaled arrows changing size and direction. As you run the sequence “Now to 3 days out” you select any of the above press the play button and then stop the clock at the time you are half way over as I call it, or what is going to happen on an overnight crossing. And before people pick me up on this is available on the web, yes but the cost to get the web via GPRS and Mobile dial up? Or some charting programmes do it Nobeltec but, £400-600 and if you don’t want to run PC charting and have invested in your instruments, Plotters, etc. So a weather only, simple to use, quick and cheap “IS” the way to go surely.

If I told you that my wife and I were sailing from Gozo to Zante (350 miles) 1 hop, we ran the test download and as normal we were going to set off at first light. We waited till 14.30 pm and the crossing over the next 2 nights and 3 days was pure delight not once did we have wind on the nose, it made for grate sail plan, you sort of knew when to put up a chute or reef in! As I say this is no surprise that the speeds from Ellen Macarthur were spot on as the team back at her base were using weather routing data via orbiting satellites.

In summing up you do not need to do a forecast as the data is overlaid on to a gird map and then we animate it over time from the data, until you see it it is hard to describe but just look at the BBC but much more local and ON-DEMAND!

My background is mobile/fixed comms, big software delivery, for corporate clients and running 2 small businesses prior to sale.

I would love to use you as a beta tester in about 6 weeks when we can bring the whole thing together on CD, or download from a web site. As you can imagine what started out as a hobby now has 4 people working all their spare time, as we can’t put it down.

Since doing this the Navtex box is on the way to the bin.

Could you send me your e-mail I’ll put you on the list for feedback we need critical observation.
 
I understand what you are saying regarding 5 days is too much for general and you can keep downloading but...

If sailing on longer passages or for example going on a holiday cruise. The weather being settled for a day or two is one thing, but if the models show a possibility of terrible weather in say 5 to 7 days you could end up leaving the boat away from your home port as you can't get back.

Or crossing Biscay it would be nice to see what is around the corner, if the outlook for 3 days is good but at 4 the model predicts gales, you can bet the gales will actually come on day 3, or at least that is how this summer seemed.

Maybe users could have options, 24, 48, 96 etc.

Just a thought.
 
What you really need to consider is the quality of the forecast, as much as the size of the download. You might be able to compress the size of the animation considerably by throwing away elements that don't use, but if the forecast is useless, no one will use or recomend it.

As I've said in another of your threads, I can download Theyr.net animated gifs, just by knowing the format of their forecast site, and taking only the gifs relevant to my location and the time frame of the forecast I need. This could be macro'd into an automated sequence to take location and timescale to nearest hours very easily, though I do it manually.

Big advantage here is I know and trust the limits of Theyr.net forecasts in the areas I use them up to 3 days out (the max they supply) and their model works far better than many others available.

Which model(s) are you planning on using, as we can comment on how effective those models are locally before you spend to much resource on making your animation specific to a particular models, many of which many would not trust?
 
Sounds interesting and would be happy to be involved with a test. You will get lots of sound advice from the likes of Brendan and others who have evolved their own systems. Would be interesting to see how they compare.
 
I've noticed a rapid increase in wireless hot-spots of late, which has prompted me to install an external wifi high gain antenna and usb wireless adaptor. I can access the internet from most ports and marinas, and if this trend continues then effectively we'll be connected whenever we're alongside. This is useful for next leg weather forecasts etc.

Although this won't help with en-route weather, it's a consideration for the short passages we mainly sail. I'd also be happy to be involved in a test.
 
Brendan
How do you select the GIF's you need - is there a code to select the area of interest? or do you just memorise the URL of that particular site?
 
See here
http://www.ybw.com/forums/showflat.php?C...true#Post686265

http://theyr.net/m/EU0/maps/EN/

plus

EN.w.xxyyzztt.dd.gif

where
EN is country code for England (see below for others)
w is map code for wind (see below for others)
xx is year forecast made - eg 05
yy is month forecast made - eg 08
zz is date forecast made - eg 30
tt is 00 for morning forecast, appears 8am, 12 for afternoon forecast, appears 8pm

dd is hours ahead for forecast, from midnight for 00 morning forecasts, from midday for 12 forecasts. This value should be in range 13 to 72

Other country codes

SCO Scotland
IE Ireland
NS Britain & North Sea
NA North Atlantic

Other map codes

cc cloud cover
pc precipitation
t10 temperature and pressure
30 300 hPa Isobar height
50 500 hPa Isobar height
70 700 hPa Isobar height

eg
http://theyr.net/m/EU0/maps/EN/EN.w.05083000.14.gif
 
Great but the file is 89kb for a 6 hour forecast. Right now we are at 40kb for a 3 day forecast, on a much more local chart. The cost for the download therefore would be much higher for less time! OK for you and I but (joe) public with his Navtex box??? The amount of of people going on about the cost of GPRS while roaming.............lots! Theyr.net say they are going to charge soon! up to 6 euro per month will you pay it?

Many thanks for putting me right though! been very good to see what is out there or not as the case maybe!
 
Not a huge file size for what is given. As I've said, the source of the information to me is more important than size or look. Theyr are far more accurate than many other sources, so yes, I'd pay for it. But they've been talking about charging for ages, and never have yet.

As before, what is the source of your weather forecasting?, as that is more important than cutting a few kb off the size of the file
 
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