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STORMPLANET - Severe Event Reports
Storm Chase!! NSW Synoptic Summary – 24th and 25th January 2004 A stalling trough over NSW was capturing everyone's attention and late on Friday I decided to target the Hunter Valley region of NSW for the weekend.... The weekend was nothing out of the ordinary for NSW in summer, with a surface trough developing along the northwest slopes and central ranges on Saturday. Dewpoints were up in the mid to high teens to the east of the trough, and down into the low single figures to the west of the trough – which set up a classic dry line scenario along the ranges. An added luxury to Saturday was not worrying about any sort of inhibitor as the entire state remained cloud free and caps remained shallow as cooler air pushed through with an upper trough, which was located on the coastal strip of the state late Saturday. The shear profile in the mid and upper levels to the east of the trough were ideal for severe storms, as mid levelled winds (the steering flow for the day) pushed 30-40 knots from the west/northeast, and upper-levelled winds strengthened to 50-60 knots from the southwest. With cloudless skies, a trigger, and that upper trough along the coast, updrafts didn’t have to work very hard to kick storms off closer to the ranges. Severe storms did develop in that atmosphere, with lifted index up around –4 to –5, locally higher along the coast. My Saturday target area was suffering however from low surface Dew Points and this was the major reason why I observed short-lived pulse storms as opposed to organised and structured cells. Sunday was very similar to Saturday, though the trough contracted northwards and closer to the coast and upper winds remained at 40-60 knots from the west/northwest. An upper trough was moving into central NSW, turning winds westerly at 500 hPa. The heat trough was now as far south as the Hunter, and was extending northwest from this point. A front was steadily moving up the NSW coast and was bringing a southeast change with it. The visible satellite image sensed low cloud already speeding up the coast, and was against the South Coast and Illawarra by late morning, nearing Sydney by early afternoon. The inland region was still under minimal cloud and storm potential was still very high, especially ahead of that change. The day was all about timing. In the end, the coastal strip south of the Hunter was dead, whilst storms lit up the lightning tracker north of Sydney, and southern, central and northern tablelands/ranges. Lifted index managed to get as high as –10 across central district, but on a whole around –6 to –7. Grateful appreciation goes to Scott Nugent for writing above summary.
Synoptic Charts
and Satellite Loops
(click to view) Original
Source:
BOM
IR Satellite Loops (click to view)
2.30 a.m. and off I go! Yes it's early but the idea is two-fold; get the jump on the long weekend traffic and also, to reach my initial target point of Dubbo by midday, I had to leave at this time! The route I took was as follows (click on map):
I travelled via Yea and Seymour and on to the Hume Highway to Albury, arriving at 0545 hrs. After the compulsory Maccas in Albury (waited 15 minutes for the 0600hrs opening!) I moved on to Wagga Wagga via Henty and The Rock, then to Junee, Cootamundra, Young & Cowra. It was nice to go through The Rock yet again, having observed a nice supercell at one stage form here back in October 2003. From Cowra I tracked to Orange via the Mid-Western Highway, through Blayney & Spring Hill. By midday I had reached Molong and started to take more notice of the sky. At Orange I had stopped to observe some convective activity in the area and whilst it was evident that some cells were breaking the cap to my east this was largely due to lifting over the ranges. I measured surface Dew Points at various intervals from Orange for a while and clearly more surface moisture was needed if any serious activity was to occur where I was. It also seemed that the cap would break late in the day and I now expected to see the commencement of some action from 3.30 - 4.00 p.m. Behind me I noticed I had left a very nice looking cell, I positioned the cell to be around the Cootamundra region and from Orange, where I had stopped for lunch, it was a pretty sight but I decided to stay on track and keep heading NE. Here's what I saw at 12.25 p.m. from Orange:
Telephone updates were coming in from Scott Nugent and Anthony Cornelius indicating that the better DP's and potential would be further NE, so I set my sights for Wellington, expecting to either travel further north to Dubbo or NE to Gulgong and Coonabarabran. I stopped along the way and at 12.40 p.m. watched a couple of TCu cells nearby that were high based but had potential. Over a ten minute period I witnessed three small funnels, one is shown here, unfortunately they were short-lived and not that easy to capture well on camera. The sky near Goolma was filling with TCu's but as you can see, high bases with DP's in low teens:
At 1.30 p.m. a pulse storm near Mudgee caught my eye and it had some nice updrafts and a much lower base than others witnessed earlier, I could clearly see the outflow region and it appeared to be producing very heavy rain:
Video 1 (3.5Mb) shows this cell as I drive towards it and stop to capture. Note the CG at the 54 second mark. Video 2 (1.7Mb) shows the same cell from a closer position, on the move. Below is the Aqua/MODIS satellite image at 2km resolution (clickable) from Saturday, 0400 UTC (1500 EDT). The image is also available at 250m; 500m; 1km; and 4km. Beware that the images are very large!
By 3.00 p.m. (when above Satellite images were taken) I was heading towards Cassilis after passing through Gulgong, having not been able to catch up with the cell that passed over the Mudgee area. My observations in Ulan indicated that the cell had some moderate outflow winds due to leaf and small tree litter scattered on the road, large puddles were observed but no sign of any hail. Between Leadville and Coolah I found a good vantage point and decided to sit it out, obs were 33/13 and there were some promising cells approaching and to my north, east and south-east:
After sunset I was reviewing the day's video when out of nowhere (so it seemed) an almighty flang (flash of lightning accompanied by an immediate bang)!!! I raced outside to see a dark and thick downburst heading towards me as CG's rapidly bore down. I had been outside and conducted an observation not more than 20 minutes earlier and nothing of interest! This cell was moving rapidly and produced a downpour, some decent outflow winds and lots of lightning. I grabbed the gear and took the batteries off the chargers etc, raced to the car and drove north to get out of the now torrential downpour so as to video the cell and be in a safer position rather than being surrounded by CG's as I was at the motel. Within minutes I had set up and started filming when a CG bore down on overhead powerlines approximately 500 metres away, as seen in this video (160kb).
After this cell had passed over the area I noticed that the horizon, particularly to my NW, North, NE & East was becoming busy with lightning, mostly filled with sensational strobing lightning in the upper parts of the storm cells with some anvil lightning and cloud to cloud lightning, plus an occasional visible CG and cloud to air. This show continued far beyond my ability to remain awake, I watched the display in the serenity and beauty of the countryside with stars shining overhead, packing up and heading back to the motel around midnight. Having been awake for 22 hours and driving 1280 kms I thought I had made pretty good use of the day! The lightning show was too far away to capture on film but I have included a few stills below as well as a short video sequence taken during the evening. Many thanks to Scott Nugent and Anthony Cornelius for the observations during the day and to Jimmy Deguara for his evening update. 35mm Scans:
Video stills:
Few seconds of video sequence here. (167kb) Breakfast arrived at 7.30 a.m. and as I was drawing up plans for the day I was again startled by very close thunder! I knew that the surface moisture would be higher this morning following last night's events but I was not expecting any residual activity before the day's heating set in so soon! Again a rush to get the gear and race off to observe what was going on! I drove a km or so up the road and saw that the offending cell was surprisingly small and producing light rain. A few more CG's were observed but the cell soon moved on. I was delighted by one particular cell to my NE that had a terrific domed anvil contrasted against a clearing sky. I was able though to photograph this and some other cells east of Mudgee as per below and also shot this video (1.9Mb):
After showering and paying my bill, I had the Hunter in mind. Scott Nugent had provided me with some useful observations and trough positioning etc and I had Muswellbrook in mind. This morning I had also spoken with Jimmy Deguara who was leaving home in Sydney to chase the Hunter as well, with Brett Vilnis joining the chase in his vehicle. We agreed to rendezvous at Denman so I was soon on the road hoping for a good day. I was concerned about the potential over-estimation of today's setup from some of the models and the cloud was not clearing towards the coast as quickly as I would have liked. At 9.40 a.m. I caught sight of a nice cell that was positioned somewhere over Wollemi National Park, as per this video (3.1Mb) (note the CG at the 1:08 interval). The cell seemed to have some really interesting base features and I would have loved to get closer but poor road networks in the area prevented this. I was particularly keen to see the lowerings at the rear of the cell as per the third image below. I observed this cell from a position just north of Urabry.
After having a good look at this cell and being frustrated that it was moving into inhospitable country out of reach, I headed for Denman again, via the Golden Highway. On the way to Denman I noticed that the sky seemed to be clearing as cloud moved towards the coast but residual mid-level cloud was not dissipating as I had hoped. Just before midday I arrived in Denman and noted immediately that the humidity and DP levels felt rather favourable. Within 20 minutes or so the Sydney crew arrived and I met Jimmy Deguara, Brett Vilnis and Mick for the first time. We had a good chat and decided that we were probably in a reasonably good area, it was just a matter of waiting things out so we headed a little further SE and found a location to wait. Jimmy was getting calls from David Croan who had also decided to meet up with us, but we weren't sure exactly where yet. Within about an hour or so things were looking interesting with some nice pulses to the West and a couple of others to the north. Mid-level cloud was proving to be a problem, although we were aware that some impressive updrafts sat above the deck. Lightning soon caught our attention and whilst sporadic and infrequent, some nice anvil crawlers started to hit all around us, as per below:
Video of the above strikes. (464kb) After becoming frustrated with anvil rain and lack of any organised cells, we headed to an area just north of Singleton and arrived just after 4 p.m.. Here we met up with David Croan and we watched a cell that certainly had some potential but really became outflow dominant and lost a lot of its structure. This was a nice cell to observe though with some attractive features:
Lightning Tracker
(Weatherzone) Sunday 25th 1700hrs EDT The cell remained fairly intense but not well organised and food became the focus of our attention, so before this cell hit us we moved to Maccas in Singleton and would you believe it, the storm hit Singleton and produced many CG's in our immediate vicinity! All in all, this day was a disappointment in terms of severe storms, but as a storm chaser you learn, accept and move on, not every chase is a supercell chase unfortunately!
After some good
discussion on conditions and what was likely to happen for the next few
hours, I decided that I would start the long journey back to Melbourne.
I took a route using Putty Road (groan) and eventually hit on the Hume
Highway at Campbelltown, after stopping in Windsor on the way to check
out Brett's WDU store, leaving Windsor at 8.00 p.m.. The return route
was going to be in two legs, with a sleep in the car in between. I had
light rain from Sydney through to Goulburn and around the Yass area I
noticed some flashes to my south, towards the Canberra area. Continuing
south the lightning became more frequent and by the time I reached
Tarcutta at around 1.15 a.m. I couldn't resist! I called Jimmy
who confirmed the activity was rather impressive over the ranges and
this was what I was seeing. I just had to see if I
could find a vantage point to watch all of this activity towards
Kosciusko, so i took the road to Tunamurra. After about 15km I realised
that it was unlikely I would find any perfect locations due to the hills
and mountains. I found a reasonable spot and enjoyed the show for a
while before deciding to turn back and get a little further south before
stopping to sleep. Here's a radar still from the area, what a great
sight, no wonder the show was so good!!
At around 4 a.m. I
stopped near Glenrowan and caught a few hours sleep in the car. I
finally arrived home at around 8.45 a.m. on Monday 26th January. Total
distance driven 2780 kilometres.
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S t o r m ! 
