Practical Meteorology question....
Just a quick question guys which has been bugging me and severla colleagues for some time now. On the UK Sig Wx charts where a jet stream is present with an area of CAT, just below the indicated height of the Jet, eg FL370 there is some text below for example (-70/+130). Just want clarification on what this means, as so far have had about ten different explanations..
Rgds
JetJockey 