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#1 DtM

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Posted 16 February 2012 - 06:12 AM

Along the same lines as the thread about navigation systems..... What do people use and recommend for weather forecasting?

#2 nixon

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Posted 16 February 2012 - 07:42 AM

Expedition :)

You can display your grib files in Expedition or Expedition LT (easier to see). You can now download gribs directly from predict wind and a few other sources. They have a few models to select from.

not familiar with the best models for the trans pac.

Personally, I get the GFS gribs via ugrib - I like to step through the model in their grib viewer to get a feeling for what is happening with the weather, then import it into Exp and have another look with track / routes etc.

Obviously there are a ton of web based stuff as well. I don't think you can get EC grib models directly, you have to go through one of the met services and their web viewer to see the data. Ascat is very useful too.

Question is how to get the grib files and the rest once you are well offshore. iridium works for us - but only just - it is about 10% of the speed of your old dial up modem. Costs $3-$6 to get a file down. More expensive sat options work very well. There are also data over HF options. Have a look at the posts in Gear Anarchy.

#3 windjunkee

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Posted 22 February 2012 - 04:32 PM

We were dissatisfied with Expedition's routing function in Transpac.
UGrib is a free GRIB display program and its easy to use. If all you're looking for is weather forecasting with the GFS model, go with UGrib. Its a lot cheaper. Also NOAA's Ocean Prediction Center will give you surface, 500 mb and wave pattern files out 96 hours so you have a reasonable idea of what's coming.
You might also try passageweather.com, but that uses the same GFS model so there is very little variation in the forecasting. A third(fourth) choice is sailflow.com, but they also use NOAA data. Its all about your comfort level with the graphics. For being underway though, nothing beats UGrib and their downloads via sailmail.

#4 rule69

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Posted 22 February 2012 - 07:28 PM

For being underway though, nothing beats UGrib and their downloads via sailmail.


I use saildocs / sailmail to get my underway GRIBs. Does UGrib provide anything that saildocs doesn't?

#5 Moonduster

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Posted 22 February 2012 - 11:33 PM

UGRIB is a pretty nice, free GRIB display and animation engine. It's certainly a far better display engine than is the simple application in the sailmail suite. That said, last I used it, I found it to be completely useless because it won't display GRIBs that cross from W to E longitude. I tried to report that but never got any response - not sure if it's been fixed.

Saildocs is mostly a service that accepts e-mail requests and generates e-mail replies that have GRIB file attachments. UGRIB has that capability build into its display engine, but it's not suitable for HF use and I don't think it's very good with a sat phone either as it requires an internet connection and that's a pretty inefficient and expensive approach to getting data downloaded.

You say you were dissatisfied with Expedition's routing ... but that has nothing to do with obtaining weather information. Expedition is a fine GRIB display solution. Why are you looking for something else? What are the parameters surrounding your needs for weather data? There's not a lot of options - HF or Sat phone are really it.

#6 rule69

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Posted 22 February 2012 - 11:58 PM

UGRIB is a pretty nice, free GRIB display and animation engine. It's certainly a far better display engine than is the simple application in the sailmail suite. That said, last I used it, I found it to be completely useless because it won't display GRIBs that cross from W to E longitude. I tried to report that but never got any response - not sure if it's been fixed.

Saildocs is mostly a service that accepts e-mail requests and generates e-mail replies that have GRIB file attachments. UGRIB has that capability build into its display engine, but it's not suitable for HF use and I don't think it's very good with a sat phone either as it requires an internet connection and that's a pretty inefficient and expensive approach to getting data downloaded.

You say you were dissatisfied with Expedition's routing ... but that has nothing to do with obtaining weather information. Expedition is a fine GRIB display solution. Why are you looking for something else? What are the parameters surrounding your needs for weather data? There's not a lot of options - HF or Sat phone are really it.


Think you were replying to two folks there. FWIW, I've got nothing against E's routing vs any of the other programs I've tried.

Anyway, I take it UGrib is pretty useless offshore unless you've got BGAN or such?

For getting data saildocs seems like a good chopper to me. I use airmail with both Iridium and HF to get GRIBs and that works pretty well. You can read the gribs with lots of programs. Viewfax is okay and it has a number of display options that are helpful (and it can also download data if you've got internet connectivity). I think all the major for money nav programs can display GRIBs to some extent (though maybe not all the parameters in the model). OpenCpn now has a grib display too that's crude but getting better. Saildocs also provides access to other free WX info so it's worth browsing its catalog. If you have HF and Pactor then getfax is a nice tool for getting WXFax images (which are expensive as digital downloads). Some sat images can be downloaded directly with the right gear but that's more a hardware issue than a wx program one.

#7 BLUE66Rose

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Posted 26 February 2012 - 07:50 AM


UGRIB is a pretty nice, free GRIB display and animation engine. It's certainly a far better display engine than is the simple application in the sailmail suite. That said, last I used it, I found it to be completely useless because it won't display GRIBs that cross from W to E longitude. I tried to report that but never got any response - not sure if it's been fixed.

Saildocs is mostly a service that accepts e-mail requests and generates e-mail replies that have GRIB file attachments. UGRIB has that capability build into its display engine, but it's not suitable for HF use and I don't think it's very good with a sat phone either as it requires an internet connection and that's a pretty inefficient and expensive approach to getting data downloaded.

You say you were dissatisfied with Expedition's routing ... but that has nothing to do with obtaining weather information. Expedition is a fine GRIB display solution. Why are you looking for something else? What are the parameters surrounding your needs for weather data? There's not a lot of options - HF or Sat phone are really it.

Posted Image
Think you were replying to two folks there. FWIW, I've got nothing against E's routing vs any of the other programs I've tried.

Anyway, I take it UGrib is pretty useless offshore unless you've got BGAN or such?

For getting data saildocs seems like a good chopper to me. I use airmail with both Iridium and HF to get GRIBs and that works pretty well. You can read the gribs with lots of programs. Viewfax is okay and it has a number of display options that are helpful (and it can also download data if you've got internet connectivity). I think all the major for money nav programs can display GRIBs to some extent (though maybe not all the parameters in the model). OpenCpn now has a grib display too that's crude but getting better. Saildocs also provides access to other free WX info so it's worth browsing its catalog. If you have HF and Pactor then getfax is a nice tool for getting WXFax images (which are expensive as digital downloads). Some sat images can be downloaded directly with the right gear but that's more a hardware issue than a wx program one.


Excellent

#8 Hitchhiker

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Posted 27 February 2012 - 06:50 PM

We were dissatisfied with Expedition's routing function in Transpac.
UGrib is a free GRIB display program and its easy to use. If all you're looking for is weather forecasting with the GFS model, go with UGrib. Its a lot cheaper. Also NOAA's Ocean Prediction Center will give you surface, 500 mb and wave pattern files out 96 hours so you have a reasonable idea of what's coming.
You might also try passageweather.com, but that uses the same GFS model so there is very little variation in the forecasting. A third(fourth) choice is sailflow.com, but they also use NOAA data. Its all about your comfort level with the graphics. For being underway though, nothing beats UGrib and their downloads via sailmail.


Why were you dissatisfied with Expedition's routing in Transpac?

#9 Expedition

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Posted 27 February 2012 - 08:07 PM


We were dissatisfied with Expedition's routing function in Transpac.
UGrib is a free GRIB display program and its easy to use. If all you're looking for is weather forecasting with the GFS model, go with UGrib. Its a lot cheaper. Also NOAA's Ocean Prediction Center will give you surface, 500 mb and wave pattern files out 96 hours so you have a reasonable idea of what's coming.
You might also try passageweather.com, but that uses the same GFS model so there is very little variation in the forecasting. A third(fourth) choice is sailflow.com, but they also use NOAA data. Its all about your comfort level with the graphics. For being underway though, nothing beats UGrib and their downloads via sailmail.


Why were you dissatisfied with Expedition's routing in Transpac?



We did ok in the Transpac a couple of times in the 52 using Exp, so it can't be all bad. At the end of the day, given good inputs it is very accurate. How you use it and what you do with the output are up the user and his individual abilities.

Ugrib and Saildocs are much the same. There are also providers such as Ocens and MailASail etc. Saildocs has a few other models, as does Ugrib in the Pro version.

Ugrib would be best used with their own download as they compress that. I recollect it was slightly more efficient than the bz2 used by saildocs.

However, if you are comparing downloads using the same system (eg sailmail), the SailDocs grib files can be a little smaller as they have put more thought into the data packing.

Apart from that, there is negligible difference between the various GFS providers.

A lot of people like to be disparaging about GFS, but it is actually a very good model.

#10 rule69

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Posted 27 February 2012 - 09:15 PM

A lot of people like to be disparaging about GFS, but it is actually a very good model.


GFS is amazing -- it's easy to forget that as it has become a bit of a utility. It is also evolving and improving all the time. It is produced on time, for free, in a readily accessible way to half a degree for the whole world. For all of those reasons it is the default choice and justifiably so. Thank you USA. Still, my feeling, and somewhat dated experience, is that despite being a world wide model it is a lot better tuned in some places than others. Particularly in the SW Pacific/Coral Sea I found NGP, for all it's faults, to be the better model most of the time. In the NE Pacific I've never seen any advantage either way. Of course, In places where there are local higher resolution models they are worth looking at but places like that tend to have lots of other resources as well. So, I think GFS is great, and the obvious place to start, but sometimes it is productive to look at some of the other options as well.

#11 WHL

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Posted 01 March 2012 - 09:02 PM

I use an Iridium satphone to download weather data via Global Marine Networks/Ocens, and use the data in Expedition. I also use the standalone GMN Grib Explorer which can display your position on the grib, run animations, plus has some other useful display features e.g. grib data wherever you place the cursor, 3D views, sectional slices through the images, both of which help in getting better sense of slope. They also have the Ocens app called MetMapper which is useful for displaying non-grib weather data

#12 Mung Breath

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Posted 03 March 2012 - 03:22 PM

I use an Iridium satphone to download weather data via Global Marine Networks/Ocens, and use the data in Expedition. I also use the standalone GMN Grib Explorer which can display your position on the grib, run animations, plus has some other useful display features e.g. grib data wherever you place the cursor, 3D views, sectional slices through the images, both of which help in getting better sense of slope. They also have the Ocens app called MetMapper which is useful for displaying non-grib weather data


As a pure appliance option, how does Sirius/XM on a Zeus MFD stack up for coastal racing?

#13 WHL

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Posted 03 March 2012 - 04:40 PM


I use an Iridium satphone to download weather data via Global Marine Networks/Ocens, and use the data in Expedition. I also use the standalone GMN Grib Explorer which can display your position on the grib, run animations, plus has some other useful display features e.g. grib data wherever you place the cursor, 3D views, sectional slices through the images, both of which help in getting better sense of slope. They also have the Ocens app called MetMapper which is useful for displaying non-grib weather data


As a pure appliance option, how does Sirius/XM on a Zeus MFD stack up for coastal racing?


I have only taken a superificial look at Sirus XM Marine Weather as it's a subscription service and not permitted for most races under RRS 41 Outside Assistance. GMN has offered "Weathernet" free to all competitors for most major offshore races so GMN is a permitted source of data.

I didn't think that Zeus was compatible with XM Marine Weather data.

#14 Mung Breath

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Posted 04 March 2012 - 02:28 PM



I use an Iridium satphone to download weather data via Global Marine Networks/Ocens, and use the data in Expedition. I also use the standalone GMN Grib Explorer which can display your position on the grib, run animations, plus has some other useful display features e.g. grib data wherever you place the cursor, 3D views, sectional slices through the images, both of which help in getting better sense of slope. They also have the Ocens app called MetMapper which is useful for displaying non-grib weather data


As a pure appliance option, how does Sirius/XM on a Zeus MFD stack up for coastal racing?


I have only taken a superificial look at Sirus XM Marine Weather as it's a subscription service and not permitted for most races under RRS 41 Outside Assistance. GMN has offered "Weathernet" free to all competitors for most major offshore races so GMN is a permitted source of data.

I didn't think that Zeus was compatible with XM Marine Weather data.


Zeus uses that standard Simrad interface. Not to hijack the thread. Just curious.

#15 diggler

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Posted 05 March 2012 - 11:18 AM

I've seen Stan Honey and some other high profile navigators mention editing their grib files, I guess usually to update progression of a front or low to match with their local wind/temp/pressure. The only program I've found that claims to have tools to do this on the tin is Deckman. Are there any other common ones or are these guys using custom software, or even just editing the tables directly?

#16 Zac

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Posted 08 April 2012 - 03:52 AM

Expedition has the capability to scale winds / currents and also rotate the wind direction and then decrease the rotation over time. Useful to speed up or slow down according to observed weather.

I heard Stan discuss this and he said you can do it with either, he is just more comfortable with Deckman.

#17 HattieIrvin

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Posted 09 April 2012 - 11:40 PM

Posted ImageI use saildocs / sailmail to get my underway GRIBs.

#18 the paradox of thrift

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Posted 10 April 2012 - 01:44 AM

I use Expedition and have found it very good.

I have found the high-res GRIB files from PredictWind very good, but they are only produced once per day, so after two or three watches the weather information can be very stale.

An example would be a Sydney coastal race like Bird Island where the

It's led me to lean back on Sail Docs and UGrib for more up-to-date data. Does anybody else find this?

#19 equivocator

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Posted 18 April 2012 - 04:37 PM

Last time I personally used this was several years ago,when I used Sailmail/Saildocs to receive grib files via Iridium sat phone email. This worked very easily and quickly. I could usually poll and receive grib files within 60 secs. provided the files requested were within Sailmail size limits. Using email also had the advantage of avoiding the monthly message limits imposed on SSB modem users by Sailmail. I utilized the grib files using Expedition, so I am not familiar with other viewing software systems. Expo did a great job with displaying the gribs, but because routing is based on predicted performance from your polar files, the accuracy of Expo routing is completely dependent on accurate polars for your boat. We found that our polars (provided by a sister-ship) over-predicted light air performance, so the resulting routing tended to steer us into areas of lighter airs.

More recently, on a different boat, we have been down-loading Ocen gribs using a satellite link, which download extremely quickly. (But the gribs are only updated twice a day, so this is still a limiting factor.) We are using Expo for viewing the gribs and routing purposes. On the recent CdM Cabo Race, minor direction and velocity errors in the gribs may have led the routing astray, in spite of heavy winds.

#20 Heriberto

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Posted 05 July 2012 - 03:31 PM

So do grib files or weather routing software account for things like this?

Posted Image




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