I am going through Phil´s Cold Front presentation once more. I thought I had got control of understanding all the stuff with backing/veering zero lines and associated cold and warm advections, but suddenly I found something that won´t fit in - at least not in my mind.
It is at slide no. 6 in the Cold Front presentation: At the doppler 1.5 PPI the backing and veering parts of the zero line is depicted. I understand that in the PBL the wind is backing and therefore cold advection is present. It is the explanation to the next part of the zero line towards the northwest, that I don´t understand. It is said "Strong Cold Advection - beam likely under frontal surface to here". As we have learned cold advection imply backing winds with height - but I can only interpret this segment of the zero line as veering with height, so shouldn´t it be warm advection? Am I right? Or else, please someone help me get my interpreting mind on track again.
