SPECTACULAR PYRO CUMULONIMBUS AND ISOLATED STORMS - JUNE 20, 2001

Very cold air aloft and reasonable surface temperature and moisture made the atmosphere unstable through much of the eastern half of SE QLD on this day, but the heat generated from a small fire on Bribie Island during the afternoon made the atmosphere extremely unstable directly above the fire, and a spectacular Pyrocumulonimbus (a storm cloud which develops above a fire) developed.  The updrafts billowed into the atmosphere with such force that it gave the appearance of a Volcano erupting!  It even produced it's own rain! (observed on radar) and static was heard on AM radio several times so it could have been producing it's own lightning, although there was a storm to it's WSW and it was impossible to tell where the static was coming from.
 

Showers and thunderstorms also developed in other areas.  A summary of the day at Coomera from Jason Rainforest is below.
 

What a surprise!! Storms in Winter? Bring that on ;). Today started like a normal Winter day, slow to warm up, cloudless, and relatively boring. Storms were the last thing on my mind..

I did notice however, around midday, rather interesting congestus formations. The tops were folding over themselves like mushrooms. I didn't take any pics as getting Emperor and Quake 3 working in Windows seemed more important at the time. The congestus persisted to early afternoon.

I drove to work around 1pm, nothing interesting to see. By 2:30pm though, while I was mowing, I noticed a nice shower to my SW. Last time I mowed something very similar happened (hehe, that'd be right ;)), but I didn't expect a low topped hail storm today. Think again..

The shower intensified and developed something resembling a gust front, and had a nice RFB (rain-free base). There appeard to be some rotation/swirling in this base, which was rather interesting. At one stage I detected a green tint. The shower moved closer, still developing. It started to rain.

The drops were very large. I thought there may be hail in this shower. The rain came in waves for a while, then stopped. The shower moved south of me.

I was disappointed slightly, but as I continued to work, *bang* .. Thunder!!! Now this I didn't expect!. I counted up to 14 occurences of thunder, then it became continuous. At this point, I started taking pictures and recording audio clips..
 

Click on any of the thumbnails below to see a full sized version

                                     

                                                    

Thunder MP3's - all between 100 and 260k
 

I wanted to leave work at this time, but I couldn't. After work, I went to my lookout to watch the storm go offshore. There was some nice lightning in it. When I got home, mum told me that we got pea sized hail from it, I just missed it at work! She didn't save any for me in the freezer, though I did ask her to do so in future.

What a great way to end a day! Need more of these :). 

The first photo below was  taken by myself from Redcliffe, looking SSE late in the afternoon (great structure!) and the second at sunset from Mt Cootha by Greg Curtis.

There were several other reports of small hail, including one from Steve Baynham of pea sized hail for 5 minutes at Currumbin along with strong winds and rain heavy enough to cause some local flooding.  Cabolture also recieved 20mm in 20 minutes from a storm mid afternoon (click here for a photo of this storm approaching Cabolture).