IMHO, Skyseeker is making the classic mistake of reading the TAFs to the exclusion of other sources of weather data. It's a mistake I used to make too.
Two things are important to know about TAFs:[list=1][*]They're not really aimed at VFR pilots. Why else do you think they fail to report visibilities above 10km, and are only available at airfields that have instrument approach procedures?
[*]They give a forecast for the
immediate vicinity of the airfield.[/list=1]
The second point often leads people to misinterpret things like "PROB30 TEMPO 1316 SCT020CB". What this actually means is that there's a 30% chance of a CB going
directly overhead the airfield (or very, very close). It certainly doesn't mean that there's a 30% chance of the whole sky being covered by scattered CB's over a wide area. Also, "SCT" means 3 to 4 oktas of cloud cover, which can easily be provided by a single CB. A TAF gives you a view "through the microscope" of what's going to happen in the 2.5 mile radius around the airfield - useful to have, but it badly needs to be put into context.
This is why you should look at Metform 215, which is the best form of weather data aimed at VFR pilots. This will give you two very important pieces of information that do not appear on the TAF/METAR:
- Visibilities above 10km. It makes a big difference if you know the vis is going to be 30km - you'll be able to spot those CB's from miles away and will have plenty of time to think about your route to avoid them.
- The Metform will usually say "ISOL" (isolated) when the TAF says "PROB30" where CB's are concerned. IMHO, "isolated" is a much more descriptive way of thinking about what's really going on.
When you see a PROB30 (or 40) for CB's, you should expect that there definitely
will be CB's around, but they'll be well separated.
So, just because you saw blue skies all day doesn't mean the TAF was wrong. If you'd been up in the air, you'd have seen that the 215 gave a very accurate picture of "isolated" CB's.