PredictWind Presentation - and some extra info on GRIB files
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David Vogel
Good ZOOM hook-up - thank you Bill & Tilo for organising and moderating.
I learnt a few good things: use of high-resolution models for local forecasts; and the better speed of the PWoffshore APP because it caches data locally. If you are like me, a little 'old school', preferring to access and study all kinds of weather information from diverse source, or for those interested in some more detail and background information about GRIB files, the attached Weather Compendium provides a general overview about how to obtain and use GRIB files, and other sources of weather data, albeit with a focus on French Polynesia. See section 32. As background, I have been using PredictWind on and off for 8 years - as only one of the many tools in my weather toolbox - and trialled the PW PROFESSIONAL level of subscription for our recent trip Fiji-NZ, during which we encountered some gnarly weather. The responsiveness and level of support from the PW team is second to none. That said, as a weather 'geek', I still prefer to run my own weather forecasting and routing tools, and my "Go To" tool is Weather4D on an iPad, which I have also been using for passage-making since 2014 without complaint. Weather4D allows me to easily run and re-run various routing scenarios whilst underway, without needing to go online each time, as is the case with the PW Offshore app. There are a number of other apps and PC/Mac applications that do the same thing. But for many cruising types, increasingly PW is a fully capable and functional tool for visualising key elements of the weather forecast. I hope the attached is of some interest. David SM#396, Perigee |
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Morning David,
When using Weather4D on an iPad during passage (see yellow highlighted section below) where & how does Weather4D gets it updates if the iPad is not connected to the internet or satellite?
Best Regards Teun SV AMELIT A54 #128
HOPE ISLAND MARINA (near BRISBANE) QLD AUSTRALIA June 19, 2022 08:30:18
You can follow AMELIT via this link: https://forecast.predictwind.com/tracking/display/AMELIT
-----Original Message-----
From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> On Behalf Of David Vogel via groups.io Sent: Sunday, June 19, 2022 07:52 To: main@AmelYachtOwners.groups.io Subject: Re: [AmelYachtOwners] PredictWind Presentation - and some extra info on GRIB files
Good ZOOM hook-up - thank you Bill & Tilo for organising and moderating.
I learnt a few good things: use of high-resolution models for local forecasts; and the better speed of the PWoffshore APP because it caches data locally.
If you are like me, a little 'old school', preferring to access and study all kinds of weather information from diverse source, or for those interested in some more detail and background information about GRIB files, the attached Weather Compendium provides a general overview about how to obtain and use GRIB files, and other sources of weather data, albeit with a focus on French Polynesia. See section 32.
As background, I have been using PredictWind on and off for 8 years - as only one of the many tools in my weather toolbox - and trialled the PW PROFESSIONAL level of subscription for our recent trip Fiji-NZ, during which we encountered some gnarly weather. The responsiveness and level of support from the PW team is second to none.
That said, as a weather 'geek', I still prefer to run my own weather forecasting and routing tools, and my "Go To" tool is Weather4D on an iPad, which I have also been using for passage-making since 2014 without complaint. Weather4D allows me to easily run and re-run various routing scenarios whilst underway, without needing to go online each time, as is the case with the PW Offshore app. There are a number of other apps and PC/Mac applications that do the same thing. But for many cruising types, increasingly PW is a fully capable and functional tool for visualising key elements of the weather forecast.
I hope the attached is of some interest.
David SM#396, Perigee
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David Vogel
Hi there Teun,
toggle quoted message
Show quoted text
With regards to: " Weather4D allows me to easily run and re-run various routing scenarios whilst underway, without needing to go online each time, as is the case with the PW Offshore app" Question: > where & how does Weather4D gets it updates if the iPad is not connected to the internet or satellite? Answer: Wx4D does not get any updated GRIBs unless connected to internet (or polling GRIBs via SailDOCs). The various routing scenarios I am referring to here are exploratory boat-scenarios. To explain, whilst underway I download the GRIB/s once a cycle (normally daily under routine circumstances, but 12-hourly under dynamic weather conditions or when decisions need to be made). With a valid GRIB loaded, you can adjust various parameters in Wx4D, such as setting different routes, RTE start-end & intermediate waypoints, ETD, or different polars, or adjust the polar weighting; then re-run the scenario locally. Calculating each run takes about 10 seconds. You can then compare the result of each scenario-set visually on-screen. For example, what is the effect of a polar set at 85%, versus 45%, or going great-circle PresentPosition-to-Destination versus via x, y or z. You can see the estimated future position of the boat with respect to the weather systems and wind/wave fields for each of the different selected scenarios (fast, slow, left, right). This all happens locally. Whereas with PW, the routing calculation for a single route (using different WX models) takes place online, with the results being downloaded to the Offshore app. Meaning, with PW, you need to go online to do each a new routing calculation (scenario analysis, WPT, polar setting), even within the same forecast period. And you cannot hold-over to see the results of a previous run. Does this answer your question? Feel free to ask if any further explanation is required. In any event, hoping to catch up if we can get back down to Hope Island marina before we wing it back to NZ. Happy to show you then. Best, David From: <main@AmelYachtOwners.groups.io> on behalf of Teun BAAS <teun@...> Reply to: <main@AmelYachtOwners.groups.io> Date: Sunday, 19 June 2022 at 8:30 am To: "main@AmelYachtOwners.groups.io" <main@AmelYachtOwners.groups.io> Subject: Re: [AmelYachtOwners] PredictWind Presentation - and some extra info on GRIB files Morning David, When using Weather4D on an iPad during passage (see yellow highlighted section below) where & how does Weather4D gets it updates if the iPad is not connected to the internet or satellite? Best Regards Teun SV AMELIT A54 #128 HOPE ISLAND MARINA (near BRISBANE) QLD AUSTRALIA June 19, 2022 08:30:18 You can follow AMELIT via this link: https://forecast.predictwind.com/tracking/display/AMELIT -----Original Message-----
From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> On Behalf Of David Vogel via groups.io Sent: Sunday, June 19, 2022 07:52 To: main@AmelYachtOwners.groups.io Subject: Re: [AmelYachtOwners] PredictWind Presentation - and some extra info on GRIB files Good ZOOM hook-up - thank you Bill & Tilo for organising and moderating. I learnt a few good things: use of high-resolution models for local forecasts; and the better speed of the PWoffshore APP because it caches data locally. If you are like me, a little 'old school', preferring to access and study all kinds of weather information from diverse source, or for those interested in some more detail and background information about GRIB files, the attached Weather Compendium provides a general overview about how to obtain and use GRIB files, and other sources of weather data, albeit with a focus on French Polynesia. See section 32. As background, I have been using PredictWind on and off for 8 years - as only one of the many tools in my weather toolbox - and trialled the PW PROFESSIONAL level of subscription for our recent trip Fiji-NZ, during which we encountered some gnarly weather. The responsiveness and level of support from the PW team is second to none. That said, as a weather 'geek', I still prefer to run my own weather forecasting and routing tools, and my "Go To" tool is Weather4D on an iPad, which I have also been using for passage-making since 2014 without complaint. Weather4D allows me to easily run and re-run various routing scenarios whilst underway, without needing to go online each time, as is the case with the PW Offshore app. There are a number of other apps and PC/Mac applications that do the same thing. But for many cruising types, increasingly PW is a fully capable and functional tool for visualising key elements of the weather forecast. I hope the attached is of some interest. David SM#396, Perigee |
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Thanks David,
All clear - I will take a look at Weather4D and maybe we can talk about it if/when you make it back to the Marina here.
So far I have, for passage etc., only relied on PDW plus for the crossing to AUSTRALIA only had 2 professional weather consultants; both with similar mixed results ☹. Purchased from both a 10 trip package with a time/usage limited validity which then rendered useless due to COVID. Was in November 2019 NOT impressed with the weather info & routing recommendations and came, in November 2019, to the conclusion that the original PDW departure & routing was more accurate than the “professionals”. The expiration of my remaining 9 consults (each) wasn’t really helpful and didn’t score bonus points either hahahahaha.
In all fairness: one of the consultants extended my usage period and I need to see if he is still willing to help me when I make passage later this year.
Best Regards Teun SV AMELIT A54 #128
HOPE ISLAND MARINA (near BRISBANE) QLD AUSTRALIA June 19, 2022 20:35:07
You can follow AMELIT via this link: https://forecast.predictwind.com/tracking/display/AMELIT
-----Original Message-----
From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> On Behalf Of David Vogel via groups.io Sent: Sunday, June 19, 2022 10:56 To: main@AmelYachtOwners.groups.io Subject: Re: [AmelYachtOwners] PredictWind Presentation - and some extra info on GRIB files
Hi there Teun,
With regards to: " Weather4D allows me to easily run and re-run various routing scenarios whilst underway, without needing to go online each time, as is the case with the PW Offshore app"
Question: > where & how does Weather4D gets it updates if the iPad is not connected to the internet or satellite?
Answer: Wx4D does not get any updated GRIBs unless connected to internet (or polling GRIBs via SailDOCs). The various routing scenarios I am referring to here are exploratory boat-scenarios.
To explain, whilst underway I download the GRIB/s once a cycle (normally daily under routine circumstances, but 12-hourly under dynamic weather conditions or when decisions need to be made). With a valid GRIB loaded, you can adjust various parameters in Wx4D, such as setting different routes, RTE start-end & intermediate waypoints, ETD, or different polars, or adjust the polar weighting; then re-run the scenario locally. Calculating each run takes about 10 seconds. You can then compare the result of each scenario-set visually on-screen. For example, what is the effect of a polar set at 85%, versus 45%, or going great-circle PresentPosition-to-Destination versus via x, y or z. You can see the estimated future position of the boat with respect to the weather systems and wind/wave fields for each of the different selected scenarios (fast, slow, left, right). This all happens locally.
Whereas with PW, the routing calculation for a single route (using different WX models) takes place online, with the results being downloaded to the Offshore app. Meaning, with PW, you need to go online to do each a new routing calculation (scenario analysis, WPT, polar setting), even within the same forecast period. And you cannot hold-over to see the results of a previous run.
Does this answer your question? Feel free to ask if any further explanation is required.
In any event, hoping to catch up if we can get back down to Hope Island marina before we wing it back to NZ. Happy to show you then.
Best,
David
From: <main@AmelYachtOwners.groups.io> on behalf of Teun BAAS <teun@...> Reply to: <main@AmelYachtOwners.groups.io> Date: Sunday, 19 June 2022 at 8:30 am To: "main@AmelYachtOwners.groups.io" <main@AmelYachtOwners.groups.io> Subject: Re: [AmelYachtOwners] PredictWind Presentation - and some extra info on GRIB files
Morning David,
When using Weather4D on an iPad during passage (see yellow highlighted section below) where & how does Weather4D gets it updates if the iPad is not connected to the internet or satellite?
Best Regards Teun SV AMELIT A54 #128
HOPE ISLAND MARINA (near BRISBANE) QLD AUSTRALIA June 19, 2022 08:30:18
You can follow AMELIT via this link: https://forecast.predictwind.com/tracking/display/AMELIT
-----Original Message----- From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> On Behalf Of David Vogel via groups.io Sent: Sunday, June 19, 2022 07:52 To: main@AmelYachtOwners.groups.io Subject: Re: [AmelYachtOwners] PredictWind Presentation - and some extra info on GRIB files
Good ZOOM hook-up - thank you Bill & Tilo for organising and moderating.
I learnt a few good things: use of high-resolution models for local forecasts; and the better speed of the PWoffshore APP because it caches data locally.
If you are like me, a little 'old school', preferring to access and study all kinds of weather information from diverse source, or for those interested in some more detail and background information about GRIB files, the attached Weather Compendium provides a general overview about how to obtain and use GRIB files, and other sources of weather data, albeit with a focus on French Polynesia. See section 32.
As background, I have been using PredictWind on and off for 8 years - as only one of the many tools in my weather toolbox - and trialled the PW PROFESSIONAL level of subscription for our recent trip Fiji-NZ, during which we encountered some gnarly weather. The responsiveness and level of support from the PW team is second to none.
That said, as a weather 'geek', I still prefer to run my own weather forecasting and routing tools, and my "Go To" tool is Weather4D on an iPad, which I have also been using for passage-making since 2014 without complaint. Weather4D allows me to easily run and re-run various routing scenarios whilst underway, without needing to go online each time, as is the case with the PW Offshore app. There are a number of other apps and PC/Mac applications that do the same thing. But for many cruising types, increasingly PW is a fully capable and functional tool for visualising key elements of the weather forecast.
I hope the attached is of some interest.
David SM#396, Perigee
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David, Tuen,
+1 for Weather4D. I have been using Weather4D for a few years and have been really happy with how it operates. I compared it side by side with PW 4 or 5 years ago and there was daylight between them, however it's clear that PW has caught up. On long passages I run it constantly, feeding it with my live navigation data via WiFi. I compare my planned routing with reality and where necessary update the plan to reflect the latest reality. Most weather models are available, but I was particularly impressed with the accuracy of the French Arpege models when sailing between Scotland and Greece. I much prefer the ability to run the route planning locally on the boat rather than remotely on a third party server. Weather4D is not marketed as vigorously as PredictWind, but hopefully the quality of the product and their support sustain it into the future. -- Dean Gillies SV Stella *****, Amel 54-154 |
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David Vogel
Hi Tuen,
toggle quoted message
Show quoted text
Yes, I agree with your experience and opinion regarding weather routers. They can be a mixed bag. However, probably no more variable than the range of good or bad decisions that any skipper can make for him or herself. Especially now that we can get the output from the various computer-generated weather model ourselves, essentially directly on-board, whilst in the middle of nowhere. And with the software available to us these days to crunch-the-numbers and with great data visualisation. When you think of it, the technology we have at our disposal is absolutely incredible. As an aside, I am fortunate enough to have been a trained MET observer since the early 80’s, and was using weather in my daily work for many years. I always do my own departure planning and routing. But nevertheless, I still maintain a weather router for most trans-oceanic passages – one specialising in our area of operation – holding a copy of my passage plan, and on standby. This is for the event that my own on-board systems might fail*, or should I become incapacitated and my crew need outside assistance to get them to the original port, or to an alternate. As well, I know the tendency to focus on achieving a desired outcome (get-there-itis), and the possibility to become blind to an ‘uncomfortable truth’. Although I would hope to remain objective, I have read enough incident and accident reports to know that the best of us fall prey to such effects. So, I ask the MET person on-shore to keep an eye out for anything that I might have missed – the broader range perspective, or using tools and imagery that I may not have ready access whilst offshore. It makes for some interesting discussions at times. But all good. And yes, like you, I have on occasion had two weather guys on the side, but found that this didn’t help matters at all; just increased the ambiguity. Just like having more models in PW, doesn’t necessarily result in a better or more certain outcome. Looking forward to catching up soon. Best, David * Arriving into Bermuda on an iPhone – I launched without paper charts (yes, I know, but extenuating weather-related circumstances dictated a change of destination). The charts on the main chartplotter failed to load. And then the backup iPad froze. Talk about the Bermuda triangle! I now have two backup iPads, each fully loaded with the suite of applicable software (and running different iOSs, different app versions). Unless absolutely necessary due to gear failure, I also now do not make any optional configuration changes (new hardware, or upgrades to firmware, operating system, or software) to anything electronic on-board within 4-6 weeks (preferably longer) of planned departure. From: <main@AmelYachtOwners.groups.io> on behalf of Teun BAAS <teun@...> Reply to: <main@AmelYachtOwners.groups.io> Date: Sunday, 19 June 2022 at 8:42 pm To: "main@AmelYachtOwners.groups.io" <main@AmelYachtOwners.groups.io> Subject: Re: [AmelYachtOwners] PredictWind Presentation - and some extra info on GRIB files Thanks David, All clear - I will take a look at Weather4D and maybe we can talk about it if/when you make it back to the Marina here. So far I have, for passage etc., only relied on PDW plus for the crossing to AUSTRALIA only had 2 professional weather consultants; both with similar mixed results ☹. Purchased from both a 10 trip package with a time/usage limited validity which then rendered useless due to COVID. Was in November 2019 NOT impressed with the weather info & routing recommendations and came, in November 2019, to the conclusion that the original PDW departure & routing was more accurate than the “professionals”. The expiration of my remaining 9 consults (each) wasn’t really helpful and didn’t score bonus points either hahahahaha. In all fairness: one of the consultants extended my usage period and I need to see if he is still willing to help me when I make passage later this year. Best Regards Teun SV AMELIT A54 #128 HOPE ISLAND MARINA (near BRISBANE) QLD AUSTRALIA June 19, 2022 20:35:07 You can follow AMELIT via this link: https://forecast.predictwind.com/tracking/display/AMELIT -----Original Message-----
From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> On Behalf Of David Vogel via groups.io Sent: Sunday, June 19, 2022 10:56 To: main@AmelYachtOwners.groups.io Subject: Re: [AmelYachtOwners] PredictWind Presentation - and some extra info on GRIB files Hi there Teun, With regards to: " Weather4D allows me to easily run and re-run various routing scenarios whilst underway, without needing to go online each time, as is the case with the PW Offshore app" Question: > where & how does Weather4D gets it updates if the iPad is not connected to the internet or satellite? Answer: Wx4D does not get any updated GRIBs unless connected to internet (or polling GRIBs via SailDOCs). The various routing scenarios I am referring to here are exploratory boat-scenarios. To explain, whilst underway I download the GRIB/s once a cycle (normally daily under routine circumstances, but 12-hourly under dynamic weather conditions or when decisions need to be made). With a valid GRIB loaded, you can adjust various parameters in Wx4D, such as setting different routes, RTE start-end & intermediate waypoints, ETD, or different polars, or adjust the polar weighting; then re-run the scenario locally. Calculating each run takes about 10 seconds. You can then compare the result of each scenario-set visually on-screen. For example, what is the effect of a polar set at 85%, versus 45%, or going great-circle PresentPosition-to-Destination versus via x, y or z. You can see the estimated future position of the boat with respect to the weather systems and wind/wave fields for each of the different selected scenarios (fast, slow, left, right). This all happens locally. Whereas with PW, the routing calculation for a single route (using different WX models) takes place online, with the results being downloaded to the Offshore app. Meaning, with PW, you need to go online to do each a new routing calculation (scenario analysis, WPT, polar setting), even within the same forecast period. And you cannot hold-over to see the results of a previous run. Does this answer your question? Feel free to ask if any further explanation is required. In any event, hoping to catch up if we can get back down to Hope Island marina before we wing it back to NZ. Happy to show you then. Best, David From: <mailto:main@AmelYachtOwners.groups.io> on behalf of Teun BAAS <mailto:teun@...> Reply to: <mailto:main@AmelYachtOwners.groups.io> Date: Sunday, 19 June 2022 at 8:30 am To: "mailto:main@AmelYachtOwners.groups.io" <mailto:main@AmelYachtOwners.groups.io> Subject: Re: [AmelYachtOwners] PredictWind Presentation - and some extra info on GRIB files Morning David, When using Weather4D on an iPad during passage (see yellow highlighted section below) where & how does Weather4D gets it updates if the iPad is not connected to the internet or satellite? Best Regards Teun SV AMELIT A54 #128 HOPE ISLAND MARINA (near BRISBANE) QLD AUSTRALIA June 19, 2022 08:30:18 You can follow AMELIT via this link: https://forecast.predictwind.com/tracking/display/AMELIT -----Original Message----- From: mailto:main@AmelYachtOwners.groups.io <mailto:main@AmelYachtOwners.groups.io> On Behalf Of David Vogel via groups.io Sent: Sunday, June 19, 2022 07:52 To: mailto:main@AmelYachtOwners.groups.io Subject: Re: [AmelYachtOwners] PredictWind Presentation - and some extra info on GRIB files Good ZOOM hook-up - thank you Bill & Tilo for organising and moderating. I learnt a few good things: use of high-resolution models for local forecasts; and the better speed of the PWoffshore APP because it caches data locally. If you are like me, a little 'old school', preferring to access and study all kinds of weather information from diverse source, or for those interested in some more detail and background information about GRIB files, the attached Weather Compendium provides a general overview about how to obtain and use GRIB files, and other sources of weather data, albeit with a focus on French Polynesia. See section 32. As background, I have been using PredictWind on and off for 8 years - as only one of the many tools in my weather toolbox - and trialled the PW PROFESSIONAL level of subscription for our recent trip Fiji-NZ, during which we encountered some gnarly weather. The responsiveness and level of support from the PW team is second to none. That said, as a weather 'geek', I still prefer to run my own weather forecasting and routing tools, and my "Go To" tool is Weather4D on an iPad, which I have also been using for passage-making since 2014 without complaint. Weather4D allows me to easily run and re-run various routing scenarios whilst underway, without needing to go online each time, as is the case with the PW Offshore app. There are a number of other apps and PC/Mac applications that do the same thing. But for many cruising types, increasingly PW is a fully capable and functional tool for visualising key elements of the weather forecast. I hope the attached is of some interest. David SM#396, Perigee |
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