Ararat chase - 10/10/99

Andrew & Claire McDonald, Nick Sykes, Paul Yole, Jane ONeill

SATURDAY - 9/10/99

I guess I should start from the ASWA meeting that was held on 9/10. There was discussion at the meeting of the chance of storms Saturday night and again Sunday with LI's forecast to be dropping to about -5 overnight Saturday and bottoming out at -8 in the Western District at about 2pm Sunday. CAPE was also expected to get fairly high with a forecast figure of 2200j/kg also in the Western District. Clyve Herbert also said that a cut-off low would develop in the west by Sunday morning.

I was hoping for a few late afternoon storms Saturday but when nothing but showers had eventuated by 6:30pm I made plans not to go to Mt Dandenong and wait for storms and instead made plans to go to a party. Of course the law of sacrificing one chaser for all the rest worked like a charm and no more than an hour and a half later storms were firing up over the ranges with some nice lightning - about 1 strike every 20 seconds. I had 30 mins to spare before I had to go out so my dad, my sister and I jumped in the car and raced up to the local high school that has nice views to the N and NE. We watched cells move along the ranges with lightning becoming more frequent to about 1 strike every 10 seconds. The time passed so quickly and we soon had to leave (sorry Claire). I went off to the party and got home at about 1:30am with lightning still visible about 20km to my east. This cloud band full of embedded thunderstorms had me worried about the lack of heating for tomorrow, as it was not looking like clearing. I fell asleep to the sound of static on the radio at about 2am.

SUNDAY - 10/10/99

I actually set my alarm early so I could get up and check the models for a potential chase as I had access to a car (thanks dad) and I had all day to spare with the night off work as well. By 9:30am I was getting a little excited as the sat pic started to clear over near the western border with a few weak storms firing up near Hamilton and a few in the far east of South Australia. The 9am-weather bulletin showed temperatures cooler than I'd hoped except for Mildura which was sitting sweet on 21C with a DP of 18C. The radar showed one cell near Pinnaroo that had pink echoes (40-100mm/h) which was a good sign. I got the go ahead from Jimmy D. and it was on - CHASE!!

By 10am it was decided that Claire and I would head west in the general direction of Ballarat and Jane ONeill and Nick Sykes would follow a little while later. Claire and I set off at about 10:30am hoping that the conditions out west would be better than Melbourne. We headed out the Western Ring Road (thanks Jeff) and then onto the Western Highway. As we left home the weather was bleak with light rain and 8/8 cloud but the rain stopped near Rockbank but started as we approached Bacchus Marsh. We stopped for some food in "the marsh" to allow Jane and Nick to catch up a bit. After a 20-minute stop we continued W towards Ballarat where we met Jane and Nick in a servo at about 12:15pm.

Chris Gribben rang to inform us that a few yellow (10-20mm/h) cells were showing up near Ballarat and we confirmed this with some dark based Cu and a heavier shower of rain. Cloud was clearing slightly as we had a fuel and food stop (yes we ate again) at a service station just outside Ballarat for about 20 minutes. Chris Gribben rang us again and he informed us that storms were really taking off right on the border between Bordertown and Pinnaroo and he told us to head to Horsham and we should get nailed there. He also told us that at Mt Gambia SRH was 221. Woohooo - looking good so far. We could now see some clear sky to the W and some Cu towers passing over us during this stop. Jane and Nick had caught up to us and there was a passenger swap as we left with Nick jumping in my car and Claire jumping in Jane's car. We continued west towards Ararat and no more than 20 minutes later we were in clear skies. We could see some high based showers not too far to the NW and Jane stopped to take a photo while Nick and I continued driving. The sun came out and it was warming up nicely and soon we could see Cu and Cb's with some great solid anvils to the WNW and NW.

We pulled over in a farmer's driveway about 3km W of Buangor for some photos of these cells and to assess the situation. We could see 4 big cells all with solid updrafts to the NNW, NW, WNW and a distant one to the S. The shower which Jane had stopped to photograph had weakened as it passed just to our N and now was heading E with plenty of mammatus which looked great.

Mammatus at Buangor (between Ballarat & Ararat)
J ONeill (ASWA Archive)

We waited here for about half an hour just watching as the cell to the N sent up fresh updrafts. I got a view of the flanking line of the cell to the WNW which was moving towards us from N of Stawell and it looked to have some sort of lowering but it was too far away to make it out. We were informed that a Severe Thunderstorm Warning had been issued for the entire W of the state which kicked up some more excitement. Jane got even more excited when the BoM rang us (yes - they rang us) with information on the storms. They told us that larger than golf ball hail had been reported from Kaniva, Mildura and Bordertown confirming the Severe Thunderstorm Warning. After several hundred phone calls (well almost) to our 4 different mobiles we finally decided to head further NW to Stawell then possibly Horsham if need be. We got 5km up the road and saw a sign for a lookout to One Tree Hill which we headed straight for and we sat up there for about 45 mins.

Rain free base NW of Ararat
Photo - A McDonald

From here we watched as the storms approached and passed us (one weaker one to the S and a stronger one to the N which sideswiped us). It was interesting to watch the Cu over the Grampians get blown off by the outflow from the cell which passed to the S of us. Some interesting features were visible through the rain curtain in the cell to the N as well as a few nice CG's (which I hope were caught on video). We then waited to see the development on the back end of the cells to the N.

Cell passing to the north of One Tree Hill
Photo - A McDonald

Another phone call from the BoM informed us that a dry-line had formed in the NW of the state. We could see the whole line of storms firing to the NW each one further NW looking stronger than the next along the dry-line. Paul Yole and friend Peter joined us up there too. Within ten minutes of them arriving I was wandering around trying to get a better view to the N and found myself looking at an awesome wall cloud under a fresh updraft about 25km to our N.

Wall cloud to the NE.
Photo - A McDonald

Cell receding to the E
Photo - A McDonald

Melbourne Storm Chasers in action!!

After lots of yelling and screaming and videos and photos we decided that even though it didn't seem to be rotating it was looking very impressive with prongs and all. As it should, it became embedded in rain within five minutes but was still visible through the rain. The chase was back on. We all jumped in our cars and headed N towards it (sort of). Through the trees we got closer views of a new wall cloud which formed under the next new updraft but this one was less impressive than the first and didn't have the same solid look to it. The chase continued to Landsborough. Everything seemed to go slightly wrong here with the line of storms racing E and the cells to the N were getting too far away to chase as sunset approached. The road network didn't help either. From here we decided to head towards Castlemaine with new growth in front (E), behind (W) and spectacular growth along the line to the (N) which was awesomely lit up by the setting sun. I stopped a few times along the road to take photos of these cells which were exploding to the N with one overshooting the tropopause by at least 4000ft.

Beautiful cell lit by the setting sun.
Photo - A McDonald

The line of storms heading E was really moving (about 70km/h) and was pulling away from us after a few stops for food, etc and the cells to the N were too far away to chase in the dark. Upon reaching Castlemaine, Paul and Peter returned towards Ballarat and then home again to Murtoa (towards the new cells in the W) and our two cars continued home towards Melbourne. We stopped for a passenger swap and food again at a service station between Kyneton and Woodend (Calder Hwy) where we watched the W cells approach with some nice lightning and shooting stars to boot. We left there at about 8:40pm and I was home by 9:32pm - gotta love the ring road!

After a quick check of the radar I decided I didn't need to go anywhere to get a decent view of the line of storms approaching from the W. A cell went red (+100mm/h) for a brief moment almost right over the city and there was plenty of green and yellow echoes approaching me. I watched it pass overhead with a few CG's fairly close and some very heavy rain for a short while and two brief flurries of pea size hail. (It was pink on radar as it passed over me). I attempted a few lightning photos and luck wasn't on my side. The cable release is buggered and I have been too lazy to get it fixed and this made it very difficult and I missed two fantastic flashes - one huge CC and the other a tuning fork shaped CG with two prongs merging into one as they hit the ground. It serves me right for not getting it fixed. Total distance travelled by me was about 500km.

Thanks to all those people who took the time to ring us and undated us on radar, conditions and warnings.

*  Anthony Cornelius, Jimmy Deguara, Kathy Jolly, Clyve Herbert, Paul Yole and Geoff at the BoM. Thanks to * Michael Scollay for arranging the archived radar and sat pics.   Very much appreciated.

A special thanks to Chris Gribben (who was absolutely furious that he had to work). Chris rang us on a regular basis to keep us up to date on radar and any other information we required. There is always next time.

• Possible/probable lack of directional shear
• Possibly a lack of heating in the area we chased where the cloud cover took longer to clear.
• Dry-line in NW - seemed to fire with the best storms of the day. Maybe we should look into how and why they form and why it formed where it did and how to look for them.
• Probably should try and plan chases earlier so transport arrangements can be made and so that destinations can be reached before storms become too developed and difficult to monitor.
• Maybe there was not quite enough CAPE with the amount of Shear that was present. I think it would be good to find out actual CAPE figures and if possible the EHI ß relationship between CAPE and Shear.
• Also look at what LI's were - it seemed to me that perhaps the best area of LI's was where there was less heating and hence may've gone to waste.
• Upper Jet Maxima and Low Level Jet Maxima didn't coincide. LLJ max. was in the E of the state and Upper Jet Max. was entering the NW of the state.

SHOULD'VE / WOULD'VE / COULD'VE

• Found out temps and DP's while we were chasing and upon realising the lack of heating in the W, headed NW to warmer air. Heating seemed to be important in sending storms severe.
• Looked at models more closely Saturday night
• Worry less about others -  when chasing in convoy feel free to drive away from others if you want
• Set target area based on LI's, CAPE, wind profiles and strengths, FZL, moisture convergence, etc
• Make a list of factors to look out for while chasing (or at least to think about). Such as : outflow boundaries - the line of storms which formed behind us later in the day were possibly forming due to the outflow air lingering from line of storms), road networks, mountains, lookouts, maps with good detail.
• Plan to be in target area well before storms occur if possible - I think we were an hour or two too late.
• Try to get on W side of cells ASAP in order to get a better idea of development (if any). That way you can decide where to go and what to do.
• Find out the mean storm motion and speed for 2 reasons: easier to plot storm paths, and if a cell moves differently to the mean storm direction then check for possibility of supercell and rotation.
• Make a list of how long it takes to get from each person's house to a certain location (major towns). For example, it takes me 1 hour to Seymour, 1 hour 10mins to Ballarat and Kyneton, 1hr 30mins to Castelmaine, 2.5hrs to Ararat, 2.5 hours to Benalla - that way it's easier to plot leaving & arrival times.

MSL Analysis courtesy Bureau of Meteorology

IR courtesy of James Cook University