Steve C Cronin
N/A
Which greek weather forecast do you trust the most?
Poseidon, Meteo Greece, Grib, Windfinder or wtw?
Poseidon, Meteo Greece, Grib, Windfinder or wtw?
Grek weather
- Thread starter Steve C Cronin
- Start date
RobbieW
Well-known member
Mostly this ... http://212.175.180.126/DTS/sea.php but given the localisation of the weather none can be 'trusted'
homer
Member
hnms and skiron both seem to have an edge over the others. It does depend upon how long a forecast you are looking for and whether you want to be able to download for future reference.
alexsailor
Active member
yr.no
Poseidon
Poseidon
sailaboutvic
Well-known member
http://poseidon.hcmr.gr is as good as any you just got to read between the lines .
www.bluewatersailorcroatia.webs.com
www.bluewatersailorcroatia.webs.com
vyv_cox
Well-known member
Have to agree. This season we have been monitoring Poseidon, Meteo.gr, Windfinder and the Turkish one. Mostly Poseidon has been the more accurate but none could be described as spot on. Today for Samos Sea Navtex says 6-7, Poseidon says 4-5 for where we are, meteo says 6. Have just sailed across Leros to Lipsi in a 3-4.
JFowler
Active member
Until recently we found Windfinder 3 day forecast to be fairly reliable, but of late it's given some very strange predictions. Agree Poseidon the best option.
DaveRo
Well-known member
As has often been mentioned, be aware that the Poseidon forecasts are sometimes not updated overnight, and this is not obvious from their website. Check that there is a forecast for the next 5 days.
Melody
Active member
For the overall picture we use the University of Athens forecast http://forecast.uoa.gr daily.
You need to select High Resolution in Forecast, then Athens (or Greece) as the area, and then Sea Surface wind in the last field.
I believe uoa modelling had a lot of funding to improve it's forecasting for the 2004 Olympics. It may not be as good for elsewhere in Greece but I find it great for the Athens & Saronic areas.
Then for details of specific ports we back it up with meteo.gr but I'm not sure how easy this is to use if you can't read Greek.
You need to select High Resolution in Forecast, then Athens (or Greece) as the area, and then Sea Surface wind in the last field.
I believe uoa modelling had a lot of funding to improve it's forecasting for the 2004 Olympics. It may not be as good for elsewhere in Greece but I find it great for the Athens & Saronic areas.
Then for details of specific ports we back it up with meteo.gr but I'm not sure how easy this is to use if you can't read Greek.
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Tony Cross
Well-known member
I use three, all of which can be had online:
US NOAA gribs (I use the zygrib viewer http://zygrib.org)
Poseidon (http://poseidon.hcmr.gr/)
National Hellenic Meteorological Service (they produce the VHF forecasts, http://www.hnms.gr/hnms/english/navigation/navigation_html#)
I use these three because they all use different and separate data sources. The gribs are US based of course, Poseidon has a series of ocean buoys and HNMS uses real live forecasters. If I get good agreement between all three then I'm reasonably confident that's what we'll get. If they are wildly different I assume the weather will be whatever is the worst forecast.
I believe it is essential to know the data source of any forecast you use. A large number of the free web-based forecasts are US grib based so even though they are presented in different ways they will of course agree with each other.
Chris_Robb
Well-known member
Zygrib gave 3 to 4 on the 4th (data set for the 3rd). We found it the most useable - down loading an 8 day forecast which enabled you to see what was coming to plan. We then also used Poseidon to confirm the more immediate forecast - but beware of them not updating the forecasts!
However things like wind finder I understand just use the Grib info and will give you exactly what the Zygrib gives you. Zygrib has the added advantage that you down load the file and it is then available even when out of data contact.
Steve C Cronin
N/A
As with all grib sites. I have used USgrib for at least ten years and pocketgrib for two. The latter is particularly useful mfor Apple and Android devices.
franksingleton
Well-known member
Yes. http://212.175.180.126/DTS/sea.php should be the best model. It is ECMWF output on the same grid as used by the global model ie 0.125 degrees. Output goes to 5 days. ECMWF starts with the best data analysis possible.YR.NO should be as good as they use the same model. So also does the WeatherPro HD App.
The NOAA GFS should be next best. Their model uses a grid about twice as big and only gives that data on a 0.5 degree grid Its analysis is as good as possible on that grid.
The Greek Met Service, http://www.hnms.gr/hnms/english/navigation/navigation_html, should be next. It is a limited area model. I am not sure about the grid but it also starts with a good analysis. It may be the best over the first 24 hours but not as good as the ECMWF beyond. In practice, due to the problems of predicting detail, it may do little better than the ECMWF even for the first 24 hours.
As far as I know, none of the other services mentioned here nor any of the commercial models start with a detailed data analysis. The models are OK but the data input is usually just the GFS 0.5 degree output. That must limit their detail. They will be OK in general terms.
http://212.175.180.126/DTS/sea.php will not always be the best, that is the nature of weather modelling. It must be the best for most of the time.
So, use http://212.175.180.126/DTS/sea.php but keep an eye on the GFS. Forget the rest.
RobbieW
Well-known member
I was playing with the Turkish website this year and using the 'forecast for a point' and 'cruise planning' functions. In the Ionian, 'forecast for a point' was as good as any of the others, ie wrong some of the time; however cruise planning proved surprisingly accurate even after 48 hrs without update. If you leave your browser open after creating a route you can track the weather along the way.
franksingleton
Well-known member
Thanks. I don not now sail in the Med but that is what I would have expected. A global model with a short grid length and using the best initial data analysis possible should beat the rest.
lille_bee
New member
Another vote for www.hnms.gr and poseidon, my favourite!
Hardmy
Member
Very interesting thread, a bit old though!
I also use poseidon and hnms, but I am still unable to determine which one is more accurate.
What I used a lot in the Adriatic is this one: http://www.lamma.rete.toscana.it/mare/modelli/vento-e-mare
Choose "Grecia" and Vento a 10m. I still use and like it!
I also use poseidon and hnms, but I am still unable to determine which one is more accurate.
What I used a lot in the Adriatic is this one: http://www.lamma.rete.toscana.it/mare/modelli/vento-e-mare
Choose "Grecia" and Vento a 10m. I still use and like it!
macd
Active member
+1
In the NE part of the Gulf of Corinth last July, when (unusually) the Meltemi was gusting 50kn off the mountains, it was the only one which came anywhere close to forecasting reality. Everything else promised a relaxing day in Paradise. The graphics aren't very good, but I can live with that if it gives an idea of what's coming.
For wider areas the Turkish model recommended by RobbieW and others is good.
charles_reed
Active member
I'd agree with Melody, that the most accurate I find to be the Athens uni site.
Turkish weather might be OK, but for the presentation, the maps are small and confusing. Posiedon is generally mediocre.
Though Frank strongly disapproves I use the NOAA data and do my own extrapolation - which I've found far the most reliable.
Turkish weather might be OK, but for the presentation, the maps are small and confusing. Posiedon is generally mediocre.
Though Frank strongly disapproves I use the NOAA data and do my own extrapolation - which I've found far the most reliable.
franksingleton
Well-known member
Hi, Charles, I really do not understand your comment. I have long regarded the NOAA GFS as one of, if not the most useful of all GRIB (ie objective) forecast services available to sailors. That is particularly so now that it computes on a grid of around 12-13 km although only providing data on a ¼ degree ie 25 km grid. It is easily available over narrow bandwidth systems using zyGrib or Ugrib or by email.
Given broadband Internet access, the Turkish Weather-wise - http://212.175.180.126/DTS/sea.php - should be as good better over the first few days. Large scale charts are available as well as meteograms for specific locations and a route planning forecast. This uses the ECMWF data analysis (currently 15 km but due to come down to 8 km) with the WRF forecast on a similar sized grid.
The GFS and Weatherwise have better initial data inputs than the Athens U , Skiron, OpenWRF or any of the various commercially available GRIB type forecasts. As far as I know these all start with the GFS 25 km grid and add no more actual weather data to initialise their models. As the models themselves are all very similar, the main difference is in the data input. That is very much an over-all statement. On any individual occasion any one forecast may do better than the others. There will also be some gains on some occasions due to use of finer scale topography. On other occasions this gain will be lost because the meteorological input is less good.
The Greek Met service numerical model output should be as good as Weather-wise and the GFS, may be a little better at the higher resolution forecasts.
In practice there will probably be little difference in general terms berween all the various services. Preferences are often a matter of presentation and ease of use. For me, zyGrib is the easiest to use. I like the viewer. When I get output by email I still use the zyGrib viewer although some may prefer the Ugrib viewer.
I am always sceptical of the real value of high resolution forecasts because of the short lifetimes of small weather detail. To me, it always seems better to use global model output, especially with their current grid lengths, remembering that all models tend to underestimate stronger winds. To which you should always add your experience and judgement.
That is the message that I give in Reeds Weather Handbook.