KS, I hope you don't mind me asking such a broad question, is predicting UK weather harder than for some other areas?
Well, I've only predicted the weather for the UK and for the Falkland Islands (and soon for Ascension Island) so it's hard for me to tell if it's harder elsewhere.
The UK has more changeable weather than other countries because we're an island and we have air masses coming at us from all directions - there are 6 different air masses which affect us and all of them bring different types of weather. However, if we know which air mass is headed our way then we can get a good idea of what type of weather we'll get, just by looking at a pressure chart.
Once we know the air mass then we can look at the real-time weather using both manual observations (someone monitoringg the current weather at their location all through the day) and automatic observations to see what's happening right now, plus model data produced by our supercomputer, to pin down the details and because our UK models are high resolution and we have hundreds of observations to look at, we can generally predict the weather pretty accurately (i.e. I can tell a pilot how many minutes it will be before a snow shower hits the airfield).
Other areas and countries have less air masses affecting them (i.e. continental US) so will have less changeable weather. However, they may have more extreme weather than the UK (tornadoes, hurricanes, much colder or hotter seasons). So it will depend on how accurate their forecast models are and how the forecasters work as to how accurately they can predict the weather.
Down here in the Falklands there's no Gulf Stream to regulate the sea temperature and very little land mass, so we also get very changeable weather (we get more sunshine than the UK, but snow is possible all year round) and pretty strong winds - on Tuesday this week it was snowing and 5 degrees, on Friday it was sunny and 16 degrees, but on Monday we'll have strong winds and snow showers again.
It's harder to predict and monitor the weather here than in the UK because we only have two manual observations (one done by ourselves on base and one by the airport in Stanley) and three automatic observations (mountain sites), available for the whole of the South Atlantic ocean. That's it. Apart from those five, there is no other real time information for hundreds of miles (unless the navy ships and RAF aircraft can give us reports from their locations), and with no rainfall radar either we're essentially working blind when it comes to the finer details.
We also only have coarse model data available... plus, we have antiquated technology and use more manual techniques than in the UK - we're still using Window NT and floppy disks at work, we have to manually type a lot of things that are done electronically in the UK and our daily sunshine hours are recorded using a glass sphere and a sunshine card (the sunlight hits the sphere and burns through the card). So, it's harder here to get the details and timings right - i.e. we can tell pilots that snow showers are on their way and may affect the airfield at times, but we aren't able to work out exactly where or when they will hit because we can't see them to track them.
