Predictwind.com

[KAM]

Is anyone using the paid for version of this.

 

[bitbaltic]

I used to, but the free version now covers a lot of what the paid for version did a couple of years ago (all the forecast models are now free). So now happily using it without paying.

Curious business model but it’s a very good tool.

 

[coopec]

Wouldn't be Ventusky be useful for predicting wind days ahead?

Ventusky - Weather Forecast Maps

 

[LadyInBed]

Wouldn't be Ventusky be useful for predicting wind days ahead?

Thanks, I didn't know that one.

 

[KAM]

I was wondering what the pay to view real time wind data looks like. I assume it's the same as available free on Windy. Seems a bit cheeky charging for something which is being provided free by amateurs setting up and maintaining weather stations.

 

[franksingleton]

Between them, XyGrib, Ventusky and Windy give you all the “official” Weather models - except the Met Office. All are free. Windy must be paying for access to ECMWF and have a prepayment service which provides data from the short period ECMWF model using 06 and 18 UTC data. I do not know what else they do. As far as I can see there are two reasons to use PW. First if you want weather routing, secondly because you like their delivery and presentation. Personally, I am quite content with the free GRIB services. As I have said in another thread, I am trying to cajole the Met Office into offering their data for open, free use in the same manner as the USA, Canada, Germany and France. I would also like to see the Met Office regional model available similar to Jersey Met who issue the UK regional model, only for the Channrl, on their site, Wind and wave map, the Spanish Met, El Tiempo. Predicción marítima: Costa de Andalucía Occidental y Ceuta - Mapas - Agencia Estatal de Meteorología - AEMET. Gobierno de España, Ireland, Ireland Wind Barb - Met Éireann - The Irish Meteorological Service to mention a few who are ahead of the UK in hoping sailors.
A fairly new service from ECMWF is ECMWF Forecasts. Many of the charts will as useful as if they had captions in Swahili. A few will be useful.

 

[Buck Turgidson]

I used the paid version in 2019 for my trip to the MED. What you pay for is the weather routing not the gribs.

 

[franksingleton]

I used the paid version in 2019 for my trip to the MED. What you pay for is the weather routing not the gribs.

As I said, use PW, or SailGrib or other services if you want routing. I guess that most of us, most of the time do not need routing. We want forecasts for our local, coastal, cross Channel type sailing. Most of us do not need routing. There really is no point in using PW for most of us.

 

[geem]

Wouldn't be Ventusky be useful for predicting wind days ahead?

Ventusky - Weather Forecast Maps

We use Windy. Love it and access to ECMWF model. Statistically the most accurate model looking 5 days forward. GFS model ranks about 4th

 

[david_bagshaw]

Is anyone using the paid for version of this.

Have used the free service for a number of years. there was a good offer for the paid version at christmas, so next year will find if there is any benefit.

 

[franksingleton]

We use Windy. Love it and access to ECMWF model. Statistically the most accurate model looking 5 days forward. GFS model ranks about 4th

In my experience, there is little difference between ECMWF, GFS, ICON out to 5 days. Also, ECMWF only issue their forecast twice a day and two hours later than the national weather services. These issue forecasts 4 times daily. For 16 hours in 24, the available GFS and ICON will be based on later data than the latest ECMWF. PW did a comparison exercise verifying against a selection of actual reports. They used Mean Absolute Error of speed and direction. The average difference between ECMWF and GFS was about 0.6 kts. Noting just how variable wind is, this difference is well below the noise level. The PW assessment has not been peer reviewed so should be treated with caution. For example, a forecadt of W20 and an outcome of N20, E20 etc is a zero error.
Using computer models, it always has to be remembered that models have smoothing for computational reasons. The effective resolution of any model is about 5 grid lengths. Those selling GRIBs and claiming high precision never tell you that.

 

[geem]

In my experience, there is little difference between ECMWF, GFS, ICON out to 5 days. Also, ECMWF only issue their forecast twice a day and two hours later than the national weather services. These issue forecasts 4 times daily. For 16 hours in 24, the available GFS and ICON will be based on later data than the latest ECMWF. PW did a comparison exercise verifying against a selection of actual reports. They used Mean Absolute Error of speed and direction. The average difference between ECMWF and GFS was about 0.6 kts. Noting just how variable wind is, this difference is well below the noise level. The PW assessment has not been peer reviewed so should be treated with caution. For example, a forecadt of W20 and an outcome of N20, E20 etc is a zero error.
Using computer models, it always has to be remembered that models have smoothing for computational reasons. The effective resolution of any model is about 5 grid lengths. Those selling GRIBs and claiming high precision never tell you that.

Chris Parker is a professional weather router providing services to Trans Atlantic sailors, those sailing to the Caribbean from US, etc. He uses ECMWF for longer range. GFS for short range as confirmation.
I forget which publication did the comparison on models but no reason to not believe it. If you pay for the Windy Professional you get four updates per day and one hour predictions .
The resolution of ECMWF is far higher than GFS. This is one of its key features.

 

[franksingleton]

Chris Parker is a professional weather router providing services to Trans Atlantic sailors, those sailing to the Caribbean from US, etc. He uses ECMWF for longer range. GFS for short range as confirmation.
I forget which publication did the comparison on models but no reason to not believe it. If you pay for the Windy Professional you get four updates per day and one hour predictions .
The resolution of ECMWF is far higher than GFS. This is one of its key features.

Well, it rather depends on who is doing the ranking and how they are ranking. ECMWF and national weather service modellers, monitor their models continually. From WMO monitoring the ranking looks like, 1. ECMWF, 2. UK UM, 3. ICON, 4=, GFS, GEM, 6. ARPEGE. Chris Parker is doing the sensible thing. ECMWF should be best over the longer term although, of course, may not be so on any particular9 occasion.
ECMWF uses a 9 km grid, UK UM uses 10 km although I do not know if they are really different. These grid lengths are usually in degrees lat/lon and conversion to km depends on latitude. ICON, GFS, GEM all use 13 km grids. ARPEGE uses a variable grid size. Large far from `France, down to around 5 km (off the top) over France. What we see is what they issue. GFS, ICON, GEM all issue data on a 25 km grid.
Grid length is the major determinant of model performance, followed by number of levels (effectively, vertical grid) and then, total depth. Most, these days have a lid at about 80 km. All now use a 4D data analysis system. There is no one best way to merge the many millions of bits of data from many disparate sources. Inevitably, there will be differences between the different centres and there is always a random element in the outcomes of models.
For my sailing, now confined to the Channel/Brittany and W France, I mainly use the GFS. I like to use Windy to see if there is consistency between models. For planning ahead, I look for day to day consistency between forecasts from one centre. If, days 6,7,8 on one day are consistent with days 5,6,7 on the following day, I plan ahead with some confidence. I find that this gives better guidance than comparing models.

 

[geem]

Well, it rather depends on who is doing the ranking and how they are ranking. ECMWF and national weather service modellers, monitor their models continually. From WMO monitoring the ranking looks like, 1. ECMWF, 2. UK UM, 3. ICON, 4=, GFS, GEM, 6. ARPEGE. Chris Parker is doing the sensible thing. ECMWF should be best over the longer term although, of course, may not be so on any particular9 occasion.
ECMWF uses a 9 km grid, UK UM uses 10 km although I do not know if they are really different. These grid lengths are usually in degrees lat/lon and conversion to km depends on latitude. ICON, GFS, GEM all use 13 km grids. ARPEGE uses a variable grid size. Large far from `France, down to around 5 km (off the top) over France. What we see is what they issue. GFS, ICON, GEM all issue data on a 25 km grid.
Grid length is the major determinant of model performance, followed by number of levels (effectively, vertical grid) and then, total depth. Most, these days have a lid at about 80 km. All now use a 4D data analysis system. There is no one best way to merge the many millions of bits of data from many disparate sources. Inevitably, there will be differences between the different centres and there is always a random element in the outcomes of models.
For my sailing, now confined to the Channel/Brittany and W France, I mainly use the GFS. I like to use Windy to see if there is consistency between models. For planning ahead, I look for day to day consistency between forecasts from one centre. If, days 6,7,8 on one day are consistent with days 5,6,7 on the following day, I plan ahead with some confidence. I find that this gives better guidance than comparing models.

We use the models in exactly the same way. If we are planning a trip across Biscay we are looking for settled weather not complex weather. Agreement between models is very high on our list but also simple weather. Complex weather is hard for the models to achieve high accuracy. We use ECMWF for 5 plus days out then look for model consistency

 

[roaringgirl]

I just started a paid subscription to PW because you can't get the free one over IridiumGO and we're about set off across the Pacific.

 

[franksingleton]

I just started a paid subscription to PW because you can't get the free one over IridiumGO and we're about set off across the Pacific.

That is as good enough reason as any, convenience. Presumably, you could have used the Saildocs free request/reply service via emai. There is, of course, my sponsor, MailASail.

 

[roaringgirl]

That is as good enough reason as any, convenience. Presumably, you could have used the Saildocs free request/reply service via emai. There is, of course, my sponsor, MailASail.

We used email over an Iridium satphone to get our forecasts across the Atlantic. It was extremely time consuming for me and expensive in terms of satphone minutes consumed. Sometimes we had to give up with nothing recieved even though tens of precious data minutes were spent in the attempt. This is because with data on an Iridium *phone* the tx/rx is not resumable so if the signal drops mid-transfer the email is lost and the transfer has to be restarted. On one particular occasion, we had to give up trying to get a forecast; we were then caught with our sails up in a squall with a max recorded speed of 55kts that resulted in a knockdown and a broken spinnaker pole - the loss of which severely impeded our progress for the rest of the crossing (10 days). The following day when we finally succeeded in getting our forecast emails, they included a warning about the very severe squall.

PredictWind offers a limitless data subscription via IridiumGO, which eliminates the running out of satphone minutes problem that we had. Behind the scenes, IridiumGO data tx/rx is resumable so mid-transfer signal drop doesn't lose all the data sent/received so eventual success is more likely.

We *could* use the IridiumGO subscription from PW to get emailed gribs and use a 3rd party app to view them rather than PW's data and app, but this would increase the human effort involved in obtaining each forecast (something which I know ends up being a barrier to doing it at all if people are tired/busy/seasick) and also seems a bit churlish.

 

[franksingleton]

We used email over an Iridium satphone to get our forecasts across the Atlantic. It was extremely time consuming for me and expensive in terms of satphone minutes consumed. Sometimes we had to give up with nothing recieved even though tens of precious data minutes were spent in the attempt. This is because with data on an Iridium *phone* the tx/rx is not resumable so if the signal drops mid-transfer the email is lost and the transfer has to be restarted. On one particular occasion, we had to give up trying to get a forecast; we were then caught with our sails up in a squall with a max recorded speed of 55kts that resulted in a knockdown and a broken spinnaker pole - the loss of which severely impeded our progress for the rest of the crossing (10 days). The following day when we finally succeeded in getting our forecast emails, they included a warning about the very severe squall.

PredictWind offers a limitless data subscription via IridiumGO, which eliminates the running out of satphone minutes problem that we had. Behind the scenes, IridiumGO data tx/rx is resumable so mid-transfer signal drop doesn't lose all the data sent/received so eventual success is more likely.

We *could* use the IridiumGO subscription from PW to get emailed gribs and use a 3rd party app to view them rather than PW's data and app, but this would increase the human effort involved in obtaining each forecast (something which I know ends up being a barrier to doing it at all if people are tired/busy/seasick) and also seems a bit churlish.

Thank you. I am not doubting that PW offer a good service. I am asking in order to improve my knowledge base. I am not a satphone user. I mention SailDocs because, as you will know, it was designed for sending/receiving emails over HF/SSB and HAM radio. A message attachment had to be less than 30kB, I seem to remember. Originally,they had a rather crude viewer. There are now several GRIB viewers for both laptops and tablets. Iam just interested to know why you cannot send an email request to Saildocs over IridiumGO. Several blue water sailors that I know would want to see GRIB file info as well as any routing advice. Presumably, you can ask PW for GRIB data in addition to a forecast. I am probably showing my ignorance and would be interested to be educated by someone who has been there and done it.

 

[geem]

I am currently weather routing a friend across the Atlantic. I have done this several time for people and used a variety of sat devices to do it. The iridium sat phone messaging services is rubbish. Very slow to use. By comparison the Garmin Inreach is a pleasure. We know several people who have ditched to sat phone in favour of text only sat device. Cheaper to operate and easy to use. The best weather info you can get at sea in my opinion is a competent person with a good internet connection, access to several weather models and a text only connection to you. The guy at home has had a good night's sleep is looking at weather in as much detail as needed and can advise accordingly

 

[roaringgirl]

Thank you. I am not doubting that PW offer a good service. I am asking in order to improve my knowledge base. I am not a satphone user. I mention SailDocs because, as you will know, it was designed for sending/receiving emails over HF/SSB and HAM radio. A message attachment had to be less than 30kB, I seem to remember. Originally,they had a rather crude viewer. There are now several GRIB viewers for both laptops and tablets. Iam just interested to know why you cannot send an email request to Saildocs over IridiumGO. Several blue water sailors that I know would want to see GRIB file info as well as any routing advice. Presumably, you can ask PW for GRIB data in addition to a forecast. I am probably showing my ignorance and would be interested to be educated by someone who has been there and done it.

PW over IridiumGO gives you grib information from 6 models (ECMWF, GFS etc...) and a means of displaying it, and weather routing based on those models and the parameters you enter for you boat's performance and your sailing preferences, should you wish. The PW app will also accept and display raw grib files, if you want to obtain them via email and the IridiumGO can send and receive emails, so you could get raw gribs and display them on whatever app you wanted to, were there some reason you didn't like PW's display.