Hi there,
New-ish member here, been lurking for a while in a futile attempt to try and learn a bit before posting!
I've got two beginner's questions relating to the legendary Greenland high. Firstly, I noticed this chart posted earlier this evening on the Model Output Discussion which I thought looked quite unusual. As I understand it, the "T" stands for Trough and signals an area of low pressure, yet there are several "T"s marked over Greenland and one over Svalbard in areas showing some of the highest pressure on the chart, over 1035MB. If I'm right, and these are troughs, what weather would you expect to find there at the time? Normally I would associate a trough with precipitation, however surely pressure at this level would inhibit convection so you might just get a bit of drizzle (in snow grains)?
This leads me to my second question! Quite often I notice that when the charts show Greenland highs, the isobars seem really tight in comparison with the type of high you would normally see over the UK, Azores or Europe. At a glance and without the figures the 1048MB high in this GFS F.I. chart would look to me more like a low pressure system (which may sound silly, but bear in mind I'm a complete beginner). Is there a reason why these type of highs tend to form over Greenland and not the UK? I appreciate this isn't a great example as I'm sure I've seen charts in the past with much tighter isobars, but hopefully you get the point.
So... putting these questions together, my basic knowledge leads me to the contradiction that in Greenland you could still have snowy and windy weather with the pressure at 1040MB?
I'm probably the only person on here wondering what is happening in Greenland and not the UK when looking at these charts! And now, having shown my ignorance, I'm going to hide in the corner again!
John