The only readily available GRIBs all come from the US GFS. Alternatives are NOGAPS and the Canadian model. These are unlikely to be better than the GFS.
Cheapest way of accession is via email
from Saildocs or MailASail. Good for emails over cell phone
or over HF.
access, zyGrib is reliable, fast to download and has many options. It is a better service
, better topography, chart projections than UGrib. Particularly useful is the CAPE parameter - an indicator of thundery activity.
PassageWeather, Windfinder, Weatheronline etc require broadband
access and all suffer from problems in saving doe future reference.
These all give the same GFS data. None is better than another.
Meso-scale forecasts are another matter. All the models in use are capable of predicting small scale weather. However, there are always problems because of uncertainties in analysis and the short lifetimes of small weather features.
The larger Met services eg the US, UK, France
are the only organisations that use good detailed meso-scale analyses, as far as I know. The US COAMPS is only available in a few areas – around the US and in the Mediterranean
. It is available from Saildocs via email
... The UK meso-scale model is available on Weatheronline but not in GRIB file form.
Weatheronline is the only, to my knowledge,useful ie easily usable source of output from the UK Met Office numerical weather prediction model. This is comparable to the US GFS. Them, they act jointly in providing the two World Aviation Forecast
The major Met services use these in a probabilistic mode by running model ensembles. That is they put small variations into the data and run the model many times. It is unsafe to use any meso-scale model in a deterministic sense.
My experience, broadly speaking, is that the GFS give generally reliable guidance to 3 days ahead. Day 4 is rarely dangerously misleading. After that there is skill but it decreases rapidly. I would not like to make a critical decision on the basis of a five day forecast
. We plan on a 3 day basis with a good long look at 4 days.
To see more, go to Frank Singleton's Weather and Sailing Pages / Franks-Weather | The Weather Window