longwinded said..
Fuzzy memory of meteorology course taken many moons ago has high pressure cells as air moving downward and low pressure as air moving up. Actual number is arbitrary as to the designation of high or low.
Yes warm rises and cools as it climbs. It then moves southward and then descends as a High pressure system.
Because it's cooled air it's more dense therefore it weighs more thus giving a higher pressure reading.
Agreed the number is somewhat arbitrary. However in the day 1013+ was nearly always the reading which designated a high and below that a
Low as it was then seen to be the average of the Highs and Lows. Not so over the last few years.
Pugwash said "Highs that used to cross Aussie are further south and weaker".
Yes I agree in the 80's and 90's I'm sure that in summer High centers were once further North in the 30-35 degree latitudes in summer.
Now they mostly are centered in the late 30's or mid 40's.
