Originally Posted by
mad_jock
So do you just pick the nearest field and use that?
I am not having a go at the way the US do it just trying to figure out how it would work in the UK going North South at FL160 and a 30mb gradient as per hurrican bawbag gave us. Maybe use the regional QNH's?
it would be quite unusual (other than right near the hurricane) to have more than about 1mb per 15 miles. So you wind up picking up weather info as you pass airports, from flight following, from a FSS, etc. If you are going to fly a couple of hundred miles into a low with no weather stations, first, there will be no CAS around (otherwise you would have a weather station) and second, you need to heed the PPL advice in the AIM of 'high to low lookout below' and be extra cautious on terrain separation altitudes (but you are VFR after all so can see the terrain or the top of the cloud).