Need weather guru adviser during passage

[Dockhead]

Originally Posted by KiwiKen

Suggest you do a basic course on Meteorology and Marine Forecasts.

Learn to interpret the forecasts, and keep your own logged observations of pressure, wind speed and direction and sea state - you relate these and the changes you have logged and compare to the synopsis and forecast

There are are no shortage of Weather reports broadcast.

Forecasts are a skilled best guess at what a meteorologists thinks is going to happen based on many plotted present weather observations on a synoptic chart coupled the changes since the last synoptic chart (usually either 4 or 6 hourly)

You should learn to put the lot together (forecasts and your observations) as an essential skill of good seamanship and ocean sailing -

One day your life may depend on it if you are unlucky.

Very good advice, but having someone on land analyzing the much richer data available, and giving routing advice, is very good practice in any case. The request is a sign of good seamanship on the part of the OP.

[Dockhead]

Originally Posted by hrsek

Dont you have a family member that can provide the weather service? I did exatly that for my brother some years ago, when he sailed from Portugal to Greece in april. Weather in the MED in april is terrible so he needed daily GRIB files that I provided in emails on a daily basis

You can get GRIB files yourself via Saildocs without help from land. But offshore, weatherfax is more useful. You don't need anyone to send that to you either - you can get that yourself via HF radio.

What the OP wants is not that - what he wants is advice and counsel as he goes along from someone who understands weather routing.. I would be glad to be getting that myself, undertaking a trip like that.

[daletournier]

Originally Posted by Dockhead

You can get GRIB files yourself via Saildocs without help from land. But offshore, weatherfax is more useful. You don't need anyone to send that to you either - you can get that yourself via HF radio.

What the OP wants is not that - what he wants is advice and counsel as he goes along from someone who understands weather routing.. I would be glad to be getting that myself, undertaking a trip like that.

The op"sfirst post he says he has Iridium Go with PredictWind, this app has a weather routing feature which is quite good, how much more do you need? And he has a inreach that gives weather.

[Tingum]

Originally Posted by stevekoerner

Yes Robert, I'm looking for a new friend to help with weather routing. If that's not you, I don't really see much purpose in your posting. Thanks for your thoughts anyway.

When asking for something for free it doesn't pay to be snippy!

[robert sailor]

Generally it's a pretty easy trip, certainly a lot less challenging that sailing back. Hurricanes do form on the Mexican side and move towards Hawaii that you wont pick up on a forecast before leaving as Paul mentioned. I've done that passage 4 times and for the most part it was easy peasy with light airs being more of a concern than storms. There is a permanent Pacific high pressure that sits to the north of you when your making that passage and my strategy was to head for it if a hurricane was getting close. The lows tend to bend around real large highs so it's not a bad idea. If it's any consolation almost all the hurricanes that come off Mexico sputter out before getting to far out so the odds are you'll have a good and safe passage. When you are approaching the Islands, especially between the Islands the venturi effect can really give you some winds with seas to match so that might be the roughest part of the whole ride.
That passage is probably, on average one of the nicest offshore passages, primarily because of the steady trade winds and great weather.

[Sambama]

Thanks for your replies to my comment, Pelagic, Paul L and Dockhead.

[Dockhead]

Originally Posted by daletournier

The op"sfirst post he says he has Iridium Go with PredictWind, this app has a weather routing feature which is quite good, how much more do you need? And he has a inreach that gives weather.

In my opinion, none of the computer-generated weather routing systems is remotely as useful as that done by a knowledgeable human. I do my own as best I can -- based on weatherfax, navtex, and gribs (I use Zygrib -- wonderful program -- to download and view them). But for something like sailing to Hawaii, or for my upcoming trip to the Arctic, I would certainly love to have a more expert person giving me advice from land. That's what commercial shipping does, and what ocean racing teams do, despite the fact that they have a certain amount of data and a certain amount of expertise with them on board. Weather routing is as much art as it is science and I don't think machines are doing it as well as really skillful humans.

For the same reason I take gribs with a box of salt, ALWAYS cross checking with something from a human forecaster, and with a look at the weatherfax.

[daletournier]

Originally Posted by Dockhead

In my opinion, none of the computer-generated weather routing systems is remotely as useful as that done by a knowledgeable human. I do my own as best I can -- based on weatherfax, navtex, and gribs (I use Zygrib -- wonderful program -- to download and view them). But for something like sailing to Hawaii, or for my upcoming trip to the Arctic, I would certainly love to have a more expert person giving me advice from land. That's what commercial shipping does, and what ocean racing teams do, despite the fact that they have a certain amount of data and a certain amount of expertise with them on board. Weather routing is as much art as it is science and I don't think machines are doing it as well as really skillful humans.

For the same reason I take gribs with a box of salt, ALWAYS cross checking with something from a human forecaster, and with a look at the weatherfax.

The key words are "knowledgable and expert". Unless your willing to pay a expert then using tools such as predictawind etc are your best option.

How many of us are "experts"? I'm not.

My point is, unless he is going to pay a professional weather router he already has tools that most mariners throughout history would die for, 24/7 access to gribs and weather routing program if he chooses, pretty good IMHO.

[conachair]

Originally Posted by Dockhead

In my opinion, none of the computer-generated weather routing systems is remotely as useful as that done by a knowledgeable human.

Have you logged & plotted data to confirm that?

Ain't easy, I've done it for GFS in Portugal & it was pretty accurate up to 5 days GFS against airport live data, (green/blue - forecast wind/gust, red/yellow - actual windspeed & gust


Point being unless you actually spend a load of time logging predicted against actual you don't really know which is better - humans are notoriously awful at seeing what they want to see

Though offshore I'd go for Wfax above grib if just one is available, but that's a lot to do with the data required for an ocean sized grib.

[Dockhead]

Originally Posted by daletournier

The key words are "knowledgable and expert". Unless your willing to pay a expert then using tools such as predictawind etc are your best option.

How many of us are "experts"? I'm not.

My point is, unless he is going to pay a professional weather router he already has tools that most mariners throughout history would die for, 24/7 access to gribs and weather routing program if he chooses, pretty good IMHO.

Well, there are people who do this for fun. Herb Hilgenberg used to do it, and I'm sure that there are others. Helping someone out from land on a passage like this would be a great chance for some of us to hone our skills. Hell, I might do it myself if the OP can't find anyone better.

Like you, I am not an expert -- weather is probably the next blank spot on the map for me in terms of skill sets. But I can say with confidence that GRIBs and computer routing tools are NOT something the seasoned mariners of yore would have been happy with. GRIBs are valuable tools for short-term planning, but they don't tell you anything about what kind of system you are dealing with or what the odds are in the longer term that the real weather will turn out differently, so they are not really useful for strategic planning on a long crossing. They are horribly misused by a large number of cruisers. Computer routing tools are the same -- they assume conditions which are machine-predicted.

A great illustration of how useless GRIBs can be is the case we see on here periodically of sailors who post GRIB forecasts connected with TRSs, and make fun of the big difference between what was predicted and what actually happened. Well, this is just foolish -- we all know that the paths of TRSs vary in unpredictable ways. So what conditions you actually see vary according to the actual path, and may be very different if the storm tracks just a few miles this way or that. A GRIB forecast is useless for this; what you need is a human forecast of the likely track of the storm based on different information available, with cone of uncertainty shown, which is the only really useful information to the sailor. On a smaller scale, strategic routing is all the same as this -- it takes judgment and can't just be ginned up by a machine (so far!).

[Dockhead]

Originally Posted by conachair

Have you logged & plotted data to confirm that?

Ain't easy, I've done it for GFS in Portugal & it was pretty accurate up to 5 days GFS against airport live data, (green/blue - forecast wind/gust, red/yellow - actual windspeed & gust


Point being unless you actually spend a load of time logging predicted against actual you don't really know which is better - humans are notoriously awful at seeing what they want to see

Though offshore I'd go for Wfax above grib if just one is available, but that's a lot to do with the data required for an ocean sized grib.

I never go to sea without looking at GRIBs -- it's what I start with.

How likely the forecasts correspond to what actually happens, depends on the type of weather you're having. For non-land influenced weather and large-scale systems the GFS models are pretty good up to a few days ahead. Where land enters the equation (heat-based phenomena like summer t-storms, katabatic winds, etc.), the model is pretty useless. Likewise with respect to any concentrated, smaller scale systems. And in any case, a few days in advance is not enough to plan a two or three weeks crossing. You need a strategic view, and to get that, you need to know the typical weather patterns of the ocean in question, you need to look at longer-term indicators like constant pressure heights, you need to understand something about the jet stream, etc., etc. You have to make judgements which can't just be spit out of a computer model.

I am still learning and am very far yet from being an expert, but I learned a large proportion of what little I know, from Simon Keeling -- do you follow his stuff? The best of it is now unfortunately behind a paywall, and a rather expensive one, but in my opinion it's really worth it, because Simon doesn't just give you his conclusions, he explains how he got to them, which is absolutely invaluable for someone struggling to understand himself. His long range forecasts are absolutely fascinating, and extremely valuable to anyone making long term sailing plans. Dr. Simon Keeling. Simon even runs a weather school for sailors -- I will attend if I can ever find time.

[daletournier]

Originally Posted by Dockhead

Well, there are people who do this for fun. Herb Hilgenberg used to do it, and I'm sure that there are others. Helping someone out from land on a passage like this would be a great chance for some of us to hone our skills. Hell, I might do it myself if the OP can't find anyone better.

Like you, I am not an expert -- weather is probably the next blank spot on the map for me in terms of skill sets. But I can say with confidence that GRIBs and computer routing tools are NOT something the seasoned mariners of yore would have been happy with. GRIBs are valuable tools for short-term planning, but they don't tell you anything about what kind of system you are dealing with or what the odds are in the longer term that the real weather will turn out differently, so they are not really useful for strategic planning on a long crossing. They are horribly misused by a large number of cruisers. Computer routing tools are the same -- they assume conditions which are machine-predicted.

A great illustration of how useless GRIBs can be is the case we see on here periodically of sailors who post GRIB forecasts connected with TRSs, and make fun of the big difference between what was predicted and what actually happened. Well, this is just foolish -- we all know that the paths of TRSs vary in unpredictable ways. So what conditions you actually see vary according to the actual path, and may be very different if the storm tracks just a few miles this way or that. A GRIB forecast is useless for this; what you need is a human forecast of the likely track of the storm based on different information available, with cone of uncertainty shown, which is the only really useful information to the sailor. On a smaller scale, strategic routing is all the same as this -- it takes judgment and can't just be ginned up by a machine (so far!).

Yer they aren't always 100% BUT I can assure you that most (a large most) if not all circumnavigators I've known over the years (and it's alot) are using gribs and tools like PredictWind iridium Go.

This year leaving cocos we with others were looking at gribs daily, three of the other guys were very experienced, NW passage, alaska , two on their second circumnavigations, one a off shore instructor. These are the tools primarily used by them.

Look at some of the more popular blogs, Delos, Totem etc, what are they using? Last I heard iridium Go.

Technology and computer models have improved alot in recent years, definitely not spot on always, But are the professionals always spot on?

I bet you less people are using the likes of Herb due to the accessibility of modern tech than they have in the past.
Go in the right season, be conservative and use modern technology and your more than likely OK.

[conachair]

Originally Posted by Dockhead

I never go to sea without looking at GRIBs -- it's what I start with.

How likely the forecasts correspond to what actually happens, depends on the type of weather you're having. For non-land influenced weather and large-scale systems the GFS models are pretty good up to a few days ahead. Where land enters the equation (heat-based phenomena like summer t-storms, katabatic winds, etc.), the model is pretty useless. Likewise with respect to any concentrated, smaller scale systems. And in any case, a few days in advance is not enough to plan a two or three weeks crossing. You need a strategic view, and to get that, you need to know the typical weather patterns of the ocean in question, you need to look at longer-term indicators like constant pressure heights, you need to understand something about the jet stream, etc., etc. You have to make judgements which can't just be spit out of a computer model.

I am still learning and am very far yet from being an expert, but I learned a large proportion of what little I know, from Simon Keeling -- do you follow his stuff? The best of it is now unfortunately behind a paywall, and a rather expensive one, but in my opinion it's really worth it, because Simon doesn't just give you his conclusions, he explains how he got to them, which is absolutely invaluable for someone struggling to understand himself. His long range forecasts are absolutely fascinating, and extremely valuable to anyone making long term sailing plans. Dr. Simon Keeling. Simon even runs a weather school for sailors -- I will attend if I can ever find time.

Simon Keelong I followed in the UK before he had to start charging - Franks book weather book is another valuable resource especially for localised. ISTR Simon took a punt on what model / mix of models looked most reasonable. WIndyty just added another Euro model as well, 4 to look at now.

But again, if you aren't logging and plotting - how do you know you're just seeing what you expect? (Frank Singleton prefers GFS for sailing, beyond 10 days is getting into guesswork).

The GFS model also falls apart a bit for ITCZ position as well, Wfax can come in handy for that.

[Auspicious]

Originally Posted by stevekoerner

Yes Robert, I'm looking for a new friend to help with weather routing. If that's not you, I don't really see much purpose in your posting. Thanks for your thoughts anyway.

Because your asking a lot for free and it comes across as entitled.

It probably doesn't matter as you have posted twice and disappeared.

Originally Posted by roland stockham

essentially this is a novice (to open ocean sailing) skipper recognizing his inexperience and asking for help. Does he even know there are professional weather routers?

I suggest that someone who doesn't understand weather and weather resources really should not be planning to cross a third of the Pacific Ocean. It's big out there and it takes a while.

Some classes from someone like Lee Chesneau and a small portable shortwave receiver for weather fax is much better than the GO! and PredictWind.

Originally Posted by Sambama

I understand how important it is to get a weather forecast and several days outlook " guess" of what to expect before you depart for HI, for a more or less 20 day trip. Here's what I don't get, other than knowing you are going to get into bad weather and batten the hatches, reef the main and tie down or remove the things on deck, what good will everyday forecast really do? You're on a sailboat. You can't out run anything, and you can't turn around and go back. Other than to know you're about to get pounded, what real options do you really have?

@Dockhead talked about this. You make tactical decisions about when to tack and whether to shift one way or another over days based on the long range forecasts. You compare the short range forecasts to the long range forecasts to see how the forecasters are doing, which indicates the degree of stability in the atmosphere. You compare the current analysis with looking out the window. There is a difference between deciding to motor off the rhumb line for a day into good wind vice diving blithly into five days of no air.

[Dockhead]

Originally Posted by daletournier

Yer they aren't always 100% BUT I can assure you that most (a large most) if not all circumnavigators I've known over the years (and it's alot) are using gribs and tools like PredictWind iridium Go.

This year leaving cocos we with others were looking at gribs daily, three of the other guys were very experienced, NW passage, alaska , two on their second circumnavigations, one a off shore instructor. These are the tools primarily used by them.

Look at some of the more popular blogs, Delos, Totem etc, what are they using? Last I heard iridium Go.

Technology and computer models have improved alot in recent years, definitely not spot on always, But are the professionals always spot on?

I bet you less people are using the likes of Herb due to the accessibility of modern tech than they have in the past.
Go in the right season, be conservative and use modern technology and your more than likely OK.

I'm not knocking GRIBs at all! I try to download them a couple of times a day at least. The GFS model is fantastic for understanding what today and tomorrow and maybe the day after tomorrow will be like, and GRIBs are invaluable for making short term plans.

That's not what I'm talking about at all -- I'm talking about what the OP is asking about -- weather ROUTING. This is a strategic process for which a few days of accurate GRIBs doesn't help you much. It's a different job altogether.