The air had dried out significantly due to warm, drier westerlies pushing into SE Queensland.  However on Thursday the seabreeze pushed through and signalled the advance of the trough out to sea that had brought the storms a few days earlier was retrograding inland.  DPs were increasing into the high teens/low 20s on the coast, while that evening the Downs DPs soared back into the mid teens which was a good sign!

Friday morning looked and felt nice, no ACCAS as such but some mid level cloud that showed some of the instability.  The only problem was that the DPs in the Downs began to fall quite quickly, by 9am they were down to 10C due to mixing!  But that didn’t end up mattering (I think Toowoomba’s DP fell to 5C at one stage during the afternoon, but there were still storms in the area!)  And no wonder too, the 9am sounding was INSANELY cold, with -18C @ 500mb!!!  With temperatures in the SEQ plains pushing into the mid 30s with PBL weighted DPs in the mid teens that saw LIs drop to around -10/-11 with CAPE pushing 2500-3000, so it was extremely unstable!!!  Had the 200-300mb ridge not moved closer over us the night before, CAPE would have been in excess of 3000!

The only problem was shear, it was rather weak (but adequate to keep storms alive).  15 knots NW at 850, 15 knots NW at 700, 20-25 knots W at 500 and 80-90 knots WNW at 300, so there was some movement up there!  Clearly though with the intense instability, severe storms were well on the cards and the Bureau issued severe thunderstorm advices accordingly for all of SE QLD and NE NSW late that morning.

I had to go to uni in the morning to sort out some assignments (and a thesis due the following week)…some dry Cu was developing on the ranges but it was going to be a while yet before anything really took off.  The cap didn’t really break until after 1pm – to which is broke in spectacular fashion on the Brisbane Valley!