Met Pressure Charts

Haven’t had the need to look at these for a few years as I haven’t been sailing. OK I understand the warm, cold and occluded fronts but what are those heavy black lines (not the isobars) - New to me
http://www.metoffice.gov.uk/weather/charts/index.html

That’s what it looks like to me

/edit It looks like we’re getting a Hurricane coming at us from the south west :eek:

Thanks Droid :amstupid:.

Yup certainly looks like it untill you realise that depression is nearly the size of the Atlantic. Defo some nasty stuff coming in though