Med Weather forecasts.

poter

poter

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Still going south currently in Corsica for winter
www.fairhead.com
Its some time since we have sailed in the med. & looking at recent posts there seems to be a consensus that Med weather forecasts are reliable & frequent.

I used the very good Wing Guru in the past in the Gulf of lyons, which is subject to the Mistral, & have only been caught once in 5 years.

But we are now looking at Sardinia & further afield towards Malta & Italy, what are the reliable weather stations & is it worth getting a top class Navtex? I do have an old Navtex onboard but no decent info is received.

poter

poter
 
med Forecasts.

Hi Poter,
Answers to this one will probably be like weather forecasts themselves, numerous, wildly different and open to interpretation. But to set the ball rolling, based on six seasons taking us from UK to Turkey we've found:

Navtex - we've a bog standard NASA unit: Worth its cost ten times over as we've no mobile-phone internet, so in most anchorages its our first line of defence. We reckon that the forecasts, whilst compiled by different national meteorological offices have all generally tended to overstate wind strengths and usually forecast the approach of any weather systems earlier than they actually arrive; to be fair the system/service is aimed at offshore commercial vessels rather than coast-hopping cruisers so it probably does arrive earlier/rougher out there. The only areas we've had problems/frustrations with it have been Portugal - fetting a forecast was the exception rather than the rule and (not good for you) in Sardinia; all along the west coast we received the Rome broadcasts, which gave forecasts for the east but not west coasts of Sardinia and it was only when we got around the bottom and onto the east side, that we finally -too late then!- picked up the Cagliari broadcasts covering the west coast. The major downside with Navtex is there's not the 3-day outlook you get on the UK service (or at least it used to give one) it's just today and possibly a usually vague 12/24 hour outlook beyond that.

Windguru - We were introduced to that in Portugal, by a local Harbourmaster as it was apparently "much more accurate than the **** our National Meteo faxes us every morning" and we have to agree with him, for coast-hopping we've found it consistently good all the way around Portugal, S Spain and through the Med. The similar 'Windfinder' website we've found to be rubbish, though I'm sure that at least one of the next half-dozen posts will say just the opposite. It's definitely an 'inshore' forecast only though and we don't give it much credence if we know we'll be going more than 5-6M out.

Passageweather - This along with windguru has been our mainstay through the Med; seven (or it may even be ten?) day outlooks which we've found to be consistently accurate for at least the first four or five days, we use it whenever we're going offshore or making a long passage and haven't been let down yet.
 
But we are now looking at Sardinia & further afield towards Malta & Italy, what are the reliable weather stations & is it worth getting a top class Navtex? I do have an old Navtex onboard but no decent info is received.
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When actually cruising you won't have the internet, and not often in harbour either!

My first source is always Navtex, the Split fcst for the Adriatic is particularly good.
I upgraded to a Furuno set last year and it's a big improvement, I recommend you do too!

The Italians broadcast continuous VHF fcsts in Italian and English, which are a reasonable guide.

I also use RTTY from Germany, which gives a five day fcst but reception is not great at least with my Nasa set.

Last but no least the Italian papers often have good synoptic charts.
 
If you have a wifi conection before moving on a day (or a long passage) then take a look at www.grib.us. You will need to load Java (www.java.com) on your machine to run their software. You also need to sign up but the service is free.

It uses the same GFS data as Windguru but is in different format. Rather than spot points it gives a 'box' area that you define with your mouse. We love it.
 
BobandLesley,

Navtex has 2 channels 490 and 518. Are both used in Greece or is it only 518. I ask because my ariel packed up on 490, but receives 518 happily, so if I don't need to buy a new ariel for 490, then I won't.
 
We used this
http://www.meteoam.it/
when we were in Sardinia and up until we got into Greece. I found it very good, as accurate as most of the others and updated a few times a day (it also has English pages as well if you don't understand Italian)- I'm told its the civilian bit of the Italian military site.

Other than that, I used gribUS and now trying out zyGrib, which at first glance seems pretty accurate. Passage weather works as does the mailasail one. All the data comes from NASA so its just down to an interpretation of the site owners and how much sponsorship they get as to accurate the info is. But so far they have all performed well for me.

We also have an old NASA target pro plus NAVTEX but I don't rely on it, as the signals don't seem to good when anchored around islands etc.
 
We found the Italian VHF transmissions to be reasonably accurate. Navtex is a transcript of the Italian waters parts of it.

French Navtex can be received along most western Italian coasts. The accuracy of their forecasts seems to be excellent, with good advance warning if big blows are expected. Like this:
P1000926.jpg
 
Almost all forecasts are just various presentations of the same model data, circumscribed by the number of words which can be used. Weather forecast areas are necessarily large, so timing of bad weather is when it first hits the area, and maxima are the maxima expected within the area over the time period. Most Navtex and VHF suffers from these limits.

Presentations from data files (like GRIB) can be more precise, but this is mainly a matter of presentation, rather than reliability.

Yes, forecasting is reliable in the Med, but you must personally allow for big local variations due to terrain or diurnal heating.
 
Weather forecast

we use Navtex, radio and various sites, many of them mentioned here (though passageweather is new to me and looks particularly enticing). The free bit of theyr.net is also user friendly and on the Atlantic coast we loved magicseaweed.com. So far, the natioanl forecasts aided by windguru and theyr have tended to be good enough most of the time.

The most difficult place we have ever found (not that we've been far compared to so many on here!) is the Ligurian sea and the Gulf of Genoa. We found this much trickier to forecast than the Gulf de Lyons where essentially you just want to see if any depression is about to funnel down the Rhone or roll in from S biscay. But in the Gulf of Genoa, you need to look at that mistral-generator, what's happening NE of the Alps and at the sirocco impact as well, to geta real sense of the future. This volatility translates into a wider variation of weather forecasts and grib models that we have seen elsewhere. Here the Navtex/VHF italian forecast was reasonably accurate but very short term, with only 12-24 hour predictability.

We were there for about 4 weeks, and it was a good opportunity to bone up on the generators of weather again, rather than looking at the gribs and thinking that I'd got all the picture.

Mobile internet does really help, but the radio and vhf, and if you wish weatherfax downloaded off your SSB will be sufficient and accurate.
 
Got to agree with all the posts. It's all in interpretation of what you are seeing and hearing. From Portugal to Sardinia we found Passageweather to be pretty accurate for the longer passages. Local weather forecasting was entirely different. Invariably, regular afternoon sea breezes are NEVER forecast but can be expected at any time if it's sunny and upto F6/7. So a day sail of 40 miles somewhere can make for some interesting sailing. I guess that reflects the comments about Windguru which I personally don't rate. However if you expect more wind than forecast then you'll be prepared. If the wind doesn't arrive either treat it as a bonus and/or relax and go swimming !

The Italian continuous forecast is never less that 6 hours old and accurate and deals with much of the western Med. but it takes time and patience to get the hang of what "she's saying - even in English. Local papers, radio etc are a good source for next day stuaff and of course all those other sailors you'll meet up with.

We also use GRIB occasionally (raise the wind figures by as much as 20 - 20%) but still prefer Passageweather as those guys have already interpretted for you !

You'll get on just fine but I'd recommend not hitting the Madelanna Islands in Sardinia in August unless you want an experience much worse that sailing in the Solent on a hot saturday afternoon in the summer........
 
We use GRIB files a lot for planning long passages and find them fairly accurate. What they are not good for is inshore, particularly the Med. Each wind arrow is 20 miles apart and the Med geography (mountains etc) has an enormous effect on local weather.

We even found the Greek area forecasts were inaccurate at a local level.
 
Adriatic weather cycles

I feel in the Med you must try and follow the weather cycles. It does help understanding in the Adriatic certainly in the summer, if you track the troughs and highs altho the pressure variation is very small. Troughs tend to form over northern Italy in the summer giving usually light to moderate SE/SW winds in the Adriatic , great going north and tedious going south. They don't last long tho, and when the next ridge pushes the trough away, the wind swings quickly round to the NW/NE and initially can be quite strong. This doesn't last long either and then a calmer period with just afternoon NWesterlies sea breezes can last for some time b4 the next trough forms.

I'd be interested to hear about cycles in other areas, especially the Aegean where I feel I must visit b4 too long.
 
Also found navtex pretty reliable on fairly bog standard receiver throughout France, Italy and Greece. As always there are odd places and times when it throws out gobblydegook. Recommend Poseidon System for Greece if you have internet access on http://www.poseidon.hcmr.gr/ Superb colour graphic representation of wind strength and direction. As already stated - they are all I think based on the same basic information.
I'm glad somedbody else had trouble deciphering "metal Michelle" of the Italian VHF forecast - worth persevering but deep concentration required!
 
Navtex/HF aerials

Can anyone help with this query ? I have a Nasa Target HF receiver for RTTY etc but feel I need an active aerial to improve reception however I am planning to replace the Navtex with a new one and was wondering if the HF aerial which covers 30Hz to 300Khz will handle the Navtex signals without problems. I would obviously split the signal with a splitter to feed both sets.

Has anyone used this set up with success ?
 
rascacio said:
Can anyone help with this query ? I have a Nasa Target HF receiver for RTTY etc but feel I need an active aerial to improve reception however I am planning to replace the Navtex with a new one and was wondering if the HF aerial which covers 30Hz to 300Khz will handle the Navtex signals without problems. I would obviously split the signal with a splitter to feed both sets.

Has anyone used this set up with success ?
Click to expand...

I get a good signal for RTTY on my Nasa Target receiver by connecting to my uninsulated back stay. I then purchased a Weatherman to save the hassle and to get forecasts 24/7. The Weatherman came with a active aerial but results were real bad, so i connected the Weatherman to the back stay and it works a lot better (although not as good as the Target). So unless i was supplied with a faulty active aerial from new, i think they are useless.
 
Med Weather

You can see a list of Navtex stations in the Med here: http://www.pcnavtex.com/AboutNAVTEX/NAVTEXStations/NAVAREAIII/tabid/69/Default.aspx
Note that, contrary to what has been said before, they transmit on both 490 and 518.

Regarding thew various GRIB forecasts, even the high res ones like Passage Weather cannot reliably forecast thermal winds, be it the Mistral, a thunderstorm or a sea breeze. The grid size used is simply too large. An alternative approach is to look at weather reports ion the area to see what is happening - our SmartMet offers this in Europe with a variety of land stations, weather buoys and QuickScat satellite-measured wind data - see http://www.smartcomsoftware.com/smartmet.html

Tim
 
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