Weather forecasts in western Med

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Spuddy

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Thanks for previous tips on pilot books. I could now do with some pointers to weather info sources.
English language radio would be good.
And also, which of the multitude of internet sites have Med sailors found to be reliable?
Thanks for any help chaps.
 
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The best bet for the weather that we've found is using one or other of the sites which enable you to download grib files - ugrib or zygrib for example. The forecasts are reasonably detailed, give you up to a week in advance and we're found them to be reasonably accurate, especially when only looking up to 3 days ahead. The advantage of them is that you only need download a small data file rather than the somewhat larger files from the specialist weather sites and as its a downloaded file, you can review it as often as required once downloaded.

The grib files all require a viewer to be installed on your pc. The viewers are free, as is the data; just google zygrib and you will find a step by step set of instructions on how to install and use the programme.

Also found that navtex is a good source for the 'official' forecasts broadcast by the local coastguard or equivilent.
 
I have found bouyweather.com to be very good, highly accurate, with wind and wave height info as well, you can get 2 day weather forecast for free or 79 dollars a year for full 7 day ones. Hope this helps.
 
duncan99210 said:
The best bet for the weather that we've found is using one or other of the sites which enable you to download grib files - ugrib or zygrib for example. The forecasts are reasonably detailed, give you up to a week in advance and we're found them to be reasonably accurate, especially when only looking up to 3 days ahead. The advantage of them is that you only need download a small data file rather than the somewhat larger files from the specialist weather sites and as its a downloaded file, you can review it as often as required once downloaded.

The grib files all require a viewer to be installed on your pc. The viewers are free, as is the data; just google zygrib and you will find a step by step set of instructions on how to install and use the programme.

Also found that navtex is a good source for the 'official' forecasts broadcast by the local coastguard or equivilent.
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I'd second that - but using grib does require a little meteo knowledge which the sites don't demand of you.
 
After trying many different sources I have settled on UGRIB as a source that gives a decent prediction far enough forwards and is remarkably accurate. I have been amazed at the accuracy of their 7 day predictions. Whilst it doesn't really cater for very local conditions, I have found this to be a minor disadvantage.

http://www.grib.us/
 
Spuddy said:
Thanks for previous tips on pilot books. I could now do with some pointers to weather info sources.
English language radio would be good.
And also, which of the multitude of internet sites have Med sailors found to be reliable?
Thanks for any help chaps.
Click to expand...

Basically, there are two choices that are not mutually exclusive. First to use GMDSS services either received by radio or the Internet. Links are at http://weather.mailasail.com/Franks-Weather/Mediterranean-Marine-Weather-Forecast-Texts. You will have to learn a few basic words but that is not too difficult in print.

Secondly, use one or another of the various objective forecasts direct from a numerical weather model. There will be little to chose between these, You may as well use one of the many GFS products eg zyGrib, Ugrib on a PC, Weathertrack, Weather4D, PocketGrib, iGrib, MobileGrib depending on your liking or not for the displays and your device. These, for the most part, are all the same data using the GFS although some do have a choice of model g COAMPS.

More detailed NWP output is available from, such as,

http://www.lamma.rete.toscana.it/modelli/vento-e-mare
http://www.puertos.es/oceanografia_y_meteorologia/redes_de_medida/index.html
http://www.puertos.es/content/prediccion-del-oleaje-mapas
http://poseidon.hcmr.gr/weather_forecast.php?area_id=gr
http://prognoza.hr/nauticari_e.php?id=jadran&param=uv10_&it=03

Some of these start from the US GFS. Some start from the ECMWF as a basis.

I doubt that there is any real difference between them some will look prettier than others. None has any human interpretation or assessment of the forecasts generated. Use whichever you like best.

ALWAYS know what the GMDSS forecasts are saying. They are written by meteorologist using computer models, probably more than one. They will contain warnings of severe or hazardous weather, as the name GMDSS implies.

Personally, I found the combination of GFS and GDSS plus a modicum of commonsense to be the best option rather than look at some of the Mickey Mouse presentations, particularly when I do not know their provenance. It is unclear whether some are simply interpolated from the GFS 50 km grid or are using some model such as HIRLAM or ALADDIN....
 
Depends where in the Med. But in the Golf de Lion all the usual candidates such as passageweather, windguru, windfinder are often spectacularly wrong. You need to check with the grib files and the official weather forecasts on Navtex and VHF and get used to working out yourself what is going on and what is the risk of severe weather.

The usual sites which just give the weather for a single site are very wrong because sometimes the weather system did not move quite as much as expected - or a bit more than expected. Hence the need to get an overview to understand the big picture.

I would not trust a windguru forcecast for Cap Bear for calm winds if I see a F9 on the gribs only a few miles away.

Also talk to the locals - they seem be able to predict what will happen during the next 24 hours far more accurately than forecast.
 
michaelchapman said:
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The usual sites which just give the weather for a single site are very wrong because sometimes the weather system did not move quite as much as expected - or a bit more than expected. Hence the need to get an overview to understand the big picture.

I would not trust a windguru forcecast for Cap Bear for calm winds if I see a F9 on the gribs only a few miles away.
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You are certainly correct about WindGuru and Cap Béar. WindGuru is simply an interpolation from the GFS 50 km spaced GRIB files. By the same token, your usual suspects are GFS or based on the GFS.

Remember that no model can define weather or topography of size less than about 5 grid lengths. A number of meso-scale models use grid lengths of around 10 km. Therefore, they cannot analyse weather features or topographical ones of less than 50 km – 25 NM.

There are some models that use shorter grids. The problem then is how well do they analyse the initial data and, more importantly perhaps, what is the lifetime of small weather details. For example a large thunderstorm cloud has a total lifetime of about 6 hours. That is a serious limitation.
 
JamesFrance said:
My two favorites are these:

http://www.passageweather.com/
http://www.windfinder.com/forecast/san_carlos_de_la_rapita

Both give good forecasts at Sant Carles and can be used for most parts of the world. Passage weather has a detailed page for the Baleares as I think the site owner is a yacht skipper based there.
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In the past I have been a fan of both of these sites but over the last couple of months I worry that they have switched to using the entrails of goats to predict the weather along the Costa del Sol?

E.g. Last weekend I believe we were promised gentle f1/2 in Estepona Marina. Actual: F4/5 gusting 7 - Ships cat refused to venture out to harass the local seagulls, and more seriously, I spilt my gin & tonic!
 
Wow, I have to agree with the last few posts. Why bother with forcasts as they are polar opposites 50% of the time. If it calls for calms, batten down the hatches! What we used was windfinder, which is exactly like windguru. Ugrib is nice to use the anamation feature.
 
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